Dissertations / Theses on the topic 'Anthropogenic activities'

The study of macroecology not only identifies patterns in the distribution and abundance of species at large spatial and temporal scales, it also gives insight into the processes underlying those patterns. The contribution of this work is not limited to helping develop the field of ecology per se, but also provides important insights into the understanding of large scale processes like climate change, the spread of introduced species, pest control and how increasing pressure from anthropogenic activities threatens biodiversity and ecosystem services. During the first decade following its formal inception, most of the progress in macroecology was made through studies of animal species, and research into plant species continues to lag far behind. This thesis contributes to the study of the macroecology of plant species by examining some selected macroecological patterns that have been studied only for animal species and by including an important issue that might have significant effects on diverse macroecological patterns, namely anthropogenic activities. The second and third chapters of the thesis address the generalised individuals-area relationship (GIAR) and the patch individuals-area relationship (PIAR), two macroecological relationships not previously explored for plant species. I show for the first time the existence of negative GIARs at the intraspecific and interspecific levels in plant species, similar to those documented for animal species. Unlike animal species, I did not find a broadly consistent intraspecific PIAR in plant species; more than half of the tested species showed negative PIARs. The resource concentration hypothesis may help explain those positive PIARs that were observed. The fourth chapter considers the effect of past human activities on current patterns of plant species richness at a landscape scale. Using a detailed database on the historical anthropogenic activities for Cornwall, U.K., I examine the relationship between species richness and the area covered by each historical land-use at two different spatial resolutions (10km x 10km and 2km x 2km). I find that at the 10km x10km scale human activities carried out since the 17th and 19th centuries explain an important proportion of the variation in current plant species richness. In contrast, a model at 2km x 2km scale with upland woods and the total land area of a grid cell explain only 5% of the variation. The fifth and sixth chapters focus on how artificial light at night (ALAN), which has increasingly come to attention as a significant anthropogenic pressure on species, is interacting with the distributions of plant species. In the fourth chapter, I consider the plant family Cactaceae to determine the proportion of the global distribution ranges of species that is being influenced by ALAN, and how this changes with the size of these distribution ranges and over a 21-year period (1992 to 2012). I found that >80% of cacti species are experiencing ALAN somewhere in their distribution range, and that there is a significant upward trend in ALAN in the ranges of the vast majority of species. For the sixth chapter, I consider similar issues for the threatened plant species of Britain, exploiting new remote sensing imagery of nighttime lighting at a very fine spatial resolution (c.340x340m2). Only 8% of Britain is free of artificial light at night and in consequence a high number of threatened plant species have a high proportion of their range under some influence of ALAN.

Since the UK industrial revolution, coal combustion, ore smelting and other industrial activities have resulted in a marked increase in emissions of potentially toxic elements (PTEs) such as antimony (Sb), lead (Pb), arsenic (As), copper (Cu) and zinc (Zn), along with polycyclic aromatic hydrocarbons (PAHs), to the atmosphere. Although stricter environmental regulation and improved technology has led to a notable decline for some contaminant emissions in recent decades, this has not been observed for all elements, e.g. Sb, where only a modest reduction in emissions have been recorded. Once emitted, Sb along with Pb, As, Cu, Zn and PAHs may persist in the environment for considerable periods of time after their release; although their chemical associations may change, elements are not broken down over time and organic contaminants may break down slowly. Above all, PTEs and PAHs are detrimental to human and environmental health, with chemical forms of Sb, Pb, As and PAHs categorised as carcinogenic. Understanding their behaviour and fate in the environment is therefore an important step towards evaluating their likely impact on both ecosystem and human health. Consequently, this study focuses on the release, behaviour and fate of contaminants from current and past anthropogenic sources in the urban and rural environment, with a specific interest in Sb and PAHs, where emissions originate from similar anthropogenic sources, with Pb, As, Cu and Zn also included for comparison purposes. Current and past industrial activity was identified as the dominant source of PTEs and PAHs to the urban environment, with emissions from vehicle, coal combustion and metal smelting identified as main contributors to total contaminant concentrations. Using road dust collected from Edinburgh at five high- and low-traffic roads at a distance of 10 and 50 m from the closest road junction, concentrations of Sb, Pb, Cu, Zn, PAHs and Pb isotope ratios were determined, with road dust undergoing further characterisation using chemical (sequential extraction) and spectroscopic (X-ray diffraction, SEM-EDX) techniques. No consistent trend for the element concentrations released from vehicles braking at 10 and 50 m from the closest road junction was observed. Mean concentrations for Sb, Cu and Zn were 5.3 ± 2.8 mg kg-1, 91.4 ± 48 mg kg-1 and 237 ± 144 mg kg-1, respectively, and were similar to road dust sampled from five high- and five low-traffic locations in Glasgow (Sb 4.5 ± 2.1 mg kg-1; Cu 117 ± 71.9 mg kg-1; Zn: 283 ± 146 mg kg-1). This was in contrast to mean concentrations for Pb and Σ16PAHs obtained from Glasgow (Pb 250 ± 283 mg kg-1, Σ16PAH 7.7 ± 4.3 mg kg-1) where values were approximately double and two-thirds greater than those found in Edinburgh (Pb 135 ± 129 mg kg-1, Σ16PAH 4.7 ± 2.9 mg kg-1), respectively. Lead isotopic analysis of Glasgow road dust (206Pb/207Pb range of 1.140-1.174) showed a strong influence of past emissions from coal combustion and metal smelting, and was in agreement with Glasgow's industrial history. For Edinburgh, the isotopic signature was considerably lower (206Pb/207Pb range of 1.116-1.151), and was influenced moreso by emissions of Australian sourced Pb in leaded fuel. Isotopic signatures in Edinburgh were lowest at easterly locations within 5 km of Edinburgh airport (206Pb/207Pb ~ 1.12), and corresponded with past vehicle emissions from leaded petrol use, and to a lesser degree, emissions from avgas, which was consistent with the mean annual wind direction for Edinburgh. The mobility of elements from the road dust to the aqueous phase were assessed by sequential extraction, and by using road surface water samples which showed mobility decreased in the order of Zn > Cu > Pb > Sb. Road dust characterised by XRD and SEM-EDX had a high proportion of quartz present (~55%), whilst the presence of less abundant minerals such as calcite were found to increase Pb mobility through ease of dissolution into the aqueous phase. For the rural environment, the behaviour and fate of elemental pollution originating from two former mining sites, an Sb mine at Glendinning, SW Scotland, and a Pb mine at Tyndrum in central Scotland was examined. Under specific environmental conditions, Sb was found to be both mobile and immobile in the environment. The chemical weathering of stibnite found in spoil heaps at Glendinning Sb mine demonstrated that ~3% of total Sb can be mobilised during the chemical weathering process, while hydrous Fe oxides and organic matter in the surrounding soil favoured its retention. The retention of Sb, along with Pb, was similarly observed in Loch Tay sediment downstream of Tyndrum Pb mine, where upon deposition, Sb and Pb remained immobile in sediment and allowed the construction of deposition chronologies for two sediment cores to be established. Excellent agreement between the sediment core deposition chronologies was observed, with both chronologies identifying atmospheric deposition as the primary source of Sb to Loch Tay sediment, whilst the dominant source of Pb was from Tyndrum Pb mine ~25 km upstream of Loch Tay. Relative to Sb and Pb, As had the greatest mobility, with its geochemical behaviour and partial retention by the solid phase influenced by the presence of Fe. This was evident in the surrounding soil at Glendinning Sb mine, where As was associated with hydrous Fe oxides present in the solid phase, while at Loch Tay, the redox cycling of Fe resulted in the post-depositional mobility of As in sediment. The use of ombrotrophic peat bogs for this study provided an effective means to assess atmospheric deposition of contaminants over past centuries; they continually accumulate and receive all their nutrients and contaminants exclusively by deposition from the atmosphere. The deposition archives of Sb and Pb from two Scottish peat cores sampled from Great Moss, Cairngorms Mountains, and, Auchencorth Moss, Midlothian, were used to construct chronologies for historic and contemporary emissions, particularly in relation to current and historic anthropogenic activities observed in urban and rural environments. At Great Moss, the deposition of Sb and Pb during the 19th century increased by a factor of 10 and 4, respectively, as a result of the industrial revolution and emissions from the combustion of coal and metal smelting. The trend continued into the 20th century where Sb and Pb deposition peaked ~1950, followed by a decline towards the early 21st century by a factor of 5 and 11, respectively. Over this period of time, the contribution from coal combustion and metal smelting towards total anthropogenic emissions was on the decline, while emissions from the combustion of leaded fuel increased until the ~1980s. Although deposition chronologies before 1970 for Sb and Pb at Auchencorth Moss were generally in agreement with those from Great Moss, several differences were observed after 1970, or more specifically, in the top ~10 cm of the peat core. This was a result of sub-surface perturbations for Ti, Sb, Pb and 210Pb concentrations, and indicated once deposited, elements were susceptible to post-depositional mobility brought about from a change in environmental conditions. The thicker acrotelm layer present at Auchencorth Moss, and the vertical movement of the peat water-table within this layer, resulted in a change in redox conditions and led to the redox cycling of Mn and Fe, which in turn, influenced vertical concentrations of Ti, Sb, Pb and 210Pb. While Sb and Pb are usually found immobile in peat systems, the post-deposition mobility of Sb and Pb at Auchencorth Moss was comparable to a peat core sampled from Flanders Moss, and indicated that under specific environmental conditions, both elements can become mobile in ombrotrophic peat bogs. It is worth bearing in mind however, that these results are the exception, and in all other cases ombrotrophic peat bogs remain a reliable archival material to use.

In many parts of the world snow melt runoff influence discharge from combined sewer overflows (CSO) and flooding in urban drainage systems. Despite this, urban snow hydrology is a field that has received little attention from the urban drainage community. The objectives of this research were to better understand urban snow hydrology and through field work and hydrological modelling quantify effects of anthropogenic activities (AA) on snow distribution, and melt in an urban environment. This means in principle how the presence (design geometry) and operation of roads and buildings influence the snow distribution and melt in urban areas. The Risvollan urban catchment (20 ha) located in Trondheim, Norway, was used as a study area. A literature review of urban snow hydrology was also carried out.

A gridded urban hydrology model (GUHM) was developed as part of the study. The principal idea of the GUHM is to subdivide an urban catchment into orthogonal equal area grid cells. The snow routine in the GUHM is based on an energy balance approach, which together with a soil-runoff routine is used to calculate a time series of rain, snow water equivalent (SWE), snow melt, and runoff, for each grid cell. In GUHM, processes such as snow clearing of roads, locally low albedos, heat/shadowing from buildings, and effects of slope and aspect are included in the model structure.

A technique for observing time series of snow covered area (SCA) for an urban catchment is presented. The method is based on image processing and neural network technology to calculate SCA from a time series of images taken from a tall building in the Risvollan catchment. It was shown that SCA on roads and roofs in general becomes more rapidly snow free during melt periods compared to the park areas of the Risvollan catchment. This can be explained by snow clearing of roads, snowdrift from roofs and high snow melt rates on roofs and roads. The high melt rates was attributed to locally low albedos in vicinity to roads, rooftop snow packs exposure to wind and solar radiation, in addition to anthropogenic heat release from the roofs themselves.

Field observations of SWE were carried out in the Risvollan catchment and it was shown that areal mean SWE located on/or nearby roads and buildings were significantly lower during mid and end of the winter, than in park areas. This can be attributed to higher melt rates caused by AA. A time series of SCA and SWE was obtained through field work for the period from 2000 to 2003 in the Risvollan catchment.

The GUHM was applied and calibrated for the Risvollan catchment for a three year period. Two seasons were used as validation period. Comparison between the simulated and observed SWE, SCA and runoff data showed that the GUHM was able to simulate snow accumulation and melt for whole seasons with short time resolution (1 hour) satisfactory.

The GUHM was used to quantify effects of AA on snow distribution and melt for six different land use scenarios in the Risvollan catchment for the period June 1998 to June 2003. The modelling results showed that when the area coverage of buildings and roads increased, the SCA and SWE more rapidly decreased during melt periods. Because of this more runoff will be produced in the early winter season (Jan-March) compared to if the catchment had been covered with only sparsely vegetated areas.

The simulation results showed that when the impervious surface covers of a catchment increase, the peak and volume runoff will also increase, as expected.

Both the field observations and the hydrological model study carried out in this work showed that AA lowers SCA and SWE more rapidly in an urban environment compared to more untouched terrain. The reasons for this are redistribution of snow, and strong snow melt rates on roads, roofs, and in snow deposit areas. Low albedos and anthropogenic heat release are the main reasons for the enhanced snow melt rates.

Atmospheric pollutants in the state of Qatar are derived from flaring and fugitive emissions due to a combination of new energy projects, operational conditions and plant operational problems. This research is the first attempt to quantitatively assess key atmospheric pollutants in Qatar, in accordance with the Kyoto agreements to reduce greenhouse gas production. Two datasets were analysed: 1. Between 2000 and 2002, data collected by industrial plants, as part of their own procedures, were assembled using a proforma questionnaire, to compile data on fuel consumption, fuel type, chemical characteristics, heat value, specific gravity etc, from industries in Qatar. The survey involved the oil & gas industry, petrochemical factories, power & desalination plants. Fuel data includes sulfur & nitrogen contents, chemical composition of flared gas and C content, some data compiled on road transport and fuel consumption. Analysis revealed significant atmospheric pollution. 2. Independent air-quality monitoring stations collected data between 2003 and 2005 to compare with data provided by industry. Three locations were chosen because of proximity to industrial plants: Mesaieed on the southeast coast, Dukhan on the west coast, and Halul Island, an offshore installation 30 km east of Qatar in the Arabian Gulf. Five key tropospheric pollutants (NO2, SO2, CO, O3 and PM10), wind speed and wind direction, were monitored hourly from three stations located near gas installations across Qatar. Registered levels of CO, NO2 and SO2 were within Qatari and European Standards. PM10, however, was higher than the standards in all three stations and measured daily O3 levels were sometimes higher than the reference for Halul Island. Therefore, in contrast to industry data, the monitoring sites showed much pollution is below (better than) accepted thresholds, the difference between the two datasets illustrating the complexity involved in correctly monitoring pollution, and the effect of wind direction and dispersal of pollutants. Therefore these results have stimulated a comprehensive response to pollution monitoring in Qatar between 2005 and the present day, leading to reduction in flaring and fugitive emissions over the last few years, by as much as 50% in some operations, as a result of more careful operational planning, upgrading and better controls applied to new and existing projects. This research therefore provided much of the stimulus for emission reduction in Qatar, currently being investigated under the Clean Development Mechanism and Technology Transfer.

The overuse of antibiotics has led to the selection of resistant strains. This thesis investigated the occurrence of antibiotic resistance genes (ARGs) in aquatic microbial communities influenced by anthropogenic activities. In this study, qPCR assays were designed to quantify the plasmid-mediated quinolone resistance in environmental samples. Then, several ARGs conferring resistance to several groups of antibiotics were quantified in biofilms and sediments from a wastewater treatment plant (WWTP) discharge point and the receiving river. Ciprofloxacin-resistant strains were also isolated an screened for the presence of qnr genes and aac(6’)-Ib-cr and their association with extended-spectrum β-lactamases. A multidrug resistance-encoding plasmid from an Aeromonas sp. was further characterized. Overall, ARGs were detected in different matrices (water, biofilm and sediment), both in bacteriophages and bacteria, and different sources (rivers, effluents from several human and veterinary hospitals, subterranean water, chicken faeces and WWTP effluents), indicating that these emerging pollutants are widely distributed in the environments exposed to anthropogenic activities
L'ús excessiu d'antibiòtics ha portat a la selecció de soques resistents. En aquesta tesi es va investigar l'aparició de gens de resistència als antibiòtics (ARGs) a les comunitats microbianes aquàtiques impactades per activitats antropogèniques. En primer lloc, es van dissenyar assajos de qPCR per quantificar gens de resistència a quinolones localitzats en plàsmids. A continuació, es van quantificar diversos ARGs que confereixen resistència a diversos grups d'antibiòtics en biofilms i sediments d'un punt d'abocament d'una planta de tractament d'aigües residuals (EDAR) i del riu receptor. També es van aïllar soques resistents a la ciprofloxacina i es va analitzar la presència de gens qnr i aac (6')-Ib-cr i la seva associació amb beta-lactamases d'ampli espectre. Per acabar, es va caracteritzar un plàsmid multiresistent procedent d'Aeromonas sp. En general, es van detectar ARGs en diferents matrius (aigua, biofilm i sediments), tant en bacteriòfags com a bacteris, i en diferents fonts (rius, efluents de diversos hospitals humans i veterinaris, aigües subterrànies, excrements de pollastre i efluents d'EDAR) , el que indica que aquests contaminants emergents estan àmpliament distribuïts en els ambients exposats a activitats antropogèniques
Programa de Doctorat en Ciències Experimentals i Sostenibilitat

In this study, I examined water chemistry of 31 Canadian Shield lakes in relation to catchment characteristics to test the hypothesis that Shield lakes with more marble may exhibit iron (Fe) deficiency and, hence, be more vulnerable to eutrophication. I performed a diatom-based paleolimnological reconstruction of one of these lakes (Heney Lake), which was subjected to anthropogenic stresses including a fish farm. Results suggest that the presence of marble influenced lake chemistry, including lowering the ratio of Fe: P. The reconstruction of historical P concentrations was not statistically possible but past Fe could be inferred, which no previous study has attempted. Certain eutrophication-associated diatom species suggest that logging and European settlement beginning in the early XXth century led to a slight increase in nutrient concentrations. However, a more important diatom species shift was likely related to climate change, as observed in other temperate lakes worldwide.

Human uses and abuses of rivers have grown and diversified over the last few centuries with increasing urban development. With increasing population growth, there has been increasing demand for the use of rivers to satisfy a diverse range of human needs including solid waste disposal and the discharge of industrial, sewage and mining effluents. Rivers have been abstracted for agricultural and potable water supply and river channels have been modified for navigation, flood defences and hydro-electric power generation. These modifications to the river system disrupt the fabric of the aquatic ecosystem and diminish its integrity, affecting equally the capacity of fish and other organisms to survive. Fish depend on undamaged interactive pathways to enhance their survival, growth and recruitment.The Don, Rother and Dearne catchment in South Yorkshire and North East Derbyshire has suffered from a legacy of pollution and land contamination that dates back to the Industrial Revolution. These rivers have been grossly polluted from industrial, sewage, and mining effluents and from the disposal of solid wastes in the catchment. Much of the lengths of these rivers were fishless into the mid 1980s.Fish populations in the catchment remain low and species diversity is poor at most locations in the Don sub-catchment. Brown trout and coarse fish species are present in the Don catchment, with the salmonid populations confined to the upper reaches. Most tributaries of the River Don provide brown trout recruits to the main rivers but poor water quality and degraded habitats have prevented the successful colonisation of the waters by the species. Coarse fish, where present, were found at the middle and lower reaches of the river.Fish populations and species diversity in the River Dearne are generally poor due to serious water quality problems. Limited numbers of brown trout and coarse fish were found at few locations in the catchment, reflecting the widespread nature of poor water and habitat quality. The sub-catchment receives diverse discharges from sewage, industry and abandoned mines. This is exacerbated by various pollution incidents, the causes of some of which remain unidentified.The River Rother has low fish population densities, and many stretches of the river are fishless due mainly to poor water quality and lack of suitable habitats. Some tributaries of the River Rother, particularly the River Hipper, Redleadmill Brook and Brookside Beck hold considerable numbers of brown trout. The Rother sub-catchment also receives sewage, industrial and mine effluents which impact on the water quality.The benthic macroinvertebrate fauna of the sites studied were mainly pollution-tolerant taxa with low species diversity reflecting poor water quality. Heavy metal levels were generally low and declining which, possibly, relate to the decline in steel and coal industry in the catchment.A concerted programme to improve effluent discharges from major sewage treatment works and industries serving the catchment area coupled with a decline in the coal, steel and manufacturing industries has resulted in marked improvements in water quality of the rivers. Reductions in ammonia and BOD levels have been achieved since 1991 due mainly to improvements to sewage treatment works. As a consequence the fisheries of the rivers have shown some evidence of recovery. Unfortunately these improvements are localised and the fish populations suffer periodic setbacks because of isolated pollution incidents.Despite considerable efforts by the Environment Agency and its predecessors (the National Rivers Authority and Yorkshire Water), to improve the fish populations through stocking and some habitat improvement measures, the general status of the fisheries remains poor particularly in the Rivers Dearne and Rother. A strategic Aquatic Resources Management Plan (ARMP) targeting the bottlenecks to recovery and improvement in the water quality and fisheries habitat is proposed for the long-term sustainable improvement of the fisheries. Project Concept Notes and Logical Project Frameworks have been developed to address the water quality, habitat and fisheries rehabilitation problem. These constitute draft proposals for which additional information would be needed before projects can be progressed.

