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Letteratura scientifica selezionata sul tema "Original vegetation remains"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 5 febbraio 2022

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Articoli di riviste sul tema "Original vegetation remains"

Soterroni, Aline C., Fernando M. Ramos, Aline Mosnier, Joseph Fargione, Pedro R. Andrade, Leandro Baumgarten, Johannes Pirker et al. "Expanding the Soy Moratorium to Brazil’s Cerrado". Science Advances 5, n. 7 (luglio 2019): eaav7336. http://dx.doi.org/10.1126/sciadv.aav7336.

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The Cerrado biome in Brazil is a tropical savanna and an important global biodiversity hot spot. Today, only a fraction of its original area remains undisturbed, and this habitat is at risk of conversion to agriculture, especially to soybeans. Here, we present the first quantitative analysis of expanding the Soy Moratorium (SoyM) from the Brazilian Amazon to the Cerrado biome. The SoyM expansion to the Cerrado would prevent the direct conversion of 3.6 million ha of native vegetation to soybeans by 2050. Nationally, this would require a reduction in soybean area of approximately 2%. Relative risk of future native vegetation conversion for soybeans would be driven by the Brazilian domestic market, China, and the European Union. We conclude that, to preserve the Cerrado’s biodiversity and ecosystem services, urgent action is required, including a zero native vegetation conversion agreement such as the SoyM.

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ACOSTA, ROXANA, CARMEN GUZMÁN-CORNEJO, FLOR ANGÉLICA QUIÑONEZ CISNEROS, ANGÉLICA ANNAY TORRES QUIÑONEZ e JESÚS A. FERNÁNDEZ. "New records of ectoparasites for Mexico and their prevalence in the montane shrew Sorex monticolus (Eulipotyphla: Soricidae) at Cerro del Mohinora, Sierra Madre Occidental of Chihuahua, Mexico". Zootaxa 4809, n. 2 (7 luglio 2020): 393–96. http://dx.doi.org/10.11646/zootaxa.4809.2.11.

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The Flora and Fauna Protection Area (Área de Protección de Flora y Fauna—ÁPFF) Cerro del Mohinora, is the highest mountain in northern Mexico, reaching an elevation of 3,300 meters. It constitutes one of the last high-elevation islands of alpine and subalpine vegetation known in the Sierra Madre Occidental, in the extreme southwestern part of Chihuahua. The ÁPFF Cerro del Mohinora is located near the state border and limits with Durango and Sinaloa. This type of ecosystem located at high altitudes is in danger of disappearing since only 1% or less of its original extension remains; it is considered a refuge for species with boreal affinities (McDonald et al. 2011).

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Cadena-Ortiz, Héctor, Santiago Varela, Daniela Bahamonde-Vinueza, Juan F. Freile e Elisa Bonaccorso. "Birds of Bosque Protector Jerusalem, Guayllabamba Valley, Ecuador". Check List 11, n. 5 (16 ottobre 2015): 1770. http://dx.doi.org/10.15560/11.5.1770.

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The Ecuadorian inter-Andean dry valleys are highly affected by human intervention. Currently, less than 5% of the original vegetation cover of these valleys remains on creeks and hillsides. Bosque Protector Jerusalem (1,110 ha), in the upper Guayllabamba River valley, protects the largest remnants of inter-Andean dry forest in Ecuador. Here, we present data derived from two recent studies (from 2009 to 2013), as well as information collected by other authors in previous studies, between the years 2002 and 2009. We present a unified list of 75 species of birds, accounts for species of particular interest, new distributional records, and considerations about the conservation of the study area.

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Macdonald, Ian A. W., Luis Ortiz, Jonas E. Lawesson e J. Bosco Nowak. "The Invasion of Highlands in Galá'pagos by the Red Quinine-tree Cinchona succirubra". Environmental Conservation 15, n. 3 (1988): 215–20. http://dx.doi.org/10.1017/s0376892900029349.

