RAPID: Historical contingency in ecology and restoration: environmental change, year effects, and priority effects in California grasslands

这个项目探讨了气候变化如何影响加州草原上的物种。 它建立在一个长期的实验中，不同的植物种植在不同的地块，然后监测多年。 四年的干旱为这些植物如何应对极端压力提供了一个意想不到的强大考验。 2017年冬、春季，干旱突然结束;降雨量恢复正常水平。 这种条件的巨大变化是罕见的，可能会对仍然生活在地块中的植物类型产生强烈影响。 该奖项提供的资金将允许科学家继续进行至少一年的实验，以衡量这种影响。 了解降雨周期对植物的影响对于管理可能发生长期气候变化的草地非常重要。这是一个长期项目的短期延续，不幸的是，该项目在干旱结束时终止。 该奖项扩展的实验测试了自然群落在干扰后如何发展的两个相反模型。一种理论预测，社区的组成将倾向于恢复到动乱前的状态，不管早期建立的变幻莫测。另一种理论预测，群落组成在很大程度上取决于优先效应（即，物种在扰动后的定居顺序）。这项研究将评估水供应的意外大干扰如何影响社区集会过程的结果。 除了为学生提供研究培训外，调查员还将协助当地的修复项目。

This project explores how climate variation affects species in California grasslands. It builds on a long-term experiment in which different plants were planted in different plots, then monitored for many years. A four-year drought provided an unexpectedly strong test of how those plants respond to extreme stress. In the winter and spring of 2017, the drought suddenly ended; rainfall returned to normal levels. This dramatic change in conditions is a rare event and will likely have a strong influence on the types of plants that still live in the plots. Funding provided by this award will allow scientists to continue the experiment for at least another year to measure that influence. Understanding how cycles of rainfall influence plants is important for management of grasslands in light of possible long-term shifts in weather.This is a short-term continuation of a long-term project that, unfortunately, expired just as the drought was ending. The experiment extended by this award tests two opposing models of how natural communities develop after disturbance. One theory predicts that community composition will tend to return to the pre-disturbance state, regardless of the vagaries of early establishment. The other theory predicts that community composition is largely determined priority effects (i.e., the order in which species colonize after disturbance). The study will assess how an unexpectedly large disturbance in water availability affects the outcome of community assembly processes. In addition to providing training for students in research, the investigator will assist in local restoration projects.