This research evaluated the extent to which forests in Virginia have either become fragmented (disconnected) and/or connected over a ten year time period. The study analyzed the accuracy of forest fragmentation analysis depending on the spatial resolution of the satellite imagery used. This analysis highlights the importance of using appropriate satellite images for forest fragmentation analysis. Secondly, this research focused on building a model to identify the significance of factors such as slope, physiographic region and forest types on Virginia's populations of Wood Thrush and Ovenbird. This assessment identified the difference in effects of variables on bird populations depending on the scale at which the analysis is carried out. Third and final analysis combined the first two assessments to determine how management policies can be used to mitigate negative effects of forest fragmentation and protect biodiversity. The research results highlight increasing forest fragmentation trends in Virginia between 2001 and 2011 and the negative impacts of this trend on Wood Thrush and Ovenbird species. The results also demonstrate the effectiveness of riparian buffers as corridors.
Doctor of Philosophy
This research evaluated the extent to which forests in Virginia have either become fragmented (disconnected) and/or connected over a ten year time period. The study analyzed the accuracy of forest fragmentation analysis depending on the spatial resolution of the satellite imagery used. This analysis highlights the importance of using appropriate satellite images for forest fragmentation analysis. Secondly, this research focused on building a model to identify the significance of factors such as slope, physiographic region and forest types on Virginia’s populations of Wood Thrush and Ovenbird. This assessment identified the difference in effects of variables on bird populations depending on the scale at which the analysis is carried out. Third and final analysis combined the first two assessments to determine how management policies can be used to mitigate negative effects of forest fragmentation and protect biodiversity. The research results highlight increasing forest fragmentation trends in Virginia between 2001 and 2011 and the negative impacts of this trend on Wood Thrush and Ovenbird species. The results also demonstrate the effectiveness of riparian buffers as corridors.

Orientador: Sérgio Luis de Carvalho
Resumo: As atividades antrópicas como agricultura, mineração, urbanização e industrialização produzem resíduos que de maneira direta ou indireta acabam chegando até os corpos hídricos, gerando mudanças na qualidade da água dos rios, córregos e lagos. Para quantificar a poluição dessas águas utiliza-se o índice de qualidade da água “IQA” que por meio de análises físicas, químicas e biológicas classifica a qualidade da água como ótima, boa, aceitável, ruim ou péssima. Este trabalho tem como objetivo diagnosticar a influência de atividades antrópicas na qualidade da água da bacia hidrográfica do Córrego das Marrecas – SP, utilizando o Índice de Qualidade da Água – (IQA). Foram analisados cinco pontos ao longo do Córrego das Marrecas – SP durante o período de abril/2017 a março/2018. Em cada ponto de amostragem foi mensurada mensalmente a concentração de oxigênio dissolvido (OD), temperatura, pH, turbidez, sólidos totais (ST), coliformes termotolerantes, demanda bioquímica de oxigênio (DBO), nitrogênio total e fósforo total conforme os métodos para análises de águas potáveis e residuárias – Standard Methods for Examination of Water and Wastewater. Foi realizada uma análise descritiva para avaliação dos resultados de média, desvio padrão, valores máximos e mínimos dos parâmetros de qualidade da água monitorados durante o período chuvoso e seco nos cinco pontos de amostragem do Córrego das Marrecas- SP. O cálculo do IQA foi feito por meio do produtório ponderado dos nove parâmetros (pH, tu... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Anthropogenic activities such as agriculture, mining, urbanization and industrialization produce waste that directly or indirectly reaches the water bodies, generating changes in the water quality of these rivers, streams and lakes. To quantify the pollution of these waters, the water quality index "IQA" is used that, through physical, chemical and biological analysis, classifies water quality as optimal, good, acceptable, bad or bad. This work aims to diagnose the influence of anthropic activities on the water quality of the Stream of Marrecas - SP water basin, using the Water Quality Index - (IQA). Five points were analyzed along the Stream of Marrecas - SP during the period from April / 2017 to March / 2018. At each sampling point, the concentration of dissolved oxygen (OD), temperature, pH, turbidity, total solids (ST), thermotolerant coliforms, biochemical oxygen demand (BOD), total nitrogen and total phosphorus were measured according to the methods for analysis of drinking water and wastewater - Standard Methods for Examination of Water and Wastewater. A descriptive analysis was performed to evaluate the results of mean, standard deviation, maximum and minimum values of water quality parameters monitored during the rainy and dry period at the five sampling points of Stream of Marrecas - SP. The calculation of the IQA was done by means of the weighted output of the nine parameters (pH, turbidity, temperature, dissolved oxygen, phosphorus, nitrogen, total solids, thermot... (Complete abstract click electronic access below)
Mestre

Doutoramento em Engenharia Florestal - Instituto Superior de Agronomia - UL
Vegetation fires are an important component of the earth’s system land processes and have a significant impact on the vegetation and CO2 dynamics. The global fire patterns are not thoroughly explored and the drivers of fire regimes in global scale are interconnected. However, several modelling assumptions are contradicted by exploring those relationships partially. At global scale, fire extent is fuel limited, with climatic variables showing both positive and negative influence on fuel moisture conditions, and humans showing a negative net effect. When isolating the influence of population density and assuming spatial nonstationarity, the human impact is very detailed and reflects the main land use activities with emphasis on cropland and rangeland management at continental scale. The footprint of fire into the Earth system can be measured in terms of radiative forcing from pre and post-fire albedo changes, with the forest biomes driving the extremes on annual basis. Additionally this thesis explores the patterns and the trends of contemporary fire activity. Contrary to previous studies, the results show non-monotonic patterns at grid cell level. The findings of this thesis give a better insight into the spatial variability and the controls of fire at global scale using satellite derived datasets with a focus to the anthropogenic land use activities

Humans are modifying the global landscape at an unprecedented scale and pace. As a result, species are declining and going extinct at an alarming rate. Here, I investigate two main aspects of species’ declines: what factors are contributing to their declines and how effective our conservation efforts have been. I assessed one of the main mechanisms for protecting species by looking at the Endangered Species Act (ESA) in the United States. I examined three separate indicators of species declines for different groups of species: range contractions in Canadian imperilled species, declines in abundance in global amphibian populations and increases in temporal variability in abundance in North American breeding birds. I found that change in recovery status of ESA listed species was only very weakly related to the number of years listed, number of years with a recovery plan, and funding. These tools combined explained very little of the variation in recovery status among species. Either these tools are not very effective in promoting species’ recovery, or species recovery data are so poor that it is impossible to tell whether the tools are effective or not. I examined patterns of species’ declines in three different groups in relation to a number of anthropogenic variables. I found high losses of Canadian imperiled bird, mammal, amphibian and reptile species in regions with high proportions of agricultural land cover. However, losses of imperiled species are significantly more strongly related to the proportion of the region treated with agricultural pesticides. This is consistent with the hypothesis that agricultural pesticide use, or something strongly collinear with it (perhaps intensive agriculture more generally), has contributed significantly to the decline of imperiled species in Canada. Global increases in UV radiation do not appear to be a major cause of amphibian population declines. At individual sites, temporal changes in amphibian abundance are not predictably related to changes in UV intensity. Variability in species’ abundance of North American breeding birds, after accounting for mean abundance, is not systematically higher in areas of high human-dominated land cover or climate change. Rather, it appears that areas with a high proportion of human-dominated cover come to have a higher proportion of highly abundant, and thus more variable, species.

Globally emphasis has been given to identify emerging and re-emerging pathogens. Rapid urban expansion creates a problem which is two-fold. Firstly, increasing slum living conditions due to inadequate rate of infrastructure development results in an increased reliance on natural resources, including the capture and consumption of surrounding wildlife to subsist, thereby facilitating the transfer of emergent zoonotic pathogens. Secondly, through activities such as pollution or alien species introductions, the rapid transformation of once pristine environments, alters natural systems, potentially exposing these environments to new bacterial pathogens. Therefore, the main aim of this study was to assess overlooked bacterial species harboured by four host species (Bathyergus suillus, Georychus capensis, Cryptomys hottentotus hottentotus and Fukomys damarensis) belonging to the subterranean rodent family Bathyergidae, which inhabit an environment well-suited for an array of bacterial species, and which varied in their exposure to human settlements. Bacterial prevalence and diversity was initially evaluated using broad-range PCR techniques in combination with nucleotide sequencing. This revealed high levels of bacterial prevalence (82.91%) and mixed infections (22.60%) in bathyergid species. Two bacterial groups, the Bacillus cereus complex (a group of soil-dwelling bacterial strains with pathogenic potential with an overall prevalence of 8.55%) and haemotropic Mycoplasma strains (vector-borne bacterial strains of zoonotic potential with an overall prevalence of 1.28%) were subsequently selected for further genetic analysis with genus and species-specific PCRs. Bacillus molecular screening and phylogenetic analyses was achieved by targeting four gene regions with seven published primer assays and two novel PCR assays. This enabled identification of two B. cereus complex strains in bathyergid lungs and revealed an overall B. cereus complex prevalence of 17.95% for the 234 bathyergid lung samples screened. Bacillus genome prevalence was significantly higher in B. suillus individuals (45.35%), sampled in a peri-urban environment, compared to the other bathyergid species sampled from pristine habitats (ranging from 0% - 4.44%). Anthropogenic activities in the area where B. suillus was sampled could, at least partially, attribute to the perceived difference between urban and naturally sampled bathyergid species, highlighting the role of B. suillus to act as both a reservoir of potentially zoonotic pathogens and as a sentinel for anthropogenic soiling. Mycoplasma molecular screening using three different PCR assays, all targeting the 16S rRNA gene region, confirmed an overall haemotropic Mycoplasma prevalence of 24.13% in the 286 bathyergid organs (lung, spleen and liver) screened. A significantly higher prevalence and diversity of haemotropic Mycoplasma strains was found in B. suillus lungs (41.86%) compared to its naturally occurring relatives (ranging from 0%-36%). Phylogenetic analyses identified six novel haemotropic Mycoplasma strains, all grouping within a discrete monophyletic cluster, sister to Mycoplasma coccoides, and comprising two well-supported sub-clusters. The human introduction of commensal rodents harbouring Mycoplasma strains transferred through cosmopolitan arthropod vectors to indigenous bathyergids, likely underlies the higher prevalence in urban areas, although other biotic and abiotic factors affecting ectoparasite load also merit consideration. The data generated by the current study indicate the need to identify largely overlooked and potentially zoonotic bacterial pathogens in subterranean mammals and emphasises the importance of monitoring anthropogenically-introduced, opportunistic pathogens and the threats they pose to vulnerable communities and co-occurring, free-living animal species
Dissertation (MSc)--University of Pretoria, 2017.
Airports Company of South Africa (ACSA)
National Research Foundation (NRF)
Zoology and Entomology
MSc
Unrestricted

Forest disturbance occurs on a wide gradient of selectiveness and creates new growth opportunities for adapted species. Across the spectrum of disturbance, anthropogenic disturbance influences community assembly in the Midwest more than other mechanisms but is its role in shaping and maintaining ecosystems is inadequately considered in most discussions on the historic range of variability (HRV). Forest resiliency is threatened by unprecedented agents of ecosystem change such as invasive species and reduced regeneration potential of native species. Historic anthropogenic disturbance largely resulted in forest conditions which commonly contained high value attributes like heterogeneity across habitat types and landscape diversity, yet also produced forests of undesirable traits due to high grading for timber and overgrazing by domesticated stock. In order to maintain historical representative forests and improve the degraded forests, active forest management is necessary to continue historic disturbance patterns and combat new threats. Forest transition theory is used here to describe the impacts of human settlement and development activities on forest ecosystems across the Middle Mississippi River Valley. To date, researchers have identified the need for information related to changes of forest attributes such as species composition and stand structure, improved descriptions of short- and medium-term dynamics within the context of the long-term transition, and the integration of biophysical drivers of forest change through time. In Midwestern U.S.A., forest dynamics were influenced by frequent, low intensity disturbance events that mediate forest composition and stand structure by selecting for disturbance regimes that create oak woodland and interspersed prairies and meadows. The onset of Euro-American settlement was accompanied by detailed land-use records with information related to forest attributes, agricultural activities, and parcel ownership patterns. We aggregated multiple sources of historic forest conditions into a geodatabase in order to document changes over the past 200 years in Elsah Township, Illinois, where the pre-settlement (1820) forest, once dominated by oak and hickory species, has largely shifted to a maple dominated system with a declining oak-hickory component, heavily influenced by an invasive shrub species, bush honeysuckle. Using on ordinary kriging interpolation, forest density was estimated at 8.7 stems per acre on average with a mean basal area of 14.6 square feet per acre prior to settlement. Conservation practices of the early 1900s, including fire suppression and erosion control resulted in changes to forest structure with density increases to 127 trees per acre with a basal area of 175.8 square feet per acre. The high degree of topographic variability near the Mississippi River influenced forest cover changes as slopes with low angles were the first to be converted from forest cover to other land uses (circa 1850). Forest re-initiation occurred in areas with steeper slope due to a lack of human activities. Forest cover declined to the lowest point in 1927 and has been rebounding steadily throughout this century. Of the original 15,252 forested acres, 11.6% remained covered throughout the past 200 years and coincided with slopes with an average of 39.1 degrees. These data can provide a spatially explicit and historically accurate tool to guide land management decisions including restoration treatment, disturbance regime management, and land use preservation activities in similarly heterogeneous environments. Forest communities along the bluffs of the Mississippi River differ in species composition and stand structure associated with specific topographic positions of floodplain, transition talus slope, bluff top, and upland. In order to assess current stand characteristics and ecosystem trajectory, we measured all woody stems in 316 fixed radius plots (79 plots per topographic position) with a plot area of 25 m2. Alpha (defined as within system diversity) and Beta (defined as between system diversity) diversity and diameter distributions were determined for seedling, shrub layer, and overstory stems. Stem density increased from 21.4 stems ha-1 in 1820 to 613 stems ha-1 in 1936 followed by reduction to 314 stems ha-1 in 2017. Average stand diameter decreased from 40.9 cm in 1820 to 25.3 cm in 2017 (for upland stems greater than 7.5 cm) while basal area increased from 3.3 m2 ha-1 in 1820 to 40.4 m2 ha-1 in 2017. Alpha diversity was highest in the upland overstory and in the river island shrub layer. Beta diversity in the overstory was highest (0.67) between the bluff and the upland while lowest (0.08) between the bluff and the river island. Importantly, mesophytic species are no longer restricted to watercourses and valleys as reported in historical accounts and confirmed by the spatial analysis of original witness tree records. Currently, bush honeysuckle, an invasive species, dominates the shrub layer on most non-hydric sites of the talus slope, upland, and particularly across the bluff top where it is an indicator. Across all forest sites in the study, we found evidence of a community shift to less diversity and more mesophytic species over the past 80 years. Hill prairie vegetation on the limestone bluffs of the central Mississippi River Valley represents a significant portion of the remaining prairie, savanna, and woodland systems of the Midwest and should be appropriately managed with prescribed fire and woody stem reduction efforts. We examined the structure, composition, and temporal community patterns of the forest-prairie gradient by employing hierarchical cluster analysis and non-metric multi-dimensional scaling in combination with indicator species analysis and dendrochronological methods. Results suggest that four general community types exist across the forest-prairie gradient: Group 1 consists of the woodland community structure with significant indicator values for the density of Juniperus virginiana (indicator value 58.4, p = 0.0002), Carya glabra (45, 0.0022), Quercus stellata (23.7, 0.0424), and Lonicera maackii (74.2, 0.0002) and a high basal area (BA) of J. virgniana (21.4, 0.0276) and L. maackii (47.9, 0.0054). The first year of L. maackii presence was 1964 with the primary wave of invasion beginning around 1990. Group 2 contains bare soil coverage in the subplot (40.4, 0.0002) as the one indicator at a significant level. The species with the highest BA in Group 2 include Acer saccharum (9.08 m2 ha-1), Q. velutina (5.89 m2 ha-1), and Q. muehlenbergii (5.32 m2 ha-1). Group 3 typifies the hill prairie community with the sole indicator of grass coverage in the subplots (39.7, 0.0196). Group 4 represents the stage of forest development following the cessation of disturbance events and the trajectory advancing towards a mesophytic forest and contains 14 significant indicators.

Mangroves are intertidal ecosystems found along the tropical and subtropical coastlines.

Though globally recognised as ecosystems of ecological, biological and economical

remarkable importance, these ecotone formations are characterised by a continuously

increasing anthropization. However, very little studies have been focused on the impact of

various anthropogenic activities on the mangrove vegetation structure.

We have firstly (a) assessed the commercial and subsistence utilization of mangrove

wood products in the Littoral region (Cameroon estuary). Then, we have confronted the

subsistence usages of mangrove wood products in the Southern region (close to the mouth of

the Nyong River and Mpalla village (Kribi)) in comparison with the Littoral region. By doing,

we have compared the local residents‟ perceptions on environmental changes that occurred

within the two regional mangrove forests. Also, we have (c) studied the structural dynamic of

mangrove vegetation neighbouring the Douala city (Cameroon). Always in the vicinity of this

town, we have (d) reconstructed the original structure of largely disturbed mangrove forests.

Moreover, we have (e) map the mangrove structure in a non peri-urban setting located within

the Cameroon estuary. Here, we have finally (f) analysed the spatial distribution of a black

mangrove namely Avicennia germinans (L.) Stearn.

Our results underlined an excessive utilization of mangrove wood products in the

Cameroon estuary. We have showed that the frequency of mangrove harvesting was relatively

fewer in Kribi (Mpalla) and the mouth of the Nyong River. The local people inhabiting these

two localities perceived mangroves as less degraded areas. In contrast, those established

within the Cameroon estuary stated that mangroves were largely disturbed. When combining

the local people statements with our field observations, we recorded that it a complex mix of

causes (e.i. clear-felled corridors, agriculture, sand and gravel extraction, over-harvesting and

anarchic urbanization) that have led to the largely degradation (vegetation and sediment) of

the peri-urban mangroves in Cameroon. A diachronic analysis (1974, 2003, 2009) of their

coverage revealed that over the 35-year period, mangrove had decreases in cover of 53.16%

around Douala. We have also showed that in the peri-urban settings, wood harvesting was

commonly applied on the structurally more complex (highly dense stands neighbouring the

habitations) mangrove forests (Mboussa Essengue) and, in a lesser extent, on the structurally

more developed mangrove stands (fewer dense stands faraway from Douala). On the other

hand, the mapping analysis of the non peri-urban mangroves (distant from Douala) has

revealed that the structure of these intertidal forests was relatively less impacted. In the

Cameroon estuary, we also showed that A. germinans trees were randomly distributed on

almost one-half of the sampling plots and clumped at some scales on the remaining plots.

Accordingly, this species might play a significant role in the recovery process of artificial

gaps found in the non peri-urban areas.

The multi-disciplinary approach employed in this study has allowed a better

understanding of the direct and indirect impacts of anthropogenic activities on the mangrove

vegetation structure in Cameroon. These results constitute a fundamental data base quite

useful for the multi-temporal monitoring of these littoral ecosystems perpetually disturbed.

