Dissertations / Theses on the topic 'Biological disturbances'

In this study, the effects of biological and physical disturbance on algal assemblages on cobbles in rainforest streams were investigated. Study sites in two rainforest streams, Stony Creek and Booloumba Creek, located in south- east Queensland, were used for both a regular sampling program and an extensive experimental schedule. Previous research has shown that physical disturbance due to spates and, in the absence of high discharge events, biological disturbance due to invertebrate grazing exert significant structuring and controlling forces on periphyton assemblages in streams. The principal objectives in this study were to deternine the relative importance of physical disturbance in the form of spates and desiccation, to outline the significance of biological effects, in particular as a result of grazing pressure, and to describe algal succession on substrates cleared after disturbance events. Periphyton chlorophyll a, biomass values and grazer numbers were monitored over a period of two years in relation to rainfall and stream discharge (to pinpoint the incidence of spates). Periphyton assemblages were composed mainly of diatoms (Cocconeis and Navicula being the dominant genera). Physical disturbance by spates was clearly an important factor structuring stream algal assemblages. Periphyton chlorophyll a and biomass values were reduced following a high discharge event, but then recovered relatively fast in the absence of any other disturbance. Furthermore, chlorophyll a values were correlated with grazer numbers. Differences were observed in the epilithon of Stony Creek and Booloumba Creek: while cobbles in the former supported more chlorophyll a containing material of algal origin and less non-algal biomass, the reverse was true for latter stream. This was most probably due to the physical characteristics of the two stream channels, primarily their slope, which was considerably steeper in Stony Creek, thus requiring less depth to facilitate a major disturbance event. This means that the physical characteristics of streams are most important determining factors regarding the effects of high discharge events, with the disturbance regime playing a significant role in the composition of the stream benthos. However, some major changes in chlorophyll a and biomass occurred in the absence of big disturbances. Periphyton on cobbles collected in the streams was subjected to various time periods out of the water to determine the effects of desiccation. Diatom assemblages on cobbles were not resistant to desiccation and did not recover following re-immersion in the streams. Thus, periods of low flow are capable of reducing periphyton assemblages, however, this type of disturbance would take place over a longer period compared to spates. A colonization experiment where polyethylene foils were introduced into the streams was used to monitor algal succession on bare substrates. Diatoms were the only algae which colonized experimental foils, exhibiting distinct successional patterns in both streams. A series of grazer manipulation experiments were employed to test for any effects of grazing; this involved the inclusion / exclusion of caddisfly larvae from cobbles enclosed in screened perspex cylinders. Signficantly, the effects of grazing invertebrates resulted in an increase in chlorophyll a and biomass values, contrary to expectations and the majority of past studies. This could mean that grazers at a certain density may actually stimulate algal growth and there exists a fine balance between when grazer numbers enhance periphyton productivity or periphyton is overgrazed. Overall, results obtained indicated that variations in stream algal assemblages were a consequence of the combined effects of spates, low flows and, to a lesser extent, grazing.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Graduate School of Environmental Science and Engineering
Science, Environment, Engineering and Technology
Full Text

Anthropogenic environmental changes can serve as drivers for evolutionary responses in wild populations. To predict the long-term impact of anthropogenic changes on populations, it is crucial to understand the genetic effects caused by these disturbances. The Baltic Sea is considered to be one of the world’s most contaminated seas, and the increase of anthropogenic chemical pollution is a major threat to its ecosystems. This thesis assesses the impact of harbors and sewage treatment plants on physiological traits and genetic structure of resident populations of blue mussels at replicated sites in the Baltic Sea. The initial evaluation of the overall genetic pattern in blue mussel populations in the Swedish West Coast, the Baltic Proper and the Bothnian Sea found genetic differentiation between the three water basins and a low genetic differentiation within each basin, especially within the Baltic Proper. Despite the low genetic differentiation among blue mussels within the Baltic Proper, a parallel genetic differentiation associated with sewage treatment plant effluents was found in this basin. This included genomic regions with a high degree of differentiation between reference sites and sites affected by sewage plants effluent. This genetic differentiation is suggested to be due to post-dispersal selection acting in each generation. In contrast, no parallel genetic differentiation was associated with harbors. We identified five genomic regions in blue mussels, showing strong signs of selection, shared among three out of four replicated reference sites and sites affected by sewage effluents in the Baltic Proper i.e. Askö, Tvärminne and Karlskrona. An initial characterization of these genomic regions revealed functions related to immune and endocrine responses, oxidative stress and shell formation. Our results indicate that selection caused by sewage effluents involves multiple loci. The same genomic regions are found across different locations in the Baltic Proper but there are also unique genomic regions at each location. No genotoxic or histopathological effects were found among blue mussels from sewage effluent-affected areas but a higher frequency of histological abnormalities in the digestive gland were observed in mussels from harbors.
Evolutionära anpassningar till miljöstörningar i marina ekosystem: genetisk ekotoxikologi i Östersjön

Wildfire is the primary natural disturbance in Interior Cedar-Hemlock (ICH) forests, and since the mid-20th century, forest harvesting (clearcutting, in this case) has become the primary anthropogenic disturbance type. Forest management in British Columbia is currently governed by a paradigm that maintains that biological diversity can be preserved by utilizing forest harvesting regimes that closely mimic "natural" disturbance regimes, but a question remains as to how closely these regimes mimic wildfire disturbances. More specifically, how do clearcutting and wildfires compare in their effects on the structure and composition of early-successional ICH plant communities? This study compares vegetation structure, composition, relative abundance and diversity among 39 sites that experienced either a stand-replacing fire or a clearcut within the last 40 years. Sites of different ages and disturbance types were located within the wet cool ICHwkl and very-wet cool ICHvk I biogeoclimatic variants near Revelstoke, B.C. For each site, overstory structural characteristics (tree and snag diameters, basal area and density), overstory composition, and surface fuels (volume of coarse woody debris (CWD)) were assessed. Understory vegetation percent cover, species richness, composition and diversity were also determined. Linear regression analysis was used to examine differences in each of these variables between disturbance types, over time. The trends in structural legacies (especially snag and CWD dynamics) varied greatly between wildfire and clearcut sites. Compared to burned sites, clearcut sites exhibited patterns of accelerated succession in several characteristics (overstory tree regeneration, vegetation cover and understory species richness) due to planting treatments and pre-disturbance relicts. Understory species composition also varied between disturbances, with clearcut sites containing more shade-tolerant survivors initially. Both disturbance types had similar levels of floristic diversity during early succession. These results suggest that clearcut harvesting may not emulate stand-replacing fires in terms of impact on early ICH plant succession in any aspect but diversity. However, it is unclear if these early-successional differences will continue through time. There is a need for further research in this ecosystem, as well as any other ecosystems where emulation silviculture is applied, in order to confirm that silvicultural effects mimic those of natural disturbance regimes.

Unsustainable patterns of consumption by humankind have increased the rate of change in the natural ecosystems and consequently the levels of stress experienced within the environment. Access to sufficient good quality water is essential and a requirement to meet a number of the Millennium Development Goals (MDGs). However, poor land management and untenable agricultural practices have become the main drivers of the declining watershed services. Upstream farmers often have little or no incentives to take these impacts into account in their decision-making process. Therefore, without investment in ensuring proper land management, the trend in watersheds degradation will continue. Payment for Environmental Services (PES) has emerged as an incentive–based tool that is expected to motivate farmers to improve their agricultural practices. PES is set up to facilitate the process whereby the beneficiaries of environmental services pay compensation to providers of environmental services for conserving the ecosystem. This tool has received increasing attention as a means of creating incentive measures for managing the ecosystem, addressing livelihood issues for the rural poor, and providing sustainable financing for protected areas. The Government of Kenya, as part of its efforts to improve water resource management, is considering use of economic incentive. However, there is insufficient information to guide policy making in that direction. Little is known about the farmers’ preferences for management schemes that will affect land use patterns, their willingness to accept compensation and the willingness of potential buyers to pay for the services. This study evaluates the willingness to accept and the willingness to pay for environmental services with a view to assessing the viability of a PES scheme for the Kuywa Watershed in particular, as well as the Mt. Elgon Ecosystem and other areas with similar conditions. The objectives of the study are threefold (i) to examine respondents preferences for management options for the provision of environmental services in the watershed of River Kuywa of Mt. Elgon Ecosystem; (ii) to evaluate households’ willingness to pay (WTP) and willingness to accept (WTA) payment for improved environmental services from the River Kuywa watershed; and (iii) to propose viable PES approaches for the management of the natural resource of the Kuywa watershed and the Mt. Elgon ecosystem in general. Using six land management attributes relevant to the local situation, the study applied the conjoint method to evaluate farmers’ preferences for management options for the provision of environmental service and assess farmers’ willingness to pay and willingness to accept payment for environmental services. To enable assessment of viability, an analysis was done of the institutional and legal framework within which the PES scheme would operate. Data were collected using literature review and document analysis, questionnaires, focus group discussions and key informant interviews. Results indicate that poor water quality was the most acute problem, followed by deforestation. Results from the conjoint models show that the length of commitment period and land size that is 40% or more of the total land holding influence the farmers’ rating of the management scenarios. The study found that a management contract that requires use of 20% of land holding for a period of 5 years, combined with a cash incentive, harvesting partially permitted, administered by a local NGO and requiring contribution of free labour for two days had the highest likelihood of being selected. The conjoint valuation exercise also came up with a WTA by farmers upstream of KSh. 7,080/= per year. The corresponding value downstream was KSh. 43/= per month over and above their regular water bill. In terms of the institutional and regulatory framework, Kenya has a wide range of policies, laws and regulation on water and other natural resources which provide an enabling environment for PES. With the decentralized institutional setup implemented in both the water sector and the agricultural sector, the institutional setting also provides an enabling environment for PES. With a positive WTA and WTP coupled with an enabling legal and institutional environment, the study concludes that PES is a viable environmental management tool for the Kuywa water shed and similar watersheds.

Among the various natural and anthropogenic threats to coastal systems, industrial activities and their heritage of local contamination play a key role, especially where new disturbances are superimposed to extant degraded conditions. This may affect the functioning of assemblages, including their ability to recover, in unpredictable ways. Organisms subject to chronic contamination may respond better to a present discrete disturbance compared to organisms from reference areas not affected by the same contamination due to their adaptation to harsh conditions. By contrast, the same organisms may be more sensitive to the new disturbance if chronic contamination kept them close to their tolerance limit. This study tested such alternatives by comparing the patterns of recovery from the experimental removal of all erect organisms of lowshore benthic assemblages between the post-industrial site of Bagnoli-Coroglio (Gulf of Naples) and reference sites located outside it. Recovery was assessed over six months. Response variables included mean values and temporal trajectories of assemblage structure, richness of taxa and abundance of conspicuous taxa. The examined assemblages showed great recovery ability that was comparable between the post-industrial site and reference sites. Discussed potential explanations include: (i) intertidal organisms would quickly recover irrespective of background contamination as an adaptation to the naturally harsh and variable environmental conditions of their living habitat; (ii) reference sites would be subject to environmental stress comparable to that of Bagnoli-Coroglio being located in the highly urbanized Gulf of Naples; (iii) large variability between- and withinsites may have masked any impacts of experimental disturbance and their differences between the post-industrial site and the reference sites; (iv) historical contamination would be limited to subtidal sediments, without propagating to adjacent rocky habitats.

Complex regional pain syndrome (CRPS) is a painful, debilitating condition that is poorly understood. The syndrome is characterised by pain, motor disturbances and abnormalities in trophic, sudomotor, vascular temperature and sensation. The underlying mechanisms are unknown. Clinical observations have identified a novel phenomenon whereby patients pay little attention to, and fail to care for, their painful affected limb. The literature describes this phenomenon in terms of neglect-like symptoms similar to neurological neglect as described in stroke literature. However, this does not seem to fully fit with or explain the nature of clinical observations. Therefore the aim of the qualitative first study was to more fully describe the phenomenon through an investigation of the patient experience and words used to describe those experiences. Six themes emerged from the data and were as follows: hostile feelings; spectrum of disassociation; disparity between what is apparent and what is felt; distorted mental image of affected parts; awareness of limb position and conscious attention. From these findings a theory emerged which serves to further our understanding of body perception disturbance in CRPS. Based on these findings, the second study aimed to quantify a feature of body perception disturbance by measuring limb position accuracy of those with CRPS compared to Healthy Controls (HC) and those with Rheumatological Pain (RP). The CRPS group were significantly less accurate in positioning of both the affected and unaffected upper limbs (median=9°, Interquartile rang e (IQR), 5.7°-13.3°) compared to both HC (6.5°, IQR, 4°-10.7°) and RP groups (7.7°, IQR, 5 °-11.7°). In the CRPS group position accuracy of the affected limb significantly improved with vision (8.3° in view, 10.7° not in view). Pain intensity was significantly greater in the CRPS (6.5, IQR, 5.4-7.7) than the RP group (4.6, IQR, 3.6-5.7). Based on the findings of this research programme, a definition of body perception disturbance in CRPS is presented. Furthermore, a disrupted body schema model is proposed as an explanation of the central mechanisms responsible for body perception disturbance in CRPS.

Within our ecosystems, soil biota control an array of functions, such as nutrient cycling and decomposition, and have been pursued as a soil quality indicator. Though microbial communities are known to be a reflection of their environment, small scales dynamics within an agricultural system have been overlooked for many years leading to gaps when inferring on relative microbial values. To further asses our current microbial knowledge, two experiments analyzing microbial phospholipid fatty acid (PLFA) structures and enzyme activities sought out to determine temporal fluctuations, cycles, and driving force behind simulated daily microbial parameter outputs. Across both studies, temporal effects, cyclical structures, and common driving forces were recorded, but further validation and characterization is needed to solidify the temporal dynamics of the microbial community. Overall, this information serves as a valuable step towards determining the most viable tillage systems based on environmental conditions, and physical proof of small scale microbial fluctuations.