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The alien tree species Cinchona succirubra, the Red Quinine-tree (Rubiaceae), was introduced to the Galápagos Islands, Ecuador, in 1946, for purposes of cultivation, but causes much concern as, by 1987, it was found to cover about 4,000 hectares in the highlands of Santa Cruz Island, changing the original, largely endemic, vegetation. Some limited herbicide trials have been made by the Galápagos National Park Service, but a really successful method of controlling this pest still remains to be found.The removal of Cinchona plants from a 1000-ha Intensive Control Area (ICA) within the Galápagos National Park has been successful to date. However, large stands of the tree exist in the adjacent agricultural area of Santa Cruz Island, as well as elsewhere in the National Park. With the maturation of these stands, an increased input of Cinchona succirubra seeds to the ICA can be anticipated.Strengthened use of manual, chemical, and biological, control measures are therefore recommended on a shortterm basis, in order to conserve the unique highland vegetation of Santa Cruz Island, Galápagos.

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Anderson, R. Scott. "A 35,000 Year Vegetation and Climate History from Potato Lake, Mogollon Rim, Arizona". Quaternary Research 40, n. 3 (novembre 1993): 351–59. http://dx.doi.org/10.1006/qres.1993.1088.

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AbstractA new record from Potato Lake, central Arizona, details vegetation and climate changes since the mid-Wisconsin for the southern Colorado Plateau. Recovery of a longer record, discrimination of pine pollen to species groups, and identification of macrofossil remains extend Whiteside's (1965) original study. During the mid-Wisconsin (ca. 35,000-21,000 yr B.P.) a mixed forest of Engelmann spruce (Picea engelmannii) and other conifers grew at the site, suggesting a minimum elevational vegetation depression of ca. 460 m. Summer temperatures were as much as 5°C cooler than today. During the late Wisconsin (ca. 21,000-10,400 yr B.P.), even-cooler temperatures (7°C colder than today; ca. 800 m depression) allowed Engelmann spruce alone to predominate. Warming by ca. 10,400 yr B.P. led to the establishment of the modern ponderosa pine (Pinus ponderosa) forest. Thus, the mid-Wisconsin was not warm enough to support ponderosa pine forests in regions where the species predominates today. Climatic estimates presented here are consistent with other lines of evidence suggesting a cool and/or wet mid-Wisconsin, and a cold and/or wet late-Wisconsin climate for much of the Southwest. Potato Lake was almost completely dry during the mid-Holocene, but lake levels increased to near modern conditions by ca. 3000 yr B.P.

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Bremond, Laurent, Christopher Carcaillet, Charly Favier, Adam A. Ali, Cédric Paitre, Yves Bégin, Yves Bergeron e Pierre J. H. Richard. "Effects of vegetation zones and climatic changes on fire-induced atmospheric carbon emissions: a model based on paleodata". International Journal of Wildland Fire 19, n. 8 (2010): 1015. http://dx.doi.org/10.1071/wf09096.

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An original method is proposed for estimating past carbon emissions from fires in order to understand long-term changes in the biomass burning that, together with vegetation cover, act on the global carbon cycle and climate. The past carbon release resulting from paleo-fires during the Holocene is examined using a simple linear model between measured carbon emissions from modern fires and sedimentary charcoal records of biomass burning within boreal and cold temperate forests in eastern Canada (Quebec, Ontario). Direct carbon emissions are estimated for each ecozone for the present period and the fire anomaly per kilo annum (ka) v. present day (0 ka) deduced from charcoal series of 46 lakes and peats. Over the postglacial, the Taiga Shield ecozone does not match the pattern of fire history and carbon release of Boreal Shield, Atlantic Maritime, and Mixedwood Plains ecozones. This feature results from different air mass influences and the timing of vegetation dynamics. Our estimations show, first, that the contribution of the Mixedwood Plains and the Atlantic Maritime ecozones on the total carbon emissions by fires remains negligible compared with the Boreal Shield. Second, the Taiga Shield plays a key role by maintaining important carbon emissions, given it is today a lower contributor.