The application of similar approach in other mangroves facing high anthropogenic pressures

appears important.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Anthropogenic impacts such as fishing and eutrophication are significant challenges to the sustainable management of aquatic ecosystems. This study used two ecosystem modelling techniques to investigate the effects of fishing and eutrophication on aquatic ecosystems in Western Australia. Firstly, a qualitative modelling technique called ‘loop analysis’ or ‘qualitative modelling’ was used to characterise the dynamics of the seagrass ecosystem in Shark Bay, Western Australia (Chapter 2). A qualitative model based on differential equations, was developed to represent the dynamics of the seagrass ecosystem, particularly interactions among tiger sharks, megafauna (e.g. dugongs), and megafauna prey (Fig. 2.2). Although the model structure generated some uncertainty about model predictions and model stability, it was possible to assess the stability of the model and to determine the response signs of model variables by applying data and magnifying loops. Qualitative modelling analyses indicated a strong top-down control by tiger sharks and suggested that this controlling effect occurred in four stages. A step-by-step increase in tiger sharks (States 1 and 2) led to a habitat shift by the megafauna out of seagrass meadows and into safer, deeper channel habitat. A step-by-step decrease in tiger shark numbers led to the megafauna returning to seagrass meadows, leading to a decrease of megafauna prey in this habitat (steps 3 and 4). Thus, tiger sharks influenced the use of seagrass habitats by megafauna species through direct and behaviourally mediated impacts. Further, megafauna responses to tiger shark predation risk established alternating predation pressure on different prey groups within seagrass habitats. Curiously, despite the fact that only some megafauna species (e.g. dugongs) are major components of diet of the adult tiger sharks, the perceived predation risk created by the high abundance of of tiger sharks in summer appears sufficient to cause megafauna species to leave (or under-utilise) feeding habitats in seagrass meadows. Thus, the modelling results suggest that the abundance of tiger sharks exerts an important top-down, regulatory influence on the other ecosystem components. This regulatory system has the potential to become imbalanced if there is a decrease in the abundance of adult tiger sharks in Shark Bay, as has occurred tiger shark populations in other areas worldwide. Targeting of tiger sharks by fishers in the waters of Northern Australia and Indonesia has increased steadily during the last years and impact the tiger shark stock in Shark Bay if, as has been hypothesized, there is single common stock. A qualitative trophic model suggested that the activities of recreational fishermen within Shark Bay reduce prey availability for juvenile tiger sharks, an impact which might adversely affect the tiger shark population and, thus, the dynamics of this seagrass ecosystem. Evidence of the ecological importance of tiger sharks and the potential impact of a population decline emphasises the need to sustain the tiger shark population in Shark Bay. In the second part of this study, a quantitative modelling technique, Ecopath with Ecosim and Ecospace, was applied to the ecosystem of the Peel-Harvey Estuary, Western Australia. A key impact on this ecosystem is the the Dawesville Channel, an artificial entrance channel was constructed in the mid-1990s to increase the flushing and reduce nutrient concentrations in the estuary. Ecopath was used to analyse the impact of the Dawesville Channel on the estuarine ecosystem. A large dataset was collected for model development, a process that uncovered significant data gaps (e.g. missing data on detritus pool and dietary information and indicated important areas for further research (Chapter 3). Two identical Ecopath models (comprising 30 living functional groups) were otherwise developed for the Peel-Harvey Estuary to describe the state of the ecosystem before (‘pre DC’) and after (‘post DC’) the opening of the Dawesville Channel (Chapter 4). Modelling found that, in addition to changes in the community structure of plants, fish and invertebrates, the entire ecosystem of the Peel-Harvey Estuary has declined drastically in total biomass since the opening of the Dawesville Channel, as has the biomass at each trophic level and in the size of flows between the functional groups. Changes in flows and transfer efficiencies suggested a change in the functioning of the ecosystem in which consumption has become a more important and more efficient flow since the opening of the channel. Analysis of network and system statistics indicated that food web structure had also changed, with more linkages in the ‘post DC’ model and thus a more web-like structure than in the ‘pre DC’ model. Modelling also identified changes in cycling processes and suggested that the ecosystem in the ‘post DC’ model was not able to keep carbon within the system, even though: (i) the food web has developed more linkages and (ii) with less primary production and less cycling, the size of the ecosystem has decreased drastically since the channel opening. Overall, the results of the Ecopath modelling indicated that the Dawesville Channel has markedly impacted the features, functioning and services of the Peel-Harvey Estuary (Chapter 4). Several indices were applied that suggested that both the ‘pre DC’ and the ‘post DC’ models were highly immature. Ecopath was also applied to investigate the impact of the Dawesville Channel on ecosystem services. Ecopath modelling indicated that all ecosystem services had declined, such as provisioning services (catches), regulating services (CO2-Fixation) and supporting services (nutrient cycling, primary production and biodiversity). Unfortunately, it was not possible to locate data relating to cultural services (tourism) for the ‘pre DC’ model. To support the reliability of the Ecopath and Ecosim predictions, model uncertainty and the sensitivity of the parameter settings were assessed in detail (Chapter 5). Overall, the results of this analysis indicated that the parameter settings for the ‘pre DC and ‘post DC’ models were robust and did not lead to uncertainties regarding modelling results and predictions. However, the vulnerability settings are crucial for Ecosim and Ecospace and need to be treated with caution. Ecosim was applied to identify: 1) the impact and effectiveness of the selective reduction of different primary producers and 2) the impacts of fishing on target and non-target species on the ecosystem model (Chapter 6). The application of Ecosim requires fitting a model to time series data; for this study, the sourcing and fitting of time-series data indicated the importance and uncertainty of vulnerability settings. Three categories of vulnerabilities were identified: (a) vulnerabilities that did not have any effect on time series fitting (category 1); (b) interactions in which the lowest sums of squares occurred at low vulnerability settings (v=1 or 2, category 2); and settings that had a drastic impact on model fitting (category 3). The Ecosim simulations indicated that fishing affected almost all functional groups in the model, not just the target species. The recreational fishing sector also had a very strong impact on many functional groups, particularly Blue Swimmer Crabs and other invertebrate groups like bivalves and gastropods. The commercial fishing sector affected functional groups less than the recreational sector, but affected a range of estuarine fish groups including non-target fish species. Thus, the results of this study suggest that it may be not advisable to close those fleets completely as some aspects of the estuary ecosystem appear to benefit from increasing fishing pressure. Some fish groups and some target species responded positively to the closure of certain fleets, while others – particularly waterbirds and other top predators – did not (Table 6.8). Ecosim analyses highlighted the need for more data to ensure sustainable management, but suggested that the coexistence of fleets might be a better solution for sustaining catches and group biomasses in the future. Ecosim modelling indicated that selective plant removal is a reasonable management tool for this estuary. However, nutrient reduction and, thus, the permanent reduction of microscopic algae appears to be more ecologically and economically worthwhile (Fig. 6.12). Removing aquatic plant groups showed no significant longterm change in biomasses and the magnitude of short-term effects was much higher than for long-term effects. The Ecosim simulations demonstrated that only a permanent reduction in microscopic algae led to a reduction in total biomass. Reducing phytoplankton might be worthwhile because, although blooms of Nodularia spumigena no longer occur in the estuary because the salinities are too high (Huber, 1985), the estuary now contains several phytoplankton species (e.g. Heterosigma akashiwo) that cause blooms in other ecosystems (Guiry & Guiry, 2010). While the effects of phytoplankton blooms on the ecosystem depend on the size (i.e. the biomass) of the bloom, even blooms that only double the biomass of microscopic algae can have drastic long-term effects. This study supports the conclusion that a reduction in phytoplankton through management of nutrient input in the estuarine catchment represents the only ecological and economical management scenario that provides long-term sustainability for this ecosystem (Chapter 6). Ecospace modelling represents biomass dynamics over two-dimensional space and time. For this study, a model with fours habitats (shallow mud, deep sand, rocks and plant habitat) was developed. By applying Ecospace, the effects of reducing plant habitat and the effectiveness of two Marine Protected Areas were investigated, with specific consideration of waterbirds (Chapter 7). The Ecospace simulations suggested that waterbirds and piscivorous waterbirds were impacted by fishing and would benefit slightly from an introduction of a MPA, in particular a MPA at Point Grey. Further, the results of this Ecospace scenario indicated that waterbirds would profit from the reduction of plant habitat, whereas piscivorous waterbirds showed a small decline in biomass after removal of aquatic plants. Under the current fishing effort, the total biomass of the system and of the fish community increased. Thus, while the major prey groups of piscivorous waterbirds increased in biomass, but piscivorous waterbirds did not benefit from increased prey biomasses in the model, presumably because of the competition for fish. Ecospace modelling indicated that the catches would also increase drastically and, thus, that piscivorous waterbirds were in direct competition with the fishing sectors and other piscivorous predators (e.g. dolphins and sharks) and were out-competed for fish. The modelling suggest that the sustainable management of the fishing sectors is essential for bird conservation. A MPA at Peel Inlet led to lower catches under the current fishing scenario and catches declined even further under lower fishing effort. In contrast, after introducing a MPA at Point Grey, the total catch only declined when the fishing effort was lessened. The Ecospace simulations indicated that an MPA at Point Grey increased the biomasses of functional groups and target species and also raised the total biomass of the system; however, these effects strongly depend on fisheries management (Chapter 7). Overall, the qualitative and quantitative modelling methods applied in this study improved our understanding of the dynamics and functioning of the Shark Bay and Peel-Harvey ecosystems (Chapter 8). Both approaches produced robust and reliable results. If precise quantitative predictions are required for a management scenario, Ecopath with Ecosim is the appropriate method to choose, as this approach can deliver detailed changes in biomass and catches. In contrast, qualitative modelling only indicates the direction of change, which might not always satisfy management needs. However, qualitative models are the ideal method when management decisions have to be made fast and when a detailed data set of the ecosystem is not available.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
This work aimed to study the diversity and distribution of marine sea turtles stranded in Potiguar Basin, Rio Grande do Norte, as well as aspects related to feeding behavior associated with human impacts. The study was conducted through the analysis of data from stranded animals, recorded in a daily monitoring in an area bounded on the north by the municipality of Aquiraz, in the state of Cear?, and the east by the municipality of Caicara do Norte, in the state of Rio Grande do Norte. Stranded dead animals were necropsied and for the analysis of the diet of animals, esophagus, stomach and intestines were fixed in 10% formalin and after that, the stomach contents were sorted and stored in 70% alcohol. Representative fragments of these organs were removed for making histological slides, with a view to histological characterization of the digestive tract. 2.046 occurrences of turtles were recorded during the period from 01/01/2010 to 31/12/2012. The Chelonia mydas species showed the highest number of records and it was observed in 66.81 % (N = 1,367) of cases; followed by Eretmochelys imbricata with 4.45 % (N = 91) and by Lepidochelys olivacea with 1.22% (N = 25). The Caretta caretta and Dermochelys coriacea species were, respectively, 0.93 % (N = 19) and 0.05 % (N = 1) records of strandings. In 26.54 % of cases, it was not possible to identify the species. Regarding the spatial distribution, the stretch A was the one that had the highest number of strandings and a larger number of records were registered in the warm months of the year. The dietary analysis showed that C. mydas fed preferentially on algae; C. caretta had a diet with a predominance of the item "coral?s fragments" and E. imbricata species showed preference for an animal origin material. Related to this anthropic interaction, 57.14 % (n = 76) of animals that died at the rehabilitation s base, showed cause of death due to complications from ingesting debris. According to the data presented, the Potiguar Basin presents itself as an area with important diversity and distribution of marine sea turtle as well is characterized as a feeding and nidification area for these species
Este trabalho objetivou estudar a diversidade e distribui??o das tartarugas marinhas encalhadas na Bacia Potiguar, RN, bem como os aspectos relacionados ao comportamento alimentar associados aos impactos antr?picos. O estudo foi realizado com animais encalhados, registrados por monitoramento di?rio, na ?rea delimitada a noroeste pelo munic?pio de Aquiraz, Cear?, e a leste pelo munic?pio de Cai?ara do Norte, RN. Os animais encalhados mortos foram necropsiados e coletados es?fago, est?mago e intestinos, fixados em formol a 10%, sendo posteriormente o conte?do estomacal triado e armazenado. Destes mesmos ?rg?os foram retirados fragmentos para confec??o de l?minas histol?gicas. Foram registradas 2.046 ocorr?ncias de tartarugas marinhas durante o per?odo de 01/01/2010 a 31/12/2012. A esp?cie Chelonia mydas apresentou o maior n?mero de registros (66,81%, N = 1.367); seguido de Eretmochelys imbricata (4,45%, N = 91) e Lepidochelys olivacea com 1,22% (N = 25). Caretta caretta e Dermochelys coriacea apresentaram, respectivamente, 0,93% (N = 19) e 0,05% (N = 1) registros. Tanto a distribui??o espacial, como a temporal, variaram evidenciando maior ocorr?ncia de encalhes no trecho A- Grossos-RN/Icapu?-CE e um maior n?mero de registros nos meses quentes do ano. A an?lise da dieta das tartarugas demonstrou que Chelonia mydas alimentou-se preferencialmente de algas; Caretta caretta de resto calc?rio e Moluscos e E. imbricata de material de origem animal. Dos animais que vieram a ?bito, 57,14% (n = 76) apresentaram como causa mortis ? ingest?o de detritos. A an?lise da histologia demonstra que o es?fago apresenta papilas esof?gicas, revestidas de epit?lio pavimentoso estratificado queratinizado, igualmente a mucosa deste ?rg?o. Aus?ncia de sub mucosa e camada muscular com m?sculos estriados e liso em diferentes dire??es. Est?mago e intestino apresentam as quatro camadas: mucosa, submucosa, muscular e serosa, com destaque para as fossetas g?stricas no est?mago e a presen?a de vilos nos intestinos. De acordo com os dados apresentados, a Bacia Potiguar apresenta-se como uma ?rea de grande diversidade de esp?cies de tartarugas marinhas, sendo caracterizada como ?rea de alimenta??o para essas esp?cies

Globally, over a million species are threatened with extinction from habitat loss, climate change, over-exploitation as well as other anthropogenic activities. Orchids are particularly at risk in part due to their distinctive ecology including high species diversity, often limited geographic range for many species, and tight ecological relations with specific symbionts. They are the most diverse group of flowering plants with ~28,000 species and are found on all but one continent. However, due to increasing pressures from humans many orchids are threatened with extinction. It is therefore important to assess what is threatening them and where. Therefore, this thesis assesses threats to orchids at a global and continental scale to highlight the most significant threats to orchids, where orchids are threatened and by what, and to prioritise conservation actions and future research. The range and diversity of threats to orchids was globally assessed and mapped using data from the International Union for Conservation of Nature (IUCN) Red List (Chapter 2). For the 442 orchids on the Red List, the most common threats were biological resource use (80% species), agriculture (53%), human intrusion and disturbance (36%) and development (35%) and were most commonly found in Africa (predominantly Madagascar), South and East Asia and South America. These threats often interacted and co-occurred with four major threat syndromes. Understanding threat syndromes is vital for orchid conservation as they can create more consistent conservation planning and help focus efforts on the specific threats in a given region. Globally the scale and extent of tourism and recreation is increasing, including nature-based tourism. As a result, tourism and recreation is increasingly recognised as a threat to plants including orchids. Therefore, the extent and nature of tourism and recreation as a threat to orchids globally was also assessed in more detail using data from the IUCN Red List (Chapter 3). This demonstrated that 149 of the 442 listed orchids were threatened by tourism and recreation including impacts of residential and commercial development for tourism infrastructure (22%), intentional collecting within protected areas (17%), and human intrusion and disturbance from recreational activities (20%). Tourism and recreation threats were severe, impacting many populations of some orchids and causing rapid decline. These findings highlight how tourism and recreation can threaten specific groups of plants in diverse habitats, but particularly in forests and shrublands and these threats often co-occurred as threat syndromes. To better facilitate orchid conservation, a more detailed analysis of geographical patterns in threatened orchids and threats to orchids was conducted at a continental scale using a methodology that could be adapted to other threatened taxa (Chapter 4). By utilising data on threatened orchids from the Australian Government, combined with species occurrence data from the Atlas of Living Australia, the distribution of the most severe threats to orchids in Australia were mapped. This included identifying locations where habitat modification, changing fire regimes, grazing, weeds, tourism and recreation and illegal collection occurred, including where they co-occurred as threat syndromes. This study shows that the loss of native vegetation is a key driver of most threats, while increases within protected areas was associated with an increased threat from tourism and recreation. This study also provides critical information for formulating conservation and management strategies for threatened orchids and other species in a changing environment. To ensure the successful conservation of orchids, researchers need to understand research and conservation priorities at a global scale. Therefore, conservation and research priorities for orchid conservation were assessed (Chapter 5) using data on research publications on orchid conservation from Scopus, data on conservation priorities from the Red List, and species occurrence records from the Global Biodiversity Information Facility (GBIF). This study highlighted the increase in conservation research and important gaps as well as key conservation priorities which were analysed to guide recommendations on future priorities. Based on the results, orchid conservation and research globally should increasingly focus on monitoring population, trends and distributions including the impacts of climate change, ecology, threats and threat mitigation, protection and management of species and their habitats and increasing education and awareness. The research in this thesis demonstrated how orchids are significantly threatened by anthropogenic activities at a global and continental scale including impacts from habitat loss, illegal collecting, tourism and recreation, increased fire regimes and invasive species. However, it is also evident that climate change is underrepresented as a threat to orchids and needs to be considered in future research. These studies highlight the prevalence and importance of threat syndromes and provide novel methods for spatially assessing them. It is evident from these studies that orchid conservation will benefit from global collaboration and focussed conservation priorities.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
Full Text

Cette thèse porte sur l'étude de la relation Homme-Mare temporaire dans la région de Benslimane. Une approche pluridisciplinaire intégrant l'écologie et la sociologie a été adoptée, afin d'apporter des réponses adaptées aux problématiques liées à ces habitats et de permettre leur développement durable. Le premier volet a pour but d'évaluer les facteurs clés déterminant la richesse de la végétation des mares de cette région. Les résultats obtenus révèlent l'influence prédominante des facteurs locaux, avec un effet significatif des facteurs régionaux et de la vulnérabilité des mares aux usages, sur l'expression de la richesse floristique. Les activités anthropiques affectent différemment la richesse en espèces Préférentielles. Le second volet se focalise sur les causes de régression des mares, en couplant l'évaluation des menaces à une enquête socio-économique. Les résultats montrent la prédominance d'une perception anthropocentrique des mares temporaires. Ce constat traduit le haut niveau de menace qui pèse sur les mares de cette région. L'évaluation de ces menaces, qui indique que 22 % des mares sont vulnérables et que 23 % sont menacées de destruction à court terme, soulignent le besoin urgent de nouvelles politiques environnementales et d'approches innovantes de gestion des mares temporaires. Enfin, le troisième volet s'intéresse à l'impact du pâturage sur la végétation des mares. Les résultats montrent que cette perturbation affecte la végétation des mares, à l'échelle régionale et locale. Ces résultats sont interprétés comme résultant de l'effet sélectif des herbivores et la tolérance différentielle des espèces aux perturbations. Au terme de cette étude, la gestion intégrée des mares apparaît comme le moyen le plus approprié pour le développement durable de cet "éco-socio-système" complexe, en conciliant développement économique et bon état écologique des ressources, et en liant les questions environnementales, économiques et sociales
This thesis focuses on the study of the relationship Man-Temporary pool. A multidisciplinary approach integrating ecology and sociology has been adopted to provide appropriate responses to the problems related to these ecosystems and to allow their sustainable development. The first section aims at evaluating the key factors determining the vegetation richness within regional pools. The obtained results reveal the predominant influence of local factors, with a significant effect of regional factors and the vulnerability of pools to use, on the expression of the vegetation. Human activities affect differently the richness in preferential pool species. The second section focuses on the major causes of the regression of pools, by coupling threats assessment and a socio-economic survey. The results point out the anthropocentric perception of pools. This translates the high level of threat concerning the temporary pools of Benslimane region. The thr eat assessment, which shows that 22 % of pools are vulnerable, and 23 % are threatened of destruction of the short term, highlights the urgent need for new environmental policies and innovative approaches of temporary pools management. Finally, the third section concerns the impact of grazing on the vegetation of temporary pools. The results demonstrate that grazing affects the vegetation of pools, both at the regional and the local scale. These results are interpreted as a result of the selective influence of herbivores, and the differential tolerance of species to disturbance. At the end of the present study, the integrated management of pools appears as the most appropriate means for the sustainable development of this complex eco-socio-system, by combining the economic development and the ecological status of resources, and by linking environmental, economic and social issues