My dissertation examines western hemlock looper (Lambdina fiscellaria lugubrosa Hulst) as an agent of disturbance in coastal forests of British Columbia. Western hemlock looper populations along coastal British Columbia have undergone seven episodes of outbreak from 1911 to 2004, leading to visible defoliation of western hemlock (Tsuga heterophylla (Raf) Sarg.)-dominated forests. My research investigates the causal factors that influence the timing of outbreaks, the impacts the resultant defoliation has on forest structure and composition, and the spatio-temporal dimensions of this biological disturbance agent. In order to identify the specific antecedent climate conditions that contributed to western hemlock looper outbreaks between 1911 and 2003, I analyzed local meteorological records to develop a moisture stress index of combined temperature and precipitation data. This index included periods of warm, dry climate between 1895 and 2004, and I hypothesized that these warm, dry conditions would improve the survival of western hemlock looper larvae and facilitate population increases. Indeed, a high moisture stress index in June was associated with the onset of visible defoliation by western hemlock looper populations later that year. Furthermore, a high moisture stress index over the entire growing season (May to September) was associated with conditions two years before visible defoliation events, thereby providing a trigger for populations to increase to outbreak levels in subsequent years. Given predicted warmer and drier climatic conditions during the growing season in coastal British Columbia, I anticipate that the frequency of western hemlock looper outbreaks will increase in future. To quantify the impacts of defoliation on the structure and composition of the coastal forests, I compared the effects of three different levels of disturbance severity on stands with comparable tree composition, density, age and stand structure within the Coquitlam River watershed during a western hemlock looper outbreak from 2000-2003. I hypothesized that defoliation from western hemlock looper would slow the growth of canopy western hemlocks at sites with low levels of defoliation and lead to the death of canopy western hemlocks at sites with more severe defoliation. I found that the degree of canopy openness increased with disturbance severity and resulted in an increase in understory vascular plant diversity, I suggest that these alterations to forest structure and composition will lead to an increase in the number of possible future successional pathways and increase forest heterogeneity at the landscape level. In a second study of disturbance effects, I analyzed the temporal pattern of tree death and the resulting rates of mortality after the 2000-2003 western hemlock looper outbreak. I hypothesized that mortality of trees in defoliated areas would be influenced by tree diameter, with smaller trees more susceptible to defoliation and dying at a greater rate than larger trees. Using repeated census data, I was able to show species-specific responses in mortality following western hemlock looper outbreaks. Western hemlock had high levels of mortality across all diameter classes, while mortality of western redcedar and amabilis fir was confined to smaller trees. To determine if the frequency of western hemlock looper outbreaks changed over the past two centuries, I employed dendroentomological methods to reconstruct outbreaks that occurred on Coquitlam Island, a 75 ha island where three outbreaks had been documented during the 20th century. I used differential rates of tree-ring growth between 'host' western hemlock and 'non-host' western redcedar to detect periods of radial growth suppression associated with western hemlock looper outbreaks using the program OUTBREAK. I used known periods of western hemlock looper outbreaks in the 20th century to calibrate and verify the reconstruction techniques. I successfully reconstructed four outbreaks over a 135-year period between 1775 and 1910. The dendroentomological method was successful at identifying low, moderate and high severity outbreaks, whereas the written record identified only periods of visible defoliation from high severity outbreaks. Based on the reconstructed outbreaks, I have determined that the frequency of defoliations has not changed significantly over the past 200 years.
Arts, Faculty of
Geography, Department of
Graduate

Riparian systems are important for breeding bird communities and are highly used as migratory corridors; however, their importance for wintering birds has not been assessed systematically. In order to assess the value of riparian areas for birds wintering in Sonora, data from 1,816 standard point counts were collected from 87 locations during January and February 2004-2006. A total of 253 species were detected across 14 vegetation types, including nine categories of riparian vegetation. The mean number of species and individuals detected per count was significantly higher in riparian vegetation than in non-riparian vegetation for migratory species, but not for residents. Riparian bird communities are different from those in non-riparian habitats, and contribute 22% of the regional avifauna's species.
Anthropogenic disturbance has imposed significant changes in riparian habitats, and is known to have negative effects on biological communities. To assess the effects of human induced disturbance on wintering bird communities, I recorded community composition, relative abundance of species, and three indicators of bird condition in relatively undisturbed and highly disturbed sites at three river systems in Sonora. There is, in general, little effect of disturbance on the composition of wintering communities, with less than 20% of the most common species having significant differences in their abundances between relatively undisturbed and highly disturbed sites. Condition indicators were similar in the two disturbance levels, but the mean heterophil/lymphocyte ratio in the blood of sampled birds showed increased levels of physiological stress in disturbed sites. A more experimental approach is needed to determine the specific cause of the stress expression in leucocytes.
Modification of natural flooding regimes has modified riparian areas, as has been the case in the Colorado River Delta. I present a summary of the changes experienced by riparian systems and some of the measures implemented for riparian restoration in the southwestern United States, and then I compare the scenario with that in central Sonora, where some of the same stressors exist on riparian systems, but where traditional management practices have also mitigated some of the negative consequences of flow control along mid-sized river systems.

Recreation and ecotourism activities are growing in demand worldwide, especially in biodiversity hotspots. Protected area managers may seek to introduce novel activities in order to generate revenue. However, disturbance effects brought about through encounters between humans and wildlife can have negative consequences, which conflict with conservation goals. De Hoop Vlei is a large coastal lake within the De Hoop Nature Reserve. It is a Ramsar site as well as a key feature of a BirdLife Important Bird Area (IBA). Proposals for motorized boat tours and kayak tours on the vlei have been made, for which this study provides an impact assessment. Repeated counts were performed in order to characterize the waterbirds present during the high water level conditions required for boating. Birds were concentrated in areas with aquatic vegetation and shallow water, mainly along the vlei's western shoreline and southern and northern ends. Two routes were designed for boat tours that would minimize disturbance by avoiding these areas as well as breeding sites. Count data were also used to revise the Ramsar and IBA assessments, which underestimated the site's conservation value. Boat tours were monitored to estimate the number of birds disturbed, and to measure agitation distances (ADs) and flight initiation distances (FIDs) in response to the boat as well as a kayak. Post-disturbance recovery was investigated, as was the likelihood of habituation using a space-for-time substitution at a site with regular boat traffic. Boat tours did not typically disturb more than 10% of birds present at the vlei, and largely avoided disturbing species of conservation concern. Responses to the kayak were more severe than to the boat, which is most likely due to the similar speeds of the two boats are similar and the kayak is more easily perceived as a threat due to its shape and stealth, the presence of a paddler, and the consistent paddling motion. Post-disturbance recovery of species was slow and incomplete after an hour, meaning that there are likely costs for foraging opportunities and breeding if important areas are disturbed. Most species did allow a closer approach at the site with regular boating, but AD did not differ between them for most species. From these results it would be dangerous to assume that habituation will mitigate against disturbance impacts. Recommendations made included that kayak tours should not be permitted. Boat tours, with correct management, can be conducted in a manner that will not be too disruptive to birds. This study is the first to document such a large difference in responses of birds to two differing boat types, and is a rare example of disturbance of birds being studied in an African context.

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Estudos sobre os mecanismos de toxicidade causados por poluentes ambientais representam um campo de investigação amplo. O efeito tóxico do Cd (cádmio) no sistema reprodutor não é um assunto novo, mas ainda possui muitas lacunas a serem preenchidas, principalmente sobre os mecanismos pelos quais o Cd desencadeia lesões. O objetivo deste estudo foi avaliar o padrão inflamatório e mineral apresentado por ratos expostos a quatro baixas doses de cádmio e analisar após a fase inflamatória inicial e antes da fibrose crônica. Ratos machos adultos foram expostos a doses únicas intraperitoneais de cloreto de cádmio, juntamente com um grupo controle salina:1- 0.9% NaCl; 2- CdCl 2 1.1 mg/kg (0.67 mg Cd/kg); 3- CdCl 2 1.2 mg/kg (0.74 mg Cd/kg); 4-CdCl 2 1.4 mg/kg (0.86 mg Cd/kg); e 5- CdCl 2 1.8 mg/kg (1.1 mg Cd/kg). Sete dias após a exposição foram coletados sangue e órgãos reprodutores sendo feitas análises: biométricas, morfométricas, estereológicas, estresse oxidativo, peroxidação lipídica e proteica, dano em DNA, ultraestrutura por microscopia eletrônica de varredura e transmissão, dosagem de minerais teciduais, testosterona sérica, citocinas inflamatórias e análises histopatológicas que incluíram marcações para apoptose e calcificação. Observou-se que em todos grupos expostos ao Cd um padrão inflamatório marcado por neutrofilia no intertúbulo e ambiente basal, sem alterações nos marcadores de peroxidação lipídica, sugerindo ausência de danos na barreira de células de Sertoli. Marcadores de estresse oxidativo e citocinas apresentaram alterações indicando ser um dos mecanismos pelos quais as lesões são induzidas. Houve redução da produção de testosterona e reduções volumétricas nos parâmetros de Leydig. Foram observadas intensa apoptose e calcificação de células germinativas e das fibras colágenas. Houve incremento do cálcio tecidual com o aumento da dose de Cd, porém outros minerais sofreram queda. Histopatologias e alterações morfométricas, estereológicas e biométricas apresentaram aumento dose-dependente. Concluímos que as lesões causadas pelo Cd são dose-dependentes e que as vias minerais e inflamatórias desempenharam papel-chave para o desenvolvimento das lesões.
The study of toxicity mechanism caused by the environmental pollutants is a broad research field. The toxic effect of Cadmium (Cd) in reproductive system is not a novel issue, but many gaps still remain to be filled, especially on the mechanisms by which the Cd triggers injuries. The objective of this study was to evaluate the inflammatory and mineral pattern presented by rats exposed to four low doses of Cd and to analyze after initial inflammatory phase and before chronic fibrosis. Thus, adult male rats were intraperitoneally exposed to single doses of Cd chloride, along with a saline control group: 1- 0.9% NaCl; 2- CdCl 2 1.1 mg/kg (0.67 mg Cd/kg); 3- CdCl 2 1.2 mg/kg (0.74 mg Cd/kg); 4-CdCl 2 1.4 mg/kg (0.86 mg Cd/kg); e 5- CdCl 2 1.8 mg/kg (1.1 mg Cd/kg). Seven days after exposure, blood and reproductive organs were collected and the following analyses were performed: biometric, morphometric and stereological, oxidative stress, lipid and protein peroxidation, DNA damage, ultrastructure by transmission and scanning electron microscopy, dosage of tissue minerals, serum testosterone, inflammatory cytokines and histopathological analyses that included markings for apoptosis and calcification. It was observed that the inflammatory pattern is marked by neutrophils in intertubule and basal environment without changing markers of lipid peroxidation, suggesting the absence of damage in the Sertoli cell barrier. Markers of oxidative stress and cytokines presented changes indicating this is one of the mechanisms by which lesions are induced. There was reduction in testosterone production and changes in the Leydig parameters. Intense apoptosis and calcification of germ cells and collagen fibers were observed. There was increase of calcium in the tissue along with the increase of Cd dose, but the other minerals decreased. Histopathology and morphometric, stereological and biometric changes increased depending on the dose. We concluded that the injuries caused by Cd are dose-dependent and mineral and inflammatory pathways play a key role in the development of lesions.

The first part of my work consisted in samplings conduced in nine different localities of the salento peninsula and Apulia (Italy): Costa Merlata (BR), Punta Penne (BR), Santa Cesarea terme (LE), Santa Caterina (LE), Torre Inserraglio (LE), Torre Guaceto (BR), Porto Cesareo (LE), Otranto (LE), Isole Tremiti (FG). I collected data of species percentage covering from the infralittoral rocky zone, using squares of 50x50 cm. We considered 3 sites for location and 10 replicates for each site, which has been taken randomly. Then I took other data about the same places, collected in some years, and I combined them together, to do a spatial analysis. So I started from a data set of 1896 samples but I decided not to consider time as a factor because I have reason to think that in this period of time anthropogenic stressors and their effects (if present), didn’t change considerably. The response variable I’ve analysed is the covering percentage of an amount of 243 species (subsequently merged into 32 functional groups), including seaweeds, invertebrates, sediment and rock. 2 After the sampling, I have been spent a period of two months at the Hopkins Marine Station of Stanford University, in Monterey (California,USA), at Fiorenza Micheli's laboratory. I've been carried out statistical analysis on my data set, using the software PRIMER 6. My explorative analysis starts with a nMDS in PRIMER 6, considering the original data matrix without, for the moment, the effect of stressors. What comes out is a good separation between localities and it confirms the result of ANOSIM analysis conduced on the original data matrix. What is possible to ensure is that there is not a separation led by a geographic pattern, but there should be something else that leads the differences. Is clear the presence of at least three groups: one composed by Porto cesareo, Torre Guaceto and Isole tremiti (the only marine protected areas considered in this work); another one by Otranto, and the last one by the rest of little, impacted localities. Inside the localities that include MPA(Marine Protected Areas), is also possible to observe a sort of grouping between protected and controlled areas. What comes out from SIMPER analysis is that the most of the species involved in leading differences between populations are not rare species, like: Cystoseira spp., Mytilus sp. and ECR. Moreover I assigned discrete values (0,1,2) of each stressor to all the sites I considered, in relation to the intensity with which the anthropogenic factor affect the localities. 3 Then I tried to estabilish if there were some significant interactions between stressors: by using Spearman rank correlation and Spearman tables of significance, and taking into account 17 grades of freedom, the outcome shows some significant stressors interactions. Then I built a nMDS considering the stressors as response variable. The result was positive: localities are well separeted by stressors. Consequently I related the matrix with 'localities and species' with the 'localities and stressors' one. Stressors combination explains with a good significance level the variability inside my populations. I tried with all the possible data transformations (none, square root, fourth root, log (X+1), P/A), but the fourth root seemed to be the best one, with the highest level of significativity, meaning that also rare species can influence the result. The challenge will be to characterize better which kind of stressors (including also natural ones), act on the ecosystem; and give them a quantitative and more accurate values, trying to understand how they interact (in an additive or non-additive way).

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The effects of fire on tree mortality can change the floristic and structure of forest depending on intensity, frequencies and duration of burnt. Besides should play a fundamental role in vegetation dynamics. Areas of semideciduous forest subject to different frequencies of fire were monitored: 0.9 ha burned in 2007 (Q1) and 0.9 ha in 2005 and 2007 (Q2). The dynamics was based the average interval of 2.03 years between T1 (outubro/2006-maio/2007) and T2 (March/2009), including individuals with PAP ≥ 15 cm. Diversity (H ) and species richness (estimated by Jackknife) were higher in Q2, both at T1 and T2. The decrease on tree density between surveys was significant for Q1 and Q2. The proportion of deaths was higher in Q1. With exception of change (based number of individuals) that was higher in Q1, there were no differences in the dynamic parameters between Q1 and Q2 considering both the number of individuals and basal area. The increase of diversity in Q2 may be partially explained by the hypothesis of intermediate disturbance. On the other hand, despite the recruitment and mortality did not differ between Q1 and Q2, the high turnover rates independent of fire frequency suggests future changes in forest if the fire continuing frequent in the area.
Os efeitos do fogo sobre a mortalidade de árvores podem alterar a composição e estrutura da vegetação, dependendo da intensidade, freqüência e duração das queimadas. Nós monitoramos áreas de floresta sujeitas à diferentes freqüências de fogo: 0,9 ha queimaram em 2007 (Q1) e 0,9 ha em 2005 e 2007 (Q2). A dinâmica foi referente ao intervalo médio de 2,03 anos entre T1 (outubro/2006-maio/2007) e T2 (março/2009), considerando indivíduos com PAP ≥ 15 cm. A diversidade (H ) e riqueza de espécies (estimada por Jackknife) foram maiores em Q2, nos dois levantamentos (T1e T2). Ocorreu a diminuição na densidade em Q1 e Q2. No entanto, a proporção de indivíduos que morreram foi maior em Q1. Os parâmetros da dinâmica baseados no número de indivíduos e na área basal não diferiram entre Q1 e Q2, exceto mudança (por número de indivíduos) que foi maior em Q1. O aumento na diversidade na área sujeita a maior freqüência de queimadas pode ser explicada pela hipótese de distúrbio intermediário. Por outro lado, apesar da mortalidade e recrutamento não terem diferido entre Q1 e Q2, as altas taxas de mudanças, independentes da freqüência, do fogo sugerem futuras mudanças florísticas e estruturais na floresta caso as queimadas continuem ocorrendo na área.

