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Conservation of the Biodiversity of Brazil's Inland Waters   总被引:6,自引:1,他引:6  
Abstract:  In terms of biodiversity, Brazilian inland waters are of enormous global significance for Algae (25% of the world's species), Porifera (Demospongiae, 33%), Rotifera (25%), Cladocera (Branchiopoda, 20%), and fishes (21%). Threatened freshwater species include 44 species of invertebrates (mostly Porifera) and 134 fishes (mostly Cyprinodontiformes, Rivulidae), primarily distributed in south and southeastern Brazil. Reasons for the declines in biodiversity in Brazilian inland waters include pollution and eutrophication, siltation, impoundments and flood control, fisheries, and species introductions. These problems are more conspicuous in the more-developed regions. The majority of protected areas in Brazil have been created for terrestrial fauna and flora, but they also protect significant water bodies and wetlands. As a result, although very poorly documented, these areas are of great importance for aquatic species. A major and pressing challenge is the assessment of the freshwater biodiversity in protected areas and surveys to better understand the diversity and geography of freshwater species in Brazil. The concept of umbrella species (e.g., certain migratory fishes) would be beneficial for the protection of aquatic biodiversity and habitats. The conservation and improved management of river corridors and associated floodplains and the maintenance of their hydrological integrity is fundamental to preserving Brazil's freshwater biodiversity and the health of its aquatic resources.  相似文献   
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Abstract:  With endangered status and more than 8,000 endemic species, the Atlantic Forest is one of the world's 25 biodiversity hotspots. Less than 100,000 km2 (about 7%) of the forest remains. In some areas of endemism, all that is left are immense archipelagos of tiny and widely separated forest fragments. In addition to habitat loss, other threats contributing to forest degradation include the harvesting of firewood, illegal logging, hunting, plant collecting, and invasion by alien species—all despite the legislation that exists for the forest's protection. More than 530 plants and animals occurring in the forest are now officially threatened, some at the biome level, some throughout Brazil, and some globally. Many species have not been recorded in any protected areas, indicating the need to rationalize and expand the parks system. Although conservation initiatives have increased in number and scale during the last two decades, they are still insufficient to guarantee the conservation of Atlantic Forest biodiversity. To avoid further deforestation and massive species loss in the Brazilian Atlantic Forest, the challenge is to integrate the diverse regulations, public policies, new opportunities, and incentive mechanisms for forest protection and restoration and the various independent projects and programs carried out by governments and nongovernmental organizations into a single and comprehensive strategy for establishing networks of sustainable landscapes throughout the region.  相似文献   
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Contamination of soil with pesticides can be evaluated using toxicity tests with worms because their ecological niche makes them good bioindicators. Bioaccumulation in compost worms of [methyl- 14C] paraquat (1,1′-dimethyl-4,4′-bipyridinium dichloride) was measured after three-month exposure in two substrates with differing physicochemical characteristics, in particular their organic matter and clay contents. The treatments were 1.2, 12, and 120 μg paraquat g?1 substrate. The action of the worms did not influence the loss of 14C from the substrates, as the 14C-recovered was essentially quantitative at the end of the study in both the presence and absence of the worms. The organic matter and clay contents of the substrates determined the extent of the paraquat uptake by the worms; worms from the substrate with smaller amounts of clay and organic matter had the higher values of the bioconcentration factor (BCF), these being about 5 (fresh-weight basis) and independent of the application rate. The BCF values in the substrate containing more organic matter and clay were smaller but increased from 1.1 to 3.8 with the increasing rates of application. However, in both substrates the amounts of paraquat bioaccumulated in the worms was always less than 1% of that applied, indicating the very strong binding of paraquat to the substrates and hence low availability to the worms.  相似文献   
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Abstract:  Applying the ecosystem services concept to conservation initiatives or in managing ecosystem services requires understanding how environmental impacts affect the ecology of key species or functional groups providing the services. We examined effects of river impoundments, one of the leading threats to freshwater biodiversity, on an important ecosystem service provided by large tropical rivers (i.e., artisanal fisheries). The societal and economic importance of this ecosystem service in developing countries may provide leverage to advance conservation agendas where future impoundments are being considered. We assessed impoundment effects on the energetic costs of fisheries production (embodied energy) and commercial market value of the artisanal fishery of the Paraná River, Brazil, before and after formation of Itaipu Reservoir. High-value migratory species that dominated the fishery before the impoundment was built constituted a minor component of the contemporary fishery that is based heavily on reservoir-adapted introduced species. Cascading effects of river impoundment resulted in a mismatch between embodied energy and market value: energetic costs of fisheries production increased, whereas market value decreased. This was partially attributable to changes in species functional composition but also strongly linked to species identities that affected market value as a result of consumer preferences even when species were functionally similar. Similar trends are expected in other large tropical rivers following impoundment. In addition to identifying consequences of a common anthropogenic impact on an important ecosystem service, our assessment provides insight into the sustainability of fisheries production in tropical rivers and priorities for regional biodiversity conservation .  相似文献   
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This paper documents zootherapeutic practices in Northeast Brazil. It is primarily based on field surveys carried out in fishing villages located in the States of Maranhão and Paraíba, where dwellers provided information on snake species used as medicine, body parts used to prepare the remedies, and the illnesses to which the remedies were prescribed. The species used as medicinal drug and their respective families were: Crotalus durissus (rattlesnake), Bothrops leucurus (‘lance head’, a venomous snake), and Lachesis muta (bushmaster) of the family Crotalidae; and Boa constrictor (boa constrictor), Epicrates cenchria (‘salamanta’), and Eunectes murinus (anaconda) of the family (Boidae). These zootherapeutical resources were used for the cure of 14 illnesses. The most commonly cited species were Crotalus durissus (n=26) e Boa constrictor (n=6), Apparently, the medicinal use of snakes does not pose a threat for their population in the studied sites.  相似文献   
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