CRB: Modeling the Effects of Habitat Degradation: An Assessment of the Risk to Population Viability and the Effectiveness of Population Monitoring

9424566鸵鸟栖息地退化经常被认为是物种濒危和灭绝的最重要原因之一。几乎所有恢复濒危物种的计划，或者任何试图保护一个物种，同时仍允许一些发展的折衷计划，都强调种群监测是衡量受威胁种群健康的一种手段。然而，监测衡量栖息地逐渐退化对种群长期生存能力的影响的能力很少得到解决。这项研究将开发具有不同生物和空间复杂性水平的源-汇模型，以探索生境退化对短期种群增长和长期生存能力的影响。将开发和探索通用模型，以及与面临栖息地退化影响的两个经过充分研究的保护兴趣物种相联系的更具体的模型：黄石灰熊和阿拉斯加和加利福尼亚州的海獭种群。模型将被用来调查栖息地退化的影响--特别是种群反应中存在的时间滞后--以及不同监测战略及时检测这些反应的能力。此外，通过将不同复杂性的模型与这些系统相匹配，将解决模型复杂性的水平和充分检测对生境退化的响应所需的现场数据的类型，以及这些预测的稳健性。这项研究不仅将使人们更科学地了解栖息地退化的影响，而且还将改进将监测数据纳入管理和政策决策过程的工作。

9424566 Doak Habitat degradation is frequently cited as one of the most important causes of species endangerment and extinction. Almost all plans for the recovery of endangered species, or any of the compromise plans that try to protect a species while still allowing some development emphasize population monitoring as a means of gauging the health of threatened populations. However, the ability of monitoring to measure impacts of gradual habitat degradation on long-term population viability has rarely been addressed. This research will develop source-sink models with varying levels of biological and spatial complexity to explore the effects of habitat degradation on short-term population growth and long-term viability. General models will be developed and explored, as well as more specific models linked to two well-studied species of conservation interest that face effects of habitat degradation: Yellowstone grizzly bears and sea otter populations in Alaska and California. Models will be used to investigate both the effects of habitat degradation - especially the existence of time lags in population responses - and the abilities of different monitoring strategies to detect these responses in a timely fashion. In addition, by fitting models of varying complexity to these systems, the level of model complexity and the type of field data needed to adequately detect responses to habitat degradation will be addressed, as well as the robustness of these predictions. This research will not only give a better scientific understanding of the effects of habitat degradation, but will also improve the incorporation of monitoring data into the process of management and policy decision-making.