No contexto da aplicação da Directiva-Quadro da Água, a ictiofauna é considerada como um relevante elemento biológico. Pela primeira vez foi desenvolvido um sistema de classificação para avaliação do estado ecológico dos ecossistemas aquáticos em Portugal, apesar dos constrangimentos impostos pela variedade e ubiquidade das pressões humanas e pelas peculiaridades dos agrupamentos piscícolas. Foram definidos grupos piscícolas para posterior estabelecimento de uma tipologia nacional de rios, foram seleccionadas métricas responsivas ás pressões humanas e foi desenvolvido um índice biótico piscícola. Os resultados evidenciam a necessidade de diferenciar correctamente a resposta da ictiofauna ás perturbações naturais e antropogénicas, considerando quer a variabilidade espacial, quer temporal dos agrupamentos piscícolas, típica dos cursos de tipo Mediterrânico. O uso de solo tem fortes consequências na degradação dos rios e na integridade da ictiofauna, sendo importante que a avaliação dos impactos considere a interacção entre diferentes pressões. A compreensão da influência relativa dos factores ambientais e humanos na ocorrência e abundância das espécies não nativas permitiu evidenciar o potencial papel das mesmas como indicadores biológicos. Esta tese contribuiu para o desenvolvimento e aperfeiçoamento de ferramentas de avaliação ecológica em Portugal, permitindo igualmente um aumento do conhecimento sobre a ecologia das comunidades piscícolas e funcionamento dos ecossistemas em rios de tipo Mediterrânico, com vista à sua conservação e reabilitação; ABSTRACT:Under the implementation of the Water Framework Directive fish fauna is considered a useful biological element. For the first time a Portuguese classification system to assess the ecological status of aquatic ecosystems was established, despite several constrains posed by the variety and ubiquity of human pressures and by the peculiarities of the fish assemblages. It was possible to define fish-based geographical groups for the subsequent establishment of a national river typology, to select metrics responsive to human pressures and to develop a fish biotic index. Results underline the needs for accurately differentiate between fish responses to natural and anthropogenic disturbances by accounting for the spatial and temporal variability of fish assemblages. Land use may lead to strong impacts on stream degradation and fish assemblages integrity and this evaluation must consider the interaction of different pressures. Understanding the influence of environmental and human factors in the occurrence and abundance of non-native species enlightened their role as a reliable tool in the ecological assessment of rivers. This thesis represents an important contribution to improve the ecological assessment tools in Portugal, while increasing knowledge on the ecology of fish communities and ecosystem functioning in Mediterranean climate rivers in view of their urgent conservation.

Studier har visat att fåglar påverkas av ökade ljudnivåer och ljudfrekvenser (Kociolek et. Al. 2011). Olika fågelarter skiljer sig i känslighet vid störning av ljud. Vissa arter kan anpassa sig och förändra sin kommunikation till den nya ljudsituationen. Andra kan påverkas i sin fortplantning då lätet är en väsentlig del av partnerkommunikationen. Vidare kan vissa fågelarter behöva flytta till ett annat habitat på grund av att de inte kunnat anpassa sig (Gill et. Al. 1999, Helldin 2004). Fågelinventeringar för nybyggnation av motorväg E6 Tanumshede, Norra Bohuslän redovisar antalet fåglar innan och efter motorvägens öppnande den 7 juli 2015. Hypotesen att ljudnivåer skiljer sig i nivå med avstånd från motorvägen och jämfört med referensskog bekräftades. Däremot visar analyser med en ANOVA inte på att antalet fåglar är påverkat av en högre ljudnivå. En del fågelarter uppvisar en signifikant ökning eller minskning i antal, vid analys av dessa fåglars kommunikationsfrekvenser kunde ingen signifikant skillnad ses. Det har inte funnits tillräckligt underlag för att göra en bedömning av mer sällsynta arter som eventuellt skulle vara mer påverkade av en förändrad ljudbild.
Studies have shown that birds are affected by increased noise levels and changes in sound frequencies (Kociolek et al. 2011). Different bird species differ in their sensitivity to noise disturbance. Some species can adapt and change their communication to the new sound situation, whereas others may be affected in their reproduction because sound in an essential part of partner communication. Furthermore, some species may need to move to another habitat because they could not adapt to the new sound situation (Gill et al. 1999, Helldin 2004). Birds inventories for the new motorway construction, E6 Tanumshede North Bohuslän, report the numbers and species of birds before and after the opening of the motorway on July 7, 2015. The hypothesis that noise levels differ at the distance from the highway and compared to reference forests were confirmed. On the other hand, analyses with an ANOVA do not indicate that the number of birds is affected by a higher noise level. Some bird species showed a significant increase in numbers after roadwork, whereas others decreased. No significant difference could be seen in the analysis of these birds’ communication sound frequencies. There has been insufficient support to make an assessment of more rare species that might be more affected by a changing noise levels.

Indo-Pacific region encompasses about 75% of world's coral reefs, but hard coral cover in this region experienced a 32% region-wide decline since 1970s. This great change is primarily ascribable to natural and anthropogenic pressures, including climate change and human activities effects. Coral reef conservation requires management strategies oriented to maintain their diversity and the capacity to provide ecosystem goods and services. Coral reef resilience, i.e. the capacity to recover after disturbances, is critical to their long-term persistence. The aims of the present study were to design and to test field experiments intended to measure changes in recruitment processes, as a fundamental aspect of the coral reef resilience. Recruitment experiments, using artificial panels suspended in the water column, were carried out in two Indo-Pacific locations affected by different disturbances: a new mine in Bangka Island (Indonesia), and the increased sedimentation due to coastal dynamics in Vavvaru Island (Maldives). One (or more) putatively disturbed site(s) was selected to be tested against 3 randomly selected control sites. Panels’ arrangement simulates 2 proximities to living corals, i.e. the sources of propagules: few centimetres and 2 meters over. Panels were deployed simultaneously at each site and left submerged for about five months. Recruits were identified to the lowest possible taxonomic level and recruited assemblages were analysed in terms of percent cover. In general it was not possible to detect significant differences between the benthic assemblages recruited in disturbed and control sites. The high variability observed in recruits assemblages structure among control sites may be so large to mask the possible disturbance effects. Only few taxa showed possible effects of the disturb they undergo. The field tests have highlighted strengths and weaknesses of the proposed approach and, based on these results, some possible improvements were suggested.

The terrestrial CO2 exchange in the Arctic plays an important role in the global carbon (C) cycle. The Arctic ecosystems, containing a large amount of organic carbon (C), are experiencing ongoing warming in recent decades, which is affecting the C cycling and the feedback interactions between its different components. To improve our understanding of the atmosphere-ecosystem interactions, the Greenland Ecosystem Monitoring (GEM) program measures ecosystem CO2 exchange and links it to biogeochemical processes. However, this task remains challenging in northern latitudes due to an insufficient number of measurement sites, particularly covering full annual cycles, but also the frequent gaps in data affected by extreme conditions and remoteness. Combining ecosystem models and field observations we are able to study the underlying processes of Arctic CO2 exchange in changing environments. The overall aim of the research is to use data-model approaches to analyse the patterns of C exchange and their links to biological processes in Arctic ecosystems, studied in detail both from a measurement and a modelling perspective, but also from a local to a pan-arctic scale. In Paper I we found a compensatory response of photosynthesis (GPP) and ecosystem respiration (Reco), both highly sensitive to the meteorological drivers (i.e. temperatures and radiation) in Kobbefjord, West Greenland tundra. This tight relationship led to a relatively insensitive net ecosystem exchange (NEE) to the meteorology, despite the large variability in temperature and precipitations across growing seasons. This tundra ecosystem acted as a consistent sink of C (-30 g C m-2), except in 2011 (41 g C m-2), which was associated with a major pest outbreak. In Paper II we estimated this decrease of C sink strength of 118-144 g C m-2 in the anomalous year (2011), corresponding to 1210-1470 tonnes C at the Kobbefjord catchment scale. We concluded that the meteorological sensitivity of photosynthesis and respiration were similar, and hence compensatory, but we could not explain the causes. Therefore, in Paper III we used a calibrated and validated version of the Soil-Plant-Atmosphere model to explore full annual C cycles and detail the coupling between GPP and Reco. From this study we found two key results. First, similar metrological buffering to growing season reduced the full annual C sink strength by 60%. Second, plant traits control the compensatory effect observed (and estimated) between gross primary production and ecosystem respiration. Because a site-specific location is not representative of the entire Arctic, we further evaluated the pan-Arctic terrestrial C cycling using the CARDAMOM data assimilation system in Paper IV. Our estimates of C fluxes, pools and transit times are in good agreement with different sources of assimilated and independent data, both at pan-Arctic and local scale. Our benchmarking analysis with extensively used Global Vegetation Models (GVM) highlights that GVM modellers need to focus on the vegetation C dynamics, but also the respiratory losses, to improve our understanding of internal C cycle dynamics in the Arctic. Data-model approaches generate novel outputs, allowing us to explore C cycling mechanisms and controls that otherwise would not have been possible to address individually. Also, discrepancies between data and models can provide information about knowledge gaps and ecological indicators not previously detected from field observations, emphasizing the unique synergy that models and data are capable of bringing together.

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The aim of this study was to analyse the physical and chemical characteristics of Tropeiros Lake (Capitólio, MG), located in Piumhi river sub‐basin, a river diverted from the Rio Grande basin to the são Francisco River basin, and to analize the taxonomic composition, abundance, diversity and the size structure of the planktonic microcrustaceans. Physical and chemical variables in the eater were measured in situ by the multiparameter Horiba U10 probe and qualitative and quantitative zooplankton sampling was carried out in both, pelagic and littoral regions of this lake using the plankton net of 69 μm mesh size, on March, 2007. Twenty seven taxa were identified, being 18 Cladocera, 3 Copepoda Calanoida and 6 Copepoda Cyclopoida. Microcrustaceans species composition in Lagoa dos Tropeiros was much more similar to the microcrustaceans composition of the water bodies from Rio Grande basin than to those from São francisco basin. The species Sarsilatona serricauda Sars, 1901 and Microcyclops alius Kiefer, 1935 constitute new records for the state of Minas Gerais biota. The assemblages from of microcrustaceans from the littoral region had higher richness of species, higher alfa diversity, and wider size spectra than the assemblages from the pelagic region. The analysis of the normalized size spectra and linear regression analysis indicated that Lagoa dos Tropeiros has a community away from the stationary state. The accumulated curves of numerical abundance and biomass (ABC curves) were different for the lake regions characterizing the pelagic region as a non‐disturbed compartment and the littoral region as a disturbed system. The gamma parameter derived from rank‐abundance diagram slopes characterized the microcrustacean assemblage of Lagoa dos Tropeiros as typical of a low trophic state environment.
Este estudo teve como objetivo analisar as características físicas e químicas da Lagoa dos Tropeiros (Capitólio, MG), localizada na sub‐bacia do rio Piumhi, rio transposto da bacia do Rio Grande para a Bacia do Rio São Francisco e analisar a composição taxonômica, abundância diversidade e estrutura em tamanho dos microcrustáceos planctônicos As variáveis físicas e químicas foram medidas in situ por sonda multiparâmetros e foram realizadas coletas de água para análises físicas e químicas da água e coletas qualitativas e quantitativas do zooplâncton. As amostragens foram feitas nas regiões litorânea e pelágica da lagoa utilizando uma rede de plâncton de 69 μm de abertura de malha, em março de 2007. Foram identificados 27 táxons de microcrustáceos, sendo 18 de Cladocera, 3 de Copepoda Calanoida e 6 de Copepoda Cyclopoida. A composição de espécies dos microcrustáceos da Lagoa dos Tropeiros é muito mais similar à composição de microcrustáceos da bacia do Rio Grande do que à da bacia do rio São Francisco. As espécies Sarsilatona serricauda Sars,1901 e Microcyclops alius são novas ocorrências para o estado de Minas Gerais. As assembleias de microcrustáceos da região litorâna tiveram maior riqueza de espécies, maior diversidade alfa e espectro de tamanho mais amplo que as assembleias da região pelágica. A análise do espectro em tamanho normalizado dos microcrustáceos e análise da regressão linear indicaram que a Lagoa dos Tropeiros apresenta uma comunidade distante do estado estacionário. As curvas ABC e a estatítica‐W mostram resultados diferentes entre a região limnética, que foi caracterizada como um sistema não perturbado e a região litorânea, que apresentou características de um sistema perturbado. O parâmetro gama derivado das inclinações das curvas de rank‐abundância evidencia uma assembleia característica de ambiente de baixo grau de trofia.

