Coexistence in a Changing Environment

气候变化对生物多样性构成日益严重的威胁。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量的变化增加。虽然理论表明气候变化对竞争物种的共存有重要影响，但缺乏适当的数据阻碍了对这一理论的严格检验。在这里提出的研究利用独特的历史数据集，以测试气候变化的影响，共存的半干旱生态系统的美国西部在早期和中期的世纪，生态学家在一些外地站的所有个别植物物种的小地块的年度地图。该项目涉及将这些原始地图数字化，然后利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，研究结果将量化气候变异性在维持五个分布广泛、具有重要经济意义的牧场生态系统的生物多样性方面的作用。这些结果将为一般生态理论提供一个重要的检验，也是预测气候变率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.