CAREER: An Undergraduate-Intensive Research Program in Experimental Conservation Ecology

生物多样性，即生活在特定地理区域的不同物种的多样性，对当地生态系统的运作非常重要，并满足了人类的许多需求。在生态学和保护生物学中，迫切需要更好地了解导致物种灭绝的潜在过程，目标是开发针对局部、区域乃至最终全球灭绝的预测模型。尽管对生物多样性的普遍威胁是有据可查的，但对于为什么一个物种可能灭绝，而另一些物种则继续对一种特定的干扰或威胁做出反应，人们的共识较少。这表明，理解现代生物多样性丧失的关键问题不是什么导致灭绝，而是为什么一些物种灭绝，而另一些物种幸存下来？这项研究考察了由于各种干扰而造成的水生和陆地环境物种的丧失。这些干扰将包括栖息地面积的丧失，以及捕食者和新物种的引入。将开发数学模型来预测和测试不同的结果。最重要的是确定物种的丧失在多大程度上是由偶然事件单独造成的，以及物种的特征在多大程度上使一些物种比其他物种更容易丧失。这项工作将使本科生参与项目每个阶段的开发、设计和实施。对本科生进行的实验设计和理论研究培训以及建模方法的使用将为下一代科学家解决紧迫的环境问题做好准备。经验数据和观点提供了相互矛盾的证据，即物种灭绝和灭绝最好的解释是随机机会还是选择性的基于特征的过程。这项建议使用人工水生和陆地中生态环境来测试一个框架，以澄清何时仅凭概率或生态决定论，通过物种身份和特征来预测和解释局部和区域灭绝的模式。通过操纵性实验、模型和零分析的结合，本研究将1)检验仅用物种稀有性来解释栖息地丧失引起的局部灭绝的预测；2)确定栖息地丧失后的延迟灭绝(灭绝债务)是随机机会的函数还是选择性的确定性过程的函数；3)检验表面上的选择性干扰，如捕食者的增加和生境的同质化，是否会压倒随机机会和稀有性在解释局部和区域灭绝模式方面的重要性。了解物种灭绝的方式和原因将有助于预测和防止物种灭绝，这对成功管理和保护生物多样性至关重要。

Biodiversity, the variety of different species living in a particular geographic region, is important to the functioning of local ecosystems and provides for many of humanity's needs. There is a pressing need in ecology and conservation biology to better understand the underlying processes leading to species extinction with the goal of developing predictive models for local, regional, and ultimately global extinctions. Although general threats to biodiversity are well-documented, there is less consensus about why one species may go extinct while others persist in response to one particular disturbance or threat. This suggests that the key question to understanding modern biodiversity loss is not what causes extinctions, but why do some species go extinct, while others survive? This study examines the loss of species from aquatic and terrestrial environments due to a variety of disturbances. These disturbances will include the loss of habitat area, and the introduction of predators and novel species. Mathematical models will be developed to predict and test for different outcomes. Of key interest is determining the degree to which the loss of species is due to chance events alone and the degree to which the characteristics of species that make some more susceptible to being lost than others. This work will engage undergraduate students in the development, design and implementation of each stage of the project. This research training of undergraduates in experimental design and theory and the use of modeling approaches will prepare the next generation of scientists to address pressing environmental issues. Empirical data and perspectives provide conflicting evidence as to whether species extirpations and extinctions are best explained by random chance or by selective trait-based processes. This proposal uses artificial aquatic and terrestrial mesocosm environments to test a framework for clarifying when probability alone or ecological determinism, acting through species identity and traits, predict and explain patterns of local and regional extinctions. Through a combination of manipulative experiments, modeling and null analyses, this study will 1) test the prediction that local extinctions caused by habitat loss will be explained by species rarity alone; 2) determine whether delayed extinctions (extinction debt) after habitat loss are the function of random chance or selective, deterministic processes; and 3) test whether ostensibly selective disturbances, such as predator addition and habitat homogenization, may overwhelm the importance of random chance and rarity in explaining patterns of local and regional extinction. Understanding how and why species go extinct will allow for the prediction and prevention of extinctions, which is essential for the successful management and conservation of biodiversity.