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Abstract:  The Natura 2000 network is the most important conservation effort being implemented in Europe. Nevertheless, no comprehensive and systematic region—or nationwide evaluation of the effectiveness of the network has been conducted. We used habitat suitability models and extent of occurrence of 468 species of vertebrates to evaluate the contribution of the Natura 2000 network to biodiversity conservation in Italy. We also estimated the population size of 101 species inside the Natura 2000 network to assess its capacity to maintain or improve the population status of listed species. In general the Italian Natura 2000 did not seem to integrate existing protected areas well. The Natura 2000 network increased from 11% to 20% the area devoted to conservation in Italy and the coverage provided to areas with high biodiversity. Nevertheless, some areas with high numbers of species were devoid of conservation areas, and more than 50% of the highly irreplaceable areas were not considered in the system. Moreover, the Natura 2000 network cannot maintain 44–80% (depending on the taxa considered) of the species in a "favorable conservation status" under World Conservation Union Red List criteria. The Natura 2000 network is probably stronger than the results of our analyses suggest. The system is based on a site-specific expert-based strategy and is driven by direct and detailed knowledge of local diversity. Nevertheless, if Natura 2000 is taken to represent the final point of all the EU conservation policies, it will inevitably fail. Its role in conservation could be enhanced by integrating the Natura 2000 system into a more general strategy that considers natural processes and the ecological and evolutionary mechanisms underlying these processes.  相似文献   
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Abstract:  The establishment of ecological networks (ENs) has been proposed as an ideal way to counteract the increasing fragmentation of natural ecosystems and as a necessary complement to the establishment of protected areas for biodiversity conservation. This conservation tool, which comprises core areas, corridors, and buffer areas, has attracted the attention of several national and European institutions. It is thought that ENs can connect habitat patches and thus enable species to move across unsuitable areas. In Europe, however, ENs are proposed as an oversimplification of complex ecological concepts, and we maintain that they are of limited use for biodiversity conservation for several reasons. The ENs are species specific and operate on species-dependent scales. In addition, the information needed for their implementation is only available for a handful of species. To overcome these limitations, ENs have been proposed on a landscape scale (and for selected "focal" species), but there is no indication that the structural composition of core areas, corridors, and buffer areas could ensure the functional connectivity and improve the viability of more than a few species. The theory behind ENs fails to provide sufficient practical information on how to build them (e.g., width, shape, structure, content). In fact, no EN so far has been validated in practice (ensuring connectivity and increasing overall biodiversity conservation), and there are no signs that validation will be possible in the near future. In view of these limitations, it is difficult to justify spending economic and political resources on building systems that are at best working hypotheses that cannot be evaluated on a practical level.  相似文献   
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Abstract:  Ongoing loss of biodiversity requires identifying large-scale conservation priorities, but the detailed information on the distribution of species required for this purpose is often missing. We present a systematic reserve selection for 1223 African mammals and amphibians in which habitat suitability models are used as estimates of the area occupied by species. In the framework of the World Conservation Union (IUCN) Global Amphibian Assessment and IUCN Global Mammal Assessment, we collected the geographic range (extent of occurrence) and habitat preferences for each species. We used the latter to build species-specific habitat suitability models inside geographic ranges, and for 181 species we verified the models by comparing suitability levels to presence-absence data collected in the field. We then used the suitable areas as estimators of the area of occupancy and compared the results of systematic reserve selection based on geographic ranges to those based on estimated areas of occupancy. Our results showed that the reserve system would need a 30-100% expansion to achieve minimal conservation targets, concentrated in the tropics, where species richness reaches a maximum. Comparative analyses revealed that using geographic ranges, which overestimate the area occupied by species, underestimates the total amount of area that needs to be conserved. The area selected for conservation doubled when we used the estimated area of occupancy in place of the geographic ranges. This happened because the suitable areas potentially occupied by each species overlapped less than their geographic ranges. As a result, any given protected area contained fewer species than predicted by the analysis of ranges. Because species are more specialized than our estimates of distribution based on extent of occurrence suggest, we propose that this is a general effect in systematic conservation planning.  相似文献   