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Polewski, P., J. Shelton, W. Yao e M. Heurich. "SEGMENTATION OF SINGLE STANDING DEAD TREES IN HIGH-RESOLUTION AERIAL IMAGERY WITH GENERATIVE ADVERSARIAL NETWORK-BASED SHAPE PRIORS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B2-2020 (12 agosto 2020): 717–23. http://dx.doi.org/10.5194/isprs-archives-xliii-b2-2020-717-2020.

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Abstract. The use of multispectral imagery for monitoring biodiversity in ecosystems is becoming widespread. A key parameter of forest ecosystems is the distribution of dead wood. This work addresses the segmentation of individual dead tree crowns in nadir-view aerial infrared imagery. While dead vegetation produces a distinct spectral response in the near infrared band, separating adjacent trees within large swaths of dead stands remains a challenge. We tackle this problem by casting the segmentation task within the active contour framework, a mathematical formulation combining learned models of the object’s shape and appearance as prior information. We explore the use of a deep convolutional generative adversarial network (DCGAN) in the role of the shape model, replacing the original linear mixture-of-eigenshapes formulation. Also, we rely on probabilities obtained from a deep fully convolutional network (FCN) as the appearance prior. Experiments conducted on manually labeled reference polygons show that the DCGAN is able to learn a low-dimensional manifold of tree crown shapes, outperforming the eigenshape model with respect to the similarity of the reproduced and referenced shapes on about 45 % of the test samples. The DCGAN is successful mostly for less convex shapes, whereas the baseline remains superior for more regular tree crown polygons.

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Lee, J. H., J. Timmermans, Z. Su e M. Mancini. "A new method to calibrate aerodynamic roughness over the Tibetan Plateau using Ensemble Kalman Filter". Hydrology and Earth System Sciences Discussions 9, n. 4 (19 aprile 2012): 5195–224. http://dx.doi.org/10.5194/hessd-9-5195-2012.

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Abstract. Aerodynamic roughness height (Zom) is a key parameter required in land surface hydrological model, since errors in heat flux estimations are largely dependent on accurate optimization of this parameter. Despite its significance, it remains an uncertain parameter that is not easily determined. This is mostly because of non-linear relationship in Monin-Obukhov Similarity (MOS) and unknown vertical characteristic of vegetation. Previous studies determined aerodynamic roughness using traditional wind profile method, remotely sensed vegetation index, minimization of cost function over MOS relationship or linear regression. However, these are complicated procedures that presume high accuracy for several other related parameters embedded in MOS equations. In order to simplify a procedure and reduce the number of parameters in need, this study suggests a new approach to extract aerodynamic roughness parameter via Ensemble Kalman Filter (EnKF) that affords non-linearity and that requires only single or two heat flux measurement. So far, to our knowledge, no previous study has applied EnKF to aerodynamic roughness estimation, while a majority of data assimilation study has paid attention to land surface state variables such as soil moisture or land surface temperature. This approach was applied to grassland in semi-arid Tibetan area and maize on moderately wet condition in Italy. It was demonstrated that aerodynamic roughness parameter can inversely be tracked from data assimilated heat flux analysis. The aerodynamic roughness height estimated in this approach was consistent with eddy covariance result and literature value. Consequently, this newly estimated input adjusted the sensible heat overestimated and latent heat flux underestimated by the original Surface Energy Balance System (SEBS) model, suggesting better heat flux estimation especially during the summer Monsoon period. The advantage of this approach over other methodologies is that aerodynamic roughness height estimated in this way is useful even when eddy covariance data are absent and is time-variant over vegetation growth, as well as is not affected by saturation problem of remotely sensed vegetation index.

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Alencar, Ane, Julia Z. Shimbo, Felipe Lenti, Camila Balzani Marques, Bárbara Zimbres, Marcos Rosa, Vera Arruda et al. "Mapping Three Decades of Changes in the Brazilian Savanna Native Vegetation Using Landsat Data Processed in the Google Earth Engine Platform". Remote Sensing 12, n. 6 (13 marzo 2020): 924. http://dx.doi.org/10.3390/rs12060924.