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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Disturbance events affect the colonization and re-colonization process of streams by benthic macroinvertebrates. The Intermediate Disturbance Theory predicts distinct community patterns resultant by disturbance, where we can found coexistence or species loss. Such patterns vary with intensity and frequency of disturbance plus species trait, which can provide resistance or resilience to the community. An experiment was carried out to test the immediate and during time effects of two intensities and three frequencies of disturbance on the benthic macroinvertebrates community at five Cerrado streams, at Goiás State, Brazil. We tested two hypothesis: 1) Disturbance affect the permanency probabilities of species on substrates along time, but it’s more likely for cylindrical body and high mobility groups of species than to hydrodynamic body and short life cycle species group; and 2) Disturbance events change the community composition of aquatic invertebrates, such a way that through time there’s a tendency of increasing similarity of community. The low intensity disturbance did not have an immediately effect on the occurrence probabilities of hydrodynamic body, large body or grabbing species group. However, increasing on disturbance intensity drove to a negative effect of all groups, except the Elmidae larvae with flattened body. Through time, we observed resilience of R-strategists groups, seeing that their permanency probabilities weren’t affected by disturbance intensity and frequency through time. Furthermore, high intensity disturbance caused an immediately effect on community composition between control and treatment differing the proportion off spatial turnover and nesting process, driving dissimilarities resultant from species loss. Nevertheless, there was no support for the increasing similarity resultant of replacement or species loss through time hypothesis. These results indicate that, despite of the distinguished immediate effect of disturbance, there’s a fast pattern of re-colonization of substrates, which results in non discrepant community structure pattern. The more likely effect of disturbance is a redistribution of individuals between the different habitats, generating unpredictability on detection of species by traditional methodologies.
Distúrbios afetam os processos de colonização e recolonização de macroinvertebrados bentônicos em riachos. A Teoria do Distúrbio Intermediário prediz que perturbações geram padrões distintos em comunidades, onde pode ocorrer a coexistência ou a perda de espécies. Tais padrões dependem da intensidade e freqüência de ocorrência dos distúrbios e das características morfofisiológicas das espécies, que podem conferir sensibilidade, resistência ou resiliência à comunidade. Um experimento foi montado para testar os efeitos imediatos e ao longo do tempo de duas intensidades e três freqüências de distúrbios sobre a comunidade de macroinvertebrados em riachos no Cerrado goiano. Foram testadas duas hipóteses: 1) Distúrbios afetam a probabilidade de permanência das espécies nos locais colonizados, mas táxons com ciclo de vida curto, com formato do corpo hidrodinâmico ou com apêndices e estruturas de fixação ao substrato são menos afetados pelas perturbações do que os táxons de corpo cilíndrico e táxons com maior mobilidade; e 2) Os eventos de distúrbios mudam a composição das comunidades de insetos aquáticos, de maneira que ao longo do tempo existe uma resposta de aumento da similaridade das comunidades. Os distúrbios de baixa intensidade não causaram efeito imediato nas probabilidades de ocorrência dos grupos de táxons de corpo hidrodinâmico, de maior tamanho corporal ou com estruturas de fixação ao substrato. Porém, o aumento da intensidade de perturbação afetou negativamente as probabilidades de ocorrência de todos os táxons, exceto das larvas de Elmidae de corpo deprimido. Ao longo do tempo, observou-se que táxons Restrategistas foram resilientes aos distúrbios, visto que suas probabilidades de permanência nos substratos não foram afetadas pelas perturbações ao longo do tempo. Além disso, distúrbios de maior intensidade causaram um efeito imediato de diferenciação da composição das comunidades entre tratamento e controle por processos de aninhamento de comunidades ou perda de espécies. Porém, não houve suporte para a hipótese de aumento da similaridade por perda ou substituição de espécies ao longo do tempo. Os resultados indicam que apesar de ocorrer um expressivo efeito imediato dos distúrbios, há um rápido padrão de recolonização dos substratos, o que resulta em padrões não discrepantes na estrutura das comunidades. O efeito mais provável do distúrbio é a redistribuição dos organismos entre os diferentes habitats, gerando imprevisibilidade na detecção de espécies por metodologias tradicionais de coleta.

1. Unterschiedliche Definitionen der Gesundheit mit verschiedenen Betrachtungsweisen (WHO: Der Mensch eine biopsychosoziale Einheit. Schulmedizin: ohne klinischen und paraklinischen Befund mit Orientierung an kritikbedürftigen Referenzmittelwerten) führt bei Fachleuten, Behörden und Laien zu Verwirrungen, wenn es um die Beurteilung gesundheitlicher Schäden geht. 2. Es wurde die Aufgabe gestellt zu prüfen, welche der beiden Definitionen der Realität näher kommt. 3. Mittels der chronopsychobiologischen Regulationsdiagnostik, des Dreiphasenentspannungstests (Hecht und Balzer 2001), wurden unter dem Aspekt der beiden Gesundheitsdefinitionen drei Gruppen untersucht (je 40 Probanden). - klinisch Gesunde (klinisch Gesunde nach Schulmedizin ) - Gesunde nach Definition der WHO - Probanden mit nichtorganische Insomnie (ohne pathologische klinische und paraklinische Befunde) 4. Die mit den verwendeten Methoden gewonnenen Daten wiesen aus, dass zwischen den klinisch Gesunden und den Probanden mit nichtorganischer Insomnie weitgehend größere Ähnlichkeiten bestehen. Beide Gruppen zeigten aber zu der Gruppe der Gesunden nach WHO-Definition, welche die biopsychosoziale Einheit des Menschen berücksichtigt, noch hochsignifikante Unterschiede. Die Gruppe der klinisch Gesunden kann daher auf Grund unserer Ergebnisse nicht den Anspruch erheben, real gesund zu sein. 5. Mit der Bezugnahme auf die Internationale Klassifikation der Krankheiten (ICD 10F) haben die von uns untersuchten klinisch Gesunden und die nichtorganischen Insomniker eine mehr oder weniger stark ausgeprägte Symptomatik von psychischen Störungen. Dies müsste bei der Beurteilung von Schadstoff-, Lärm-, und EMF-Wirkungen auf den Menschen, wie auch bei den klinisch-pharmakoloischen Untersuchungen beachtet werden. Die in der Arbeit erzielten Ergebnisse bedürfen durch weitere Untersuchungen eine Fundierung. Sie signalisieren aber sowohl unter praktischen als auch unter theoretischen Aspekten einen dringenden Forschungsbedarf.
1. Differing definitions of health using different criterea (WHO: The human being as a bio- psycho-social unit versus classical medicine: without clinical and paraclinical results based on suspect reference values) bring confusion to experts, authorities and laymen when assessing health damages. 2. The given task was to check which of the two definitions is closer to reality. 3. Using the chrono-psycho-biological diagnostic of regulation, the three-phase-relaxation test (Hecht and Balzer 2001), three groups were examined considering the aspects of the two health definitions (40 test subjects in the study group). - clinically healthy (clinically healthy per classical medicine definition) - healthy per definition of the WHO - test persons with non organic insomnia (i.e. no pathological or paraclinical findings) 4. The data gained from the employed methods revealed bigger similarities between clinically healthy persons and those with non organic insomnia. Both groups still showed highly significant differences to the group which fulfils the definition of the WHO regarding a human as a bio-psycho-social unit. As a result of this study, persons, though classified as "clinically healthy" might nevertheless not absolutely be healthy in reality. 5. In reference to the international classification of illnesses (ICD 10 F) the groups examined, both of clinically healthy and those with non organic insomnia, have more or less severe psychological symptoms. This should be taken into account when assessing the effects of pollution, noise, and EMF as well as clinical pharmacological studies. These present findings still need broader confirmation by further investigations. However, they clearly indicate, for practical and theoretical considerations, an urgent need for further research.

As bacias hidrográficas mediterrânicas, são consideradas importantes hotspots de biodiversidade piscícola, no entanto encontram-se sujeitas a elevada pressões antrópicas, nomeadamente devido à introdução de espécies piscícolas não-nativas. O presente estudo tem como objectivo determinar os padrões de abundância e riqueza de espécies piscícolas nas bacias hidrográficas do Sul de Portugal e avaliar a contaminação biológica e risco de bio-poluição causado por não-nativas, como também identificar os factores ambientais, incluindo pressões antropogénicas, que determinam os padrões de bio-contaminação. A densidade, a proporção, o número de espécies não-nativas assim como os índices de contaminação biológica foram superiores em locais degradados relativamente aos locais de referência, os quais apresentaram maior número de espécies nativas. A bacia do Sado destacou-se das restantes bacias com maiores valores médios de contaminação biológica e risco ecológico de bio-poluição devido a apresentar condições ambientais e de pressão antropogénicas favoráveis para o sucesso do estabelecimento de um grande número de espécies não-nativas introduzidas em Portugal. As bacias do Mira e das Ribeiras do Algarve apresentaram relativamente baixa contaminação biológica e risco ecológico por bio-poluição, devendo ser alvo de programas de prevenção para potenciais invasões. Os factores de invasibilidade estão relacionados tanto com aspectos ambientais puros, que tendem a variar de bacia para bacia e de espécie para espécie, como com o nível e o tipo de pressão antropogénica, que em conjunto, potenciam o sucesso de invasão das espécies não-nativas; Biological contamination of freshwater fish Mediterranean type streams: geospatial factors of invasibility Abstract Mediterranean basins are important fish biodiversity hotspots, however are subject to high anthropogenic pressures, particularly due to introduction of non-native fish species. This study aims to define patterns of fish species abundance and diversity in the river basins of southern Portugal and evaluate the biological contamination and bio-pollution risk caused by non-native species, but also identifies the environmental factors, including anthropogenic pressures, which determine biological contamination patterns. Non-native species density, proportion, number as well biological contamination indexes were higher in disturbed sites in relative to reference sites, which showed large number of native species. The Sado basin stood out from the other basins with higher mean values of biological contamination and ecological risk of bio-pollution because of environmental and anthropogenic pressure favorable conditions for the successful establishment of a huge number of non-native species introduced in Portugal. Mira and Ribeiras of Algarve basins showed relatively low biological contamination and ecological risk for bio-pollution, must be the prevention programs focus for potential invasions. The invasibility factors are related to pure environmental features, which tend to differ from basin to basin and from species to species, as well with the anthropogenic pressure level and type, which together increase the success of invasion by non-native species.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The main objective of this dissertation is to describe the limnological co-determinatives variations in temporal (monthly) and spatial (vertical/horizontal) scales of the Acauã reservoir by diagnosing its current trophic state. Monthly samples were collected and analyzed between August 2004 and July 2005. They were collected in six different regions of the reservoir in order to represent all of its compartments. The samples in the dam zone were collected at different levels of light penetration: 75%, 50% and 1% from the water surface, and at the bottom; and in the other regions water was sampled just about the water surface. The analyzed variables were volume, rainfall rate, temperature, pH, electric conductivity, dissolved oxygen, alkalinity, NH3, NO3, NO2, total phosphorus and orthophosphate. To calculate the Trophic State Rate, total phosphorus concentrations, chlorophyll a and water clearness data were used. To establish the summarization of the reservoir variability statistically the data were analyzed through the Principal Component Analysis (PCA). By analyzing the amplitude of the matrix variation data, it was observed that the main source of variability of the limnological characteristics was temporal/monthly to the detriment of spatial-vertical/horizontal mainly due to the rain that determines the two characteristic climatic seasons, rainy and dry. Despite the relative homogeneity of the reservoir s spatial structure, the vertical profile in the dike zone presented a greater environmental significance than the horizontal structure and showed micro-stratifications that influence the clinograde profile of oxygen and more alkaline water in the surface. The optical structure showed a good level of transparency of the water and an extensive euphotic zone. The electrical conductivity is considered high and has increased with the rains, as the nitrogen that was 2,2 times high on the average during the rainy days in relation to the dry period. The nitrate ion was predominant as well as the total phosphorus whose highest indicators were found in the deepest part of the reservoir. The principal component analysis distinguished the temporal system based on the hydrologic period and hydrodynamic variables. As for the Trophic State Rate and considering the classification according to the chlorophyll and 24 total phosphorus indicators, the lake environment is considered eutrophic to hypertrophic in every month and season of sampling. This fact shows the influence of the sub-basin of Bodocongó, which is rich in nutrients because it drains the in-coming waters of domestic, agricultural and industrial effluents of the Borborema region. The high rate of calcium carbonate in the lake shows the saline condition of the sub-basins such as Taperoá, Monteiro and Namorados. Thus, the analyses of Acauã reservoir summarize information about the main elements that characterize the environment around its hydraulic basin, since it is the dike for the sub-basins of Paraíba River
O propósito maior deste trabalho foi o de descrever as variações de codeterminantes limnológicos nas escalas temporal (mensal) e espacial (vertical/horizontal) do reservatório de Acauã, diagnosticando seu atual estágio de evolução trófica. Para tanto foram realizadas amostragens mensais no período de agosto de 2004 a julho de 2005. Estas foram realizadas em seis pontos distribuídos de modo a se representar todos os compartimentos do reservatório. Na zona de barragem as coletas foram realizadas na sub-superfície, 75%, 50% 1% de penetração de luz e no fundo; nos demais pontos realizaram-se apenas na superfície. As variáveis analisadas foram: volume do reservatório, precipitação pluviométrica, temperatura da água, transparência, pH, condutividade elétrica, oxigênio dissolvido, alcalinidade, NH3, NO3, NO2, fósforo total e ortofosfato. Para o cálculo do Índice de Estado Trófico (IET), foi utilizado as concentrações do fósforo total, da clorofila a e os dados de transparência da água. Para sumarização da variabilidade do reservatório, estatisticamente os dados foram tratados através de Análise de Componentes Principais. Ao se analisar a amplitude de variação da matriz de dados obtida observa-se que a maior fonte de variabilidade das características limnológicos foi a temporal/mensal em detrimento da espacial vertical/horizontal em função, principalmente, das chuvas que discriminou dois períodos climáticos característicos, o seco e o chuvoso. Apesar da relativa homogeneização da estrutura espacial do reservatório, o perfil vertical da zona de barragem apresentou maior significado ambiental que a estrutura horizontal, apresentando microestratificações que influenciaram no perfil clinogrado do oxigênio e águas mais alcalinas nas camadas superficiais. A estrutura óptica caracterizou-se por apresentar elevada transparência da água e zona eufótica extensa. A condutividade elétrica foi considerada alta e se ampliou com o aumento das chuvas, a exemplo nitrogênio que foi 2,2 vezes em média maior no período chuvoso em relação ao período seco. O íon nitrato foi à forma predominante e assim como o fósforo total os maiores valores foram encontrados com o aumento da profundidade do reservatório. A analise de componentes principais 22 discriminou o sistema temporal com base nos períodos hidrológicos e variáveis hidrodinâmicas. Em relação ao IET considerando a classificação em função da clorofila e do fósforo total, o ambiente para todos os meses e estações de coleta, é considerado de eutrófico a hipereutrófico, fato que reflete a influência da sub-bacia do Bodocongó, rica em nutrientes por drenar as descargas de efluentes domésticos, agrícolas e industriais do compartimento da Borborema. O elevado teor de carbonato de cálcio em suas águas também reflete a condição salina de sub-bacias tais como a do Taperoá, Monteiro e Namorados. Neste contexto, o reservatório de Acauã, por ser o barramento final de uma cascata de sub-bacias do Paraíba, sintetiza as informações das principais funções de força que caracterizam os ambientes a montante de sua bacia hidráulica

The human gut microbiome is a complex ecosystem with hundreds of species interacting with each other and the host. One function of the microbiome is to break down undigested nutrients into smaller nutrients, sometimes available for uptake by the host. The digestion of such macromolecules can involve several species where one feeds on another’s byproducts, forming a large cross-feeding network. The method of digital evolution can be of great aid in studying such complex ecosystems by creating models of the studied system. In this study, the digital evolution software Avida was used to study the effects of perturbations in the system on byproduct cross-feeding chain length. Intense perturbations were found to shorten the chain lengths in general whereas weaker perturbations had either a small or no effect. When perturbations ceased, most byproduct chains displayed recovery to lengths similar to the preperturbation lengths. This indicates that byproduct chain lengths may be kept short by common ecological mechanisms alone, explaining why very long chains are rarely observed while still theoretically possible.

Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul
Environmental changes resulting from climatic conditions may limit the reproductive activity of anurans. The calling activity is an important indicator of the temporal patterns of anuran activity, which may be regulated by several factors. Reproductive strategies, including the period of calling activity, time of tadpole and juvenile recruitment, and the larval rate of development, can be used for minimizing the adverse influence of environmental variables. Moreover, local environmental changes may generate disturbances (e.g., flooding, grazing, climatic events) and alter the availability of resources in the environment, which may lead to either a reduction or an increase in the local species diversity. In this context, the intermediate disturbance hypothesis (IDH) predicts that the species diversity would be higher at intermediate levels of disturbance. In freshwater systems, for instance, water bodies with intermediate hydroperiods (temporary ponds) would have higher species diversity because they would have fewer predators in relation to permanent ponds, and more resources availability in relation to ephemeral ponds. Thus, we aimed to determine the environment abiotic effects on the calling activity of an anuran community from the temperate wetlands of the extreme southern Brazil. We identified the reproductive patterns of species considering the periods of tadpole and juvenile recruitment, the larval development rate, and the influence of environmental variables on the species activity seasonality. We also established the disturbance frequency, duration and extent in water bodies, through the investigation of the relationship between the disturbance levels, the hydroperiod and the diversity of anurans. Data were collected over 17 months in coastal wetlands of the extreme portion of southern Brazil. Between December 2012 and April 2014 we registered 11 active species, distributed in the families Hylidae, Leptodactylidae, and Bufonidae. The calling activity of the community was positively related to water temperature and rainfall. The recruitment of tadpoles occurred during the rainy period, regardless of variation in the measured abiotic variables. The recruitment of juveniles also occurred during the rainy period and was related to increased water temperature. Our results indicate a link between the frequency and duration of the disturbance with the hydroperiod, as well as with tadpole richness and abundance. Overall, much of the species abiotic dependence was linked to the patterns of reproductive behavior and phylogeny; the occurrence of many species was also linked to the hydrological regime of water bodies. Also, our study demonstrates the direct effect of a disturbance event and the IDH on the studied anuran community, in which temporary water bodies presented a richest anuran community than ephemeral or permanent ones.
As variações ambientais decorrentes do clima representam um limitador para a atividade reprodutiva em anuros. A atividade de vocalização, por exemplo, é um importante indicativo do padrão de atividade diária e sazonal dos anuros e pode ser regulada por diversos fatores. As estratégias reprodutivas, tais como períodos de vocalização, época de recrutamento de girinos e juvenis, são utilizadas para amenizar a influência dessas variáveis. Adicionalmente, as variações climáticas podem refletir na forma de distúrbios sobre uma comunidade. Os distúrbios (e.g. alagamentos, pastejo, eventos climáticos) agem no ambiente alterando a disponibilidade de recursos, podendo causar o declínio ou aumento da diversidade de espécies. Nesse contexto a hipótese do distúrbio intermediário (HDI) prediz que em níveis intermediários de distúrbio a diversidade de espécies seria máxima. Em sistemas dulcícolas, por exemplo, corpos d água com hidroperíodos intermediários (temporários) apresentariam maior diversidade, por possuir menor número de predadores em relação aos permanentes e mais recursos disponíveis em relação aos efêmeros. Dessa forma, objetivamos averiguar os efeitos de fatores abióticos sobre a atividade de vocalização em uma comunidade de zona úmida temperada no extremo sul do Brasil. Identificamos os padrões reprodutivos das espécies, através do período de recrutamento de girinos e juvenis e tempo de desenvolvimento larval, bem como a influência de variáveis abióticas sobre a sazonalidade das espécies. Por fim, estabelecemos os atributos frequência, duração e extensão de distúrbio em corpos d água continentais, verificando a relação dos níveis de distúrbio com o hidroperíodo e diversidade de espécies de anuros. Os dados foram coletados ao longo de 17 meses em campos úmidos costeiros no extremo sul do Brasil. Foram registradas 11 espécies ativas de dezembro de 2012 a abril de 2014, distribuídas em três famílias: Hylidae, Leptodactylidae e Bufonidae. A atividade de vocalização sazonal da comunidade foi relacionada com a temperatura da água e pluviosidade, havendo respostas diferentes quando consideradas as espécies separadamente. O recrutamento de girinos ocorreu no período de chuvas, sendo independente das variáveis abióticas. O recrutamento de juvenis também ocorreu no período de chuvas e foi relacionado ao aumento da temperatura da água. Observamos, também, uma ligação entre os níveis dos atributos frequência e duração de distúrbio com o hidroperíodo, bem como com a abundância e riqueza de espécies de girinos presentes nesses ambientes. De uma forma geral, os resultados adquiridos mostram que grande parte da dependência abiótica apresentada pela atividade das espécies esteve ligada à filogenia e padrões comportamentais reprodutivos, onde a ocorrência de muitas espécies está ligada ao regime hídrico dos corpos d água. Por fim, os resultados encontrados no presente estudo demonstram a ação direta de um evento de distúrbio, bem como da HDI, sobre a comunidade de anuros, onde corpos d água temporários, com níveis intermediários de distúrbio, apresentam um maior número de espécies que efêmeros ou permanentes.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
In Brazil, economic growth causes rapid increases in marine transports. The impact of this increase on marine mammals, combined with the lack of legal enforcement, is potentially dangerous. Knowledge of vessel-dolphin interaction is essential to Brazilian marine ecology. The study of dolphin behavior can identify problems and support actions for conservation. Our principle aim was to study vessel-dolphin interactions and determine whether group and infant behaviors were being affected. Observations (600hs) were conducted in Pontal do Paraná and Guaraqueçaba (Southern Brazil), in 2010. We used a mixed method of \"focal-group sampling\" and \"sequential sampling\" for behavior records. Boats were classified according to engine type: central (diesel) and outboard (petrol). Interactions were classified into positive, neutral and negative based on observed behaviors before, during and after vessel passage (947 events were recorded). The dolphins behavioral responses varied according to the engine type, speed and distance. Results showed increased frequency of neutral interactions when the observed distance between boats and dolphins was greater than 100m with vessel at low speed (0.1 to 2.0 km/h). The neutral and positive interactions were more frequent with center engine boats, probably because these vessels do not reach high speed (faster than 5km/h). All vessel types changed the dolphin s behaviors in some way. The distance between boats and dolphins influences the animal s surface behavior when interaction occurred with central motor vessels in Guaraqueçaba (z =- 5105, p= 0.000) and with outboard boats in Pontal (z = -3682, p =0.000) and Guaraqueçaba (z =- 3931, p = 0.000). The variable speed influenced surface behavior when interaction occurred with outboard boats in Guaraqueçaba (z = 2,107, p = 0.035). Changes in group structure, after vessel passage, such as mother and calve separation were observed, especially when the boat split the group. These data will contribute to human activities management in the region.
No Brasil, o crescimento econômico provocou um rápido aumento no tráfego de embarcações. O crescimento desse impacto sobre os mamíferos marinhos somado a falta de legislação específica é potencialmente perigoso. Conhecer as interações entre embarcações e golfinhos é essencial para ecologia marinha brasileira. O estudo do comportamento deste grupo pode identificar problemas e subsidiar ações para a conservação. O objetivo deste estudo foi analisar interações entre o botos e embarcações e se estas alteram os comportamentos dos grupos e infantes. As observações (600hrs) foram realizadas em Pontal do Paraná e Guaraqueçaba (Sul do Brasil), em 2010. Para registro dos comportamentos foi utilizado um método misto de \"grupo focal\" e \"amostragem sequencial\". As embarcações foram separadas de acordo com o tipo do motor: centro (diesel) e popa (gasolina). As interações foram divididas em: positiva, neutra e negativa, baseadas nos comportamentos observados antes, durante e depois da passagem das embarcações (947 interações observadas). A resposta comportamental dos golfinhos observados variaram em relação ao tipo de motor, velocidade e distância entre os indivíduos e embarcações. Os resultados mostraram um aumento na frequência de interações neutras quando a distância observada entre os barcos e golfinhos foi maior que 100m com embarcações em velocidade baixa (0,1-2,0 km/h). As interações positivas e neutras foram mais frequentes com embarcações de motor de centro, provavelmente porque estas embarcações não atingem velocidade alta (maior que 5km/h). Todos os tipos de embarcações alteraram de alguma forma as atividades que vinham sendo desenvolvidas pelos botos. A distância entre barcos e golfinhos influenciou o comportamento de superfície do boto-cinza quando a interação ocorreu com embarcações de motor de centro em Guaraqueçaba (z = - 5,105, p = 0,000) e com os barcos de motor de popa em Pontal (z = -3.682, p = 0,000) e Guaraqueçaba (z = - 3,931, p = 0,000). A variável velocidade influenciou o comportamento de superfície quando a interação ocorreu com barcos de popa em Guaraqueçaba (z = 2.107, p = 0,035). Mudanças na estrutura, após a passagem da embarcação, tais como separação de mãe e filhote, também foram observadas, principalmente quando a embarcação passava sobre o grupo. Estes dados irão contribuir para a gestão de atividades humanas na região.
Mestre em Ecologia e Conservação de Recursos Naturais

Mining has caused ecosystem losses worldwide, with surface mining disturbing >2.4 million hectares in the United States since 1930. The Appalachian region of the US is home to extensive temperate deciduous forests that provide many ecosystem services and economic benefits. However, >400,000 hectares of forest have been lost due to surface coal mining, with most not being restored back to native forests or other productive land uses. These areas are left fragmented, heavily modified, unmanaged, and densely invaded by non-native plants. Autumn olive (Elaeagnus umbellata) is one of the most prevalent invasive species on reclaimed mines in Appalachia and viewed as one of the main hindrances to the successful reclamation of mined land to restore native forests. In order to better assess the impact autumn olive can have on reclamation success, we characterize autumn olive's performance in various reclamation scenarios and also how the management of autumn olive affects hardwood tree establishment. We review how exotic species impact restoration outcomes, and advocate for a better understanding of how these species could contribute towards a more ecological understanding of reclamation. Reclamation goals are currently assessed after 5 years, prioritizing short-term goals (e.g. erosion control) instead of longer-term goals such as the return of ecosystem function. With a better understanding of plant function and ecological processes, we hope to continue to advance successful reclamation on surface mined lands.
Master of Science in Life Sciences

Doutoramento em Biologia
The effects of wildfires in Mediterranean lotic communities are still poorly documented. Despite some progress in recent years, the published data refer mainly to studies conducted in North America, with little information on European rivers. Given the importance of regional geographic context, both on the effects of fire and on the resilience of the communities, the gap in the biogeographical knowledge represent a limitation to the implementation of appropriate management measures. This thesis consists in a systematic study of the effects of fire on the macroinvertebrate communities of streams of North and Central Portugal. A chronosequence survey was conducted in order to analyze long-term effects of wildfires (1-18 years) and provide chronological information on the ecological recovery of macroinvertebrate communities. The results indicated that the macroinvertebrate communities recover in abundance and taxa richness and in terms of community structure about two years after the fire impact. A short-term survey was also carried out, where the initial response of macroinvertebrates to fire disturbance was documented, in streams recently affected by wildfires. The parameters analyzed were compared with reference sites without fire impact for the last 20 years. In all sampling periods, lower abundance and lower species richness were recorded in impacted streams, and differences in community structure were found between burnt sites and reference sites. In our study, both on long -term and short-term surveys, the environmental features that conditioned the response of biological communities were evaluated. River size, the extent of the burnt area, conductivity, along with channel characteristics and riparian vegetation, were considered determinant in the response of macroinvertebrates communities to fire impact, and can influence the susceptibility of stream ecosystems. We also analyzed the data of the short-term survey on a trait approach. Differences on functional diversity and on frequency of several trait modalities were analyzed. Specific differences in the food group and reproductive strategies between burned and not burned sites were recorded. Despite the unequivocal negative impact of wildfire on macroinvertebrate communities of Portuguese streams, the recovery seems to be rapid, demonstrating their resilience to this type of disturbance.
Os efeitos dos fogos nas comunidades lóticas mediterrânicas estão ainda mal documentados. Apesar do progresso verificado nos últimos anos, os dados publicados referem-se principalmente a estudos efetuados na América do Norte, sendo escassa a informação relativa aos rios Europeus. Dada a importância do contexto geográfico regional, quer nos efeitos do fogo no meio ambiente quer na resiliência das comunidades, a lacuna no conhecimento biogeográfico representa uma limitação à implementação de medidas de gestão adequadas. A presente tese consiste um estudo sistemático dos efeitos do fogo nas comunidades de macroinvertebrados dos ribeiros do Norte e Centro de Portugal. Foi analisada uma cronosequência para averiguar o efeito do fogo numa escala temporal mais alargada (1 a 18 anos) providenciando informação cronológica sobre a recuperação ecológica das comunidades de macroinvertebrados a longo prazo. Os resultados indicaram que as comunidades de macroinvertebrados recuperam em abundância, riqueza taxonómica e em termos de estrutura das comunidades cerca de dois anos após o impacto Num estudo a curto prazo, em ribeiros recentemente afetados por fogos florestais, foi documentada a resposta inicial dos macroinvertebrados à perturbação pelo fogo e os parâmetros analisados foram comparados com locais de referência onde não ocorreram fogos nos últimos 20 anos. Em todos os períodos amostrados registou-se menor abundância e menor riqueza específica nos ribeiros impactados, bem como diferenças ao nível da estrutura das comunidades entre locais ardidos e os locais de referência. Tanto no estudo a longo prazo como no estudo a curto prazo, foram avaliados os fatores ambientais que condicionaram a resposta das comunidades biológicas. O tamanho do rio, a extensão da área ardida, condutividade, bem como as características do canal e da vegetação ripária, são determinantes na resposta dos macroinvertebrados ao impacto do fogo, e podem influenciar o grau de susceptibilidade dos ecossistemas lóticos. Foram ainda analisados os resultados dos levantamentos a curto prazo numa abordagem do ponto de vista funcional. Foram analisadas as diferenças ao nível da diversidade funcional e ao nível da frequência das várias características funcionais dos organismos. Foram registadas diferenças pontuais em termos do grupo alimentar e estratégias de reprodução, entre locais ardidos e não ardidos. Apesar do inequívoco impacto negativo do fogo nas comunidades de macroinvertebrados aquáticos, a recuperação parece ser rápida, demonstrando a sua resiliência perante este tipo de perturbação.

