The causes and consequences of diversity in ecological communities

我的长期目标是确定栖息地的丧失和退化如何影响生态群落，以及这些生态群落的变化如何影响生态系统的结构和功能。我将使用大规模实验和研究综合技术来做到这一点。短期内我将回答三个问题，1.生物相互作用对推动种群和群落动态是否重要？2.全球两栖动物数量下降的主要原因是什么？3.道路和道路建设如何影响池塘繁殖的两栖动物群落？为了回答第一个问题，我将用两种方法来回答第一个问题。第一种方法是全池塘实验，6个池塘被从池塘表面延伸到池塘底部的巨大不透水帷幕分开。所有两栖动物物种都被排除在6个重复池塘的一半之外，但允许进入另一半池塘。然后，我们监测池塘两边的水质和水生无脊椎动物和植物的丰度，看看两栖动物群落是否在池塘动态中发挥重要作用。第二种方法使用公开的数据集来检验生态群落中物种之间的协方差。我们使用一个简单的统计程序来检验自然群落中物种之间的负协方差，为了回答第二个问题，我们将使用1000多个两栖动物种群时间序列的数据集，并检查两栖动物丰度与两栖动物数量下降的可疑机制之间的相关性，如UV-B射线暴露和栖息地丧失和退化。为了回答第三个问题，我们设计了一个控制后影响(BACI)实验，以监测拟建道路建设区附近池塘中的两栖动物种群，包括道路建设前后。我们将比较这些池塘中的变化与不在道路建设工地附近的类似池塘中的变化。

My long-term objectives are to determine how habitat loss and degradation affect ecological communities, and how those changes in ecological communities affect ecosystem structure and  function.  I will do this using large-scale experiments and research synthesis techniques.  In the short-term I will address three questions, 1. Are biotic interactions important in driving population and community dynamics?; 2.  What are the primary causes of global amphibian declines?; 3.  How do roads and road construction affect pond-breeding amphibian communities?To answer the first question I will use two approaches.  The first involves whole-pond experiments where 6 ponds are split by a large impermeable curtain extending from the surface of the pond to the pond bottom. All amphibian species are excluded from one half of 6 replicate ponds, but allowed access in the other half.  Then we monitor water quality and the abundance of aquatic invertebrates and plants in both halves of the ponds to see if the amphibian communities play an important role in pond dynamics.  The second approach uses publicly available datasets to examine covariance among species in ecological communities.  Using a simple statistical procedure we test for negative covariance among species in natural communities, which we would expect if competition is an important driver of population and community dynamics.To answer the second question we will use a dataset of more than 1000 amphibian population time series and examine the correlation between amphibian abundance and suspected mechanisms of amphibian decline like UV-B ray exposure and habitat loss and degradation.To answer the third question we have designed a Before-After-Control-Impact (BACI) experiment to monitor amphibian populations at ponds near proposed road construction areas, both before and after road construction.  We will compare changes over time in those ponds with changes in similar ponds that are not near road construction sites.