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To meet their needs the man began a steady transformation of the middle giving you other settings according to new interests that arise, which promotes and creates imbalances often conflict situations in land use and occupancy in areas in many cases, they should be protected. Many of these actions taken, especially in watersheds, can generate negative consequences for the whole community, especially when there is lack of planning of land occupation. His aim of this study was to analyze the dynamics of the use and occupation of the land from the use of the concepts of environmental conflict and hemeroby in the basin of the São Lourenço River in the municipality of Itaiópolis - SC, between 1977/79 and 2011. The adoption of this basin is justified by the same form in the area of wealth, fueling the county seat. Regarding the methodological procedures were performed based on bibliographic publications and public institutions and generating maps for the period 1977/79 and 2011. We identified five classes of land use: Urbanized Area, Culture,Forest, Grassland / Rural and Forestry. Classes of Environmental Conflicts adopted were: use area corresponding area overused and underused area. Regarding hemeroby was identified the degree of human interference in the basin, based on the dependence of technological systems from the classes: Ecosystems natural, seminatural Ecosystems, Ecosystem (biotic) anthropogenic 1, Ecosystem (biotic) anthropogenic 2, and Tecno-ecosystems. The results showed that the most significant changes occur in the classes pasture / country, or is semi ecosystems and class culture represented by Ecosystem (biotic) anthropogenic 1, the first of which was the one that lost area (-30.91%) and the second a more expanded (19.96%). The data presented in this analysis reveal that the use and occupation of the land in the basin follow the trend of expansion in the activities related to agribusiness that constitute spatial configuration occurred generally throughout the municipality. The class corresponding usage totaled the largest parcel of land in the basin and the main differences between aptitude and land uses are mainly in areas of permanent preservation.
Para suprir suas necessidades o homem iniciou uma constante transformação do meio dando-lhe outras configurações de acordo com novos interesses que vão surgindo, o que promove com frequência desajustes e cria situações conflitantes no uso e ocupação da terra em áreas que em muitos casos, deveriam ser protegidas. Muitas dessas ações praticadas, de modo especial, em bacias hidrográficas, podem gerar consequências negativas para toda a coletividade, sobretudo quando há falta de planejamento na ocupação da terra. O objetivo desse estudo foi analisar a dinâmica do uso e ocupação da terra a partir da utilização dos conceitos de conflito ambiental e hemerobia na bacia do rio São Lourenço no município de Itaiópolis - SC, no período de 1977/79 a 2011. A adoção desta bacia hidrográfica justifica-se pela mesma constituir-se em área de manancial, abastecendo a sede do município. Quanto aos procedimentos metodológicos foram realizados levantamentos bibliográficos com base em publicações de instituições e órgãos públicos e geração de mapas para o período 1977/79 e 2011. Foram identificadas cinco classes de uso da terra: Área Urbanizada; Cultura; Floresta; Pastagem/Campestre e Silvicultura. As classes de Conflitos Ambientais adotadas foram: área de uso correspondente, área sobreutilizada e área subutilizada. Com relação a hemerobia foi identificado o grau de interferência antrópica na bacia, com base na dependência tecnológica dos sistemas a partir das classes: Ecossistemas naturais, Ecossistemas seminaturais, Ecossistema (biótico) antropogênico 1, Ecossistema (biótico) antropogênico 2 e Tecno-ecossistemas. Os resultados permitiram verificar que as mudanças mais significativas ocorrem nas classes pastagem/campestre, ou seja ecossistemas seminaturais e na classe cultura representada pelo Ecossistema (biótico) antropogênico 1, sendo que a primeira foi a que mais perdeu área (-30,91%) e a segunda a que mais se expandiu (19,96%). Os dados apresentados nesta análise revelam que o uso e ocupação da terra na bacia seguem a tendência de expansão das atividades ligadas ao agronegócio que constituem configuração espacial ocorrida de maneira geral em todo o município. A classe de uso correspondente somou a maior parcela ocupada na bacia e as principais divergências entre a aptidão e os usos da terra se encontram principalmente em áreas de preservação permanente.

La Directive Cadre sur l'Eau exige le retour au bon état des cours d'eau en Europe. Ces cours d'eau reçoivent en effet différentes pollutions liées aux différentes activités économiques des populations installées le long de leurs rives. On s'intéresse souvent de façon isolée à des types particuliers de pollution: pollution agricole dues aux pesticides, engrais et résidus d'élevage en milieu rural, pollution spécifique d'une industrie (sidérurgie, papeterie, etc.), pollution domestique plus ou moins bien traitée, etc. Or dans de nombreux cas, on a affaire à un mélange de polluants. Dans le cas de la Moselle, la pollution générée par les activités humaines dans la partie française du bassin versant de la Moselle impacte la qualité des eaux de surface en aval, et donc celle du Rhin. Notre but est de contribuer à caractériser l’état de certains affluents de la Moselle (Madon, Meurthe, Vologne et Fensch) en fonction de leurs pressions anthropiques et de proposer une stratégie pour calculer les flux des polluants le long de ces cours d’eau. Dans ce contexte des compagnes de prélèvement avec un pas spatial fin. Outre les paramètres habituels de caractérisation de l’état des masses d’eau (conductivité, pH, carbone organique dissous, azote ammoniacal, nitrates, etc.) une attention particulière a été portée aux propriétés optiques (absorbance UV-visible, fluorescence synchrone) de la matière organique dissoute afin de mieux comprendre son origine. Les spectres de fluorescence synchrone ont été étudiés par déconvolution ou par analyse en composantes principales. En outre une méthode a été développée, basée sur la spectroscopie de fluorescence synchrone, pour détecter la présence des azurants optiques. Enfin une méthodologie a été mise au point appliquée au Madon pour calculer les flux journaliers moyens de pollution à chaque station d'échantillonnage pour chaque période d'échantillonnage à partir de données géographiques. Cette méthode permet ensuite d’évaluer les flux de pollution
The Water Framework Directive demands a return to good condition for rivers in Europe. These rivers receive different types of pollution related to various economic activities of populations installed along their banks. We are often interested in an isolated manner to particular types of pollution: pollution due to agricultural pesticides, fertilizers and livestock waste in rural areas, pollution due to a specific industry (steel, paper mill, etc.), more or less well treated domestic pollution, etc. But in many cases, we are dealing with a mixture of pollutants. In the case of the Moselle, the pollution generated by human activities in the French part of the Moselle watershed impacts surface water quality downstream and therefore the Rhine. Our goal is to characterize the state of some tributaries of the Moselle (Madon, Meurthe, Vologne and Fensch) versus anthropogenic pressures and propose a strategy to calculate the flow of pollutants along these rivers. In this context, sampling campaigns with a dense spatial stations have been organized. In addition to the usual parameters characterizing water quality (conductivity, pH, dissolved organic carbon, ammonia nitrogen, nitrate, etc.) a particular attention has been given to optical properties (UV-visible absorbance, synchronous fluorescence) of dissolved organic matter in order to understand its origin. Synchronous fluorescence spectra were studied by deconvolution or by principal components analysis. A method has been developed, based on the synchronous fluorescence spectroscopy, to detect the presence of optical brighteners. Finally, a methodology has been developed in Madon watershed in order to calculate the mean daily pollution flux at each sampling station for each sampling period from geographic data

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Agriculture, urbanization and industrialization are some of the human activities that are constantly generating negative impacts on the environment. Much of this degradation directly affects exhaustible lotic systems that are important sources of water supply for the population. This provides the aggravation of problems in obtaining clean water. From this context, the present study aims to assess visual characteristics of habitats in the longitudinal gradient of Araras River and along with the seasonal monitoring of physical and chemical parameters of water quality, state of the natural environment conservation status, while characterizing the changes caused by anthropic activity. For the survey data, 6 points of evaluation were select, ranging from stretches of rural and urban areas. The evaluation took place using the Rapid Assessment Protocol of Habitat Diversity, which at the end of the application, defines the environment preservation level. The monitoring with collection of water samples complied with the climate (drought, intermediate and wet), totaling 13 parameters measured, submitted to analysis of simple variance (ANOVA), using as multiple comparisons test the Tukey test at 5% level of significance. Both, the results of water quality analysis and the PARs analysis showed degradation of shares in the Ribeirão das Araras, as a result of human activities. Regarding seasonality, there was a significant difference only between the parameters: total nitrogen, total phosphorus, chloride, sulfate and electrical conductivity, but without apparent climate relationship. Total phosphorus parameter, except for the 3rd poit, showed values above the limit, established by CONAMA, in the Resolution 357/05, with higher concentrations in the dry season. However, in the 5th point, it was highlighted by having higher concentrations in almost all parameters and also by disagreement in turbidity parameter in the interim period. The protocol described the whole gradient evaluated as amended (48.6 points). The points of greatest environmental criticality were the points 4 and 5, both classified as impacted. Together the tools showed that the points located in the urban area (4 and 5), are the most affected by human activities, mainly because of the margins occupation, channeling, rectification, removal of riparian vegetation, domestic sewage disposal, garbage on the banks, erosion, etc. So, the low-cost of tools adopted here, Ecokit and RAPs, provided to be an efficient way to evaluate the water resources.
Agricultura, urbanização e industrialização são algumas das atividades antrópicas, que estão constantemente gerando impactos negativos ao meio ambiente. Grande parte dessa degradação afeta diretamente os esgotáveis sistemas lóticos que são importantes fontes de abastecimento de água para a população. Isso propicia o agravamento dos problemas em se obter água limpa. Partindo deste contexto, a presente pesquisa teve como objetivo avaliar características visuais de habitats no gradiente longitudinal do Ribeirão das Araras e juntamente com o monitoramento sazonal dos parâmetros físicos e químicos de qualidade da água, indicar o estado de conservação do ambiente natural, sem deixar de caracterizar as alterações ocasionadas pela atividade antrópica. Para o levantamento dos dados, foram selecionados 6 pontos de avaliação, compreendidos entre trechos da zona rural e urbana. A avaliação se deu com a utilização do Protocolo de Avaliação Rápida da Diversidade de Habitats, que ao final da aplicação, define o nível de preservação do ambiente. O monitoramento com coletas de amostras de água obedeceu à sazonalidade climática (períodos de seca, intermediário e chuvoso), sendo no total 13 parâmetros mensurados, submetidos à análise de variância (ANOVA) simples, utilizando como teste de comparações múltiplas o teste de Tukey ao nível de 5% de significância. Tanto os resultados das análises de qualidade da água, quanto o PARs apontaram ações de degradação na microbacia do Ribeirão das Araras, em decorrência das atividades antrópicas. Quanto a sazonalidade, houve diferença significativa apenas entre os parâmetros: nitrogênio total, fósforo total, cloreto, sulfato e condutividade elétrica, porém sem relação climática aparente. O parâmetro fósforo total, exceto no ponto 3, apresentou valores acima do limite estabelecido pela Resolução CONAMA 357/05, com maiores concentrações no período seco. No entanto, o ponto 5 teve destaque por apresentar maiores concentrações em quase todos os parâmetros e ainda, pela desconformidade no parâmetro turbidez do período intermediário. O protocolo classificou o todo do gradiente avaliado como alterado (48,6 pontos). Os pontos de maior criticidade ambiental foram os pontos 4 e 5, ambos classificados como impactados. Juntas as ferramentas permitiram concluir que os pontos localizados na região urbana (4 e 5) são os mais afetados pelas atividades antrópicas, sobretudo, pela ocupação das margens, canalização, retificação, retirada da vegetação ciliar, despejo de esgotos domésticos, lixo nas margens, processos erosivos, etc. Portanto, as ferramentas de baixo custo aqui adotadas (Ecokit e PARs), mostraram-se de maneira eficiente no que tange a avaliação dos recursos hídricos.

Darbe nagrinėta Šalčios upė, jos tyrimui buvo pasirinkti 24 vandens mėginių ėmimo taškai, kuriuose nustatytos tokių biogeninių medžiagų koncentracijos: amonio azoto, nitratų azoto, nitritų azoto, pH ir bendrojo fosforo. Pagal gautus duomenis iš hidrometeorologijos tarnybos nustatyta debito priklausomybė nuo klimato veiksnių. Atsižvelgiant į fizines-geografines sąlygas ir įvertinus maksimalius metinius kritulius bei vienos liūties kritulius, nustatytas susidarančio nuotėkio pobūdis. Išanalizavus gautus natūrinių tyrimų rezultatus, nustatyti veiksniai, lemiantys didžiausią upės vandens taršą. Pagal gautus duomenis nustatyta upės ekologinė būklė. Darbą sudaro 6 dalys: įvadas, mokslinės literatūros apžvalga, tyrimo objektas ir metodika, tyrimų rezultatai, išvados, literatūra. Darbo apimtis: 69 p. teksto be priedų, 34 iliustracijos, 9 lentelės, 65 literatūros šaltiniai.
The scientific literature related to the issue and research methodology is discribed in this master work. In the work was analyzed Šalčia’s River, there were selected 24 sampling points where was detected concentrations of these nutrients: ammonium nitrogen, nitrate nitrogen, nitrite nitrogen, pH, and total phosphorus. According to the data obtained from the Hydrometeorological Service there were determined flow dependence on climatic factors. In view of the physical-geographical conditions and the evaluation of the maximum annual rainfall and the rainfall of a storm there were generated runoff patterns. The analysis of the results obtained during the experimental helped to determine the factors leading to maximum river water pollution. According to the data obtained there was found ecological status of the river. The work consists of six parts: introduction, literature review, research and methodology, results, conclusions and references. Work size: 69 p. text, 34 figures, 9 tables, 65 references.

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Inúmeros impactos antrópicos vêm afetando os ecossistemas aquáticos e identificar respostas da biota aquática a esses impactos persiste em um grande desafio aos ecólogos. Com o objetivo de determinar essas respostas sobre diferentes níveis de organização biológica e suas interfaces, são abordadas a ecologia trófica dos peixes e a estrutura e dinâmica das teias tróficas em 20 riachos de 3ª ordem de quatro bacias da região de Mata Atlântica (RJ), em gradiente de impactos relacionados ao uso de solo da microbacia e às medidas estruturais e limnológicas locais. Foram realizadas análises do conteúdo estomacal e de isótopos estáveis de carbono (C) e nitrogênio (N) dos peixes e seus recursos alimentares (macroinvertebrados e recursos basais). O gradiente de alguns impactos tanto em escala local (% de cobertura de dossel) quanto de microbacia (uso de solo e input de nutrientes) afetaram a integridade estrutural e funcional das comunidades aquáticas (Capítulos 1, 3 e 4). Foram identificadas variações da proporção de guildas tróficas de peixes e conexões com seus recursos (Capítulo 1), com o aumento das guildas dos Detritívoros e Detritívoros-insetívoros em riachos com alta concentração de nitrogênio total, alta turbidez e baixa temperatura. A métrica H2 (Especialização da teia) foi relacionada a riachos com maior porcentagem de dossel, indicando maior partilha de recursos entre as espécies de peixes (Capítulo 1). Os valores de δ13C do perifíton foram maiores em riachos com menor cobertura vegetal, ao passo que os de δ15N se relacionaram ao conjunto de impactos em escala local e regional (Capítulo 2). Já as alterações isotópicas na biota foram reflexo, em parte, da mudança dos valores do perifíton (Capítulo 2), principal fonte de carbono basal para os consumidores aquáticos (Capítulo 3), e, em parte, da variação da dieta dentro das guildas (Capítulos 3 e 4), influenciando a posição trófica de algumas espécies e guildas de peixes na teia alimentar (Capítulo 4), como os Insetívoros e Detritívoros, e as espécies Gymnotus pantherinus e Astyanax spp. As influências dos gradientes de impactos sobre os vários compartimentos foram sintetizadas em diagramas conceituais (Capítulo 3), demonstrando as variações dos valores isotópicos de todos os consumidores (insetos e peixes), e as mudanças da proporção de insetos consumidos por todas as guildas tróficas de peixes frente aos impactos. Os resultados demonstram que o gradiente de impactos, tanto em escala local quanto regional, atuam em conjunto na determinação da estrutura e dinâmica trófica das comunidades aquáticas, nem sempre sendo possível isolar seus efeitos sobre os diversos parâmetros analisados. Ao mesmo tempo em que demonstrou alguns efeitos idiossincráticos, o presente trabalho permitiu identificar padrões de resposta das comunidades aquáticas em relação a alguns dos principais impactos sofridos por sistemas lóticos em ambientes tropicais.
Numerous anthropic impacts have been affecting aquatic ecosystems. Identifying responses of aquatic biota to these impacts remains a major challenge for ecologists. In order to determine these responses on different levels of biological organization and their interfaces, the trophic ecology of the fish and the food web structure and dynamics were analyzed in 20 streams (3rd order) of four watersheds in the Mata Atlântica (RJ). These streams are arranged in a gradient of impacts related to the watershed land use and the local structural and limnological features. Stomach contents and stable isotopes of carbon (C) and nitrogen (N) of fish and their food resources (macroinvertebrates and basal resources) were analyzed. The gradients of some impacts on the local scale (% canopy cover) and the microbasin (land use and nutrient input) affected the structural and functional integrity of aquatic communities (Chapters 1, 3 and 4). Variations in the proportion of fish trophic guilds and connections with their resources were identified (Chapter 1), with the increase of the guilds of Detritivores and Detritivorousinsectivores in high concentration of total nitrogen, high turbidity and low temperature. The metric H2 (Food web specialization) was related to streams with higher canopy cover, indicating a high resource partitioning among the fish species (Chapter 1). Values of periphyton δ13C were higher in streams with lower canopy cover, while δ15N values were related to the set of impacts at the local and the regional scale (Chapter 2). Isotopic variation in the biota were in part a reflection of the variation of the periphyton (Chapter 2), which is the main source of basal carbon for aquatic consumers (Chapter 3), and in part of the variation of diet within the guilds (Chapters 3 and 4), influencing the trophic position of some fish species and guilds (Chapter 4), such as Insectivores and Detritivores, and the species Gymnotus pantherinus and Astyanax spp.. Influences of the impact gradients upon the biota compartments were summarized in conceptual diagrams (Chapter 3), showing the variations of the isotopic values of all the consumers (insects and fish), and the changes in the proportion of insects consumed by all the fish trophic guilds. The results show that the impact gradients, both local and regional, determine the structure and trophic dynamics of aquatic communities, and it is not always possible to isolate their effects. At the same time that it demonstrated some idiosyncratic effects, the present work allowed to identify patterns of response of aquatic communities related of the main impacts suffered by lotic systems in tropical environments.