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Widespread in the subtropics and tropics of the Southern Hemisphere, savannas are highly heterogeneous and seasonal natural vegetation types, which makes change detection (natural vs. anthropogenic) a challenging task. The Brazilian Cerrado represents the largest savanna in South America, and the most threatened biome in Brazil owing to agricultural expansion. To assess the native Cerrado vegetation (NV) areas most susceptible to natural and anthropogenic change over time, we classified 33 years (1985–2017) of Landsat imagery available in the Google Earth Engine (GEE) platform. The classification strategy used combined empirical and statistical decision trees to generate reference maps for machine learning classification and a novel annual dataset of the predominant Cerrado NV types (forest, savanna, and grassland). We obtained annual NV maps with an average overall accuracy ranging from 87% (at level 1 NV classification) to 71% over the time series, distinguishing the three main NV types. This time series was then used to generate probability maps for each NV class. The native vegetation in the Cerrado biome declined at an average rate of 0.5% per year (748,687 ha yr−1), mostly affecting forests and savannas. From 1985 to 2017, 24.7 million hectares of NV were lost, and now only 55% of the NV original distribution remains. Of the remnant NV in 2017 (112.6 million hectares), 65% has been stable over the years, while 12% changed among NV types, and 23% was converted to other land uses but is now in some level of secondary NV. Our results were fundamental in indicating areas with higher rates of change in a long time series in the Brazilian Cerrado and to highlight the challenges of mapping distinct NV types in a highly seasonal and heterogeneous savanna biome.

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Fensham, Roderick J., Owen Powell e James Horne. "Rail survey plans to remote sensing: vegetation change in the Mulga Lands of eastern Australia and its implications for land use". Rangeland Journal 33, n. 3 (2011): 229. http://dx.doi.org/10.1071/rj11007.

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There is a prevailing paradigm that woody vegetation is expanding at the expense of grassland with reduced burning under pastoralism in the Mulga Lands biogeographic region in eastern Australia. This raises the possibility that the region is acting as a carbon sink. Vegetation boundaries were precisely positioned from rail survey plans dating from 1895 to 1900. This baseline was compared with the position of boundaries on 1952 aerial photography and 2010 Google Earth imagery. The conversion of forest to non-forest by mechanical clearing was also mapped from satellite imagery. There was no consistent trend in the direction of boundary movement for mulga (Acacia aneura F.Muell. ex Benth.), gidgee (Acacia cambagei R.T. Baker) forest or miscellaneous other forest types. The stability of the boundaries, despite the transition from aboriginal management to rangeland pastoralism, contrasts with dramatic declines in tree cover resulting from mechanical clearing. Mapping of forest cover from satellite imagery reveals that conversion of forest to non-forest has reduced mulga forest to 74%, gidgee forest to 30% and miscellaneous forest types to 82% of their original area. Annual clearing rates for the period between 1997 and 2005 were 0.83, 0.95 and 0.43% for those forest types, respectively. Clearing has declined substantially in the period 2005–09 since the advent of recent regulations in Queensland. The area remains a source of carbon emissions but this situation may reverse if restoration of mulga dry forest becomes an attractive land use with an emerging carbon market.

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Capitoli di libri sul tema "Original vegetation remains"

Koster, Eduard, e Tim Favier. "Peatlands, Past and Present". In The Physical Geography of Western Europe. Oxford University Press, 2005. http://dx.doi.org/10.1093/oso/9780199277759.003.0018.

