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Protected areas (PAs) on tropical mountains undergo greater forest destruction in their lower altitudes. We compared the extent of forested, nonforested, and fragmented areas between lowland (<1000 m asl) and montane zones of the Blue Mountains inside the Blue and John Crow Mountains National Park established in Jamaica in 1993. We found that in 2008, inside the montane zone, only 4 percent of forest was cleared, and forest fragmentation was minimal. In the lowland zone, however, the percentage of forest cleared was seven times as high, and the density of fragments was 11-fold higher. We established twenty-five 0.04 ha lowland plots; ordination of tree species composition in these plots reflected a rainfall gradient, showing that plots on the wetter northern side of the Blue Mountains were floristically different from those on the drier southern side. The conservation value of the remaining lowland forest is high because of its high endemism (18% of species in our plots) and beta diversity. In addition, IUCN Red List data show that about 71 percent of threatened tree species in the Blue Mountains grow in the lowland region, 92 percent of which are endemic. From these findings, we identify a ‘protected area hotspot zone’, which lies between the PA boundary and the core high-altitude zone, and which should be instituted in IUCN categories I and II PAs. 相似文献
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Marcelo Tabarelli 《Biotropica》2010,42(5):553-554
Many conservationists are now convinced that the expansion of the world system of protected areas combined with appropriate levels of biodiversity persistence within human-modified landscapes would drastically mitigate the announced impoverishment of tropical biotas. In this context, an inherent/intrinsic biodiversity ability to persist and recover within human-modified landscapes has emerged as a ‘trump card’ in the conservation battle, renewing our hope in a more sustainable development of the tropical region. However, this optimistic perspective on the conservation value of human-modified landscapes sounds, a priori, a little unrealistic in face of the current knowledge on the nature of human environments and the spectrum of native species that is likely to persist there. Rather than relying on illusory levels of biodiversity resilience and consequent flexible land-use regulations, our real trump card reposes on a radical and ambitious shift from freely exploited landscapes to strictly managed ones, despite the misleading noise produced by those voices advocating for immediate and almost unlimited access to natural resources. Otherwise, we are condemning future human populations to live in biologically impoverished and fragile environments with limited opportunities for life support. 相似文献
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G. Simchen 《Genetics》1974,76(4):745-753
Sporulation of diploid yeasts (Saccharomyces cerevisiae), homozygous or heterozygous for temperature-sensitive mitotic cell-cycle mutations, was examined at the restrictive and permissive temperatures. Twenty genes, represented by 32 heterozygotes and 60 homozygotes, were divided into three groups, showing (i) normal sporulation, (ii) no sporulation at the restrictive temperature but normal sporulation at the permissive temperature, (iii) no sporulation at both temperatures. Group (i) as well as several other strains were tested for their meiotic behavior with regard to intragenic recombination and haploidization. The conclusion reached was that all the mitotic nuclear-division and DNA-synthesis functions were required in meiosis. The only cell-division mutations not to affect meiosis were in three cytokinesis loci and in one budemergence locus. 相似文献
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Kobe De Pourcq Evert Thomas Bas Arts An Vranckx Tomas Léon-Sicard Patrick Van Damme 《PloS one》2015,10(12)
Natural resource-related conflicts can be extremely destructive and undermine environmental protection. Since the 1990s co-management schemes, whereby the management of resources is shared by public and/or private sector stakeholders, have been a main strategy for reducing these conflicts worldwide. Despite initial high hopes, in recent years co-management has been perceived as falling short of expectations. However, systematic assessments of its role in conflict prevention or mitigation are non-existent. Interviews with 584 residents from ten protected areas in Colombia revealed that co-management can be successful in reducing conflict at grassroots level, as long as some critical enabling conditions, such as effective participation in the co-management process, are fulfilled not only on paper but also by praxis. We hope these findings will re-incentivize global efforts to make co-management work in protected areas and other common pool resource contexts, such as fisheries, agriculture, forestry and water management. 相似文献
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Justine D. Shaw Aleks Terauds Martin J. Riddle Hugh P. Possingham Steven L. Chown 《PLoS biology》2014,12(6)
Antarctica is widely regarded as one of the planet''s last true wildernesses, insulated from threat by its remoteness and declaration as a natural reserve dedicated to peace and science. However, rapidly growing human activity is accelerating threats to biodiversity. We determined how well the existing protected-area system represents terrestrial biodiversity and assessed the risk to protected areas from biological invasions, the region''s most significant conservation threat. We found that Antarctica is one of the planet''s least protected regions, with only 1.5% of its ice-free area formally designated as specially protected areas. Five of the distinct ice-free ecoregions have no specially designated areas for the protection of biodiversity. Every one of the 55 designated areas that protect Antarctica''s biodiversity lies closer to sites of high human activity than expected by chance, and seven lie in high-risk areas for biological invasions. By any measure, including Aichi Target 11 under the Convention on Biological Diversity, Antarctic biodiversity is poorly protected by reserves, and those reserves are threatened. 相似文献