A Araucaria angustifolia, conhecida como Pinheiro-do-Paraná é uma espécie ameaçada de extinção no Brasil, está inserida num bioma rico em biodiversidade, a Mata Atlântica, e muito pouco se conhece sobre os atributos microbiológicos dessas florestas. Este trabalho teve como objetivo avaliar potenciais atributos microbiológicos do solo e algumas variáveis ambientais (atributos químicos, físicos e efeito sazonal), a fim de estabelecer bioindicadores de qualidade do solo em Florestas de Araucária. Os estudos foram conduzidos em dois parques estaduais localizados em diferentes regiões do Estado de São Paulo, no município de Campos do Jordão (Parque Estadual de Campos do Jordão - PECJ), nos municípios de Apiaí e Iporanga (Parque Estadual Turístico do Alto Ribeira - PETAR) e também no município de Barra do Chapéu. Foram escolhidas três áreas no PETAR: FN floresta nativa de araucária, ND floresta de araucária com distúrbio antropogênico e PL plantio de araucária; e quatro áreas foram selecionadas no PECJ: FN floresta nativa de araucária, ND floresta de araucária com distúrbio antropogênico, PL plantio de araucária e PF plantio de araucária com ocorrência de fogo acidental. Ao acaso, foram selecionadas quinze árvores de araucária por área e sob a copa de cada uma delas foram retiradas amostras na profundidade de 0 a 20 cm, nas épocas seca e de chuva. Foram avaliados os atributos microbiológicos: arilsulfatase (ARIL), fosfatase ácida (FOSF), -glicosidase (GLIC), desidrogenase (DESID), nitrogênio (NBM) e carbono da biomassa microbiana (CBM), Número Mais Provável (NMP) de amonificantes (AMO), nitritadores (NITRI), nitratadores (NITRA) e desnitrificantes (DESN), respiração basal (RESP), respiração induzida por substrato (RIS), quociente metabólico (qCO2) e microbiano (qMIC). Além disso, foram estabelecidos perfis de ácidos graxos ligados a ésteres de fosfolipídios (EL-PLFAs) e o perfil de capacidade de utilização de substratos de carbono (Biolog). Alguns parâmetros químicos foram avaliados (pH, H++Al3+, Al3+, Ca2+, Mg2+, K+, P, S, N, carbono orgânico total e a capacidade de troca catiônica) e físicos (teores de argila, silte e areia). Verificou-se que o PL do PETAR e PF do PECJ foram relacionados aos atributos microbiológicos ARIL, DESN, CBM e qMIC nos dois períodos. A partição da variabilidade revelou que a atividade microbiana foi influenciada mais pelas variáveis físico-quimicas do solo do que pelas áreas e épocas de coleta. Foram identificados perfis de ácidos graxos semelhantes aos aqui obtidos, PETAR e PECJ, em um trabalho anterior no PECJ, o que pode ser indicação de um padrão de EL-PLFA próprio do ecossistema de araucária. Os ácidos graxos 10Me18:0 (actinobactéria), a relação ácido graxo saturado/insaturado (sat/insat), o consumo dos substratos -metil-D-glicosídeo e o ácido 2-hidroxibenzóico foram também relacionados às áreas PL (PETAR) e PF (PECJ) nos períodos avaliados. Já os ácidos graxos 18:19c (fungo) e 16:17c (bactéria Gram-), o consumo dos substratos glicose-1-fosfato, -D-lactose e ácido -hidroxibutírico estavam relacionados às áreas impactadas dos dois parques durante os períodos de seca e chuva. Portanto, esses atributos microbiológicos são potenciais indicadores de qualidade do solo em Florestas de Araucária, no entanto, novas avaliações são necessárias para as devidas validações dos bioindicadores e monitoramento dessas áreas.
Araucaria angustifolia, also called Brazil Pine, is an endangered species in Brazil. It is part of one of the richest ecosystems in biodiversity, the Atlantic Forest, and little is known about the soil microbiological attributes in this forest. The objective was to evaluate the potential of the soil microbiological attributes and some environmental variables (physical-chemical properties and seasonal effect) to act as bioindicators of soil quality in Araucaria Forests. This study was undertaken in two different state parks in the São Paulo State, in Campos do Jordão county (Campos do Jordão State Park - PECJ), and in Apiaí and Iporanga counties (Alto Ribeira Touristic State Park - PETAR) and also in Barra do Chapéu county. Three areas were surveyed in PETAR: FN Native Araucaria forest, ND Native Araucaria forest with anthropogenic disturbance, and PL Reforested Araucaria; and four areas in PECJ: FN Native Araucaria forest, ND Native Araucaria forest with anthropogenic disturbance; PL Reforested Araucaria, and PF Araucaria reforestation submitted to an accidental fire. Fifteen Araucaria trees were selected at random in each area and the soil and roots were sampled at 0 20 cm depth, in two contrasting seasons (dry and wet). The microbiological attributes evaluated were: arylsulfatase (ARIL), acid phosphatase (FOSF), -glucosidase (GLIC), dehydrogenase (DESID), carbon (CBM) and nitrogen microbial biomass (NBM), most probable number (NMP) of bacterial ammonium oxidizers (AMO), nitrite oxidizers (NITRI), nitrate oxidizers (NITRA) and denitrifiers (DESN), basal microbial respiration (RESP), substrate induced respiration (RIS), and metabolic (qCO2) and microbial quotient (qMIC). Additionally we determined the phospholipid fatty acid profiles (ELPLFA) and the community level physiological profile (Biolog). Some chemical attributes were evaluated (pH, H++Al3+, Al3+, Ca2+, Mg2+, K+, P, S, CEC, C/N ratio, total organic carbon (COT), total nitrogen (NT), as well as some physical ones (soil texture: clay, sand and silt contents). There was a high correlation between the PL of PETAR and the PF of PECJ and the microbiological attributes ARIL, DESN, CBM and qMIC in both periods. The partitioning of the variability evidenced that microbial activity was influenced in a higher degree by the physical-chemical properties of soil than by study areas or periods. We identified similar fatty acid profiles in PETAR and PECJ and they were also similar to the ones found in a previous work in PECJ, what could indicate a specific EL-PLFA pattern in the Araucaria ecosystem. The fatty acids 10Me18:0 (actinobacteria), the saturated/unsaturated fatty acid ratio (sat/insat), the substrate utilization of -methyl-D-glucoside and 2-hydroxybenzoic acid were also related to PL (PETAR) and PF (PECJ), in both periods. The 18:19c fatty acid (fungi) and 16:17c (Gram-), the glucose-1-phosphate, -D-lactose and -hydroxybutyric acid were C-source for microbial communities of the impacted areas in both parks during the wet and dry periods. Therefore, these attributes are potential microbial indicators of soil quality in Araucaria forests, however, new evaluations are required to confirm these biomarkers and to monitor these areas.

La contamination des systèmes riverains par les polluants organiques persistants et les contaminants émergents a reçu ces dernières années une attention particulière à leur impact sur les écosystèmes exposés. Les petites rivières méditerranéennes présentent des variations importantes et rapides du débit hydrologique au cours de l'année et contribuent à la pollution de la Méditerranée à travers le transport de la contamination survenant dans la zone côtière, surtout lorsque la densité de population est élevée. La rivière Kadicha au nord du Liban est un exemple des pressions anthropiques exercées au niveau du bassin méditerranéen. Cette petite rivière côtière est impactée par une urbanisation désorganisée et rapide, une croissance démographique et l’absence de traitement adapté des eaux usées. Dans ce contexte, plusieurs contaminants, témoins de différentes activités anthropiques, ont été sélectionnés et analysés au niveau du bassin versant de la rivière Kadicha.L’objectif principal de cette thèse est de déterminer l’impact des activités anthropiques sur le bassin versant de la rivière Kadicha à travers l’étude de la contamination par les polluants organiques persistants et les contaminants émergents. Le risque environnemental potentiel associé à leur présence est par la suite évalué. Parmi les contaminants émergents l’étude a porté sur deux groupes de composés à usage continu ayant des propriétés physico-chimiques différentes : les produits de soins personnels (absorbants ultraviolets et muscs), biocides, insecticides et tensioactifs (alkylphénols) et les produits pharmaceutiques. Ainsi 41 molécules lipophiles et 23 molécules hydrophiles (résidus de médicaments et leurs métabolites) sont recherchées dans les matrices sédiments et eau respectivement. Les matrices sont prélevées au cours de deux campagnes d’échantillonnage correspondant aux saisons humides et sèches au niveau de sites urbains, ruraux et de zones mixtes (résidentielles et agricoles).Les résultats indiquent : i) une détection de la totalité des polluants organiques persistants et des produits de soins personnels, biocides, insecticides et tensioactifs recherchés et 6 médicaments détectés, ii) une contamination (en terme de concentration et de diversité des molécules retrouvées) bien plus marquée en milieu urbain qu’en milieu rural, iii) une détermination de traceurs potentiels de l’activité urbaine (perméthrine, galaxolide, UV-326) iv) un risque environnemental élevé identifié pour certaines molécules (l’ofloxacine (médicament), les HAPs à faibles poids moléculaire et les polychlorobiphényles) et v) un risque potentiel plus élevé associé à la présence de polluants organiques persistants.Ces résultats constituent une base de connaissances sur les pressions anthropiques et les niveaux de contamination par les polluants organiques persistants et les contaminants émergents du bassin versant de la rivière Kadicha. Les données acquises sur la présence de ces contaminants au niveau du bassin versant de la rivière Kadicha ainsi que les risques environnementaux potentiels associés avec la présence de certaines molécules conduisent à proposer ces molécules comme molécules à suivre dans des futurs programmes de surveillance des rivières anthropisées au niveau du bassin méditerranéen
The river contamination with persistent and emerging organic pollutants has raised an increasing concern about their impact on exposed ecosystems. Small Mediterranean coastal rivers have great and fast variations of hydrological flow along the year and can rapidly bring to the mediterranean sea the contamination occurring in the coastal area, especially where population density is high. The Kadicha river basin in Northern Lebanon is an illustrative example of multiple pressures encountered in the Mediterranean basin: it is a small coastal river affected by disorganized and rapid urbanization, a population growth and a chronic default of wastewater collection and treatment. In this context, various contaminants, witness of different anthropic activities were selected and analyzed within the Kadicha river basin.The main objective of this thesis was to determine the impact of anthropogenic activities on the Kadicha River watershed through the study of the contamination with persistent and emerging organic pollutants. Then, the potential environmental risk associated with their presence was assessed. Among emerging contaminants, several compounds having different physico-chemical properties were selected: personal care products (ultraviolet absorbents, musks), insecticides, biocides and surfactants (alkylphenols) and pharmaceutical products. Thus 41 hydrophobic compounds and 23 hydrophilic compounds were studied in sediments and water respectively. The environmental matrices were collected during two sampling campaigns corresponding to wet and dry seasons along sites impacted by urban, rural and mixture land uses (residential and agricultural zones).The results indicate : i) a detection of the totality of persistant organic pollutants and personal care products, insecticides, biocides and surfactants and 6 pharmaceuticals were detected, ii) a higher contamination (in terms of concentrations and diversity of molecules) in urban than in rural zones, iii) a selection of potential markers of urbanization (permethrin, galaxolide and UV-326) iv) an environmental risk for several compounds (ofloxacine (pharmaceutical), low molecular weight PAHs and polychlorinated biphenyls) was identified and v) a higher potential risk associated with the presence of persistent organic pollutants.These results can be considered a knowledge base on anthropogenic pressures and levels of contamination with persistent and emerging organic pollutants in the Kadicha river watershed. The data acquired as well as the potential environmental risks associated with the presence of certain molecules in the Kadicha river watershed lead to propose these molecules as a part of future monitoring programs for anthropized rivers in the Mediterranean basin

En Afrique Sub-Saharienne, les problématiques de contamination de la ressource en eau par les pesticides et les résidus pharmaceutiques commencent à être mises en évidence. La problématique de la thèse porte sur la caractérisation de l’impact des activités humaines sur la qualité de la ressource en eau, par l’étude de la contamination par les pesticides et les résidus pharmaceutiques. Le site d’étude choisi est le bassin versant de la Méfou, qui draine la capitale du Cameroun, Yaoundé. Dans un premier temps, le site est caractérisé par ses spécificités environnementales (relief, occupation des sols) et sociodémographiques afin d’identifier les pressions anthropiques. Les pratiques d’agriculture urbaine, et en particulier le maraîchage intensif dans les bas-fonds entraîneraient l’utilisation massive de pesticides. L’absence d’assainissement efficace et les multiples latrines, drains et fosses septiques constitunt autant de sources diffuses de contamination par les résidus de médicaments. En prenant le cas des pesticides, une méthode cartographique a permis de confirmer l’hypothèse selon laquelle les parcelles agricoles pourraient être identifiées comme des sources de pollution diffuses de pesticides via le ruissellement. La méthode multicritère SIRIS-Pesticides de l’INERIS (Institut National de l’Environnement Industriel et des Risques) appliquée sur deux scénarios de pratiques agricoles indique un potentiel transfert des pesticides ciblés vers les eaux de surface. Afin de conforter ces hypothèses, deux diagnostics de pollution ont été réalisés entre 2015 et 2018 en saisons pluvieuses, couplant des méthodes d’échantillonnages ponctuels et passifs. Une liste de 32 pesticides et de 24 résidus pharmaceutiques a été recherchée dans les eaux de surface et les eaux souterraines du bassin de la Méfou. Les résultats généraux indiquent (i) de fortes concentrations en herbicides et en anti-inflammatoires non stéroïdiens ainsi que la détection et la quantification d’une large gamme de composés recherchés, (ii) une contamination bien plus marquée en milieu urbain qu’en milieu péri-urbain, (iii) un risque environnemental à ces concentrations pour deux herbicides (diuron et atrazine) et (iv) la contamination de certains points d’eau souterraine (forages, puits, sources) par les résidus pharmaceutiques. Une enquête sociologique réalisée autour des points d’eau de prélèvement a permis d’identifier les enjeux liés à l’utilisation de cette ressource en eau. La contamination des eaux souterraines pourrait entraîner une exposition potentielle des populations aux résidus pharmaceutiques présents dans leur eau de boisson. Les résultats principaux constituent donc une base d’information sur les pressions anthropiques, les niveaux de contamination et les enjeux liés à l’eau à Yaoundé. Ils soulèvent des questionnements sur (i) les transferts des pesticides et des résidus médicamenteux dans l’hydrosystème de la Méfou, et (ii) à propos de l’exposition et des risques sanitaires potentiels posés par leur occurrence et leurs niveaux de contamination dans la ressource en eau
Demographic growth and urbanization create pressure on water resources. Among urban contaminants, pesticides and pharmaceuticals can be discharged into the aquatic environment through agricultural activities and untreated waste waters. Their presence is also reported in global water bodies. Measured contamination levels can have ecotoxicological effects on aquatic organisms as well as on human populations. In Sub-Saharan Africa, these problems are beginning to be highlighted. Local agricultural practices and consumption of pharmaceuticals lead to specific concerns.The aim of this thesis is to identify and characterize the impacts of human activity on the quality of the water resource in urban Sub-Saharan Africa, by analyzing pesticide and pharmaceutical contamination. The study area was the Méfou watershed that drains the political capital of Cameroon, Yaoundé (Center Region).First, the study area was characterized by its environmental (reliefs, land use) and socio-demographic specificities to identify anthropogenic pressures. Urban agricultural practices and in particular the intensive market gardening in the humid lowlands involves the use of massive amounts of pesticides. The absence of a sewage system and the numerous pit-latrines, drains and septic tanks are the sources of diffuse pharmaceutical contamination.Using the example of pesticides, a contaminated runoff mapping method based on susceptibility maps (from the IRIP method) confirmed that some treated plots located in situations that favor runoff were sources of diffuse pesticide contamination. Several areas in the study basin can accumulate this polluted runoff. Next, the multi-criteria SIRIS-Pesticides method from INERIS was applied based on two agricultural scenarios constructed with data sources from the literature. Results pointed to the potential transfer of pesticides from crops to both surface and groundwater.To reinforce these hypotheses, two water quality surveys were conducted in the rainy season between 2015 and 2018, combining grab and passive sampling. Thirty-two pesticides and twenty-four pharmaceuticals were searched for in surface and groundwater in the Méfou watershed. The main results indicate that (i) high concentrations of herbicides and analgesics were detected and quantified in the water samples along with a wide range of targeted compounds; (ii) the contamination pattern showed that the urban area is more polluted than the peri-urban area of Yaoundé; (iii) the measured concentrations pose an environmental risk, in particular the herbicides atrazine and diuron; and (iv) some groundwater sampling points used for drinking water were contaminated by the targeted pharmaceuticals.A social survey conducted in March 2018 around the sampling points identified the risks related to water use. The lack of a sewage system and the discharge of untreated waste water into the immediate surroundings facilitate contamination of the sampling sites. As groundwater is used as an alternative to the tap water network in Yaoundé, the population is also exposed to the risk of pharmaceutically contaminated drinking water.The main results provide baseline information about anthropogenic pressures, contamination levels and related issues in Yaoundé. They raise questions about (i) the transfer of contaminants in the Méfou hydrosystem and (ii) population exposure and potential health risks due to their presence and to the levels of contamination of the water resources

Les tourbières sont des zones humides qui ne couvrent que 3% des surfaces émergées mais qui sont très riches en matière organique. A la croisée des cycles du carbone et de l’eau, elles stockeraient près de 20 % du carbone organique des sols de la planète et par conséquent elles sont considérées comme des sources importantes dans le transfert de carbone organique vers les eaux de surface. Dans les bassins versants de montagne, les tourbières ne représentent qu’une faible proportion de la couverture paysagère et sont sujettes à l’influence d’activités anthropiques locales. Jusqu’à présent les conditions climatiques et d’accessibilité des zones montagneuses ont limité les études biogéochimiques dans les tourbières de montagne, mais de récentes avancées technologiques optiques permettent dorénavant de mesurer les concentrations de carbone organique in situ et à haute fréquence dans les ruisseaux drainant ces écosystèmes. Cette thèse a pour objectif de quantifier et d’identifier les mécanismes qui régissent le transfert de matière organique des tourbières vers les eaux de surface dans des bassins versants de montagne faisant l’objet d’activités anthropiques contemporaines. Pour cela deux tourbières situées dans les Pyrénées françaises ont été instrumentées et ont fait l’objet d’un suivi haute fréquence (30 min) sur plus de deux cycles hydrologiques. En premier lieu, ces travaux ont permis d’isoler le contrôle prédominant des crues dans les exports de matière organique des tourbières ainsi que la proportion majoritaire de la forme dissoute du carbone organique (COD) dans les exports. En fonction des cycles hydrologiques, les flux spécifiques de COD des tourbières de montagne sont très variables [16.1 ; 35.9] g.m².an-1 mais correspondent aux gammes observées pour les tourbières des plaines septentrionales. Ces mêmes flux placent les tourbières comme sources majoritaires de COD (>63%) en tête de bassin versant. Dans un second temps, l’analyse des pics observés sur les séries temporelles de concentration de COD a montré que, contrairement aux exports, la variabilité des concentrations aux exutoires des tourbières n’est pas contrôlée par le débit, mais par la température du sol et les battements de nappe phréatique. Calculés à partir des relevés piézométriques, des temps de récession hydrologiques permettent d’appréhender plus justement ces variabilités dans les modèles de concentration de COD ainsi que d’apprécier l’hétérogénéité hydrologique des tourbières. La troisième phase illustre la difficulté de séparer influence climatique et anthropique dans les exports de carbone organique des tourbières suite à deux évènements anthropiques, intervenus sur les sites d’études pyrénéens : un brulis et une coupe forestière. En complément une revue bibliographique à l’échelle mondiale rapporte cependant des flux de COD 30% plus importants à l’exutoire de tourbières influencées par des pratiques anthropiques. Ces travaux soulignent le besoin de disperser l’instrumentation haute fréquence sur davantage de tourbières afin de déterminer plus justement leur rôle dans le cycle du carbone global. L’ensemble des résultats confirme l’importance des exports de carbone organique dans le bilan carbone des tourbières mais également l’importance des tourbières dans l’hydrochimie des eaux de surface, notamment dans les zones anthropisées
Peatlands are a type of wetlands covering 3% of the continental areas. They store approximately 20% of the global soil organic carbon and therefore they are considered as a major source of organic carbon for inland waters. In mountainous areas, peatlands are relatively small, scattered and they may be under the influence of local anthropogenic activities. Until now, harsh mountainous climatic conditions have limited biogeochemical investigations in these remote areas but recent improvements in optical technologies make high frequency monitoring of stream organic concentration possible. This thesis aimed at quantifying the exports of organic matter and identifying the parameters that control these exports at the outlet of peatlands in mountainous watersheds influenced by local anthropogenic activities. To investigate these parameters, two peatlands in the French Pyrenees were monitored on several hydrological cycles at a high frequency (30 min). Quantification work showed that floods controls the export of organic carbon from peatlands and that dissolved organic carbon (DOC) was the main form exported. Depending on annual discharge, peatland DOC specific fluxes varied drastically [16.1 ; 35.9] g.m².yr-1 but they remained consistent with the fluxes measured in Northern lowland peatlands. Moreover, peatlands appeared as the main source of DOC (>63%) of these headwaters. In contrast with the exports, DOC concentration variability was not driven by discharge. Peaks in the times series revealed that peat soil temperature and water table fluctuations were the main drivers of the DOC concentration variability. Water recession times were calculated from water table time series and helped to improve stream DOC concentration models. In addition, the water recession times seemed to be a useful quantitative parameter to describe the hydrological heterogeneity of peatland complexes. Anthropogenic influence (prescribed burning and forest clearing) was difficult to disentangle from climatic influence driving stream organic exports from peatlands at the two Pyrenean experimental sites. However, these observations were completed by a global literature review reporting that DOC specific fluxes were 30% stronger in peatlands impacted by anthropogenic activities. This thesis has underlined the need to monitor more peatlands at a high frequency in order to determine more accurately their role in the global carbon cycle. All of the results confirmed that organic carbon exports are a crucial parameter in the carbon balance of peatlands. They also confirmed the influence of peatlands on the chemistry of inland waters, especially in areas subject to local anthropogenic disturbances