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Peatlands are fascinating wetland ecosystems. They provide a habitat for a wide range of highly adapted plant and animal species. In addition to the floristic and ornithological richness, peatlands have been recognized for many other values. For instance, drained peatland soils often have good agricultural properties, and peat has been and still is in some places extensively used as fuel. In coastal wetlands peat has even been used for salt extraction. Furthermore, peat is an interesting material for science, as it contains information on the palaeoecological environment, climate change, carbon history, and archaeology. In north-western Europe, peatlands were once quite extensive, covering tens of thousands of square kilometres. However, most of them have been strongly exploited by humans during past centuries. Many peatlands have been cultivated for agriculture and forestry, or have been exploited by commercial or domestic peat extraction for fuel. As a result, only a very small part of north-western Europe’s peatlands remains today in a more or less natural state. This chapter focuses on the peat deposits and peatlands in north-western Europe that have formed since the Late Glacial (c.13 ka BP). First, the most common concepts in peatland terminology are explained, and the distribution of peatlands is described. Next, processes of peat formation and the relationship between peatforming processes and climate, hydrology, vegetation, and other factors are discussed. In the following section, frequently used classification methods are presented. A historical overview of the cultivation and exploitation of peatlands is given and the present land use and characteristics of peatland soils are discussed. The following section deals with methods of conservation and rehabilitation of the remaining mires. The importance of peatlands as palaeoecological archives is examplified. Finally, the role of peatlands as a source and/or sink of CO2 and the relations with climate change are briefly explained. Peat is the unconsolidated material that predominantly consists of slightly decomposed or undecomposed organic material in which the original cellular and tissue structures can often be identified. Peat forms in lakes and mires under waterlogged, anaerobic conditions.

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Armstrong, David M., e James C. Halfpenny. "Vertebrates". In Structure and Function of an Alpine Ecosystem. Oxford University Press, 2001. http://dx.doi.org/10.1093/oso/9780195117288.003.0013.

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Vertebrates of alpine tundra are near the limits of their genetic tolerance, and thus the alpine provides a natural laboratory for the study of the ecology of these organisms in a climatically stressful environment. The alpine supports a greater species richness of vertebrate herbivores than does arctic tundra (Halfpenny and Southwick 1982). Hoffmann (1974) provided an extensive review of terrestrial vertebrates of arctic and alpine ecosystems, emphasizing circumpolar patterns. For a variety of reasons, however, vertebrates of alpine tundra are considerably less studied than are those of the Arctic, and much remains to be learned about the physiological and behavioral adaptations of vertebrates that allow this group to exist in this extreme and variable ecosystem. May (1980) offered some generalizations about the state of knowledge of alpine animals. Terrestrial systems are better known than aquatic systems; the magnitude of environmental variability is better known than its predictability and significance to populations of animals; life histories of animals are better known than their roles and functions; dynamics of single species are better known than interactions between and among species; habitat selection by animals is more often defined in terms of the perception of the investigator than in terms of the perception of the organism; the response of animals to patterns of vegetation is better known than the influence animals have in creating and maintaining those patterns; and densities of animals are better known than are patterns of dispersion and their causes. Those generalizations remain broadly accurate. The purpose of this chapter is to develop a perspective on the structure and function of the vertebrate fauna of alpine environments of the Southern Rocky Mountains, with an emphasis on the fauna found on Niwot Ridge. It considers the origin and ongoing development of the fauna and its biogeographic and ecological relationships. A pattern of distributions is described that is dynamic in space and time. A principal focus is the role of vertebrates to the structure and function of the tundra ecosystem, including both the biotic and physical impacts of vertebrate populations. Some attention is paid to vertebrate trophic guilds, but plant-animal interactions are detailed in this volume by Dearing (chapter 14).

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Peters, Debra P. C., e William H. Schlesinger. "Future Directions in Jornada Research: Applying an Interactive Landscape Model to Solve Problems". In Structure and Function of a Chihuahuan Desert Ecosystem. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195117769.003.0022.

