845 resultados para Conservation of biodiversity


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Biodiversity surveys were conducted in 13, 10x50 m(2) plots located between 1400 to 3100 in abode mean sea level in a range of habitats in temperate mixed Oak and Coniferous forests through sub-alpine to the alpine grasslands in Chamoli district of Uttaranchal state in the Indian Garhwal Himalaya. Cross-taxon congruence in biodiversity (alpha-diversity and beta-diversity) across macrolichens, mosses, liverworts, woody plants (shrubs and trees) and ants was investigated, so as to examine the extent to which these group, of organisms can function as Surrogates for each other. Although woody plants provided a major substrate for macrolichens and mosses, there was no species-specific association between them. Woody plant species richness was highly positively correlated with mosses (r(2) = 0.63, P < 0.001) but the relationship, as not particularly very strong with lichens and liverworts. While there was a significant correlation in the species turnover (β-diversity) of macrolichens with mosses (r(2) = 0.21 P < 0.005). the relationship was relatively poor with the woody plants. On the other hand. negative correlations emerged in the species richness of ants with those of macrolichens, mosses and woody plants (r(2) = -0.44 P < 0.05). but most of the complementarity (turnover) relationships among them were positive, Since diversity between taxonomic hierarchies within the group was consistently significantly positively correlated in all these taxa, the higher taxonomic categories Such as genus and family may be employed as surrogates for rapid assessment and monitoring of species diversity, Although no single group other than macrolichens has emerged as a good indicator of changes in species richness in all other groups, some concordant relationships between them conform to the hypothesis that species assemblages of certain taxonomic groups could still be used as surrogates for efficient monitoring of species diversity in other groups whose distribution may further predict the importance of conserving overall biodiversity in landscapes such as the Garhwal Himalaya. (C) 2002 Elsevier Science Ltd. All rights reserved.

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Invertebrate conservation relies not only on public support and political will, but also on possessing an adequate understanding of the distribution and ecology of invertebrate species and communities. In the UK, RIVPACS is making an important contribution to assessing the conservation importance of river invertebrate assemblages. So far, work has largely centred on using RIVPACS as an integral part of SERCON (System for Evaluating Rivers for Conservation), in which data collected using the standard RIVPACS method are interpreted with reference to conservation criteria such as species richness and representativeness. Applications of RIVPACS to other areas of conservation - whether providing information on the ecological requirements of rare species, monitoring the success of river restoration projects, or making broader assessments of sustainability - are probably more limited, but merit further examination. It is important to develop closer links between RIVPACS and techniques such as SERCON and RHS (River Habitat Survey) in order to maximise the benefit each can bring tostudies on conservation and biodiversity. It should also be recognised that there are limitations in transferring such systems to other countries where approaches to nature conservation may be very different.

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The loss of biodiversity resulting from extinctions is receiving increasing attention. Over several thousands of animal species have been evaluated and recognized as endangered species. Inbreeding depression has been demonstrated in many wild animal speci

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Cichlids are known for their explosive radiation especially in the African Great Lakes marked with a high level of lake endemism. These fishes have been characterized mainly along trophic and habitat differences, by variation in morphological structures such as teeth and jaws and by differences in body shape and coloration. Cichlids are important as a microcosm of macroevolution. The explosive radiation, young evolutionary scale, and the isolation of groups characterized with high levels of endemism and presence of living fossils makes the group important for evolutionary and genetic studies. Lake Victoria region cichlids which are isolated and relatively more recent in evolution were the last to be appreciated in their diversity. Recently Ole Seehausen has found scores of rock fishes in Lake Victoria which were up to then thought to be absent from the Lake and only known to occur in Lakes Malawi and Tanganyika. Greenwood put together the species groups of Lake Victoria, and later in the early 1980's revised the classification of haplochromine species to reflect the phyletic origin and interrelationship of the various groups in Lake Victoria region. Melan Stiassny has been interested in early evolution of cichlids while the likes of Paul Fuerst and Lees Kaufman and Axel Meyer have been interested and are working to explain the speciation mechanisms responsible for the explosive radiation and evolution of cichlids. Locally S.B Wandera and his student Getrude Narnulemo are spearheading the biodiversity and taxonomic studies of cichlids in Lake Victoria region

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Biodiversity values provide objective data and advice from which policy makes could assess the conservation options and determine optimal policies that would balance the needs of conservation with the socia-economic needs of the people in the area.