Le déclin des populations de nombreuses espèces animales depuis un siècle est associé aux activités anthropiques. La surexploitation des espèces ou encore la fragmentation des habitats en sont les principales causes mais d’autres activités humaines ont des effets plus subtils sur les animaux et impactent indirectement leur survie et leur reproduction. Le dérangement anthropique représente toutes les perturbations générées par la présence humaine, des objets ou des bruits anthropiques qui provoquent un stress chez l’animal. Le comportement et la physiologie des animaux en lien avec leurs traits d’histoire de vie peuvent être affectés par ce dérangement, mais de manière différente entre les individus d’une même population en fonction de leur personnalité. De cette façon, le dérangement anthropique pourrait contribuer à long terme au déclin des populations. Le busard cendré (Circus pygargus) est une espèce patrimoniale qui niche au sol dans les cultures céréalières, ce qui l’expose aux activités agricoles, récréatives et bruits anthropiques. De plus, sur le site d’étude, la Zone Atelier Plaine et Val de Sèvre, le suivi de sa population implique plusieurs visites au nid et des mesures répétées sur les poussins pouvant générer un dérangement. Mes travaux de thèse se sont intéressés aux impacts des activités et des infrastructures humaines sur le comportement et les traits d’histoire de vie du busard cendré et comment ces effets peuvent varier en fonction des différences comportementales inter-individuelles au sein de la population. Grâce à une approche expérimentale, un phénomène de sensibilisation a été mis en évidence chez les poussins manipulés par les mêmes expérimentateurs au cours de visites successives au nid. Par la suite, la témérité (personnalité et plasticité) des mâles et femelles adultes a été caractérisée. Un patron d’appariement positif à travers la témérité des individus a été montré au sein de la population. Cependant, ce patron d’appariement ne procurerait pas de bénéfices en termes de succès reproducteur, ce qui questionne sur son origine. Ce résultat suggère que d’autres processus que la sélection sexuelle, pourraient induire ce patron d’appariement. L’association parentale dans la témérité a ensuite été reliée à l’approvisionnement en proies des couples, puis aux conditions corporelle et physiologique des poussins. Les couples moins plastiques dans leur témérité délivraient une plus grande proportion d’insectes à leur progéniture, ce qui expliquerait des concentrations plus élevées en caroténoïdes trouvées chez leurs poussins. Aucun effet de la similarité comportementale des parents n’a été montré sur la qualité des poussins. Enfin, les nids de busard cendré étaient distribués différemment par rapport aux infrastructures en fonction de la témérité des femelles. Les femelles timides évitaient plus le bâti dans leur choix de site de nidification que les femelles téméraires. Cette différence de répartition spatiale des phénotypes pourrait être à l’origine du patron d’appariement. La densité de chemins autour du nid affectait négativement le succès reproducteur des femelles quelle que soit leur témérité. Ce résultat nécessite de futures recherches pour identifier la nature du dérangement et limiter ses effets. Ces travaux de thèse apportent des éléments de réponses sur les effets directs et indirects du dérangement anthropique et permettent de remettre en question certaines pratiques dans le suivi des populations afin de les améliorer. Enfin, évaluer les effets du dérangement en fonction des différences inter-individuelles apparait essentiel pour mieux comprendre ses conséquences sur la dynamique des populations
The decline of populations for many animal species in the last century has been linked to anthropogenic activities. The species overexploitation or even habitat fragmentation are the major causes but other human activities may have more subtle effects on animals and indirectly may impact their survival and reproduction. Anthropogenic disturbance represents any disruption due to human presence, anthropogenic objects or noise that induce stress for animals. Animal behaviour and physiology linked to life-history traits could be affected by this disturbance but differently among individuals from a same population depending on their personality. In this way, the anthropogenic disturbance may contribute to the population decline. The Montagu’s harrier (Circus pygargus) is a flagship species that nests on the ground in cereal crops exposing it to agricultural practices, recreative activities and anthropogenic noise. Moreover, the population monitoring on the study site, the Zone Atelier Plaine et Val de Sèvre, involves several nest visits and repeated measures on chicks that may induce a disturbance. My thesis work has been focused on the impacts of human activities and infrastructures on the behaviour and life-history traits of Montagu’s harriers and how these impacts may vary depending on behavioural inter-individual differences within the population. Through an experimental approach, a sensitization phenomenon has been highlighted in chicks handled by the same experimenters over repeated nest visits. Thereafter, male and female boldness (personality and plasticity) was characterized. A positive assortative pairing pattern for boldness was highlighted within the population. However, this pattern did not provide fitness benefits which questions about its origin. This result suggests that other process than sexual selection could explain the pairing pattern. Then, the parental association in boldness has been linked to prey provisioning from pairs, and to nestling body and physiological conditions. Less plastic pairs in boldness provided a higher proportion of insects to their offspring that could explain greater carotenoids concentrations found for their chicks. Any effect of behavioural similarity within pairs has been shown on nestling quality. Finally, Montagu’s harrier nests were differently distributed in relation to infrastructures depending on female boldness. Shy females would avoid more buildings through nest site selection than bold females. This difference in spatial distribution of phenotypes could result in the positive pairing pattern. The path density around nest negatively affected the reproductive success regardless of female boldness. This result needs further investigations to identify the disturbance nature and limit its effects. This thesis work provides some answers on the direct and indirect effects of anthropogenic disturbance and allows questioning certain practices in the population monitoring to improve them. Finally, the assessment of disturbance effects depending on inter-individual differences is essential to better understand the consequences on population dynamic

L’impact anthropique sur les cours d’eau a significativement augmenté suite à la révolution industrielle engagée par les pays occidentaux. Ainsi, les modifications de la géomorphologie des cours d’eau pour le stockage de l’eau et la navigation, la conversion des surfaces à des fins agricoles, industrielles et d’urbanisation illustrent cette pression environnementale, qui se traduit, en autre, par une augmentation de rejets de divers contaminants dans les compartiments environnementaux et notamment les rivières. Une part de ces rejets peut donc se retrouver dans les matières en suspension, considérées alors comme des puits de stockage, qui transitent dans les rivières. Les aménagements des rivières et notamment la construction de barrages favorisent alors la sédimentation de ces particules contaminées au cours du temps. Ces sédiments d’origines anthropiques, également appelés legacy sediments, sont donc les témoins des activités anthropiques et permettent de reconstruire les trajectoires temporelles des contaminations au sein des bassins versants. L’Eure, affluent majeur de l’estuaire de Seine, a connu d’importantes pressions anthropiques depuis le vingtième siècle. La reconstruction temporelle des pressions anthropiques a nécessité l’association de différentes approches méthodologiques : (i) une analyse diachronique des modifications morphologiques de la rivière a été menée, conjointement à (ii) une analyse de la dynamique sédimentaire et de la nature des dépôts sédimentaires par couplage de méthodes géophysiques, sédimentologiques et géochimiques, et à (iii) la mise en place d’un réseau de suivi du comportement hydro-sédimentaire avec un échantillonnage en continu des matières en suspensions. De profondes modifications géomorphologiques se sont produites en aval du bassin versant, avec pour principales conséquences un exutoire déplacé d’une dizaine de kilomètres en direction d’un barrage et la formation d’annexes hydrauliques favorisant l’accumulation de sédiments dès les années 1940. Ceux-ci ont permis de montrer que le bassin versant de l’Eure avait connu d’importantes contaminations dont les conséquences sont encore enregistrées malgré l’arrêt des activités ou usages. Les tendances temporelles des éléments traces métalliques et métalloïdes ont montré de fortes contaminations en As dans les années 1940 et des contaminations d’origines industrielles en Cr, Co, Ni, Cu, Zn, Ag et Cd durant les années 1960–1970, ainsi que des contaminations en Sb et Pb en 1990–2000. Ces dernières sont toujours enregistrées malgré l’arrêt des activités responsables des rejets, comme l’ont attesté les résultats issus des matières en suspension actuellement collectées dans le cours d’eau. A l’instar d’une majorité des métaux traces, les contaminants organiques, tels les HAPs, ont montré d’importantes contaminations durant les années 1940–1960, dont les signatures indiquent une origine majoritairement pyrogénique. Les PCBs ont montré des contaminations importantes lors de la période 1950–1970, en lien avec la production et les usages nationaux de mélanges composés en majorité de congénères faiblement chlorés. Enfin, l’intérêt porté à une troisième famille de contaminants organiques persistants, les pesticides organochlorés, a montré l’utilisation de lindane et du DDT notamment lors de la période 1940–1970, et a mis en avant d’une part une utilisation post-interdiction du lindane et d’autre part la présence d’un métabolite du DDT plusieurs décennies après l’arrêt d’utilisation de ce dernier, en lien avec l’augmentation de l’érosion des sols cultivés
The anthropogenic impact on rivers has significantly increased following the industrial revolutioninitiated by Western countries. Thus, changes in the geomorphology of rivers for water storage andnavigation, the conversion of land for agricultural, industrial and urbanization purposes illustrate thisenvironmental pressure, which results, among other things, in an increase in discharges of variouscontaminants into environmental compartments, particularly rivers. Therefore, part of these dischargescan end up in suspended particulate matter, which is then considered as storage wells, which transit inrivers. River development, particularly the construction of dams, encourages the sedimentation of these contaminated particles over time. These sediments of anthropogenic origin, also called legacy sediments, are therefore witnesses to human activities and make it possible to reconstruct the temporal trajectories of contamination within watersheds. The Eure River, a major tributary of the Seine estuary, has experienced significant anthropogenic pressures since the twentieth century. The temporal reconstruction of anthropogenic pressures has required the combination of different methodological approaches: (i) a diachronic analysis of the morphological modifications of the river was carried out, in conjunction with (ii) an analysis of the sedimentary dynamics and the nature of the sediment deposits by coupling geophysical, sedimentological and geochemical methods, and (iii) the setting up of a network for monitoring the hydro-sedimentary behaviour with continuous sampling of suspended particulate matter. Significant geomorphological changes have occurred in the lower reaches of the watershed, with the main consequences being an outlet moved some ten kilometres in the direction of a dam and the formation of hydraulic annexes favouring the accumulation of sediments as early as the 1940s. These made it possible to show that the Eure River watershed had experienced significant contamination, the consequences of which are still being recorded despite the cessation of activities or uses. The temporal trends of trace metal and metalloid elements showed strong contaminations in As in the 1940s and contaminations of industrial origin in Cr, Co, Ni, Cu, Zn, Ag and Cd in the 1960s and 1970s, as well as contaminations in Sb and Pb in 1990–2000. The latter are still recorded despite the cessation of the activities responsible for the discharges, as evidenced by the results from the suspended particulate matter currently collected in the river. Like most trace metals, organic contaminants such as PAHs showed significant contamination during the 1940–1960s, with signatures indicating a predominantly pyrogenic origin. PCBs showed significant contamination during the period 1950–1970, in connection with the production and national uses of mixtures composed mainly of low chlorinated congeners. Finally, interest in a third family of persistent organic contaminants, organochlorine pesticides, showed the use of lindane and DDT, particularly during the 1940–1970 period, and highlighted the post-ban use of lindane and the presence of a metabolite of DDT several decades after the cessation of its use, in connection with the increase in erosion of cultivated soils

Etude du role des termites dans 3 sites: une foret secondaire et 2 plantations. Les populations de termites sont plus importantes en foret. Le defrichement provoque une chute des effectifs qui se reconstituent ensuite rapidement. En saison seche, les termites s'enfoncent dans le sol. La recolte de bois mort par les termites varie selon la saison. Les termites sont inoffensifs pour les arbres eb bon etat. Par contre, l'action des termites constitue un reel danger pour les jeunes arbres, surtout chez les sujets fletris. Il existe une correlation positive entre le degre de fletrissement et le taux d'attaque. C'est apres 2 ans que les termites attaquent et fragmentent la litiere d'eucalyptus

Tese dout., Ciências do Mar, Universidade do Algarve, 2007
O declínio de ervas-marinhas é um fenómeno documentado à escala global, principalmente devido a distúrbios de origem antropogénica. Esta tese tem como objectivo avaliar o impacto das principais actividades antropogénicas que afectam a erva-marinha Zostera noltii na Ria Formosa. O distúrbio por nutrientes originado pela descarga de efluentes urbanos afecta claramente a estrutura da população, a morfologia das plantas e o conteúdo de N das folhas. As elevadas concentrações de amónia (158-663 μM) na estação mais próxima do efluente de descarga (270 m) revelou ser tóxica para esta espécie, reduzindo a sua biomassa e o tamanho das folhas e internós. Dois dos principais processos bióticos identificados pela análise multivariada nas populações de Z. noltii, i.e. o tamanho geral das plantas e a dinâmica da biomassa-densidade, estão significativamente correlacionados com os processos abióticos claramente relacionados com o efeito do efluente urbano, i.e. com os nutrientes e anóxia do sedimento e com o contraste entre a salinidade e a concentração de nutrientes na água, respectivamente. Os efeitos adversos do efluente urbano nas pradarias de Z. noltii da Ria Formosa parecem estar espacialmente restritos a áreas até 600 m de distância da descarga. As variações nas relações da biomassa-densidade reflectem os gradientes antropogénicos de nutrientes, descrevendo os parâmetros derivados da estrutura da população um padrão de variação com a disponibilidade de nutrientes. As estações impactadas por nutrientes apresentaram correlações significativas entre a biomassa e a densidade, enquanto que nas estações não-impactadas, os dados de biomassa-densidade não se correlacionaram. O marisqueio afectou negativamente as pradarias de Z. noltii, reduzindo significativamente a densidade de rebentos e a biomassa total. O marisqueio experimental revelou um impacto a curto prazo na densidade, que recuperou rapidamente para níveis controlo em um mês. A recuperação pode ocorrer mesmo que plantas com apenas 1 ou 2 módulos, incluindo o rebento apical, permaneçam no sedimento. O nível crítico de soterramento tolerado por esta espécie é extremamente baixo (entre +4 e +8 cm), devido ao seu pequeno tamanho e falta de rizomas verticais. Apesar desta ser uma espécie de crescimento rápido, a sua recuperação não ocorreu durante o período experimental (2 meses), mas plantas completamente soterradas sobreviveram em laboratório por 1-2 semanas. As ervas-marinhas mostraram ser extremamente sensíveis a alterações do nível do sedimento. A sua capacidade para resistir ao soterramento é significativamente dependente do seu tamanho. O comprimento das folhas e o diâmetro dos rizomas são as características que melhor predizem o impacto do soterramento nas ervas-marinhas. Os distúrbios antropogénicos estudados revelaram ser adversos para a erva-marinha Z. noltii, representado uma séria ameaça para esta espécie. No entanto, o seu rápido crescimento e elevada plasticidade permitem-lhe sustentar, até certo ponto, o distúrbio.
Fundação para a Ciência e Tecnologia

碩士
國立陽明大學
環境與職業衛生研究所
105
Fine particulate matters (PM2.5) induce a lot of adverse health effects on the human body, especially the respiratory and cardiovascular system, based on the numerous of epidemiological and toxicological researches, PM2.5 was delimited to be a carcinogen and listed in “Group 1” by International Agency for Research on Cancer (IARC). In Taiwan, high densities of traffic activity (378 vehicle/km2 in 2017), and specific culture, such as Night Market is the most interested attraction for tourists. In this research, PM2.5 samples were collected from long range transport event (LRT), traffic emission activity and cooking smoke fume of the night market. And tried to extract the ions, metals, and organic compounds on PM2.5, used an in vitro experiment to evaluate the cytotoxic potential of PM2.5 composition on human lung carcinoma cell line A549, and genotoxic potential on Salmonella typhimurium. The PM2.5 mass concentration of three anthropogenic emission ambient are 39.0 μg/m3 on LRT, 42.9 μg/m3 in traffic emission area, and 28.3 μg/m3 in the night market with cooking smoke source. Based on the results of MTT assay for cell viability, metal and organic extracts from the cooking smoke source exposed on A549 cells cause the strongest effect. We used statistics analysis to evaluate the key factor for cell viability on the PM2.5 extracts. The results indicated that the metal elements, Zn (r=-0.577, p=0.008)、Mo (r=0.480, p=0.032)、Cd (r=-0.565, p=0.009)、Sb (r=-0.526, p=0.017), and V (r=-0.606, p=0.005) have a significant relationship with cell viability. The results of reactive oxygen species (ROS) detection of ion and metal extracts by traffic emission and LRT source samples show the highest effects in all the exposed groups. On umu test for genotoxicity for organic extracts, the organic extracts obtained from cooking smoke source cause the highest genotoxicity of the three anthropogenic emission, and the organic components in the extracts induced higher bacterial inhibition than the components which was metabolized by CYP1A1, and the situation getting stronger when the higher concentration (20 μg) exposed. Overall the LRT organic extracts with the concentration of 20 μg cause cytotoxicity on cell viability and genotoxicity, and the bacterial inhibition by the chemical compositions were metabolized by CYP1A1. The extracts from traffic emission did not show any significant effect. The metal and organic extracts of cooking smoke source cause the strongest cytotoxicity on cell viability and ROS determination, and the organic extracts also induce the strongest effect on umu genotoxicity test. Even if the extracts of different pollutant sources caused some effects on cell viability, ROS detection and umu genotoxicity test, all the effects did not achieve the threshold of toxic define, which may be attributed to less concentration or exposure time.

Human activities are increasingly altering the ways in which energy and elements cycle within and move between ecosystems. Through fossil fuel combustion and the use of synthetic fertilizers we continue to expose much of the biosphere to new rates and ratios of essential element supply. We are also shifting climate patterns on local, regional and global scales in ways that affect reaction rates and residence times of elements within ecosystems. Even the simplest ecosystems are usually too complex to predict many of the potential consequences that human activities will have on their sustained functioning. Because of this, we often monitor ecosystems as integrated wholes, looking to explain processes that account for important patterns observed across space and time. This dissertation consists of 3 data chapters, all of which use the small watershed ecosystem as the principal unit of study for understanding how human activities have altered element cycling in temperate forests in the southern Appalachian Mountains.

In Chapter 2, we present results from repeated synoptic surveys of streamwater chemistry for ~30 watersheds spanning one of the largest nitrogen (N) deposition gradients in North America, located within the Great Smoky Mountains National Park. We primarily focus on patterns in dissolved organic matter (DOM) concentrations and composition across the N gradient, with particular attention given to dissolved organic nitrogen (DON). DON dominates the global flux of N between terrestrial and aquatic systems, yet we have little understanding of how this prevailing N form responds to human N pollution. We found that DON concentrations often declined significantly with increasing catchment N loading and, through laboratory bioavailability assays, found that when N limitation is alleviated increased microbial demand for labile carbon (C) may drive this pattern. We use these findings to suggest a new hypothesis for the potential responses of DON to anthropogenic N pollution that accounts for the dual role that DON plays in both C and N cycles.

Chapter 3 is an extension of Chapter 2, in which we attempt to assess the role of DON as either a C or N source within an entire stream reach through a series of independent manipulations of labile C and inorganic N availabilities. In the second order reach of Walker Branch, a well-studied stream in eastern Tennessee, we performed a series of progressive (i.e., sequentially increasing concentrations), kinetic (i.e., very short duration), enrichments of acetate and nitrate on two successive days during April of 2009 before the tree canopy emerged and when in-stream algal production was high. In this system and on these short timescales, we were unable to elicit the same responses observed at sites across the chronic N deposition gradient in Chapter 2. We did, however, observe that DOM processing and composition was significantly altered. Using fluorescence characterization of DOM, we found that adding acetate displaced heterotrophic demand for terrestrially derived DOM. Conversely, nitrate additions stimulated production of highly bioavailable autochthonous DOM within the stream channel, which resulted in an indirect displacement of demand for terrestrially derived DOM. Understanding DOM dynamics in streams has long been a priority for stream ecologists because it represents an important energy and nutrient source fueling stream metabolism. Our results provide new insight into the processes controlling DOM concentrations and composition in Walker Branch, as well as demonstrate the potential of this method for future investigations of DOM in stream ecosystems.