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Financiadora de Estudos e Projetos
In the semi-arid North-east region of Brazil occurs the second highest density of dams in the world (or açudes , as they are locally known) which supply water to ca. 40 millions inhabitants, mainly during the dry period, a catastrophic and frequent event in that Brazilian region. The limnological functioning of such water system in the Taperoá II dam (07o11 44 S and 07o13 44 S, 36o52 03 W and 36o50 09 W) was investigated through sampling carried out between September/1998 and September/2000. Sampling was performed at four collecting stations: three of them at the pond margins and one in its pelagic zone, where four depths were selected: surface, 50% and 1% light penetration, and at 4.0m depth. Climatological characteristics of the region (air temperature, evaporation, winds, and rainfall) were analysed, as well as the physical and chemical properties of the water (temperature, dissolved oxygen, pH, electric conductivity, alkalinity, turbidity, transparency, total dissolved inorganic carbon, ammonia, nitrite, nitrate, total phosphorus, orthophosphate, and silicate). Climatic variations due to El Niño event (1997-1998) caused, between September/98 and January/99, a drastic reduction of the available stock of water in the pond, which determined a strong concentration of dissolved salts, an alkaline pH, high electric conductivity and high inorganic nutrient contents. The diluter effect of the increased rainfall in February and March/1999 exerted a reduction of oxygen, conductivity, and dissolved nutrients and caused water acidity. The recovery of the pond hydrometric volume and its stability, maintained the limnological variables almost unchanged up to the next rainy period. A relative thermal stratification occurred between February and April/2000 simultaneously to a chemical stratification. The Principal Components analysis allowed to distinguish the system based on the highest limnological variables here studied and the water volume fluctuation, showing that the interaction of extreme dry season and rainfall in a short period, are the strongest determinants of the high interannual variability of the sampled variables and of the reduced spatial oscillations of the horizontal and vertical axes of the dam.
A região semi-árida do Nordeste do Brasil conta com a segunda maior densidade de açudes do mundo, responsável pelo abastecimento de 40 milhões de pessoas, principalmente, nos períodos de seca, evento climático freqüente e conseqüentemente catastrófico nesta parte do Brasil. Com o objetivo de analisar o funcionamento limnológico destes sistemas aquáticos foram realizadas no açude Taperoá II (07°11 44 S e 07°13 44 S, 36°52 03 W e 36°50 09 W), amostragens mensais durante o período de setembro de 1998 e setembro de 2000. Estas foram realizadas em quatro estações de coletas: três localizadas na região marginal e uma na região pelágica do açude, sendo nesta em quatro profundidades (superfície, 50%, 1% de penetração de luz e a 4,0 m de profundidade). Foram analisadas as características climatológicas da região (temperatura do ar, evaporação, ventos, precipitação pluviométrica) e aspectos físicos e químicos da água (temperatura, oxigênio dissolvido, pH, condutividade elétrica, alcalinidade, turbidez, transparência da água, carbono inorgânico dissolvido total, amônia, nitrito, nitrato, fósforo total, ortofosfato e sílica). As alterações climáticas decorrentes do fenômeno El Niño 1997-1998 provocaram entre setembro/98 e janeiro/99 redução drástica do volume útil de armazenamento do açude, acarretando forte concentração de sais dissolvido, pH alcalino, elevada condutividade elétrica e altos teores de nutrientes inorgânicos. O efeito diluidor das chuvas concentradas nos meses de fevereiro e março de 1999, provocou redução do oxigênio, acidez do meio, redução acentuada nos valores de condutividade e nutrientes dissolvidos. A recuperação do volume hidrométrico do açude e sua estabilidade manteve as variáveis limnológicas pouco alterados até o período chuvoso seguinte. A relativa estratificação térmica ocorrida entre os meses de fevereiro e abril de 2000 foi acompanhada por estratificação química. A análise de Componentes Principais discriminou o sistema com base nos maiores valores registrados para as variáveis limnológicas estuda e a flutuação do volume do açude, indicando que a interação seca extrema e chuvas concentradas em curto período, são os maiores determinantes da alta variabilidade interanual das variáveis amostradas e as reduzidas oscilações espaciais dos eixos horizontal e vertical do açude.

Made available in DSpace on 2014-07-29T16:21:19Z (GMT). No. of bitstreams: 1 Dissertacao Cecilia Santiago.pdf: 860839 bytes, checksum: f9b8cd8d503e76ba7346ce5cf34b8356 (MD5) Previous issue date: 2011-04-28
Among several environmental impacts caused by human activities, the release of domestic and industrial effluents has been major disturbances that cause degradation of water quality in natural systems by altering their physical, chemical and biological features. For this reason, the aim of this work was to evaluate the effect of discharging organic waste from five Sewage Treatment Plants (STP) on abundance, richness and composition of aquatic insect fauna present in streams receiving sewage, in addition to test the hypotheses that i) disturbance caused by the discharge of effluents from STP alters the abundance of some groups of aquatic insects in the site downstream when compared to the upstream of site and ii) the taxonomic composition of the downstream impact of STPs is modified by the presence of resistant taxa.Thus, the sampling of aquatic insects and measures of some limnological variable was carried out during the drought of 2010, with the Surber sampler, 100m upstream and 100m downstream from the effluent discharge. Chironomidae and EPT larvaes (Ephemeroptera, Plecoptera and Trichoptera) were identified to genus. To test the hypothesis, a paired t test was performed with logarithmic data of total abundance, a paired t test with the richness of taxa identified at family and genus level. To evaluate the composition of the taxa sampled in two parts in relation to environmental variables were carried out two CCA separately, one with the taxa of Chironomids and one with the EPT. The results showed that abundances recorded downstream (μ = 4523.8 ± 2578.9) was higher than that recorded upstream (μ = 863.4 ± 508.4) on all STP. The results of paired t test using values of total abundance of taxa showed significant differences between upstream and downstream (paired t test: t = 4.21, d.f. = 4, p = 0.01), indicating the elimination of sensitive taxa and the increase abundance of dominant taxa, favored by the physical and chemical changes of water, such as Chironomus, resistant to high concentrations of organic debris. Both genera richness (paired t test: t = 0.791, d.f. = 4, p = 0.473) as the families (paired t test: t = 1.537, df = 4, p = 0.199) were not different in two sites, showing that this indicator is not the most appropriate in cases in which there is replacement of taxa.The ordinations produced by the CCAs were complementary, confirming the replacement of taxa between upstream and downstream, where larvaes like Farrodes, Tricorythodes, Alisotrichia and Mortoniella were favored by more oxygenated water. Thus, it was evident that the organic sewage discharge by STP modified the community structure of aquatic insects found in streams increasing the abundance, altering the dominance order and causing replacement of taxa between upstream and downstream
Dentre os diversos impactos ambientais causados pelas atividades antrópicas, o despejo de efluentes domésticos e industriais tem sido um dos principais distúrbios que causam a degradação da qualidade da água em sistemas naturais por alterarem suas características físicas, químicas e biológicas. Por esta razão, o objetivo deste trabalho foi verificar o efeito do lançamento de resíduos orgânicos de cinco Estações de Tratamento de Esgoto (ETEs) sobre abundância, riqueza e composição da entomofauna aquática presentes nos córregos receptores, além de testar as hipóteses de que: i) o distúrbio causado pelo despejo de efluentes de ETEs altera a abundância de alguns grupos de insetos aquáticos no trecho de jusante quando comparado ao trecho de montante e ii) a composição taxonômica a jusante do impacto das ETEs é modificada devido à presença de táxons resistentes. Desta forma, a coleta de insetos aquáticos e medidas de algumas variáveis limnológicas foram realizadas no período de estiagem de 2010, com o auxílio do amostrador Surber, 100m a montante e 100m a jusante do despejo do efluente. As larvas de Chironomidae e de EPT (Ephemeroptera, Plecoptera e Trichoptera) foram identificadas até gênero. Para testar as hipóteses foi realizado um teste t pareado com os dados de abundância total logaritmizados, um teste t pareado com a riqueza de táxons identificados em nível de família e em nível de gênero. Para avaliar a composição dos táxons nos dois trechos amostrados em relação às variáveis ambientais foram feitas duas CCA separadamente, uma com os táxons de Chironomidae e uma com os de EPT. Os resultados mostraram que abundância registrada a jusante (µ= 4.523,8 ± 2.578,9) foi maior que a registrada a montante (µ= 863,4 ± 508,4) em todas as ETEs. O resultado do teste t pareado utilizando valores de abundância total dos táxons mostrou diferenças significativas entre montante e jusante (Teste t pareado: t= 4,21; g.l.= 4; p= 0,01), indicando a eliminação de táxons sensíveis e o aumento na abundância de táxons dominantes, favorecidos pelas mudanças físicas e químicas da água, como é o caso de Chironomus, resistente a altas concentrações de detritos orgânicos. Tanto a riqueza de gêneros (Teste t pareado: t= 0,791; g.l.= 4; p= 0,473) quanto a de famílias (Teste t pareado: t= 1,537; g.l.= 4; p= 0,199) não foram diferentes nos dois trechos, mostrando que este indicador não é o mais adequado em casos em que ocorre substituição de táxons. As ordenações produzidas pelas CCAs foram complementares, confirmando a substituição de táxons entre montante e jusante, em que larvas como Farrodes, Tricorythodes, Alisotrichia e Mortoniella foram favorecidas pelas águas mais oxigenadas. Desta forma, foi evidente que o lançamento de resíduos orgânicos pelas ETEs modificou a estrutura da comunidade de insetos aquáticos presentes nos córregos receptores aumentando a abundância, alterando a ordem de dominância e causando substituição de táxons entre montante e jusante.

This thesis is a comparative study of two distinct forms ('long pod' and 'short pod') of an invasive vine, cat’s claw creeper. The two forms have differing prevalence rates in Australia. The thesis examines important plant traits that could explain this variation in prevalence between the forms. The thesis covers seed biology, anatomical and growth traits, together with physiological traits in response to two levels of light, water and nutrients resources. In addition, the study assesses preferences of two bio-agents (insects) against the two forms of cat’s claw creeper to ascertain bio-control efficacy. This is because in Australia, the same insects are used to control both forms. The outcome of the study is a prospectus of traits that help explain why the short pod form is more widespread than the long pod form. Short pod possesses many of the traits that are associated with fast growing plants that easily colonize habitats. Generally, insects feed and lay eggs on both forms.

La biosphère traverse une crise de biodiversité pour laquelle les milieux insulaires sont l’épicentre. Les invasions biologiques y constituent l’un des principaux facteurs de forçage, notamment du point de vue de l’altération des mutualismes, pour le fonctionnement et le maintien des écosystèmes. Durant notre travail en Nouvelle-Calédonie, nous nous sommes intéressés à un groupe clé de voute pour le fonctionnement des écosystèmes, les fourmis, et leur implication vis-à-vis de la dispersion de graines (myrmécochorie). Nous avons réalisé la première identification de plantes autochtones myrmécochores, avec une prépondérance des espèces sur substrats ultramafiques. Puis, nous avons testé la dispersion par les fourmis sur ces substrats. Après avoir caractérisé les communautés selon un gradient de perturbation anthropique, nous avons évalué la dispersion et la contribution des fourmis invasives à ce service par rapport aux fourmis natives. Ainsi, Solenopsis geminata semble capable d'une meilleure dispersion que les espèces natives. A contrario, Wasmannia auropunctata exclue les espèces natives sans assurer de dispersion efficace. Dans le contexte d’un régime de perturbations intense, nos travaux illustrent une communauté néo-assemblée de fourmis, dominée par des exotiques dont certaines pourraient assurer un relai de fonction pour la dynamique des maquis. Nos travaux illustrent la « contexte dépendance » des impacts d’espèces invasives en fonction du niveau de perturbation anthropique. Ils permettent de discuter la contribution possible de ces fourmis pour la restauration après perturbation sur substrats ultramafiques, voire de leur valorisation en ingénierie écologique
The biosphere is experiencing a biodiversity crisis, which for islands are the epicenter. Biological invasions are there, one of the main drivers, especially regarding the alteration of mutualistic relationships for the functioning and the maintenance of ecosystems. Thus, during our work in New Caledonia, we focused on a key group for ecosystem functions: ants, and their involvement in seed dispersal (myrmecochory). We carried out the first assessment of this mutualism in New Caledonia with the identification of indigenous myrmechorous plants, with a preponderance of species on ultramafic soils. Then, we evaluated the magnitude of seed dispersal by ants on these soils. After the characterisation of ant communities across an anthropic disturbance gradient, we evaluated seed dispersal capabilities of exotic ant compared to native ones. Solenopsis geminata appears to offer a more efficient seed dispersal than natives. On the other hand, Wasmannia auropunctata excludes native species without ensuring effective dispersal. In the context of an intense disturbance regime, our work illustrates a neo-assembled community of ants, dominated by exotic ones, some of which could provide a function relay with respect to maintaining the dynamic of maquis. Our work illustrates the “context dependency” of invasive species’ impacts as a function of anthropogenic disturbance’s level. It also discusses the possible contribution of these ants in a context of restoration after disturbance of habitats on ultramafic substrates, or even their use in ecological engineering program

We are currently faced with the global challenge of conserving biological diversity while also increasing food production to meet the demands of a growing human population. Land-use change, primarily resulting from conversion to production land, is currently the leading cause of biodiversity loss. This occurs through habitat loss, fragmentation of remaining natural habitats, and resulting edge effects. Land-sparing and land-sharing approaches have been discussed as alternative ways to engineer landscapes to mitigate biodiversity loss while meeting production objectives. However, these represent extremes on a continuum of real-world landscapes, and it will be important to understand the mechanisms by which adjacent land use affects natural remnant ecosystems in order to make local land-management decisions that achieve conservation, as well as production, objectives. This thesis investigates the impact of juxtaposing production and natural forest on the community-wide interactions between lepidopteran herbivores and their parasitoids, as mediated by parasitoid spillover between habitats. The first and overarching objective was to determine whether herbivore productivity drives asymmetrical spillover of predators and parasitoids, primarily from managed to natural habitats, and whether this spillover alters trophic interactions in the recipient habitat. The study of trophic interactions at a community level requires understanding of both direct and indirect interactions. However, community-level indirect interactions are generally difficult to predict and measure, and these have therefore remained understudied. Apparent competition is an indirect interaction mechanism thought to be very important in structuring host-parasitoid assemblages. However, this is known primarily from studies of single species pairs, and its community-wide impacts are less clear. Therefore, my second objective was to determine whether apparent competition could be predicted for all species pairs within an herbivore assemblage, based on a measure of parasitoid overlap. My third objective was to determine whether certain host or parasitoid species traits can predict the involvement of those species in apparent competition. My key findings were that there is a net spillover of generalist predators and parasitoids from plantation to native forest, and that for generalists, this depends on herbivore abundance in the plantation forest. Herbivore populations across the edge were linked by shared parasitoids in apparent competition. Consequently, an experimental reduction of herbivore density in the plantation forest changed parasitism rates in the natural forest, as predicted based on parasitoid overlap. Finally, several host and parasitoid traits were identified that can predict the degree to which host or parasitoid species will be involved in apparent competition, a finding which may have extensive application in biological control, as well as in predicting spillover edge effects. Overall, this work suggests that asymmetrical spillover between production and natural habitats occurs in relation to productivity differences, with greater movement of predators and parasitoids in the managed-to-natural forest direction. The degree to which this affected species interactions has implications for landscape design to achieve conservation objectives in production landscapes.

