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51.
DANIEL P. FAITH 《Conservation biology》2008,22(6):1461-1470
Abstract: New species conservation strategies, including the EDGE of Existence (EDGE) program, have expanded threatened species assessments by integrating information about species' phylogenetic distinctiveness. Distinctiveness has been measured through simple scores that assign shared credit among species for evolutionary heritage represented by the deeper phylogenetic branches. A species with a high score combined with a high extinction probability receives high priority for conservation efforts. Simple hypothetical scenarios for phylogenetic trees and extinction probabilities demonstrate how such scoring approaches can provide inefficient priorities for conservation. An existing probabilistic framework derived from the phylogenetic diversity measure (PD) properly captures the idea of shared responsibility for the persistence of evolutionary history. It avoids static scores, takes into account the status of close relatives through their extinction probabilities, and allows for the necessary updating of priorities in light of changes in species threat status. A hypothetical phylogenetic tree illustrates how changes in extinction probabilities of one or more species translate into changes in expected PD. The probabilistic PD framework provided a range of strategies that moved beyond expected PD to better consider worst‐case PD losses. In another example, risk aversion gave higher priority to a conservation program that provided a smaller, but less risky, gain in expected PD. The EDGE program could continue to promote a list of top species conservation priorities through application of probabilistic PD and simple estimates of current extinction probability. The list might be a dynamic one, with all the priority scores updated as extinction probabilities change. Results of recent studies suggest that estimation of extinction probabilities derived from the red list criteria linked to changes in species range sizes may provide estimated probabilities for many different species. Probabilistic PD provides a framework for single‐species assessment that is well‐integrated with a broader measurement of impacts on PD owing to climate change and other factors. 相似文献
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Pollution due to persistent pesticides is not a regional but a global problem. Organochlorine pesticides are persistent chemicals, stored and accumulated in the tissues of a wide variety of invertebrates and vertebrates including marine species. In the present study the organochlorine residues HCHs, DDTs and PCBs were measured in different trophic groups of birds (scavengers, inland piscivores, coastal piscivores, insectivores, granivores and omnivores) collected from Tamil Nadu Coast, India. The residue accumulation as a function of sex did not depict distinct variation. However, females had lower residue levels than males in terms of their mean weight and feeding habits. A continuous monitoring programme is recommended to establish the studied organisms as indicator species. 相似文献
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Nickel pollution is a serious environmental problem, and its effects may provoke alterations in the ecosystem and in organism of animals and humans. Dermatitis, eczema, and asthma are some illnesses caused by Ni2+ poisoning. In this work, fish fed either Ni2+-enriched pellets or commercial pellets were studied. The amount of Ni2+ in fish were measurements by adsorptive stripping voltammetry (AdSV) with dimethylglyoxime as a complexing agent. The analysis of Ni2+ in fish by AdSV established that its accumulation occurs principally in viscera (670.86 ± 5.82 µg g?1), in the head (697.12 ± 2.77 µg g?1) and in the muscle (405.82 ± 3.26 µg g?1), both after 12 months of experiments. Ni2+ adsorbs preferentially in organs such as the stomach, the intestine, and the kidneys and acts in the central nervous system as well. Tilapia growth and mass were significantly affected by Ni2+ poisoning. From statistical analysis, observed that the results for lengths, weights and metal concentration were different for each sampling at significance level of p < 0.05. The Ni2+ concentration in tilapia was enough to cause the death of tilapias; however, it did not occur because the presence of Zn2+ might act as protective agent of heavy metals. 相似文献
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Six Biological Reasons Why the Endangered Species Act Doesn't Work—And What to Do About It 总被引:1,自引:0,他引:1
DANIEL J. ROHLF 《Conservation biology》1991,5(3):273-282
Abstract: Law plays an important role in shaping land management decisions. The success of efforts to conserve biodiversity thus depends to a large degree on how well scientific knowledge is translated into public policy. Unfortunately, the Endangered Species Act, the United States's strongest legal tool for conserving bidodiversity, contains serious biological flaws. The statute itself, as well us agency regulations and policies that implement the law include provisions that fail to account accurately for important biological concepts such us ecosystem conservation, patch dynamics, and the probabilistic nature of stochastic threats to a species' persistence. Moreover, the procedures of federal agencies charged with implementing the Endangered Species Act in some cases make it difficult for interested outside reviewers to evaluate the agencies' scientific findings and methodology. However, the Endangered Species Act also gives interested individuals and groups several opportunities to provide input into the process of managing threatened and endangered species. Conservation biologists should practice focused advocacy by taking advantage of such opportunities to steer law in a more biologically sound direction. 相似文献
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Isla Victoria (Nahuel Huapi National Park, Argentina), a large island dominated by native Nothofagus and Austrocedrus forest, has old plantations of many introduced tree species, some of which are famed invaders of native ecosystems elsewhere.