Chapter 4 deviates from the preceding chapters' focus on N availability and ecosystem DOM dynamics, instead assessing the role of climate change on long-term streamwater concentrations and fluxes from the West Fork of the Walker Branch watershed. At this site, mean annual temperatures have increased by ~2˚C, while mean annual precipitation and runoff have declined by ~20% and >40%, respectively, since 1989. We use weekly streamwater samples to assess trends in concentrations and fluxes for 9 different solutes over this period and, using wet deposition data, also evaluate changes in approximate watershed input-output budgets. The observed change in runoff was accompanied by a change in the proportional contributions of different soil flowpaths to streamflow generation through time, with deep groundwater playing an increasingly important role in recent years. Solutes that increase in concentration deeper in the soil profile exhibited significant increases in streamwater concentrations through time, while solutes with higher concentrations in soil solution in the upper profile decreased in concentration. Nutrient solutes, which exhibit much less variation across soil flowpaths, typically display large seasonal patterns in streamwater concentrations that are driven by in-stream biological uptake. However, most nutrient solutes exhibited little or no trend in concentrations through time, indicating that the biological controls on these solutes have remained relatively unaltered by the observed changes in climate over the 20-year period. On shorter timescales, changes in the frequency or severity of multi-year droughts, as well as changes in the frequency or intensity of storms that disrupt in-stream uptake, can have large impacts on watershed input-output budgets of nutrient solutes even if the effects do not manifest as linear trends through time. Our results demonstrate the important role that changing climates can have on watershed element cycles, illustrating that climate effects can manifest through either changes in hydrologic regime or through changing biogeochemical process rates.

Taken together, these chapters illustrate that human activities are indirectly but substantially changing biogeochemical cycles in temperate forests throughout the Southern Appalachians. Ecosystem structure and function depends on the ways in which energy and elements move within and between ecosystems. We rely on the sustained integrity of ecosystems for their many services and, because of this, it is essential that we understand ecosystem responses to current and future human impacts.

Dissertation

Stocks of salmon are declining in the Pacific Northwest. Based on region-wide studies that list and categorize the status of salmon stocks (Nehlsen et al., 1991; Huntington et al., 1994; and Nawa, 1995), I analyze the watersheds where stocks of salmon spawn for several anthropogenic variables, most of which are known to affect salmon. A total of 202 watersheds (stocks of salmon) in Washington, Oregon, California, and Idaho are coded for 13 anthropogenic variables such as dams, forest, agriculture, human population, hatcheries, Indian tribes, and watershed organizations. Most variables are ordinally coded 1 to 5 with the help of maps, some survey results, and visual assessment. Hypotheses are that the human activities that are detrimental to the health of salmon are associated with the poor status of salmon stocks in watersheds where they spawn. Salmon watersheds are also analyzed according to ecoregions and salmon management regions. Principal components analysis is performed to reduce the number of anthropogenic variables into factors. Kendall's tau, partial correlation, multiple linear regression, logistic regression, and discriminant analyses are performed separately for five species/races of salmon (coho, spring chinook, summer chinook, fall chinook, winter steelhead) and for the watershed average for salmon stock status, against the anthropogenic variables and factors. Statistical results using both variables and factors support most of the hypotheses relative to salmon and anthropogenic activities in watersheds. Results suggest that the 5 species/races of salmon are associated differently with most anthropogenic activities. The greater the amount of dams below watersheds where salmon spawn, the less healthy the salmon stocks. Summer chinook are least healthy where hatcheries are absent, while wild and scenic rivers are associated with healthier spring chinook. Coho are least healthy where there is more agriculture, more human population, and less forest. Fall chinook are least healthy where there is more US Forest Service land. Winter steelhead are least healthy where hatcheries are absent and less Indian tribal land. Ecoregional differences coupled with the absence of dams on the Coast compared to the Columbia Basin are associated with healthier coastal stocks.
Graduation date: 1998

In South Africa water is recognized as a crucial element in the battle against poverty, the cornerstone of prosperity, and a limiting factor to growth. The National Water Act 36 of 1998 recognizes that basic human and environmental needs should be met and that the use of water in all aspects must be sustainable. The Crocodile River (East) is situated in the north east of the Republic of South Africa and it is recognized as a stressed catchment in South Africa. The main impacts are domestic, industrial, agricultural, mining and afforestation activities. These activities pollute the river by discharging effluent as well as seepage from areas that support mining and intensive agriculture in to the river. The river catchment has been a center of research studies for many scientists either focusing on water quality or biological indicators separately. The aim of study was to determine the present ecological condition and the health of the Crocodile River. The objectives were to determine water quality status, identify possible sources of pollution and assess the spatial and temporal trends in ecological state. Fourteen monitoring sites were selected from the Crocodile River and its tributaries. The macro-invertebrates data were collected using the SASS 5 protocol and fish were collected using an electroshocker- catch and release method during high and low flow conditions of the year 2013. Water quality data was obtained by sampling using a polyethylene bottle from different sites within the Crocodile River and its tributaries from September 2012 until August 2013. The samples were analyzed by Mpumamanzi laboratory in Nelspruit and Waterlab in Pretoria. Additional water quality data was obtained from the Department of Water Affairs. Multivariate statistical methods were used to analyze all the data obtained. The multivariate statistical methods indicated that fish and macro-invertebrates species abundance, richness and evenness increase with the river flow distance downstream. Water temperature was one of the leading environmental variables for the structuring of fish and macro-invertebrates assemblage in the Crocodile River and its tributaries. A group formation of site during high and low flow condition by the Bray Curtis similarity and NMDS ordination indicated that many sites share similar macro-invertebrates or fish species. The one way ANOVA analysis indicated that there was no significance difference between macro-invertebrates richness and abundance during both flow conditions but there was a significance difference in fish richness and abundance between the two flow conditions. The PCA indicated that sodium has the highest physico-chemical impact amongst the physico-chemical parameters in the bi-plot followed by ammonium and nitrate. A correlation of physico-chemical parameters such as chlorine, total dissolved solid, electrical conductivity, sulphate and pH was observed. The levels of total dissolved solids and electrical conductivity were found to increase longitudinally as the river flows downstream. The dominance of single species within the macro-invertebrates and fish communities was an indication of imbalance of the communities within the sites. The presence of the macro-invertebrate family Beatidae and the fish species Chiloglanis pretoriae at sites CR3 and CR4 indicates a good water quality in the upper reaches during low flow condition as these species are sensitive to changes in water quality, while the presence of the macro-invertebrate family Pleidea and fish species Barbus viviparus at sites CR10 and KR1 during low flow condition indicated possible water pollution as these species tolerate changes in water quality and this was linked to the discharge of effluent from industrial, abandoned mines and run-offs from agricultural activities in the downstream reaches of the river. The low flow condition was dominated by sensitive species especially in the upper reaches than during high flow condition. The macro-invertebrates assessment index indicated that during low flow condition the Crocodile River was mostly at ecological class B (largely natural with few modification) above the Kwena dam, but from downstream of the dam the ecological category was in C class (moderately modified), while its tributaries are in ecological category B (largely natural with few modification). The fish response assessment index indicated that the ecological category for fish was mostly at C class (moderately modified) in the Crocodile River. The changes in macro-invertebrates communities and fish in the Crocodile River were believed to be associated with change of water quality and habitat modification due to flow modification. Agricultural activities in the upper reaches and a combination of industrial and mining activities in the middle and lower reaches of the Crocodile River were believed to be the sources of pollution that results in the change of water quality, fish and macro-invertebrates assemblage in the Crocodile River. Investing in the health of the Crocodile River is important for many Mbombela citizens and river dwellers as they rely on the functioning of the river for survival.
Environmental Sciences
M. Sc. (Environmental Science)

The occurrence of As in groundwater in Argentina was known since 1917; however, the occurrence, distribution and mobilization of As and other trace elements (TEs) in groundwater in the Bolivian Altiplano are still quite unknown. An investigation applying a geochemical approach was conducted in the Poopó Basin and Lake Titicaca to understand processes of TEs in different systems such as water, soils, crops and sediments in mining areas. In Poopó Basin,As, Cd and Mn concentrations exceed World Health Organization (WHO) guidelines and Bolivian regulations for drinking water in different places around the basin, but Cu, Ni, Pb and Zn do not. In soils, the sequential extraction methods extracted up to 12% (fractions 1 and 2), which represent < 3.1 mg/kg of the total As content, as potentially mobilized fractions, that could be transferred to crops and/or dissolved in hydrologic system. The large pool of As can be attached due to amorphous and crystalline Fe oxide surfaces (fractions 3, 4, and 5) present in the soils. Furthermore, the concentrations of As, Cd and Pb in the edible part of the crops revealed that the concentrations of As and Cd do not exceed the international regulation (FAO, WHO, EC, Chilean) (0.50 mg/kgfw for As and 0.10 mg/kgfw for Cd), while Pb exceeds the international regulations for beans and potatoes (for beans 0.20 mg/kgfw and for potato 0.10 mg/kgfw). In the Lake Titicaca, principal component analysis (PCA) of TEs in sediments suggests that the Co-Ni-Cd association can be attributed to natural sources such as rock mineralization, while Cu-Fe-Mn come from effluents and mining activities, whereas Pb-Zn are mainly related to mining activities. The Risk Assessment Code (RAC) indicate “moderately to high risk” for mobilization of Cd, Co, Mn, Ni, Pb and Zn, while Cu and Fe indicate “low to moderate risk” for remobilization in the water column.

QC 20140604

Hydrochemistry: Arsenic and heavy metals in the Lake Poopó Basin (Sida contribution: 7500707606)
Catchment Management and Mining Impacts in Arid and semi-arid South America (CAMINAR) (INCO-CT-2006-032539)

碩士
國立臺灣師範大學
生命科學研究所
97
To approach the effects of anthropogenic activities and environmental factors on local native and naturalized plant communities, this study was conducted in the Northern Taiwan. A total of 2,242 quadrats in 1m2 of 100 plots in 1km2 were sampled according to designated habitat types. Selected anthropogenic and environmental factors were obtained, and biodiversity indices were applied on the field data for further analyses. According to the results, habitat types with higher anthropogenic activities (e.g. roadside, cemetery, crop field) were highly invaded. Plant invasions were facilitated by anthropogenic activities (including both diversity and intensity) as well as environmental factors. Significantly positive relationships were found between anthropogenic activities (e.g. landscape heterogeneity, exploitation intensity, and agriculture factor) and the biodiversity and dominance of naturalized species. On the other hand, exploitation intensity was negatively correlated to native biodiversity. Propagule pressure and disturbances created by anthropogenic activities may be the major mechanism facilitating biodiversity and dominance of naturalized species. II Environmental factors including elevation-temperature and precipitation factors were negatively correlated to naturalized biodiversity but positively correlated to native biodiversity. Native—exotic richness relationships were also examined under different plot characteristics at same spatial scale. Negative relationships (more native less exotic) were found at plots with lower anthropogenic activities, while positive relationships (more native more exotic) were found at plots with higher anthropogenic activities. The mechanisms related to the native—exotic relationship transformation may be biotic resistance in negative relationships and abiotic factors including landscape heterogeneity in positive relationships. This result demonstrated the new evidence of how anthropogenic activities affect plant invasions and also made the current discussions in native—exotic richness relationships more comprehensive. These results can provide valuable direction in the management of naturalized plants.

碩士
國立臺灣海洋大學
海洋環境資訊學系
101
The main tributaries of the Danshui Estuary are the Tanhan, the Hsintien and the Keelung Rivers. It is found that the Keelung River was the most polluted river among these three rivers because of the dense population. These rivers were cleaned since 1990 and the EPA declared that the water quality of these rivers has been improved. This study bi-weekly investigated the water quality of the upper reach of the Keelung River from May 2011 to March 2012. The water quality of the middle and lower estuary of the Danshuei Eutuary were also investigated twice during the study period. The river pollution index (RPI) was employed to examine the water quality of the Keelung River. The concentration ranges of the studied parameters found in the upper reach of the Keelung River, and the middle and lower estuary of the Danshuei Eutuary were as follows: pH, 6.92-8.72 and 7.70-8.07; DO, 7.12-8.99 mg/L and 4.15-8.99 mg/L; BOD5, 0.03-7.54 mg/L and 0.76-8.45mg/L; Phosphate, 0.05-4.33 μM and 0.59-4.56 μM; Silicate, 55.3-178.7 μM and 19.2-178.7 μM; NH3-N, 0.56-36.35 μM and 20.1-283.3 μM; Nitrite, 0.13-25.32μM and 1.81-18.67μM; Nitrate, 4.47-86.28 μM and 1.91-312.3μM; chl.a, 0.12-13.76 μg/L and 0.20-60.78 μg/L. The RPI results indicated that the water quality of the upstream of the Keelung River, Hou-Dong and Ray-Fone Bridge, was good and the anthropogenic pollution was minor. However, the RPI value from the Badu area, the midstream of the Keelung River, to the lower estuary ranged within 1-5.25, indicating that the water quality was bad because of the dense population. This study suggests that weathering factor influences the water quality of the upstream of the Keelung River is minor. In contrast, the water quality of the mid and lower estuary of the Danshuei estuary is still bad and is strongly influenced by the anthropogenic activity.

A dissertation submitted to the Faculty of Science, School of Geography, Archaeology and Environmental Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. 14 April 2016.
South Africa has seen a significant loss and degradation of its urban wetlands, all in the name of development. The natural and strategic location of Wetlands, subject these natural systems to a host of extraction processes, leading to the ultimate destruction and demise of these Wetlands. The biggest threats to wetlands are people and their innate exploitative and destructive nature. Anthropogenic activities that lead to degradation and total loss of wetlands in South Africa are: drainage, mining activities, clearing of large tracts of land for infrastructural and agricultural practices and over- harvesting of wetland resources. The drastic alteration of a wetland system has severe and far reaching environmental, economic and social consequences. The value of a single wetland system is so unique and is yet, not stressed enough in legislation governing the protection and conservation of natural ecosystems. A typical example of an undervalued wetland is the case of the Kwa-Thema Ext 3 Wetland, which has been subjected to partial degradation as a result anthropogenic activities. The study concluded that activities such as over-grazing, extraction of natural vegetation, clearing large tracts of land for housing development and extensive farming practices (to name a few) have all contributed to the degradation and devaluing of the Kwa-Thema Ext 3 wetland. Interesting aspects of this study revealed that, whilst some individuals were aware of their prolonged and unsustainable use of the wetland’s resources, little room for choice was left but to utilize the wetland, on account of poverty- stricken living conditions. It seems that perhaps, through understanding why people are using the wetland in such extreme ways, methods of wetland rehabilitation and improvement in the socio-economic dynamic of the community can be attained in the near future. As a result of this study, a number of recommendations are made: (i) Integrate wetland value educational programmes into the lives of all South Africans; (ii) Consolidate and realign policy and legislation that specifically focus on wetland protection and conservation; (iii) Improve communication between governmental and respective local authorities; and (iv) Strengthen the national wetland inventory.
GR 2016