Minimising the potential impact of forest management requires an understanding of the key elements that maintain forest diversity and its role in ecological processes. Invertebrates are the most diverse of all biota and play important roles in maintaining forest processes. However, little is known about invertebrates in New Zealand's beech forests or the degree to which selective beech harvest might impact on their diversity and ability to carry out ecosystem processes. Studying ecosystem responses to disturbance is considered vital for understanding how ecosystems are maintained. One of the main objectives of this research was to assess whether litter-dwelling invertebrates were susceptible to the impacts of selective harvest and, if so, whether they could be used as indicators of forest health. Changes in invertebrate diversity could have important implications for nutrient cycling and primary production in forests. Litter-dwelling invertebrates contribute to the process of decomposition by increasing the surface area of the leaves, mixing soil organic matter and by infecting leaf particles with soil microbes. This investigation into the function of invertebrates in beech forest was carried out in the context of ecological theories which relate diversity to ecosystem stability and resilience. A replicated study was established in Maruia State Forest (South Island, New Zealand) to assess the potential biotic and abiotic impacts of sustainable beech harvest. Litter-dwelling invertebrates and environmental factors were monitored during 1997, before harvest, to determine how much variability there was between study sites. Specifically, litter pH, light intensity, litter fall, litter temperature, moisture as well as invertebrate abundance and diversity were compared before and after selective harvest. On 17 January 1998, two to three trees were selectively harvested from three of the nine study sites. On 15 February 1998 a similar number of trees were winched over or felled manually to create artificial windthrow sites. The remaining three undisturbed sites were used as controls. Invertebrates belonging to the detritivore guild were assessed from litter samples and a series of litter-bags containing pre-weighed leaf litter which were placed in each of the sites to assess rates of litter decomposition. Millipedes (Diplopoda: Polyzoniidae, Schedotrigonidae, Dalodesmidae, Habrodesmidae, Sphaerotheridae), earthworms (Oligochaeta: Annelida), tipulid larvae (Diptera: Tipulidae), weevils (Coleoptera: Curculionidae), moth larvae (Lepidoptera: Oecophoridae, Tortricidae and Psychidae), slaters (Isopoda: Styloniscidae), Oribatid mites (Acarina: Cryptostigmata) and landhoppers (Crustacea: Amphipoda) were extracted from the litter-bags and their abundance and diversity was compared between the three treatments. Weight loss from the litter-bags and the carbon and nitrogen content of litter were used to measure the rate of decomposition in each treatment. An additional study investigated whether exclusion of invertebrates from leaf litter resulted in reduced rates of decomposition. The results indicated that there was an increase in light intensity and a small increase in temperature following selective harvest and artificial windthrow. There was no significant difference in litter moisture or the amount of litter fall between the treatments. Invertebrate abundances were significantly affected by season but did not appear to be affected by selective harvest or artificial windthrow. The diversity of invertebrates remained relatively constant throughout the year, as did the rate of decomposition. When invertebrates were excluded from the leaf litter there was no consequential effect on the rate of litter decomposition. This suggests that there may be compensatory mechanisms taking place between the trophic levels of the food web to maintain processes and that direct links between invertebrates and decomposition are relatively weak. In conclusion, it appears that the effects of selective beech harvest on forest-floor processes were minimal and are comparable to those created by natural windthrow disturbance. It also appears that macroclimatic effects such as seasonal climatic effects have a large effect on forest biota. As none of the invertebrates studied appeared to be detrimentally affected by selective harvest and as there was no direct link demonstrated with decomposition, it was considered inappropriate to advocate the use of this group of invertebrates as indicators of sustainable forest management. The results from this study provide information which may help inform decisions on the future management of diversity in beech forest ecosystems.

The role of, and response to, disturbance, in the dynamics of the mountain beech forest at western Mt Ruapehu, was examined, using palynology, dendrochronology, and vegetation survey. The pollen record indicates that, two thousand years ago, the west Ruapehu forest was dominated by Nothofagus solandri. About 1800 years B.P., the eruption of Lake Taupo devastated the forest. Though Halocarpus spp. and Phyllocladus asplenifolius were important early colonizers, Nothofagus solandri re-established itself close to its present limits after the eruption. Fire, from about 650 years ago onwards, did not affect the beech forest, but did affect the coniferous vegetation on the ring plain near the mountain. The age structure of the forest shows that there was a large disturbance event shortly before 1740. A dieback occurring about 1969 appears to have been the largest episode of mortality since 1740, larger than the dieback episode described by Cockayne at the beginning of this century. Dieback occurred as a short peak-period of Nothofagus solandri death about 1969. It was the large trees of the mature cohort which tended to be killed by dieback rather than the smaller individuals. Tree-ring analysis, showed that narrow tree-rings occurred in beech in the 1960's. Extreme rainfall years in the early 1960's may have put the beech trees under stress, making them susceptible to dieback. The drought in 1969 may have precipitated extensive mortality. The characteristics of N. solandri rings from Ruapehu are similar to ring characteristics of that species from South Island studies. The 1982 cyclone had a noticeable impact on the forest, affecting some areas severely. However, the impact was relatively minor compared to the influence of dieback. The mean density of trees >= 10cm dbh was 520 stems/ha., of which 220 stems/ha. were Nothofagus solandri. The mean basal area was 22m2 /ha., of which 11m2 /ha. was N. solandri. The basal area is very low compared to that in other N.Z. forests. N. solandri, Griselinia littoralis, Phyllocladus asplenifolius, Podocarpus hallii, and Libocedrus bidwillii, made up 35, 22, 16, 9, and 8 percent, respectively, of the total density. Basal area, density, and species composition varied as much within sites, as between them. The shrub layer formed a large part of the vegetation at west Ruapehu. Coprosma species were particularly abundant. There is sufficient regeneration to indicate that a new cohort of N. solandri is becoming established in most areas. Some areas will probably remain in shrubland for many decades. The result of dieback and windthrow has been to virtually eliminate the canopy of large old beech trees, and to increase the heterogeneity of stand structure. N. solandri seedling densities are not as high as those found in many South Island beech forests. Nothofagus solandri is growing faster than are most of the co-existing tree species, and it appears likely that it will continue as the dominant tree species. Implications for forest management are discussed.

The world’s coral reefs are being impacted by myriad disturbances, from localized overfishing and nutrient pollution to global climate change-induced temperature increases and ocean acidification. Conservation of coral reefs in the face of increasing variability and uncertainty requires an understanding of the interacting effects of multiple stressors on the diverse components of these vital ecosystems. In this thesis, I use data from reefs around Kiritimati atoll (Republic of Kiribati) in the central equatorial Pacific Ocean to examine the effects of a severe pulse heat stress event and local human disturbance on two important components of the coral reef ecosystem – three-dimensional (3D) structural complexity and reef fish assemblages. Using 3D reef models constructed through structure-from-motion photogrammetry, I examined changes in reef structural complexity in the year following the 2015-2016 El Niño and mass coral bleaching event. I found that exposure to prolonged thermal stress and subsequent coral mortality resulted in declines in reef structural complexity, particularly reef surface rugosity and terrain ruggedness. Baseline levels of structural complexity were also negatively influenced by local human disturbance, while complexity was positively related to the densities of branching and massive coral growth forms. These findings have important implications for the maintenance of healthy reef ecosystems, as high levels of structural complexity are important for supporting diverse reef-associated fish assemblages. Next, using underwater visual censuses of reef fish assemblages, I quantified fish abundance, biomass, species richness, and assemblage structure before, during, and after the 2015-2016 El Niño. Total reef fish abundance, biomass, and species richness declined during the El Niño, suggesting that pulse heat stress events may have short-term, negative consequences for reef fish. Although these metrics did not vary substantially across the local human disturbance gradient, recovery of assemblages following the heat stress event was impeded by higher levels of local human disturbance. Reef fish assemblage structure was influenced by a more diverse array of factors, showing significant shifts in response to heat stress, human disturbance, and net primary productivity. Given the many important roles that fish play on coral reefs, declines such as those observed here may impair the ecological functioning of these ecosystems. Together, my results highlight the negative impacts of heat stress and local human disturbance on coral reefs, demonstrating ways in which these stressors may interact to limit reef resilience in the face of increasing anthropogenic pressures.
Graduate
2019-12-07

Thesis (M.S.)--University of Wisconsin--Madison, 1999.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 58-77).

Tese de mestrado, Biologia da Conservação, Universidade de Lisboa, Faculdade de Ciências, 2017
A expansão humana ameaça não só toda a biodiversidade mas também os serviços que esta fornece e dos quais dependemos. Actividades como a desflorestação, a conversão agrícola, a caça ilegal e o tráfico de animais potenciam o desaparecimento dos ecossistemas e a extinção de espécies a estes associadas, com graves consequências também para o ser humano. A desflorestação foi responsável pela destruição de 230 milhões de hectares de floresta somente entre o período de 2000 a 2012, sendo que as florestas tropicais são dos biomas mais afectados por tal perturbação. A desflorestação é frequentemente acompanhada pela conversão de solo para fins agrícolas, o que acaba por fragmentar as paisagens, alterar a sua conectividade e criar novos acessos a zonas até aí livres da intervenção humana. Esta fragmentação não só aumenta o número de conflitos entre a fauna selvagem e o ser humano, dado o maior contacto entre ambos, como também potencia a caça e a captura de animais vivos para mercados ilegais ou a venda directa. Os grandes símios, um dos grupos animais sob os quais a pressão humana mais se faz sentir –sendo também o grupo ao qual pertencemos, em conjunto com o Gorila Gorilla spp., o Chimpanzé Pan troglodytes, o Bonobo Pan paniscus e o Orangotango Pongo spp. – vêem-se ameaçados devido aos seus longos ciclos reprodutores e exigentes necessidades ecológicas, sendo, por isso, extremamente vulneráveis à desflorestação, à fragmentação das paisagens e à caça e captura ilegais. Uma das regiões do globo onde estes fenómenos mais se fazem sentir é o Sudeste Asiático, onde o crescimento populacional e a desflorestação tomam proporções cada vez maiores. A adequabilidade dos terrenos para o cultivo de bens essenciais, como o óleo de palma Elaeis guineensis, a cana-de-açucar Saccharum officinarum, ou a árvore-da-borracha Hevea brasiliensis, e o reduzido custo de produção das mesmas, tornam esta área do globo extremamente requisitada para a apreensão de espaço e recursos. É aqui que encontramos um dos grandes símios mais ameaçados do planeta: o orangotango da Sumatra, Pongo abelii. O orangotango da Sumatra, juntamente com o orangotango do Bornéu, Pongo pygmaeus, formam o único género de grandes símios que está presente fora do continente Africano. Tendo sido a primeira linhagem dos grandes símios a se separar das restantes, os orangotangos são os únicos grandes símios quase exclusivamente arborícolas e considerados dos menos sociais, organizando-se numa estrutura de fissão-fusão, onde os encontros são pouco comuns e geralmente breves, exceptuando momentos de acasalamento que podem durar até vários dias. Ambas as espécies de orangotangos são sexualmente dimórficas, sendo o macho consideravelmente maior, e alguns indivíduos, após atingirem a maturidade sexual, desenvolvem flanges. Estas são um caracter sexual secundário que se exprime sob a forma de discos de matéria adiposa na face, e que acompanham o início do uso das “long-calls”, um chamamento característico desta faixa etária, fundamental na coesão social dos orangotangos. Embora ambas as espécies de orangotangos sejam consideradas “Criticamente em Perigo” pela IUCN, as populações de orangotangos da Sumatra são hoje consideravelmente menores do que as da sua espécie irmã. A última avaliação do estado destas populações indicava que existiam cerca de 14613 orangotangos da Sumatra e 54000 do Bornéu. Grande parte dos orangotangos que residem na ilha da Sumatra vivem dentro e nas imediações do Parque Nacional de Gunung Leuser, que é partilhado por duas províncias, a Sumatra do Norte e Aceh. Ambas têm-se desenvolvido excepcionalmente nos últimos anos, em especial Aceh, devido ao gás natural, o que tem levado ao contínuo decréscimo não só das populações de orangotangos, mas também de outras espécies icónicas e endémicas desta ilha, como o tigre-da-Sumatra Panthera tigris sumatrae ou o elefante-da-Sumatra Elephas maximus sumatranus. Dado o crescente conflito e competição entre o homem e a vida selvagem, seja a nível de espaço ou de recursos, torna-se cada vez mais imperativo compreender como é que as espécies respondem às perturbações causadas pelo homem, de maneira a podermos proteger as suas populações e gerir e potenciar os seus serviços. Uma das maneiras da vida selvagem reagir a tais distúrbios é através dos seus sistemas de comunicação, maneira pela qual transmitem informação seja a outros membros da mesma espécie, seja à comunidade, ou até mesmo à fonte de perturbação no sentido de a demover e afastar. Uma das vertentes mais abordadas da comunicação são as vocalizações, nomeadamente os chamamentos de alarme, que são uma peça-chave na compreensão da dinâmica de interacção entre a espécie e o seu predador, ou outro tipo de perturbação, como o da presença humana. Os chamamentos de alarme são produzidos quando uma fonte de perigo é detectada, servindo para dar o alerta aos outros membros do grupo e/ou para sinalizar à fonte de perigo que esta foi detectada. Em orangotangos existem alguns chamamentos descritos como chamamentos de alarme, sendo os mais observados o Kiss-Squeak e o Grumph. Estes chamamentos são usados pelos orangotangos em encontros com os seus predadores naturais, sendo o mais importante o tigre-da-Sumatra, mas também em encontros com seres humanos. Quando os animais, e os orangotangos em particular, respondem com chamamentos de alarme a perturbações no seu habitat, seja pela presença de tigres, seja pela presença de seres humanos, eles estão a alocar tempo e energia a essa actividade em detrimento de outras actividades. Dado o caracter invasivo e persistente das actividades humanas no habitat natural do orangotango, o tempo e energia despendidos a vocalizar na presença de seres humanos – perturbação humana – pode reduzir significativamente o tempo útil total alocado à alimentação, reprodução, cuidados parentais, descanso e bem-estar em geral. As consequências dos distúrbios humanos podem até afectar a condição corporal e o fitness dos animais de forma semelhante à pressão exercida pelos seus predadores naturais, como sugerido na hipótese de risco-distúrbio proposta por Alejandro Frid e Lawrence Dill, em 2002. Quando assim é, a perturbação humana deve ser considerada como mais um factor a contribuir negativamente para o estatuto de conservação das espécies. Como tal, o objectivo deste trabalho foi o de explorar esta hipótese de forma a compreender o impacto da perturbação humana numa população de orangotangos da Sumatra, focando-nos nas suas vocalizações. Esta população reside dentro do Parque Nacional de Gunung Leuser, cuja área foi alvo de programas de deflorestação há poucas décadas. Focámo-nos, essencialmente, nos chamamentos de alarme, de modo a conseguirmos medir o seu estado de alerta na presença de humanos e o esforço que este poderá representar comparativamente ao esforço empregado pelos orangotangos na presença de tigres. A maioria dos dias (sessões de mostragem) em que os orangotangos foram seguidos por um grupo de observadores humanos (investigadores e guias) houve produção de vocalizações direccionadas para os observadores, num total de 12 chamamentos diferentes. Como esperado, a grande maioria foram efectivamente chamamentos de alarme, demonstrando que os orangotangos são sensíveis à presença humana e que a percepcionam como um distúrbio. As duas vocalizações mais utilizadas foram o “Kiss- Squeak” e uma variação deste chamamento, o “Kiss-Sequeak Hand”, que torna o chamamento mais grave, criando a falsa impressão de que o orangotango que o emite é maior do que o seu tamanho real. São, no entanto, vocalizações pouco agressivas, comparativamente ao Complex Call, que foi só raramente produzido. Houve também algum grau de habituação à presença humana – já que o grupo de observadores era sempre o mesmo e não era agressivo. Estes dois resultados sugerem que a resposta à presença humana, apesar de ser uma resposta de alarme, é uma resposta moderada. No entanto, depois de compararmos o esforço de chamamento dos orangotangos perante os observadores humanos com o esforço destes, descrito na literatura, perante tigres – e tendo em conta a abundância de tigres na Sumatra – descobrimos que a frequência de chamamentos, a duração de chamamentos e a duração dos estados de alarme podem ser iguais ou superiores aos utilizados com os tigres. Portanto, apesar de a resposta dos orangotangos à presença humana aparentar ser moderada, ela parece indicar que os humanos induzem comportamentos crónicos de evasão-risco, semelhantes àqueles induzidos pelos seus predadores naturais. Isto indica que, com base em vocalizações de resposta ao perigo, a hipótese de risco-distúrbio se comprova em orangotangos. Quer a frequência, quer a duração dos chamamentos e dos estados de alerta constituem uma alocação significativa de tempo, o que pode indicar que a presença humana tem bastante impacto nas actividades dos orangotangos. Ainda assim, os dados recolhidos podem não representar o dispêndio real de energia dos orangotangos, pois não tivemos em conta o tempo de recuperação de um orangotango após um encontro com o ser humano. Este é o primeiro trabalho a testar a hipótese de risco-distúrbio em orangotangos e em grandes símios, em geral, demonstrando pela primeira vez que as actividades humanas podem também ter este tipo de impacto nestas espécies emblemáticas. O contacto prolongado com o ser humano devido à diminuição e constrição do habitat pode, assim, ter mais esta repercussão negativa para os animais, para além de todas as que já contribuem, directa – caça p.e. – e indirectamente – desflorestação e conversão de solo p.e. – para a diminuição das suas populações.
Forest loss, land conversion, poaching and illegal trading are some of the major drivers for the loss of biodiversity and ecosystem services. As conflict between humans and wildlife increases, comprehending how wildlife responds to human disturbances in the wild becomes vital to the sustainability of species, ecosystems and ultimately human kind. Vocalizations are a key feature to understand the interaction dynamics of a species with its predators or other types of danger, such as disturbance stimuli derived from human presence. Alarm calls are usually the first response to signal and deter the origin of disturbance. However, effort spent on anti-predator strategies can change a species time and energy budgets, reducing the allocation of resources in activities such as feeding and mating. If human disturbance resembles the pressure done by a predator – the risk-disturbance hypothesis – it should constitute a serious threat to a species survival. As such, we studied the impact of human disturbance to a population of the Sumatran orangutan Pongo abelii, one of the most endangered great ape species in the world. We studied a natural population that resides in a secondary forest targeted for logging programmes and other human related activities, within the most important National Park in Indonesia – the Gunung Leuser National Park. We focused on recording orangutan vocalizations, analysing especially alarm calls towards human observers (a group of researchers and guides). During most of the days following the orangutans they produced vocalizations, the majority of which were, indeed, alarm calls. Despite a certain degree of habituation, we found evidence that orangutans’ call effort was similar or even greater than the effort they employ when facing their natural predator, the Sumatran tiger. These findings suggest that besides human pressure on orangutans’ habitat, human presence has also a significant impact on the species daily activities, constituting an additional threat to its survival.