There are also large populations of introduced deer and shrubs that may interact in a complex way with the introduced trees,
as well as a recently arrived population of wild boar. Long-standing concern that the introduced trees will invade and transform
native forest may be unwarranted, as there is little evidence of progressive invasion, even close to the plantations, despite
over 50 years of opportunity. Introduced and native shrubs allow scattered introduced trees to achieve substantial size in
abandoned pastures, but in almost all areas neither the trees nor the shrubs appear to be spreading beyond these sites. These
shrub communities may be stable rather than successional, but the technology for restoring them to native forest is uncertain
and probably currently impractical. Any attempt to remove the exotic tree seedlings and saplings from native forest would
probably create the very conditions that would favor colonization by exotic plants rather than native trees, while simply
clear-cutting the plantations would be unlikely to lead to regeneration of Nothofagus or Austrocedrus. The key to maintaining native forest is preventing catastrophic fire, as several introduced trees and shrubs would be favored
over native dominant trees in recolonization. Deer undoubtedly interact with both native and introduced trees and shrubs,
but their net effect on native forest is not yet clear, and specific management of deer beyond the current hunting by staff
is unwarranted, at least if preventing tree invasion is the goal. The steep terrain and shallow soil make the recently arrived
boar a grave threat to the native forest. Eradication is probably feasible and should be attempted quickly. 相似文献
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Job dimensions of autonomy, variety, and feedback were objectively manipulated to evaluate their effect on perceptions of job characteristics and on job outcomes. Except for feedback level, manipulations and perceptions independently predicted satisfaction, and one significant two-way interaction emerged. In a high variety task, increased autonomy led to increased satisfaction, while in a low variety task, increased autonomy had a negligible effect on satisfaction. For performance, objective variety and autonomy also interacted, indicating that in a low variety task, autonomy had little impact, while in a high variety task, increased autonomy contributed 16 per cent to performance. In addition, autonomy and feedback interacted with one another, with increased feedback in a high autonomy task again contributing 16 per cent to performance, while increased feedback in a low autonomy task had little impact on performance. Findings are discussed from both the Job Characteristics Model and control theory perspectives. 相似文献
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GRAEME C. HAYS JEANNE A. MORTIMER DANIEL IERODIACONOU NICOLE ESTEBAN 《Conservation biology》2014,28(6):1636-1644
Large marine protected areas (MPAs), each hundreds of thousands of square kilometers, have been set up by governments around the world over the last decade as part of efforts to reduce ocean biodiversity declines, yet their efficacy is hotly debated. The Chagos Archipelago MPA (640,000 km2) (Indian Ocean) lies at the heart of this debate. We conducted the first satellite tracking of a migratory species, the green turtle (Chelonia mydas), within the MPA and assessed the species’ use of protected versus unprotected areas. We developed an approach to estimate length of residence within the MPA that may have utility across migratory taxa including tuna and sharks. We recorded the longest ever published migration for an adult cheloniid turtle (3979 km). Seven of 8 tracked individuals migrated to distant foraging grounds, often ≥1000 km outside the MPA. One turtle traveled to foraging grounds within the MPA. Thus, networks of small MPAs, developed synergistically with larger MPAs, may increase the amount of time migrating species spend within protected areas. The MPA will protect turtles during the breeding season and will protect some turtles on their foraging grounds within the MPA and others during the first part of their long‐distance postbreeding oceanic migrations. International cooperation will be needed to develop the network of small MPAs needed to supplement the Chagos Archipelago MPA. Uso de los Patrones de Migración a Larga Distancia de una Especie en Peligro de Extinción para Informar a la Planeación de la Conservación del Área Marina Protegida más Grande 相似文献
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Abstract: Climate change affects individual organisms by altering development, physiology, behavior, and fitness, and populations by altering genetic and phenotypic composition, vital rates, and dynamics. We sought to clarify how selection, phenotypic plasticity, and demography are linked in the context of climate change. On the basis of theory and results of recent empirical studies of plants and animals, we believe the ecological and evolutionary issues relevant to population persistence as climate changes are the rate, type, magnitude, and spatial pattern of climate‐induced abiotic and biotic change; generation time and life history of the organism; extent and type of phenotypic plasticity; amount and distribution of adaptive genetic variation across space and time; dispersal potential; and size and connectivity of subpopulations. An understanding of limits to plasticity and evolutionary potential across traits, populations, and species and feedbacks between adaptive and demographic responses is lacking. Integrated knowledge of coupled ecological and evolutionary mechanisms will increase understanding of the resilience and probabilities of persistence of populations and species. 相似文献