A thesis submitted in partial fulfillment of the requirements for the degree of Doctor in Information Management, specialization in Geographic Information Systems
Landuse and Landcover (LULC) is the common aspect that influences several ecological issues, environmental degradations, changes in Land Surface Temperature (LST), hydrological changes and ecosystem function at regional to global level. Research on the drivers and progressions of LULC change has been key to developing models that can project and predict future LULC extent, level and patterns under different assumptions of socioeconomic, ecological and environmental situations. Rapid and extensive urbanization and Urban Sprawl (US), propelled by rapid population growth leads to the shrinkage of productive agricultural lands, boosting mining, decrease in surface permeability and the emergence of Urban Heat Islands (UHI), and in turn, adversely affects the provision of ecosystem services. Mining for resources extraction may lead to geological and associated environmental changes due to ground movements, collision with mining cavities, and deformation of aquifers. Geological changes may continue in a reclaimed mine area, and the deformed aquifers may entail a breakdown of substrates and an increase in ground water tables, which may cause surface area inundation. Consequently, a reclaimed mine area may experience surface area collapse, i.e., subsidence, and degradation of vegetation productivity. The greater changes in LULC, US, LST and vegetation dynamics due to increasing human population not only affects inland forest and wetland, it also directly influences coastal forest lands such as mangroves, peat swamps and riparian forest and threats to ecosystem services. Mangroves provide valuable provisioning (e.g. aquaculture, fisheries, fuel, medicine, textiles), regulation (e.g. shoreline protection, erosion control, climate regulation), supporting (nutrient cycling, nursery habitat), and cultural (recreation and tourism) ecosystem services with an important impact on human well-being. However, the mangrove forest is highly threatened due to climate changes, and human activities which ignore the ecological and economic value of these habitats, contributing to its degradation. There is an increasing number of studies about mangrove distribution, changes and re-establishment activities, denoting a growing attentiveness on the value of these coastal wetland ecosystems. Most of these studies address mangrove degradation drivers at regional or local levels. However, there has not been yet enough assessment on the drivers of mangrove degradation at global level. Thus, complexity of inland and coastal landscape degradation should be addressed using multidisciplinary methodology and conditions. Therefore, this dissertation aimed to assess the impact of LULC associated with vegetation, temperature and wetland changes. To understand the relation among three different types of landscape changes associated with anthropogenic activities: Urbanization, Geological changes and Forest degradation at local to global level, we have selected thirty-three global regions. In chapter 2, We employed the Random Forest (RF) classification on Landsat imageries from 1991, 2003, and 2016, and computed six landscape metrics to delineate the extent of urban areas within a 10km suburban buffer of Chennai city, Tamilnadu, India. The level of US was then quantified using Renyi’s entropy. A land change model was subsequently used to project land cover for 2027. A 70.35% expansion in urban areas was observed mainly towards the suburban periphery of Chennai between 1991 and 2016. The Renyi’s entropy value for year 2016 was 0.9, exhibiting a two-fold level of US when compared to 1991. The spatial metrics values indicate that the existing urban areas became denser and the suburban agricultural, forests and particularly barren lands were transformed into fragmented urban settlements. The forecasted land cover for 2027 indicates a conversion of 13,670.33 ha (16.57% of the total landscape) of existing forests and agricultural lands into urban areas with an associated increase in the entropy value to 1.7, indicating a tremendous level of US. Our study provides useful metrics for urban planning authorities to address the social-ecological consequences of US and to protect ecosystem services. In chapter 3, We studied landscape dynamics in Kirchheller Heide, Germany, which experienced extensive soil movement due to longwall mining without stowing, using Landsat imageries between 2013 and 2016. A Random Forest image classification technique was applied to analyse landuse and landcover dynamics, and the growth of wetland areas was assessed using a Spectral Mixture Analysis (SMA). We also analyzed the changes in vegetation productivity using a Normalized Difference Vegetation Index (NDVI). We observed a 19.9% growth of wetland area within four years, with 87.2% growth in the coverage of two major waterbodies in the reclaimed mine area. NDVI values indicate that the productivity of 66.5% of vegetation of the Kirchheller Heide was degraded due to changes in ground water tables and surface flooding. Our results inform environmental management and mining reclamation authorities about the subsidence spots and priority mitigation areas from land surface and vegetation degradation in Kirchheller Heide. In chapter 4, We demonstrated the advantage of fusing imageries from multiple sensors for LULC change assessments as well as for assessing surface permeability and temperature and UHI emergence in a fast-growing city, i.e. Tirunelveli, Tamilnadu, India. IRS-LISSIII and Landsat-7 ETM+ imageries were fused for 2007 and 2017, and classified using a Rotation Forest (RF) algorithm. Surface permeability and temperature were then quantified using Soil-Adjusted Vegetation Index (SAVI) and Land Surface Temperature (LST) index, respectively. Finally, we assessed the relationship between SAVI and LST for entire Tirunelveli as well as for each LULC zone, and also detected UHI emergence hot spots using a SAVI-LST combined metric. Our fused images exhibited higher classification accuracies, i.e. overall kappa coefficient values, than non-fused images. We observed an overall increase in the coverage of urban (dry, real estate plots and built-up) areas, while a decrease for vegetated (cropland and forest) areas in Tirunelveli between 2007 and 2017. The SAVI values indicated an extensive decrease in surface permeability for Tirunelveli overall and also for almost all LULC zones. The LST values showed an overall increase of surface temperature in Tirunelveli with the highest increase for urban built-up areas between 2007 and 2017. LST also exhibited a strong negative association with SAVI. South-eastern built-up areas in Tirunelveli were depicted as a potential UHI hotspot, with a caution for the Western riparian zone for UHI emergence in 2017. Our results provide important metrics for surface permeability, temperature and UHI monitoring, and inform urban and zonal planning authorities about the advantages of satellite image fusion. In chapter 5, We identified mangrove degradation drivers at regional and global levels resulted from decades of research data (from 1981 to present) of climate variations (seal-level rising, storms, precipitation, extremely high water events and temperature), and human activities (pollution, wood extraction, aquaculture, agriculture and urban expansion). This information can be useful for future research on mangroves, and to help delineating global planning strategies which consider the correct ecological and economic value of mangroves protecting them from further loss.
O uso e a cobertura da Terra (UCT) são o aspeto comum que influencia várias questões ecológicas, degradações ambientais, mudanças na temperatura da superfície terrestre, mudanças hidrológicas, e de funções dos ecossistemas a nível regional e global. A investigação sobre os determinantes e progressão da mudança de UCT tem sido fundamental para o desenvolvimento de modelos que podem projetar e prever a extensão, o nível e os padrões futuros de UCT sob diferentes hipóteses de situações socioeconómicas, ecológicas e ambientais. A rápida e extensa urbanização e expansão urbana impulsionada pelo rápido crescimento populacional, levou ao encolhimento de terras agrícolas produtivas, impulsionando a mineração, a diminuição da permeabilidade da superfície e o surgimento de ilhas urbanas. Por outro lado, tem afetado negativamente a produção de serviços de ecossistemas. A mineração para extração de recursos pode levar a mudanças geológicas e ambientais devido a movimentos do solo, colisão com cavidades de mineração e deformação de aquíferos. As mudanças geológicas podem continuar numa área de mina recuperada, e os aquíferos deformados podem acarretar uma quebra de substratos e um aumento nos lençóis freáticos, causando a inundação na superfície. Consequentemente, uma área de mina recuperada pode sofrer um colapso à superfície, provocando o afundamento e a degradação da produtividade da vegetação. As mudanças na UCT, no crescimento urbano rápido, na temperatura da superfície terrestre e na dinâmica da vegetação devido ao aumento da população humana não afetam apenas a floresta interior e as zonas húmidas. Estas também influenciam diretamente as terras florestais costeiras, tais como mangais, pântanos e florestas ribeirinhas, ameaçando os serviços de ecossistemas. Os mangais proporcionam um aprovisionamento valioso (por exemplo, aquacultura, pesca, combustível, medicamentos, têxteis), a regulação (por exemplo, proteção da linha de costa, controlo da erosão, regulação do clima), os serviços de ecossistema de apoio (ciclo de nutrientes, habitats) e culturais (recreação e turismo) com um impacto importante no bem-estar humano. No entanto, a floresta de mangal é altamente ameaçada devido às mudanças climáticas e às atividades humanas que ignoram o valor ecológico e económico desses habitats, contribuindo para a sua degradação. Há um número crescente de estudos sobre distribuição, mudança e atividades de restabelecimento de mangais, denotando uma crescente atenção sobre o valor desses ecossistemas costeiros de zonas húmidas. A maioria desses estudos aborda os fatores de degradação dos mangais a nível regional ou local. No entanto, ainda não há avaliação suficiente sobre os determinantes da degradação dos mangais a nível global. Assim, a complexidade da degradação da paisagem interior e costeira deve ser abordada usando uma metodologia multidisciplinar. Portanto, esta dissertação teve, também, como objetivo avaliar o impacto do UCT associado à vegetação, temperatura e mudanças de zonas húmidas. Para compreender a relação entre a dinâmica da paisagem associada às atividades antrópicas a nível local e global, selecionámos quatro áreas de estudo, duas da Ásia, uma da Europa e outro estudo a nível global. No capítulo 2, empregamos a classificação Random Forest (RF) nas imagens Landsat de 1991, 2003 e 2016, e computamos seis métricas de paisagem para delinear a extensão das áreas urbanas numa área de influência suburbana de 10 km da cidade de Chennai, Tamil Nadu, Índia. O nível de crescimento urbano rápido foi quantificado usando a entropia de Renyi. Um modelo de UCT foi posteriormente usado para projetar a cobertura de terra para 2027. Uma expansão de 70,35% nas áreas urbanas foi observada principalmente para a periferia suburbana de Chennai entre 1991 e 2016. O valor de entropia do Renyi para 2016 foi de 0,9, exibindo uma duplicação do nível de crescimento urbano rápido quando comparado com 1991. Os valores das métricas espaciais indicam que as áreas urbanas existentes se tornaram mais densas e as terras agrícolas, florestas e terras particularmente áridas foram transformadas em assentamentos urbanos fragmentados. A previsão de cobertura da Terra para 2027 indica uma conversão de 13.670,33 ha (16,57% da paisagem total) de florestas e terras agrícolas existentes em áreas urbanas, com um aumento associado no valor de entropia para 1,7, indicando um tremendo nível de crescimento urbano rápido. O nosso estudo fornece métricas úteis para as autoridades de planeamento urbano para lidarem com as consequências socio-ecológicas do crescimento urbano rápido e para proteger os serviços de ecossistemas. No capítulo 3, estudamos a dinâmica da paisagem em Kirchheller Heide, Alemanha, que experimentou um movimento extensivo do solo devido à mineração, usando imagens Landsat entre 2013 e 2016. Uma técnica de classificação de imagem Random Forest foi aplicada para analisar dinâmicas de UCT e o crescimento das áreas de zonas húmidas foi avaliado usando uma Análise de Mistura Espectral. Também analisámos as mudanças na produtividade da vegetação usando um Índice de Vegetação por Diferença Normalizada (NDVI). Observámos um crescimento de 19,9% da área húmida em quatro anos, com um crescimento de 87,2% de dois principais corpos de água na área de mina recuperada. Valores de NDVI indicam que a produtividade de 66,5% da vegetação de Kirchheller Heide foi degradada devido a mudanças nos lençóis freáticos e inundações superficiais. Os resultados informam as autoridades de gestão ambiental e recuperação de mineração sobre os pontos de subsidência e áreas de mitigação prioritárias da degradação da superfície e da vegetação da terra em Kirchheller Heide. No capítulo 4, demonstramos a vantagem de fusionar imagens de múltiplos sensores para avaliações de mudanças de UCT, bem como para avaliar a permeabilidade, temperatura da superfície e a emergência do ilhas de calor numa cidade em rápido crescimento, Tirunelveli, Tamilnadu, Índia. As imagens IRS-LISSIII e Landsat-7 ETM + foram fusionadas para 2007 e 2017, e classificadas usando um algoritmo de Random Forest (RF). A permeabilidade de superfície e a temperatura foram então quantificadas usando-se o Índice de Vegetação Ajustada pelo Solo (SAVI) e o Índice de Temperatura da Superfície Terrestre (LST), respectivamente. Finalmente, avaliamos a relação entre SAVI e LST para Tirunelveli, bem como para cada zona de UCT, e também detetamos a emergência de pontos quentes de emergência usando uma métrica combinada de SAVI-LST. As nossas imagens fusionadas exibiram precisões de classificação mais altas, ou seja, valores globais do coeficiente kappa, do que as imagens não fusionadas. Observámos um aumento geral na cobertura de áreas urbanas (áreas de terrenos secos e construídas), e uma diminuição de áreas com vegetação (plantações e florestas) em Tirunelveli entre 2007 e 2017. Os valores de SAVI indicaram uma extensa diminuição na superfície de permeabilidade para Tirunelveli e também para quase todas as classes de UCT. Os valores de LST mostraram um aumento global da temperatura da superfície em Tirunelveli, sendo o maior aumento para as áreas urbanas entre 2007 e 2017. O LST também apresentou uma forte associação negativa com o SAVI. As áreas urbanas do Sudeste de Tirunelveli foram representadas como um potencial ponto quente, com uma chamada de atenção para a zona ribeirinha ocidental onde foi verificada a emergência de uma ilha de calor em 2017. Os nossos resultados fornecem métricas importantes sobre a permeabilidade da superfície, temperatura e monitoramento de ilhas de calor e informam as autoridades de planeamento sobre as vantagens da fusão de imagens de satélite. No capítulo 5, identificamos os fatores de degradação dos mangais a nível regional e global resultantes de décadas de dados de investigação (de 1981 até o presente) de variações climáticas (aumento do nível das águas do mar, tempestades, precipitação, eventos extremos de água e temperatura) e atividades humanas (poluição, extração de madeira, aquacultura, agricultura e expansão urbana). Estas informações podem ser úteis para investigações futuras sobre mangais e para ajudar a delinear estratégias de planeamento global que considerem o valor ecológico e económico dos mangais, protegendo-os de novas perdas.

Lake Tana is a biodiversity and natural reservoir for fresh water supply contributing significantly to the economy of Ethiopia and downstream recipient countries, namely: Sudan and Egypt. The Lake Tana Ecosystem provides a variety of goods and services such as: provisioning, regulating, amenity and supporting services. These services are affected by high human activities which threaten the water quality and biodiversity of the lake. Hence, this study aims to assess the impact of human activities on water quality, biodiversity and livelihood of Lake Tana and its shore sides.To assess the impact of anthropogenic activities of Lake Tana; physicochemical parameters, macroinvertebrates, macrophytes and livelihood of the Lake side communities were collected in the year 2014/2015 during dry and wet seasons for 11 sampling sites as indicated in Figure 1.1 and Table 1.1. The variations of physicochemical, metals and bacterial parameters were investigated. The overall water quality parameters (mean analytical results) of Lake Tana were found to be: Temp (Temperature)23.0OC, pH 7.5, EC (Electrical conductivity)180.1 μS/cm, BOD5 (Biological oxygen demand in 5 days)37.3 mg/l, COD (Chemical oxygen demand)316.5 mg/l, TSS 0.3 mg/l, TDS 93.1 mg/l, SO4 2- 11.0 mg/l, PO4 3- 42.4 mg/l, Cr (0.08 mg/l), (Mn (0.01 mg/l), E. Coli (13.4 Cell/ml), F. Coliform (82.5 Cell/ml), T. Coliform (113.0 Cell/ml), etc. These parameters did not show significant variation among the sites but were significantly different between wet and dry seasons (P<0.05). The highest concentration values were recorded during the wet season. However, most of the parameters under investigation were within the Ethiopian EPA (Environmental protection agency) permissible range except PO4 3-, S2-, E. Coli (Cell/ml), F. Coliform (Cell/ml) and T. Coliform (Cell/ml). Based on the analysis of the water quality index (WQI), Lake Tana water was unfit for drinking purpose and needs treatment. For theMacroinvertebrates analysis, a total number of 629 macroinvertebrate individuals are belonging to 9 orders and 38 families were found. In the study year impacted areas number of identified macroinvertebrates were 478 (76%); of this, 233 (37%) were in the wet season and 245 (39%) in the dry season and the total number of individuals identified in the reference area was 151 (24% of the total) in the wet season 61 (9.7%) and in the dry season 90 (14.3%) individuals. The diversity was more in the dry season. The dominant orders were Odonata (156 individuals), Coleoptera (153 individuals) and Hemiptera (141 individuals). The literature indicated that the presence of more Odonata, Coleptera and Hemipteran larvae is an indication of water quality deterioration due to pollution. From the collected samples, the total number of tolerant individuals was 303 (48.2%) and facultative individuals were 243 (38.7%) while intolerant individuals were 80 (12.7%). Most of the taxa (48.2%) had tolerance scores ranging from 7 to 10. The analysis of different forms of indices showed poor water quality. The water quality of Lake Tana was also determined by developing the LTMI (Lake Tana Metric Index). The index indicated the impairment levels of the study sites. Seven of the sites were in the category of poor (disturbed) and the other three were very poor (highly disturbed). The study on macrophytes recorded 43 species and 18 families during the two seasons (wet and dry), throughout the study year. 2687 individual macrophytes were collected; 1756 in the wet season and 931 in the dry season. Poaceae (15 species) with abundance mean 215.40 ± 421.7 was the most dominant family, followed by Cyperaceae (5 species) 35.40 ± 68.3. Sacciolepis africana was the dominant macrophyte species in Lake Tana. But in the study area Ambobahir, the dominant species was Cyperus papyrus while the Megech study area was invaded by the nuisance exotic weed Eichhornia crassipes. In the present study, the low macrophyte diversity values of Shannon Wiener index (2.90), Simpson Diversity Index (1-D) (0.90), Simpson Dominance Index (D) (0.10), Margalef’s index (M’) richness index (5.32) and Evenness Index (E) (0.77) throughout the study year indicate moderate water quality status while the presence of certain bio-indicator species like Eichhornia, Potamogeton and Cyperus in the lake also confirm pollution. Because of the effect of human activities on water quality and biodiversity, the livelihood of the riparian community is affected indirectly. Hence, to recommend mitigation and remediation actions, this study also focused on the assessment of the change of livelihoods of people living in the study area using qualitative research methods (key informant interview, focus group discussion (FGD), observations, published and unpublished materials and photographes). Lake Tana is a home to different flora and fauna including endemic species. The flora such as macrophytes and forest resources are used mainly for traditional medicine, fuel wood, rope, pole, habitat for birds, animal feed, etc. and the fauna includes fish, hippos, crocodiles, invertebrates, etc. Further, the Lake Tana area is a good habitat for indigenous cattle breeds (Fogera breed) and field crops gene center. The major resources around Lake Tana are land (the major source of livelihood), vegetation resources (macrophytes and forest resources), wildlife resources (fish, the other important source of livelihood) and cultural landscapes (churches and monasteries). Lake Tana is exposed to a set of interrelated environmental problems induced by human influence such as deforestation, erosion, sedimentation, water level reduction, erratic rainfall, flood, and competition for water resources, pollution and introduction of alien species. The causes to these problems were overgrazing, farmland expansion, cultivation of marginal lands (shorelines), encroachment of communal land, pollution and vegetation removal to meet demand for food and fuel wood. It is observed that alteration of Lake Tana and its fringe wetlands has affected the whole dynamics of the Lake’s ecosystem and the livelihood of the surrounding community. Ecosystem components are interlinked; hence correlation analysis was done between physicochemical parameters and macroinvertebrates of Lake Tana. Thus, correlations among many of the physicochemical parameters and macroinvertebrates families have been observed. To mention some of the correlations, the changes in the physical, chemical and biological characteristic of the lake affected the aquatic life forms and significantly affect economic activities that the lake supports. The RDA(Canonical redundency analysis) ordination of the species-environmental variable association indicated that pH, Cd, Pb and SO42- and Velidae, Chironomidae, Physidae, Gerridae, Corixidae, Dytiscidae, Caenidae, Coenogrionidae Simuliidae and Psephenidae were negatively correlated while Mussidae positively correlated with these environmental variables. This study concludes that the main threat to aquatic ecosystems in Lake Tana arises from agricultural activities, urbanization and industrialization that deteriorated water quality and biodiversity. Thus, it is recommended that proper management of Lake Tana should be put in place to prevent further deterioration of water quality and biodiversity of the lake for its sustainable development.
Environmental Sciences
Ph. D. (Environmental Science)

Resistance to antibiotics is a rising concern in respect to community and personal health, health-access social discrepancy and the future of the natural world. This work aimed to understand the role of environmental bacteria as the origin of the genetic determinants of antibiotic resistance (AR), as well as to explore the impact of anthropogenic pressures on the evolution and spread of AR. Shewanella’s genus role as progenitors and reservoir of AR genes was assessed through the analysis of a collection of environmental isolates and genomes of this genus deposited in public databases. The presence and the genetic context of the gene encoding for carbapenemase OXA-48 and the presence of qnrA-like genes was assessed. These genes were detected in several Shewanella species, in certain cases for the first time, being speciesspecific at times. Furthermore, several new variants were identified in this work. Insertion sequences associated with gene transfer were identified, suggesting its contribution to the spread of these genes to other phylogenetic groups. The impact of human action on the spread of AR in aquatic compartments was addressed through the analysis of groundwater used for irrigation and vegetables consumed raw. Multiresistant strains with virulent characteristics were found, common to both environments, suggesting irrigation water as the source of the contamination detected in the vegetables. Genome analysis of some of these strains revealed virulence determinants, mobile genetic elements and resistance genes, suggesting a potential risk to human health. In addition, the diversity and abundance of bacteria resistant to carbapenems were evaluated in a wastewater treatment plant, throughout the process, which includes an ultraviolet radiation disinfection step. This treatment showed significant results in reducing the number of bacteria, either total and resistant to carbapenems. In untreated samples, Enterobacteriaceae strains were detected carrying blaGES-5 -associated with integrons-, which is rarely found in clinical settings in Portugal. In the final effluent were found bacteria intrinsicallyresistant to carbapenems, namely Stenotrophomonas. The results obtained in this work reveal additional evidence regarding the role of environmental bacteria as progenitors of AR genes, as well as the role of humans in the spread of AR in aquatic compartments. This knowledge is crucial to define mitigation strategies for this problem, both in the environment and in the clinic.
A resistência a antibióticos é uma preocupação crescente no que diz respeito à saúde pessoal e comunitária, à discrepância social no acesso à saúde e ao futuro do mundo natural. Este trabalho teve como objetivos compreender a origem dos determinantes genéticos da resistência a antibióticos (RA) em bactérias ambientais, bem como explorar o impacto da pressão antropogénica na evolução e dispersão da RA. O papel do género Shewanella como origem e reservatório de genes de RA foi avaliado através da análise de uma coleção de isolados ambientais e de genomas deste género, depositados em bases de dados públicas. A presença e o contexto genético do gene que codifica para a carbapenemase OXA-48 e a presença de genes qnrA foram avaliados. Estes genes foram detetados em várias espécies de Shewanella, nalguns casos pela primeira vez, sendo específicos para algumas destas espécies. Além disso, várias variantes novas foram identificadas neste trabalho. Sequências de inserção associadas à transferência de genes foram identificadas, fundamentando a sua contribuição na dispersão destes genes para outros grupos filogenéticos. O impacto da ação humana na disseminação da RA em compartimentos aquáticos foi abordado através da análise de vegetais consumidos crus e da água subterrânea utilizada para irrigação. Foram encontradas estirpes multirresistentes e com características de virulência, comuns aos dois ambientes, sugerindo a água de irrigação como origem da contaminação detetada em vegetais. A análise do genoma de algumas destas estirpes revelou determinantes de virulência, elementos genéticos móveis e genes de resistência, sugerindo um risco potencial para a saúde humana. Além disso, a diversidade e abundância de bactérias resistentes a carbapenemos foram avaliadas numa estação de tratamento de águas residuais, ao longo do processo que inclui um passo de desinfeção com radiação ultravioleta. O tratamento reduziu significativamente o número de bactérias, totais e resistentes a carbapenemos. Em águas não tratadas, foram detetadas estirpes de Enterobacteriaceae com o gene blaGES-5 -associado a integrões-, raramente encontrado no contexto clínico em Portugal. No efluente final foram encontradas bactérias intrinsecamente resistentes aos carbapenemos, nomeadamente Stenotrophomonas. Os resultados obtidos revelam evidência adicional no que diz respeito ao papel das bactérias ambientais como progenitores dos genes de RA, tal como o papel do homem na disseminação da RA nos compartimentos aquáticos. Este conhecimento é crucial para definir estratégias de mitigação deste problema, tanto no meio ambiente como na clínica.
Programa Doutoral em Biologia e Ecologia das Alterações Globais

Doutoramento em Engenharia Florestal - Instituto Superior de Agronomia
Vegetation fires actively participate in ecosystem dynamics and atmospheric composition. Their contemporaneous occurrence and impacts – described under the concept of “fire regimes” – is driven by climate, vegetation, and human activities – the components of the “fire triangle”. The gaps in our understanding of those drivers hamper the proper consideration of fires in various domains, including ecosystems management, vegetation modeling, and climate change investigation. This thesis capitalizes on satellite observations to depict the anthropogenic and climatic influence on fire regimes. Fire inter-annual variability is shown to be dominated by large scale climatic patterns, of which the El Niño-Southern Oscillation has the most widespread and long term footprint. Fire frequency and seasonality are more complex, being determined by the interaction of all three factors of the fire triangle. The evaluation of a vegetation-fire model thus reveals significant discrepancies. It suggests a great margin of progress on representing of the anthropogenic factor, supported by the wide range of fire practices identified from fire season dynamics. A model specific to tropical deforestation fires is developed, as a regional application of this thesis contributions. Climate is a forceful safeguard against forest conversion progress, but ongoing environmental changes could revert the situation.