Study 1:

Biases in invasion science lead to a taxonomic focus on plants, particularly a subset of well-studied plants, and a geographic focus on invasions in Europe and North America. Geographic biases could also cause some branches of invasion science to focus on a subset of environmental conditions in the invaded range, potentially leading to an incomplete understanding of the ecology and management of plant invasions. While broader, country-level geographic biases are well known, it is unclear whether these biases extend to a finer scale and thus affect research within the invaded range. This study assessed whether research sites for ten well-studied invasive plants in the U.S. are geographically biased relative to each species’ invaded range. We compared the distribution, climate, and land uses of research sites for 735 scientific articles to manager records from EDDMapS and iMap Invasives representing the invaded range. We attributed each study to one of five types: impact, invasive trait, mapping, management, and recipient community traits. While the number of research sites was much smaller than the number of manager records, they generally encompassed similar geographies. However, research sites tended to skew towards species’ warm range margins, indicating that researchers have knowledge on how these plants might behave in a warming climate. For all but one species, at least one study type encompassed a significantly different climate space from manager records, suggesting that some level of climatic bias is common. Impact and management studies occurred within the same climate space for all species, suggesting that these studies focus on similar areas – likely those with the greatest impacts and management needs. Manager records were more likely to be found near roads, which are both habitats and vectors for invasive plants, and on public land. Research sites were more likely to be found near a college or university. Studies on these plants largely occur across their invaded range, however, different study types occur within a narrower climate range. This clustering can create gaps in our general understanding of how these plants interact with different environments, which can have important policy and management consequences.

Invasive exotic species threaten the biodiversity and function of native ecosystems. Existing models, attempting to predict and control successful invaders, often emphasize isolated stages of in their life history and fail to formalize interactions between exotic species and recipient environments. In order to elucidate key mechanisms in the success of select invaders, I investigated the role of dispersal, establishment, proliferation, and persistence in their threat to natural areas. Focusing on Riding Mountain National Park, Manitoba, Canada, I integrated the native climatic range and biological traits of 251 exotic vascular plants reported inside and outside the park. Based on their climatic range in Europe, 155 among 174 exotic plant species absent from the Park were predicted to establish within its boundaries; among these, 40 clonal perennials were considered the highest threat to the Park’s biodiversity. Focusing on smooth brome (Bromus inermis Leyss.), a Eurasian perennial, threatening the structure and function of native prairies throughout the Great Plains, I extended my research to investigate the role of dispersal, establishment, proliferation, and persistence in characterizing its threat to the endemic diversity of northern fescue prairies, protected within Riding Mountain National Park. Patterns of smooth brome invasions were contingent on the type of propagules dispersed. The shallow dispersal gradient of individual florets combined with the steeper gradient of panicles and spikelets suggested that smooth brome is capable of simultaneously invading along dense fronts as well as by establishing isolated foci. While low correlations between the number of dispersed seeds and their recruitment suggested post-dispersal transport, seedling establishment remained contingent on prairie diversity. Seedling biomass increased with declining plant diversity, however, its impact depended on the availability of soil nitrogen. As a result, disturbed areas, preserving the root function of native plants, resisted smooth brome establishment. Even though low nitrogen contributed to a decline in seedling biomass, physiological integration between ramets facilitated their vegetative proliferation in low resource environments. Despite its rapid establishment and proliferation, smooth brome productivity declined at the center of invading clones. Although field and greenhouse observations failed to implicate soilborne pathogens, reasons for the observed decline remain unresolved. My research demonstrates that while Riding Mountain National Park and other natural areas in western Canada will continue to be impacted by exotic plants, integrating key stages in their life history provides an important conceptual framework in predicting their threat to natural areas and prioritizing management.
October 2008

Tese de doutoramento em Biociências, na especialidade de Ecologia Marinha, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Research based on species traits can lead to a deeper understanding on how anthropogenic disturbance and environmental gradients may impact communities and ecosystem functioning, thereby improving ecosystem-based management and conservation, which is vital in the current era of rapid environmental change. Because of this potential, trait-based studies are rapidly expanding. Yet, the utilisation of trait-based approaches in estuaries and coastal zones is still largely unexplored, despite the increasing demand for environmental assessments of these systems to include more functional orientated approaches. This context sets the main objective of this study, which was to explore whether trait-based approaches can provide an improved picture on how environmental change may impact macrobenthic community functioning in estuarine and coastal environments. Therefore, this study aims to contribute to a deeper knowledge of the overall functioning of these ecosystems, helping to improve ecosystem-based management. To achieve this goal, we specifically focussed on testing and evaluating multiple complementary and novel trait-based indices. These include the: “community-weighted mean trait values” (CWM) defining the dominant traits in a community; several functional diversity (FD) indices expressing the extent of trait differences in a community; and a new index developed during this study that is based on the relation between taxonomic and functional diversity. The indices were tested for their ability to reflect anthropogenic disturbance and/or environmental gradients on macrobenthic communities in estuaries and coastal zones located in different biogeographical regions, i.e. a temperate European estuary (Mondego estuary, Portugal) and coastal zone (Basque coast, Bay of Biscay, Spain), and in two tropical estuaries (Paraíba and Mamanguape, N-E Brazil). One of the main lessons learned from the Mondego estuary case study, is that abundance-weighted FD indices should be used with caution in estuarine systems where few and dominant species naturally occur. Within this respect, non-weighted indices, reflecting the extinction of rare species with often-rare combinations of traits, such as the new developed redundancy index, are potentially more useful, particularly when used in combination with the CWM index. The Basque coastal zone case study showed us primarily that trait-based indices can face difficulties assessing anthropogenic seafloor disturbance caused by effluents, when traits simultaneously respond to multiple other sources of environmental change (anthropogenic and naturally induced) existing in the area. In the final case study of this thesis, we explored the trait-based approach in two tropical Brazilian estuaries. An important lesson learned from this study is that different taxonomic groups (Polychaetes and Molluscs) within the macrobenthic community might behave differently in response to environmental change. Therefore, we need to be cautious when evaluating the results given by only one macrobenthic group in isolation. Preferably, the entire macrobenthic community should be included in environmental assessment studies. Overall, our results showed that trait-based approaches have potential to complement the classical taxonomic-based approaches for benthic assessment in estuarine and coastal systems. By using both approaches we could better determine changes in community structure (i.e. taxonomic and the underlying functional structure) that has, potentially, key consequences in the functioning of these ecosystems. Trait-based approaches, despite not being very helpful for detecting subtle gradients in the form of anthropogenic disturbance, were capable of detecting strong environmental gradients. There is, nevertheless, sufficient room for improvement. Particularly important is the acquisition of abundant and accurate trait data on marine macroinvertebrates, which is currently missing for many species, especially for tropical species. Trait-based research is very recent, and new approaches, frameworks, indices and tools are swiftly being developed. All this is promising news for the future of ecosystem-based management and a sustained conservation of estuarine and coastal ecosystems. RESUMO: A investigação baseada em atributos (traits) de espécies pode levar a uma compreensão mais profunda de como perturbações antropogénicas e gradientes ambientais podem afetar as comunidades e o funcionamento dos ecossistemas, permitindo desta forma melhorar a gestão e conservação destes sistemas. Este contributo para uma gestão mais eficiente é particularmente vital atualmente, numa época de rápidas mudanças ambientais. Graças ao potencial deste tipo de ferramentas de avaliação, o número estudos baseados em traits está a aumentar rapidamente. No entanto, a utilização de abordagens baseadas em traits em estuários e zonas costeiras ainda é reduzida, apesar da crescente exigência de incluir abordagens mais funcionas aquando da avaliação ambiental destes sistemas. Foi neste contexto que se delineou o objetivo principal deste estudo, i.e., analisar se as abordagens baseadas em traits podem fornecer uma imagem mais detalhada e precisa sobre como as alterações ambientais podem afetar o funcionamento das comunidades macrobentónicas de ambientes estuarinos e costeiros. Este estudo visou ser uma contribuição de relevo para um conhecimento mais aprofundado do funcionamento geral desses ecossistemas, contribuindo para uma gestão mais adequada e rigorosa destes sistemas. Para atingir esse objetivo, focámo-nos essencialmente no teste e avaliação de vários índices complementares e inovadores baseados em traits. Estes índices incluíram o "community-weighted mean trait value" (CWM) que define os traços dominantes numa comunidade; vários índices de diversidade funcional (FD) que expressam a presença dos diversos traits numa comunidade; e um novo índice desenvolvido durante este estudo que se baseia na relação entre diversidade taxonómica e a diversidade funcional. Os índices foram testados quanto à sua capacidade de refletir o impacto de perturbações antropogénicas e/ou gradientes ambientais nas comunidades macrobentónicas de estuários e zonas costeiras situadas em diferentes regiões biogeográficas. Como casos de estudo, (Baía de Biscaia, Espanha), e dois estuários tropicais (Paraíba e Mamanguape, NE do Brasil). Uma das principais lições do caso de estudo do estuário do Mondego foi que os índices FD ponderados pela abundância devem ser usados com cautela em sistemas estuarinos onde podem ocorrer naturalmente poucas espécies mas com elevada dominância. Neste contexto, os índices não ponderados, que refletem a extinção de espécies raras com combinações de traços frequentemente raras, são potencialmente mais úteis (o novo índice de redundância desenvolvido é um bom exemplo), particularmente quando utilizados em combinação com o índice CWM. Os resultados obtidos no caso de estudo da zona costeira basca mostraram claramente que os índices testados não conseguiram capturar adequadamente o estado das comunidades sujeitas a efluentes. Este resultado mostrou a dificuldade de utilizar traits que respondem simultaneamente a múltiplas fontes de pressão ambiental (antropogénicas e naturalmente induzidas) existentes na área. Por último, explorámos a abordagem baseada em traits em dois estuários tropicais brasileiros. Uma lição importante retirada deste caso estudo foi que diferentes grupos taxonómicos (Poliquetas e Moluscos) pertencentes às comunidades macrobentónicas podem apresentar comportamentos distintos face às pressões ambientais. Devemos pois ser cautelosos na generalização dos resultados obtidos quando analisados grupos taxonómicos isoladamente. De preferência, toda a comunidade macrobentónica deve ser incluída em estudos de avaliação ambiental. No geral, os resultados desta tese indicam que as abordagens baseadas em traits têm potencial para complementar as abordagens taxonómicas clássicas no contexto da avaliação da condição das comunidades macrobentônica estuarinas e costeiras. Usando simultaneamente ambas as abordagens, podemos determinar com maior precisão a resposta das comunidades a diferentes tipos de pressão (tanto em termos de alterações na estrutura taxonômica como nas funções que lhe são subjacentes). Apesar das abordagens baseadas em traits não terem sido muito bem sucedidas a detectar o impacto de perturbações antrópicas ligeiras, estas abordagens foram capazes de detectar o impacto de fortes gradientes ambientais nas comunidades macrobentónicas. Há, no entanto, ainda bastante espaço para aperfeiçoar estas ferramentas, sendo particularmente importante o investimento na aquisição de dados precisos sobre os traits de espécies de macroinvertebrados marinhos, particularmente de espécies tropicais. A investigação baseada em traits é muito recente e novas abordagens, índices e ferramentas têm sido propostas e testadas nos últimos tempos. Tudo isto são notícias esperançosas e promissoras para o futuro da gestão baseada em ecossistemas e para uma conservação sustentada dos ecossistemas estuarinos e costeiros.
DEVOTES – DEVelopment Of innovative Tools for understanding marine biodiversity and assessing good Environmental Status) funded by the European Union under the 7th Framework Program ‘The Ocean of Tomorrow’ Theme (grant agreement no. 308392) e MARE UC – Marine and Environmental Sciences Centre, University of Coimbra