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991.
CARLOS ROBERTO FONSECA 《Conservation biology》2009,23(6):1507-1515
Abstract: Habitat loss is silently leading numerous insects to extinction. Conservation efforts, however, have not been designed specifically to protect these organisms, despite their ecological and evolutionary significance. On the basis of species–host area equations, parameterized with data from the literature and interviews with botanical experts, I estimated the number of specialized plant‐feeding insects (i.e., monophages) that live in 34 biodiversity hotspots and the number committed to extinction because of habitat loss. I estimated that 795,971–1,602,423 monophagous insect species live in biodiversity hotspots on 150,371 endemic plant species, which is 5.3–10.6 monophages per plant species. I calculated that 213,830–547,500 monophagous species are committed to extinction in biodiversity hotspots because of reduction of the geographic range size of their endemic hosts. I provided rankings of biodiversity hotspots on the basis of estimated richness of monophagous insects and on estimated number of extinctions of monophagous species. Extinction rates were predicted to be higher in biodiversity hotspots located along strong environmental gradients and on archipelagos, where high spatial turnover of monophagous species along the geographic distribution of their endemic plants is likely. The results strongly support the overall strategy of selecting priority conservation areas worldwide primarily on the basis of richness of endemic plants. To face the global decline of insect herbivores, one must expand the coverage of the network of protected areas and improve the richness of native plants on private lands. 相似文献
992.
ANNI ARPONEN MAR CABEZA JOHANNA EKLUND HEINI KUJALA JOONA LEHTOMÄKI 《Conservation biology》2010,24(5):1198-1204
Abstract: Recent literature on systematic conservation planning has focused strongly on economics. It is a necessary component of efficient conservation planning because the question is about effective resource allocation. Nevertheless, there is an increasing tendency toward economic factors overriding biological considerations. Focusing too narrowly on economic cost may lead us back toward solutions resembling those obtained by opportunistic choice of areas, the avoidance of which was the motivation for development of systematic approaches. Moreover, there are many overlooked difficulties in incorporating economic considerations reliably into conservation planning because available economic data and the free market are complex. For instance, economies based on free markets tend to be shortsighted, whereas biodiversity conservation aims far into the future. Although economic data are necessary, they should not be relied on too heavily or considered separately from other sociopolitical factors. We suggest focusing on development of more‐comprehensive ecological‐economic modeling, while not forgetting the importance of purely biological analyses that are needed as a point of reference for evaluating conservation outcomes. 相似文献
993.
Abstract: The search for generalities in ecology has often been thwarted by contingency and ecological complexity that limit the development of predictive rules. We present a set of concepts that we believe succinctly expresses some of the fundamental ideas in conservation biology. (1) Successful conservation management requires explicit goals and objectives. (2) The overall goal of biodiversity management will usually be to maintain or restore biodiversity, not to maximize species richness. (3) A holistic approach is needed to solve conservation problems. (4) Diverse approaches to management can provide diverse environmental conditions and mitigate risk. (5) Using nature's template is important for guiding conservation management, but it is not a panacea. (6) Focusing on causes not symptoms enhances efficacy and efficiency of conservation actions. (7) Every species and ecosystem is unique, to some degree. (8) Threshold responses are important but not ubiquitous. (9) Multiple stressors often exert critical effects on species and ecosystems. (10) Human values are variable and dynamic and significantly shape conservation efforts. We believe most conservation biologists will broadly agree these concepts are important. That said, an important part of the maturation of conservation biology as a discipline is constructive debate about additional or alternative concepts to those we have proposed here. Therefore, we have established a web‐based, online process for further discussion of the concepts outlined in this paper and developing additional ones. 相似文献
994.
995.
PAUL D. HIRSCH WILLIAM M. ADAMS J. PETER BROSIUS ASIM ZIA NINO BARIOLA JUAN LUIS DAMMERT 《Conservation biology》2011,25(2):259-264
Abstract: There is a growing recognition that conservation often entails trade‐offs. A focus on trade‐offs can open the way to more complete consideration of the variety of positive and negative effects associated with conservation initiatives. In analyzing and working through conservation trade‐offs, however, it is important to embrace the complexities inherent in the social context of conservation. In particular, it is important to recognize that the consequences of conservation activities are experienced, perceived, and understood differently from different perspectives, and that these perspectives are embedded in social systems and preexisting power relations. We illustrate the role of trade‐offs in conservation and the complexities involved in understanding them with recent debates surrounding REDD (Reducing Emissions from Deforestation and Degradation), a global conservation policy designed to create incentives to reduce tropical deforestation. Often portrayed in terms of the multiple benefits it may provide: poverty alleviation, biodiversity conservation, and climate‐change mitigation; REDD may involve substantial trade‐offs. The gains of REDD may be associated with a reduction in incentives for industrialized countries to decrease carbon emissions; relocation of deforestation to places unaffected by REDD; increased inequality in places where people who make their livelihood from forests have insecure land tenure; loss of biological and cultural diversity that does not directly align with REDD measurement schemes; and erosion of community‐based means of protecting forests. We believe it is important to acknowledge the potential trade‐offs involved in conservation initiatives such as REDD and to examine these trade‐offs in an open and integrative way that includes a variety of tools, methods, and points of view. 相似文献
996.