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The long history of research at the Jornada Basin (through the Agricultural Research Service [ARS] since 1912, New Mexico State University in the late 1920s, and joined by the Long-Term Ecological Research [LTER] program in 1981) has provided a wealth of information on the dynamics of arid and semiarid ecosystems. However, gaps in our knowledge still remain. One of the most perplexing issues is the variation in ecosystem dynamics across landscapes. In this concluding chapter to this volume, we propose a new conceptual model of arid and semiarid landscapes that focuses explicitly on the processes and properties that generate spatial variation in ecosystem dynamics. We also describe how our framework leads to future research directions. Many studies have documented variable rates and patterns of shrub invasion at the Jornada as well as at other semiarid and arid regions of the world, including the Western United States, northern Mexico, southern Africa, South America, New Zealand, Australia, and China (York and Dick-Peddie 1969; Grover and Musick 1990; McPherson 1997; Scholes and Archer 1997; see also chapter 10). In some cases, shrub invasion occurred very rapidly: At the Jornada, areas dominated by perennial grasses decreased from 25% to < 7% from 1915 to 1998 with most of this conversion occurring prior to 1950 (Gibbens et al. 2005; Yao et al. 2002a). In other cases, shrub invasion occurred slowly, and sites were very resistant to invasion; for example, perennial grasses still dominate on 12 out of 57 research quadrats originally established in black grama (Bouteloua eropoda) grasslands in the early twentieth century (Yao et al. 2002b). Soil texture, grazing history, and precipitation patterns are insufficient to account for this variation in grass persistence through time (Yao et al. 2002a). It is equally perplexing that although many attempts to remediate these shrublands back to perennial grasses have led to failure, some methods worked well, albeit with long (> 50 year) time lags (Rango et al. 2002; see also chapter 14). Although variations in vegetation dynamics and shrub invasion are the most well known, other lesser known aspects of arid and semiarid systems have been found to be quite variable as well.

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Scott, Andrew C. "Fire and the Coming of the Modern World". In Burning Planet. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198734840.003.0009.

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What kind of world dawned after the K/P boundary? We know from studies across localities in the USA that there is evidence of frequent wildfires continuing into the earliest Paleogene. But what happened to the atmospheric oxygen level after recovery from the K/P mass extinction—did it remain above modern levels? Were we still in a high-fire world? If there were fires, what is the evidence in the charcoal record, and do we know anything about the vegetation that was burning? When the charcoal in the coal database was originally compiled, one of the important issues was how we recorded and represented our data. Early to mid-Paleocene Epoch coals (from around 65 to 55 million years ago) are often recorded as ‘earliest Tertiary’ in coal literature. (The Tertiary was the name we used to use for what we now call the Paleogene and Neogene Periods, stretching from around 65 to 1 million years ago.) However, coals that are nearer to the start of the Eocene Epoch, just older than 55 million years ago, are notoriously difficult to date. This is a problem we have with many coal sequences, as they are deposited on land, and most of the fossils used to give ages are found in marine waters. Many coals of this age are often simply recorded as coming from the late Paleocene or early Eocene. Where we have good dating information, Paleocene coals all tend to have high inertinite (charcoal) contents, well above 19 per cent. By the mid to late Eocene (50–40 million years ago), however, worldwide the charcoal contents are low, around 5 per cent or even less. There must, therefore, have been a fundamental change in the Earth system at this time. Another problem is the way in which we chose to represent our data and show the calculated oxygen curve. In order to get sufficient data to plot the curves we decided to use 10-millionyear bins. This was not a problem for the Paleozoic–Mesozoic transition, covering the great Permian mass extinction, which took place 250 million years ago.