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Maximiliano A. Sepúlveda Randall S. Singer Eduardo Silva-Rodríguez Paulina Stowhas Katharine Pelican 《PloS one》2014,9(1)
Although domestic dogs play many important roles in rural households, they can also be an important threat to the conservation of wild vertebrates due to predation, competition and transmission of infectious diseases. An increasing number of studies have addressed the impact of dogs on wildlife but have tended to ignore the motivations and attitudes of the humans who keep these dogs and how the function of dogs might influence dog-wildlife interactions. To determine whether the function of domestic dogs in rural communities influences their interactions with wildlife, we conducted surveys in rural areas surrounding protected lands in the Valdivian Temperate Forests of Chile. Sixty percent of farm animal owners reported the use of dogs as one of the primary means of protecting livestock from predators. The probability of dog–wild carnivore interactions was significantly associated with the raising of poultry. In contrast, dog–wild prey interactions were not associated with livestock presence but had a significant association with poor quality diet as observed in previous studies. Dog owners reported that they actively encouraged the dogs to chase off predators, accounting for 25–75% of the dog–wild carnivore interactions observed, depending on the predator species. Humans controlled the dog population by killing pups and unwanted individuals resulting in few additions to the dog population through breeding; the importation of predominantly male dogs from urban areas resulted in a sex ratios highly dominated by males. These results indicate that dog interactions with wildlife are related to the role of the dog in the household and are directly influenced by their owners. To avoid conflict with local communities in conservation areas, it is important to develop strategies for managing dogs that balance conservation needs with the roles that dogs play in these rural households. 相似文献
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Brett A. Melbourne Kendi F. Davies Chris R. Margules David B. Lindenmayer Denis A. Saunders Christian Wissel Klaus Henle 《Biodiversity and Conservation》2004,13(1):275-284
We summarise the contributions of empiricists, modellers, and practitioners in this issue of Biodiversity and Conservation, and highlight the most important areas for future research on species survival in fragmented landscapes. Under the theme uncertainty in research and management, we highlight five areas for future research. First, we know little about the effects of density dependence on the viability of metapopulations, a requirement for fragmented landscapes. Second, successful early attempts suggest that it is worth developing more rigorous calibration methods for population viability analysis with spatially explicit, individual-based models. In particular, the balance between model complexity, ease of calibration, and precision, needs to be addressed. Third, we need to improve methods to discriminate between models, including alternatives to time-series approaches. Fourth, when our ability to reduce model uncertainty is weak, we need to incorporate this uncertainty in population viability analysis. Fifth, population viability analysis and decision analysis can be integrated to make uncertainty an explicit part of the decision process. An important future direction is extending the decision framework to adaptive management. Under the theme tools for quantifying risk and predicting species sensitivity to fragmentation, we highlight three areas for future research. First, we need to develop tools to support comparative approaches to population viability analysis. Second, population modelling can be used to find rules of thumb to support conservation decisions when very little is known about a species. Rules of thumb need to be extended to the problem of managing for multiple species. Third, species traits might be useful for predicting sensitivity but predictions could be further refined by considering the relative importance of population processes at different scales. Under the theme tools for reassembling fragmented landscapes, we consider the focal species approach, and highlight aspects of the approach that require more rigorous testing. Finally, we highlight two important areas for future research not presented in the previous themes or papers in this volume. First, we need to incorporate the deterministic effects of habitat modification into the modelling framework of population viability analysis. Second, an avenue of research that remains largely unexplored is the combination of landscape-scale experiments and population modelling, especially using data from existing fragmentation experiments and from experiments designed to test the effects of defragmenting landscapes. 相似文献
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Rodrigo Fagundes Braga Vanesca Korasaki Lívia Dorneles Audino Julio Louzada 《Ecosystems》2012,15(7):1173-1181