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Elevational and latitudinal patterns of species richness for birds and mammals were compared with human population density in relation to nature reserve designation in two areas of Yunnan Province, China. Results suggest that species richness is not the same for the two areas. In Gaoligongshan Region, species richness is inversely correlated with elevation and altitude, while reserve designation is positively correlated with elevation and latitude. In Jingdong County, reserve designations are positively correlated with elevation, but species richness shows no clear trends. In general, the present situation is strongly influenced by human activities. It appears that reserve designation is mismatched with species richness in Gaoligongshan Region, while there is a better fit between the two in Jingdong County. In both areas, however, it appeared that reserves were located primarily in order to reduce conflict with humans rather than to maximize conservation of biodiversity, probably because humans were responsible for forest-especially primary forest-destruction and degradation in the low-lying areas.

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The Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) is currently limited to the middle and lower reaches of the Yangtze River from Yichang to Shanghai, China, and the adjoining Poyang and Dongting Lakes. Its population size has decreased remarkably during the last several decades due to the heavy impact of human activities, including overfishing of prey species, water development projects that cause attendant habitat loss and degradation, water pollution, and accidental deaths caused by harmful fishing gear and collisions with motorized vessels. It was estimated that the number of remaining individuals was down to approximately 1800 in 2006, a number that is decreasing at a rate as high as 5% per year. Three conservation measures - in situ and ex situ conservation and captive breeding have been applied to the protection of this unique porpoise since the early 1990s. Seven natural and two "semi-natural" reserves have so far been established. Since 1996, a small group of finless porpoises has been successfully reared in a facility at the Institute of Hydrobiology of the Chinese Academy of Sciences; three babies were born in captivity on July 5, 2005, June 2, 2007 and July 5, 2008. These are the first freshwater cetaceans ever born in captivity in the world. Several groups of these porpoises caught in the main stream of the Yangtze River, or rescued, have been introduced into the Tian'e-Zhou Semi-natural Reserve since 1990. These efforts have proven that, not only can these animals survive in the area, they are also to reproduce naturally and successfully. More than 30 calves had been born in the reserve since then, with one to three born each year. Taking deaths and transfers into account, there were approximately 30 individuals living in the reserve as of the end of 2007. Among eight mature females captured in April 2008, five were confirmed pregnant. This effort represents the first successful attempt at off-site protection of a cetacean species in the world, and establishes a solid base for conservation of the Yangtze finless porpoise. A lesson must be drawn from the tragedy of Chinese River Dolphin (Lipotes vexillifer), which has already been declared likely extinct. Strong, effective and appropriate protective measures must be carried out quickly to prevent the Yangtze finless porpoise from becoming a second Chinese River Dolphin, and save the biodiversity of the Yangtze River as a whole.

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We show that globally declining fisheries catch trends cannot be explained by random processes and are consistent with declining stock abundance trends. Future projections are inherently uncertain but may provide a benchmark against which to assess the effectiveness of conservation measures. Marine reserves and fisheries closures are among those measures and can be equally effective in tropical and temperate areas—but must be combined with catch-, effort-, and gear restrictions to meet global conservation objectives.

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Bees are major pollinators of Angiosperms and therefore their apparent decline is of importance for humans and biodiversity. We synthesise results of 12 recent reviews to provide a global picture of the threats they face. Habitat loss is the major threat to bee diversity, whilst invasive species, emerging diseases, pesticide use, and climate change also have the potential to impact bee populations. We suggest that future conservation strategies need to prioritise (i) minimising habitat loss, (ii) making agricultural habitats bee-friendly, (iii) training scientists and the public in bee taxonomy and identification, (iv) basic autecological and population genetic studies to underpin conservation strategies, (v) assessing the value of DNA barcoding for bee conservation, (vi) determining the impact of invasive plants, animals, parasites and pathogens, and (vii) integrating this information to understand the potential impact of climate change on current bee diversity.