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Abstract:  Conservation in Europe (including the establishment of protected areas) is undertaken mainly through legislation and on densely populated private land. Consequently, conflicts of interest arise between human economic activities and biodiversity conservation. We used a systematic approach to conservation planning to explore different conservation scenarios for the Apennine populations of wolves (Canis lupus) and bears (Ursus arctos marsicanus) in Italy. The conservation measures we considered were electrified fences and guard dogs to prevent wolves and bears from preying on sheep. We used habitat suitability models of the two species as an estimate of their distributions. Across the study area, we estimated the potential intensity of conflict caused by predation on sheep and the cost of the antipredator measures. We examined scenarios for the conservation of wolves and bears that identified systems of sites where antipredator measures should be applied to either minimize the economic cost of the plan or tackle a predetermined amount of conflict. The overall cost of the conservation plans ranged between €1,486,000 and €16,876,000, depending on the scenario and on the size of the conservation target. Because potential conflict intensity (i.e., potential predation) and cost of conflict resolution were correlated, the scenarios that minimized cost also minimized the amount of conflict that was addressed. Conserving these two species by addressing their predation on sheep was up to 4.36 times more expensive than conserving them by providing suitable habitat in areas of low conflict. Yet avoiding conflicts is not always desirable because it can drastically reduce the options for conservation. Choosing a conservation plan requires consideration of the level of threat to the target species and their sensitivity to conflicts.  相似文献   
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Assessing temporal changes in species extinction risk is necessary for measuring conservation success or failure and for directing conservation resources toward species or regions that would benefit most. Yet, there is no long‐term picture of genuine change that allows one to associate species extinction risk trends with drivers of change or conservation actions. Through a review of 40 years of IUCN‐related literature sources on species conservation status (e.g., action plans, red‐data books), we assigned retrospective red‐list categories to the world's carnivores and ungulates (2 groups with relatively long generation times) to examine how their extinction risk has changed since the 1970s. We then aggregated species’ categories to calculate a global trend in their extinction risk over time. A decline in the conservation status of carnivores and ungulates was underway 40 years ago and has since accelerated. One quarter of all species (n = 498) moved one or more categories closer to extinction globally, while almost half of the species moved closer to extinction in Southeast Asia. The conservation status of some species improved (toward less threatened categories), but for each species that improved in status 8 deteriorated. The status of large‐bodied species, particularly those above 100 kg (including many iconic taxa), deteriorated significantly more than small‐bodied species (below 10 kg). The trends we found are likely related to geopolitical events (such as the collapse of Soviet Union), international regulations (such as CITES), shifting cultural values, and natural resource exploitation (e.g., in Southeast Asia). Retrospective assessments of global species extinction risk reduce the risk of a shifting baseline syndrome, which can affect decisions on the desirable conservation status of species. Such assessments can help conservationists identify which conservation policies and strategies are or are not helping safeguard biodiversity and thus can improve future strategies. Una Evaluación Retrospectiva de la Declinación Global de Carnívoros y Ungulados  相似文献   
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Agricultural soils of two Italian maize farms were treated for five years with an industrially produced high-quality compost. Cattle manure and the usual mineral fertilizer were used for comparison purposes. The effects of the organic and mineral fertilizer treatments were studied by analyzing the compost and manure, cultured soils, and harvested material. The grain yield was also determined. Organic fertilization improved soil pH, CEC, content of organic matter and NPK. Soil respiration and N mineralization were found to be higher than in the purely mineral-treated soil. Plant K take-up was improved, whereas grain yield was not affected. It was confirmed that organic fertilization, particularly compost use, maintained and increased soil fertility. The study demonstrated the feasibility of using in loco analytical facilities to follow the entire recycling process—from waste to compost production—and the use of the final product in the field.  相似文献   
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