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"of control. The state of Queensland has generous expertise in this area, with the CSIRO Division of Entomology – Lands Department group in Brisbane boasting spectacular success against Salvinia and Eichhornia, and near the reservoir at James Cook University a USDA unit was involved in successes with the Tennessee Valley Authority (TVA) (see Chapter 12) using a range of stem-boring and leaf-mining insects (Balciunas et al. 1993). One might consider the herbivorous grass carp Ctenopharyngodon idella, originally from China, more as a harvester than a biological control agent. This fish grazes on submerged weeds such as Hydrilla, Myriophyllum, Chara, Potamogeton and Ceratophyllum, and at stocking rates of 75 fish/ha control is rapidly achieved. Some introductions in the USA have resulted in removal of all vegetation (Leslie et al. 1987), and in the Australian context the use of sterile (triploid) fish (Cassani and Canton 1985) could be the only consideration. However, in view of the damage already done by grass carp to some inland waterways in Australia, it is suspected that this option would be greeted with horror. Mechanical control involves the physical removal of weeds from a problem area and is useful in situations where the use of herbicides is not practical or poses risks to human health or the environment. Mobile harvesters sever, lift and carry plants to the shore. Most are intended for harvesting submerged plants, though some have been designed or adapted to harvest floating plants. Handling the harvested weed is a problem because of their enormous water content, therefore choppers are often incorporated into harvesting machinery design. However, many mechanical harvesters have a small capacity and the process of disposing of harvested plant material is time-consuming. Any material that remains may affect water quality during the decay process by depleting the water of oxygen. Furthermore, nutrients released by decay may cause algal blooms (Mitchell 1978). Another disadvantage of mechanical removal is that disturbance often promotes rapid new growth and germination of seed, and encourages the spread of weed by fragmentation. Some direct uses of macrophytes include the following: livestock food; protein extraction; manufacture of yeast; production of alcohol and other by-products; the formation of composts, mulches and fertilizers; and use for methane generation (Williams 1977). Herbicides either kill on contact, or after translocation through the plant. Some are residual and retain their toxicity for a period of time. Where herbicides are used for control of plants, some contamination of the water is inevitable (Bill 1977). The degree of contamination depends on the toxicity of the material, its fate and persistence in the water, the concentration used and the main purpose served by the water. After chemical defoliation of aquatic vegetation, the masses of decaying organic debris produced can interfere with fish production. Several factors must be taken into account when selecting and adapting herbicides for aquatic purposes, including: type of water use; toxicity of the herbicide to humans, fish, stock, and wildlife; rate of disappearance of residues, species affected and duration of control; concentration of herbicide; and cost (Bill 1977). The TVA has successfully used EPA-approved herbicides such as Endothall, Diquat, Fluridone and Komeen against Hydrilla (Burns et al. 1992), and a list of approved". In Water Resources, 153–54. CRC Press, 1998. http://dx.doi.org/10.4324/9780203027851-40.

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Atti di convegni sul tema "Original vegetation remains"

Gattuso, Caterina, Marco Castriota, Philomène Gattuso e Francesca Saggio. "Memoria e conoscenza. Il castello di Belmonte in Calabria". In FORTMED2020 - Defensive Architecture of the Mediterranean. Valencia: Universitat Politàcnica de València, 2020. http://dx.doi.org/10.4995/fortmed2020.2020.11486.

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Memory and knowledge. The castle of Belmonte in CalabriaA small A small village located in Italy on the Calabrian Tyrrhenian coast, Belmonte Calabro has its historic center with a typical medieval urban structure that has remained almost unchanged over the centuries and is characterized by the presence of the ruins of a castle and its surrounding environments whose. The planimetry succeeds to be identified because it is bordered by a wall, only partially preserved, pronounced by towers and marked by a road that, in its main points still existing, follows its development. The castle, built on the hill’s top of a tuff nature, in an elevated position respect to the urban core, had a plan with a roughly quadrangular shape with four imposing square towers. Of particular note is its curtain wall that originally had four doors, which opened in correspondence at the four cardinal points. In addition to having suffered several collapses in many parts of its structure due to the various earthquakes that occurred over time, as well as various looting and the siege by the French artillery dating back to the early 1800s, the castle is currently subjected to degrading actions due to the attack of biological type, which manifests itself with a widespread presence of patinas, as well as those due to a thick weed vegetation that affects many of the surfaces of its structure. The study aims to provide a useful contribution to reconstructing the profile of the original structure of the ancient castle. To obtain, therefore, more information about it, a specific survey plan was developed to characterize its constituent materials and also its state of preservation. To this end, in correspondence of structural parts still intact, samples were collected that were analyzed and characterized in the laboratory by Raman Spectroscopy.

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