We evaluated the effects of different land-use systems on the ability of dung beetles to control the population of detritus-feeding flies. We tested the hypotheses that intensification of land use will reduce dung beetles richness, abundance and biomass and, consequently, their dung burial ability, affecting the interaction between dung beetles and flies and reducing its effectiveness as a natural biological control. In the Brazilian Amazon we sampled dung beetles, fly larvae and adults; and recorded the rate of dung removal by dung beetles across a gradient of land-use intensity from primary forest, secondary forest, agroforestry, agriculture to pasture. Our results provide evidence that land-use intensification results in a reduction of the richness, abundance and biomass of dung beetles, and this in turn results in lower rates of dung removal in the most simplified systems. We found no significant differences in the abundance of fly larvae between the different systems of land use. However, the number of adult flies differed significantly between land-use systems, presenting higher abundance in those sites with greater intensity of use (pasture and agriculture) and a lower abundance of adult flies in forested systems (primary and secondary forests, and agroforestry). Information-theoretic model selection based on AICc revealed strong support for the influence of land-use systems, dung removal rates and dung beetle abundance, biomass and richness on adult dung-fly abundance. Our results also reveal that dung beetles are not solely responsible for fly control and that other factors linked to land use are influencing the populations of these detritus-feeding insects. 相似文献
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Markus Bernhardt-Römermann Christine Römermann Valério DePatta Pillar Thomas Kudernatsch Anton Fischer 《Folia Geobotanica》2010,45(2):111-124
The current study tested the assumption that floristic and functional diversity patterns are negatively related to soil nitrogen content. We analyzed 20 plots with soil N-contents ranging from 0.63% to 1.06% in a deciduous forest near Munich (Germany). To describe species adaptation strategies to different nitrogen availabilities, we used a plant functional type (PFT) approach. Each identified PFT represents one realized adaptation strategy to the current environment. These were correlated, next to plant species richness and evenness, to soil nitrogen contents. We found that N-efficient species were typical for low soil nitrogen contents, while N-requiring species occur at high N-contents. In contrast to our initial hypotheses, floristic and functional diversity measures (number of PFTs) were positively related to nitrogen content in the soil. Every functional group has its own adaptation to the prevailing environmental conditions; in consequence, these functional groups can co-exist but do not out-compete one another. The increased number of functional groups at high N-contents leads to increased species richness. Hence, for explaining diversity patterns we need to consider species groups representing different adaptations to the current environmental conditions. Such co-existing ecological strategies may even overcome the importance of competition in their effect on biodiversity. 相似文献
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Jeffrey Sayer 《Biotropica》2009,41(6):649-652
The landscape approach is being used for initiatives that have the dual objectives of conserving biodiversity and alleviating poverty. However, working at such landscape scales greatly expands the level of ambition of conservation organizations and requires them to use skills that differ from those that they have traditionally deployed. Influencing landscape change requires major commitments for long periods of time and since there is still little evidence for the success of such approaches they should be used cautiously. Landscape programmes must be based on a comprehensive understanding of landscape dynamics and of the underlying drivers of social, economic and ecological change. Just as in any other investment in conservation it is important to set objectives in clear and measurable terms. Landscape approaches should therefore complement and not replace more conventional biodiversity conservation measures. They should be guided by scenarios agreed by concerned stakeholders, should be constructivist and in most cases their success will require major changes in the behavior of local people. 相似文献
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The boreal forest plays a key role in the global carbon (C) cycle, and black spruce (Picea mariana (Mill.) BSP) forests are the dominant coniferous forest type in the Canadian boreal forest. National-scale forest C models currently do not account for the contribution of moss-derived organic matter that we hypothesize to be significant in the C budget of black spruce ecosystems. One such model, the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3), is designed to meet Canada’s forest-related greenhouse gas reporting requirements. In this study our goal was to determine if black spruce forest soil C stocks are significantly underestimated by the CBM-CFS3, and if so, to determine if estimates could be improved by adding moss-derived C. We conclude that in black spruce sites, organic layer C is significantly underestimated by CBM-CFS3 compared to sites with all other leading tree species analyzed. We compiled and used published moss net primary productivity rates for upland forest systems, with decomposition rates, in mass-balance calculations to estimate mean moss-derived C in black spruce forests for feather mosses at 64 Mg C ha?1, and for sphagnum mosses at 103 Mg C ha?1. These C pools are similar to the CBM-CFS3 mean underestimation of black spruce soil organic layers (63 Mg C ha?1). We conclude that the contribution of mosses is sufficiently large that a moss C pool should be added to national-scale models including the CBM-CFS3, to reduce uncertainties in boreal forest C budget estimation. Feather and sphagnum mosses should be parameterized separately. 相似文献