Dissertation Research: The influence of metacommunity size and habitat destruction on the scaling of species diversity

栖息地的破坏是物种灭绝的主要原因，因此是一个严重的保护问题。景观中剩余适宜栖息地的数量，以及这些栖息地斑块彼此之间的隔离，可以对景观中的生物多样性产生深远影响。本研究旨在预测生境破坏如何通过对斑块面积和隔离度的影响来改变景观生物多样性，以及生境破坏对生物多样性恢复力的影响。模拟模型对生境破坏对景观生物多样性的影响提供了两种相反的预测。根据栖息地破坏如何改变物种的迁移和灭绝速度，栖息地破坏对生物多样性的影响可能比基于破坏前栖息地面积的随机灭绝模型所预期的更严重或更轻。淡水生态系统受到栖息地破坏（如湿地排水）和干扰（如污染物）的影响，它们可以相互作用，改变其生物多样性的模式，这是本研究的实证部分的重点。对池塘两栖动物和无脊椎动物生物多样性的初步调查结果表明，生境破坏对生物多样性损失的影响比随机灭绝模型所预测的更为严重。为了确定这种模式背后的生物学机制，一项使用人工池塘的实验将研究栖息地破坏如何改变物种迁移和灭绝速度，并影响景观生物多样性丧失的严重程度。第二个实验将研究栖息地破坏如何影响栖息地干扰后水生生物多样性的恢复。这个项目提供了许多机会，包括向公众推广，以及为年轻科学家提供真正的研究经验。到目前为止，已有6名本科生和6名高中生实习生参与了该项目的实地调研。除了获得该领域的经验外，学生们还学习如何将他们所学到的知识传播给他人。本科生有机会写一篇高级荣誉论文，而高中生则通过正式和非正式的环境向他们的社区担任科学推广大使。

Habitat destruction is a leading cause of species extinctions, and thus a serious conservation concern. The amount of remaining suitable habitat within a landscape, as well as the isolation of these habitat patches from one another, can have profound effects on biodiversity across a landscape. This research strives to predict how habitat destruction will alter landscape biodiversity through its effects on patch area and isolation, as well as the consequent influence on the resilience of biodiversity following habitat disturbance. Simulation modeling provides two opposing predictions for the effect of habitat destruction on landscape biodiversity. Depending on how habitat destruction alters species' immigration and extinction rates, habitat destruction can have either more severe or less severe effects on biodiversity than expected from a random-extinction model based upon the pre-destruction habitat area. Freshwater ecosystems are subject to both habitat destruction (e.g. draining of wetlands) and disturbances (e.g. contaminants), which can interact to alter patterns of their biodiversity, and are the focus of the empirical part of this study. Preliminary results from surveys of pond amphibian and invertebrate biodiversity indicate that habitat destruction will have more severe effects on biodiversity loss than expected by a random extinction model. To identify a biological mechanism behind this pattern, an experiment using artificial ponds will examine how habitat destruction can alter species immigration and extinction rates and influence the severity of landscape biodiversity loss. A second experiment will investigate how habitat destruction can affect the recovery of aquatic biodiversity following a habitat disturbance. This project provides many opportunities to incorporate outreach to the general public, as well as to provide young scientists with genuine research experiences. Thus far, 6 undergraduate and 6 high school student interns have had hands-on field research experiences as part of this project. In addition to gaining experience in the field, students learn how to disseminate what they have learned to others. Undergraduate students have opportunities to a write senior honors thesis, while high school students act as science outreach ambassadors to their communities through formal and informal settings.