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Public concern over biodiversity loss is often rationalized as a threat to ecosystem functioning, but biodiversity-ecosystem functioning (BEF) relations are hard to empirically quantify at large scales. We use a realistic marine food-web model, resolving species over five trophic levels, to study how total fish production changes with species richness. This complex model predicts that BEF relations, on average, follow simple Michaelis-Menten curves when species are randomly deleted. These are shaped mainly by release of fish from predation, rather than the release from competition expected from simpler communities. Ordering species deletions by decreasing body mass or trophic level, representing 'fishing down the food web', accentuates prey-release effects and results in unimodal relationships. In contrast, simultaneous unselective harvesting diminishes these effects and produces an almost linear BEF relation, with maximum multispecies fisheries yield at approximate to 40% of initial species richness. These findings have important implications for the valuation of marine biodiversity.

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To value something, you first have to know what it is. Bartkowski et al. (2015) reveal a critical weakness: that biodiversity has rarely, if ever, been defined in economic valuations of putative biodiversity. Here we argue that a precise definition is available and could help focus valuation studies, but that in using this scientific definition (a three-dimensional measure of total difference), valuation by stated-preference methods becomes, at best, very difficult.We reclassify the valuation studies reviewed by Bartkowski et al. (2015) to better reflect the biological definition of biodiversity and its potential indirect use value as the support for provisioning and regulating services. Our analysis shows that almost all of the studies reviewed by Bartkowski et al. (2015) were not about biodiversity, but rather were about the 'vague notion' of naturalness, or sometimes a specific biological component of diversity. Alternative economic methods should be found to value biodiversity as it is defined in natural science. We suggest options based on a production function analogy or cost-based methods. Particularly the first of these provides a strong link between economic theory and ecological research and is empirically practical. Since applied science emphasizes a scientific definition of biodiversity in the design and justification of conservation plans, the need for economic valuation of this quantitative meaning of biodiversity is considerable and as yet unfulfilled.

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Habitat conversion and environmental degradation have reached alarming levels in the Pantanal, endangering all its biodiversity. This scenario is complicated by the fact that the biome relies on only a few protected areas, which combined do not exceed 10% of the territory. Felids, as predators, play a vital role in the maintenance of this ecosystem, but require large areas, have low population densities and, typically, are very sensitive to environmental disturbances. Amolar Mountain Ridge is considered an area of extreme importance and high priority for conservation within the biome. There are four species of felids in this region: the jaguar (Panthera onca), the puma (Puma concolor), the ocelot (Leopardus pardalis), and jaguarundi (Puma yagouaroundi). However, little is known about the ecology of these species in this region or the magnitude of interaction between the communities living around the protected areas and the animals. The goal of this study was to increase our knowledge about these felids and understand how people interact with them in order to contribute to their conservation in the network of parks within Amolar. Camera trapping surveys were carried out in two areas of the network, covering approximately 83,000 hectares, in order to identify the species of mammals occurring in the region, those that may be potential prey for the felids, and to obtain basic ecological data about both felids and prey. In addition, we conducted surveys in three riverside schools in order to assess the knowledge, perceptions and attitudes of schoolchildren regarding the four focal felids, and surveys among the adult population to assess their perceptions and attitudes towards the jaguar. We recorded a total of 33 species of mammals from both study areas. The large cats were cathemeral, reflecting the temporal activity of larger prey, whereas the ocelot was nocturnal, mirroring the activity of smaller prey. Jaguar occupancy was influenced by prey abundance, while puma occupancy was influenced by patch density in drier dense forest. Jaguars and pumas may be competitors over temporal and spatial scales, while no resource overlap was found for ocelots. Overall, both adults and children tended to have negative perceptions about the cats, which were related to the fear of being attacked. To increase awareness about the species and to maximize the effectiveness of protective measures in the network of reserves, it is recommended to develop and implement an Environmental Educational Program in the medium- to long-term in order to minimize the fear of these felids and to counsel locals on the role of felids in the maintenance of the Pantanal’s biodiversity.

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Tese de doutoramento (co-tutela), Biologia (Biologia da Conservação), Faculdade de Ciências da Universidade de Lisboa, University of East Anglia, School of Environmental Sciences, 2014