RAPID: Using the historic Californian drought to gain a predictive understanding of the effects of severe climatic events on plant communities

加利福尼亚州弗洛里斯特省的干旱最近达到了创纪录的严重程度，2013年的降雨量是历年有记录以来最低的。这项拟议的研究将测试关于哪些植物物种和植物群落最容易受到严重干旱的影响，以及哪些植物更耐干旱的预测。这将通过从加利福尼亚州之前的五项研究网站收集新数据来完成。这些先前的研究中的每一项都考察了水的可获得性如何影响植物群落，使用的方法要么是试验性的水量增加，要么是多雨和少雨年份的比较，或者是不同降雨量的地理位置的比较。这些研究中的每一项都提供了证据，表明植物物种和群落的哪些特征使它们对水的可获得性或多或少敏感。利用2014年收集的数据，之前研究过的同一植物群落将在干旱前后进行比较，从而使这项研究能够记录哪些物种和群落在应对干旱方面变化最大。接下来，这项研究将检验干旱前后的变化是否与基于之前五项研究的预测一致。作为预期结果的一个例子，预测具有小而厚的叶片的物种将比具有更宽和更薄的叶片的物种的丰度下降得更少，因为这些特征以前被发现预测植物物种对可用水的敏感性。这项研究迫在眉睫，因为干旱的影响只能通过在2014年春夏对五个数据集的密集重采样来量化。这项研究将确认或拒绝关于陆地植物物种和群落属性的概括性预测，这些属性使它们或多或少容易受到干旱的影响。预计严重干旱将随着气候变化而恶化，因此本研究可能在预测植物群落组成随气候变化而变化方面具有很大的应用潜力。此外，这项研究将涉及一名女性博士后研究员。在主要研究地点，研究人员将继续为一个外展计划做出贡献，该计划每年向服务不足地区的500名K-12学生提供实地科学学习机会。

Drought in the California Floristic Province has recently reached record-setting severity, with 2013 having the lowest precipitation ever recorded in a calendar year. The proposed study will test predictions about which plant species and plant communities are most vulnerable to severe droughts and which ones are more resistant to drought. This will be done by gathering new data from the sites of five previous studies across California. Each of these previous studies examined how water availability affected plant communities, using either experimental water additions, comparisons of wetter and drier years, or comparisons of geographic locations with differing amounts of rainfall. Each of these studies provided evidence about which characteristics of plant species and communities make them more or less sensitive to water availability. Using the data collected in 2014, the same plant communities previously studied will be compared after versus before the drought, allowing this study to document which species and communities have changed the most in response to the drought. Next, this study will test whether the changes seen after versus before the drought are consistent with predictions based on the five earlier studies. As one example of the expected results, it is predicted that species with small, thick leaves will decline less in abundance than species with broader and thinner leaves, because these characteristics were previously found to predict the sensitivity of plant species to water availability. This research is urgent because effects of the drought can only be quantified by intensive resampling of the five datasets in spring-summer 2014.This study will confirm or reject generalizable predictions about the attributes of terrestrial plant species and communities that render them more or less vulnerable to drought. Severe droughts are expected to worsen with climate change, and so this research may have great potential applications to prediction of plant community composition with climate change. Additionally, the research will involve a female postdoctoral researcher. At the principal study location, the researchers will continue contributing to an outreach program that provides field science learning opportunities to 500 K-12 students per year in an under-served area.