Coexistence in a Changing Environment

气候变化对生物多样性构成越来越重要的威胁。许多研究都集中在平均气温上升将如何影响生态群落，但气候变化也预计会导致降水变异性的增加。尽管理论表明，气候变化可能会对相互竞争的物种的共存产生重要影响，但由于缺乏适当的数据，这一理论无法进行严格的测试。这里提出的研究利用独特的历史数据集来测试气候变化对美国西部半干旱生态系统共存的影响。在20世纪初和中期，许多野外站点的生态学家在小块土地上绘制了所有单个植物物种的年度地图。该项目包括将这些原始地图数字化，然后使用统计分析和计算机模型来测试气候变异性是促进还是减少物种多样性。这项研究的结果将量化气候变异性在维持五个广泛且具有经济重要性的牧场生态系统中的生物多样性的作用。这些结果将是对一般生态学理论的一次重要检验，也是预测气候变异性预测增加的生态影响的第一步。对历史数据进行数字存档是一项同样重要的贡献，因为它将为整个科学界提供一个无与伦比的机会，通过研究过去来了解未来。

Climate change poses an increasingly important threat to biodiversity. Much research has focused on how increasing mean temperatures will affect ecological communities, but climate change is also predicted to cause an increase in precipitation variability. Although theory shows that climate variability can have important effects on the coexistence of competing species, a lack of appropriate data has prevented rigorous tests of this theory. The research proposed here takes advantage of unique historical datasets to test the influence of climate variability on coexistence in semiarid ecosystems of the western U.S. During the early and mid-20th century, ecologists at a number of field stations made annual maps of all individual plants species in small plots. This project involves digitizing these original maps and then using statistical analyses and computer models to test whether climate variability promotes or reduces species diversity.Results from this research will quantify the role of climate variability in maintaining biodiversity in five widespread and economically important rangeland ecosystems. These results will provide an important test of general ecological theory as well as a first step towards forecasting the ecological effects of predicted increases in climate variability. Digitally archiving the historical data represents an equally important contribution, since it will give the entire scientific community an unparalleled opportunity to learn about the future by studying the past.