M. T. H. Ragab M. H. K. Abdel‐Kader J. A. Ivany 《Journal of environmental science and health. Part. B》2013,48(2):301-304
Abstract Carbofuran was applied over seeded rutabaga cv. York and residues (corrected for recovery) of carbofuran, 3‐hydroxy‐ and 3‐ketocarbofuran in the harvested roots averaged 0.15, 0.23 and 0.07 ppm in peel and 0.09, 0.14 and 0.05 ppm in pulp, respectively. Samples were extracted by hot acid digestion, partitioned in methylene chloride and cleaned up on Florisil. The 3‐hydroxy‐carbofuran was ethoxylated and the compounds were converted into their dinitrophenyl ethers and analysed by electron capture gas chromatography using 3% OV‐3 column. 相似文献
997.
Effects of Forest Fragmentation on Seed Dispersal and Seedling Establishment in Ornithochorous Trees
Abstract: Habitat fragmentation increases seed dispersal limitation across the landscape and may also affect subsequent demographic stages such as seedling establishment. Thus, the development of adequate plans for forest restoration requires an understanding of mechanisms by which fragmentation hampers seed delivery to deforested areas and knowledge of how fragmentation affects the relationship between seed‐deposition patterns and seedling establishment. We evaluated the dispersal and recruitment of two bird‐dispersed, fleshy‐fruited tree species (Crataegus monogyna and Ilex aquifolium) in fragmented secondary forests of northern Spain. Forest fragmentation reduced the probability of seed deposition for both trees because of decreased availability of woody perches and fruit‐rich neighborhoods for seed dispersers, rather than because of reductions in tree cover by itself. The effects of fragmentation went beyond effects on the dispersal stage in Crataegus because seedling establishment was proportional to the quantities of bird‐dispersed seeds arriving at microsites. In contrast, postdispersal mortality in Ilex was so high that it obscured the seed‐to‐seedling transition. These results suggest that the effects of fragmentation are not necessarily consistent across stages of recruitment across species. Habitat management seeking to overcome barriers to forest recovery must include the preservation, and even the planting, of fleshy‐fruited trees in the unforested matrix as a measure to encourage frugivorous birds to enter into open and degraded areas. An integrative management strategy should also explicitly consider seed‐survival expectancies at microhabitats to preserve plant‐population dynamics and community structure in fragmented landscapes. 相似文献
998.
Abstract: Information required to evaluate the extent to which species are at risk of extinction is usually limited and characterized as highly uncertain. In this context, we define information availability as the presence or absence of information used to determine the value of an ecological variable. We examined which of three hypothetical approaches best matched how levels of risk are assigned to species: (1) precautionary approach in which analysts designate levels of risk regardless of the amount of information available, (2) worst‐case approach in which analysts assign the maximum level of risk possible from the criteria, and (3) insurance approach in which analysts assign poorly known species to a high‐risk category when little information is available. We used the quantitative assessment criteria of the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as a case study. We created a binary (0/1) matrix of all 2.4192 × 107 logical combinations of available information for the 14 ecological variables included in the quantitative criteria. We processed each combination of information availability represented in the matrix with a computer algorithm designed to emulate COSEWIC decision‐making rules. Low information availability was associated with a relatively high frequency of not being able to assign a candidate taxon to a risk category, which does not follow the precautionary principle. Information availability and the level of risk assigned to species were directly related, which is associated with the worst‐case approach, and counter to the insurance approach. Our results suggest that information availability can have a major effect on the level of risk assigned to a species. We recommend a conscious determination of whether such effects are desired, and we recommend the development of methods to explicitly characterize and incorporate information availability and other sources of uncertainty in decision‐making processes. 相似文献
999.
利用3D打印灵活可控的特点和复合材料混合打印的优势,将可见光响应的ZnO/g-C3N4催化剂掺入ABS塑料,利用3D打印制成催化剂均匀稳定分布的光催化系统,使用流体动力学仿真模拟对反应器结构进行优化设计,用于处理相对密闭的室内空间中的病毒气溶胶.结果表明,病毒气溶胶比细菌气溶胶具有更强的抗逆性,添加螺旋导流板可以显著提升反应器传质性能并有效改善系统光催化效果,以提高对病毒气溶胶的去除率.以商业LED灯为光源的螺旋式反应器对高浓度病毒气溶胶(MS2、PhiX174噬菌体)和细菌气溶胶(大肠杆菌)具有高效去除效果,在3.75min停留时间可以实现对气溶胶的完全去除. 相似文献
1000.
Abstract: Domestic dogs (Canis familiaris) and cats (Felis catus) are the most abundant mammalian carnivores worldwide. Given that domestic carnivores rely on human‐provided food, their densities are usually independent of prey densities. Nevertheless, underfed pets may need to hunt to meet their energetic and nutritional requirements. We explored the effects of different levels of care (provision of food) of dogs and cats on their predation rates on wild vertebrates in 2 areas of southern Chile. We interviewed cat and dog owners and analyzed prey remains in scats of pets to examine how domestic dogs and cats were managed and to gather information on the wild vertebrates killed and harassed by pets. We used logistic regression to examine the association between pet care and the frequency of wild vertebrate remains in scats. The probability of a dog preying on vertebrates was higher for poorly fed than for adequately fed dogs (odds ratio = 3.7) and for poorly fed than for adequately fed cats (odds ratio = 4.7). Domestic dogs and cats preyed on most endemic and threatened mammals present in the study sites. Our results provide support for the hypothesis that the less care domestic animals receive from owners the higher the probability those animals will prey on wild vertebrates. 相似文献