Using Paleospecies-Area Curves to Predict Biodiversity Changes in Mammals: Linkage of Macroecology and Paleontology

利用古物种-面积曲线预测哺乳动物的生物多样性变化：宏观生态学和古生物学的联系地球的生态系统正受到各种人类影响的围困。因为随着影响的累积，生态系统可能会突然超过可能显著改变它们的阈值，因此必须找到方法来识别何时接近这些阈值。接近阈值的一个早期预警信号是生态系统中相互作用的物种数量--即物种丰富度--的变化。因此，这项研究的重点是建立美国西部物种丰富度的自然基线，以便可以利用观测到的偏离基线的情况来识别生态系统何时处于危险之中。为了确定自然基线，有必要考虑物种丰富度模式如何在比人类寿命长得多的时间内发生变化。这个项目利用哺乳动物的异常良好的化石记录来做到这一点。有关化石和现代哺乳动物出现的信息将被汇总到数据库中，这些数据库将向公众提供，并允许对哺乳动物物种按地理区域和它们生活的时间间隔进行分类。然后对每个地理区域、每个区间的物种丰富度进行统计分析和比较。这样，现代物种丰富度数值可以在这一经验性确定的长期基线的背景下进行解释，而超出自然变异性范围的数值是令人担忧的。这项工作还将培训博士后和研究生有关全球变化问题的知识。

Using Paleospecies-Area Curves to Predict Biodiversity Changes in Mammals: Linkage of Macroecology and PaleontologyThe ecosystems of the Earth are under siege from a variety of human impacts. Because as impacts accumulate, ecosystems can suddenly cross thresholds that may significantly change them, it is imperative to develop ways to recognize when such thresholds are approached. One early warning sign of approaching thresholds is changes in the number of species -- that is, species richness -- that are interacting in the ecosystem. Therefore, this research focuses on establishing the natural baseline for species richness in the American West, so that it becomes possible to use observed deviations from the baseline to recognize when ecosystems are in peril. To establish the natural baseline, it is necessary to take into account how species richness patterns vary over times much longer than human life spans. This project uses the exceptionally good fossil record of mammals to do this. Information on fossil and modern mammal occurrences will be aggregated into databases that will be made available to the public, and which allow sorting of the mammal species into the geographic area and the time interval in which they lived. The species richness per geographic area per interval will then be statistically analyzed and compared. In this way, modern species richness values can be interpreted in the context of this empirically determined, long-term baseline, with values falling outside the natural range of variability being cause for concern. The work also will train postdoctoral and graduate students in global change issues.