Dissertation Research: Taking the Heat: Mechanisms of adaptive differentiation in response to extreme heat events

有许多研究考察物种对平均条件变化的反应，但很少有研究考察物种对极端事件（如热浪）的反应。极端事件通常是短期事件，对物种的挑战超出了它们的适应能力。在加州，热浪季节预计将延长13周，但目前还不清楚它是开始得早还是结束得晚。这两种可能会对植物产生不同的影响，因为在凉爽潮湿的春天突然出现的高温对植物的影响不同于在干燥的夏天结束时出现的极端高温，那时植物已经适应了高温，但土壤水分利用率很低。此外，由于加利福尼亚的气候差异，物种的反应可能在它们的范围内有所不同，在加利福尼亚，沿海地区受到高温的缓冲，它们的年气候比内陆地区更稳定。如果在气候稳定地点发现的植物适应了稳定的气候，它们可能会受到极端气候增加的不成比例的伤害。我们将确定一个种群内、内陆和沿海种群之间、或偏远种群之间对热浪的反应差异是否更大。我们将制造人工热浪，测量这些热浪前后幼苗的表现和压力，并研究自然发生的热浪对成年植物的影响。热浪对生物多样性构成严重威胁。为了确定威胁的程度，并为保护和管理战略提供强有力的科学依据，我们必须预测对气候变化的反应。这项提议的研究是首批检验当地基因库对热浪反应的影响的研究之一。一种提出的人类适应气候变化的方法是辅助移民。我们的数据将为了解将本地种子移出其家乡气候的后果提供有价值的见解。该项目将直接涉及来自加州大学伯克利分校不同人群的本科生，该项目的科学过程将通过Flat Stanley @ Cal项目向公众传播，该项目将一个学生寄来的纸娃娃与一位在网上写下“冒险”的科学家配对。

There are many studies examining species' responses to changes in average conditions but few studies examine species responses to extreme events (e.g. heatwaves). Extreme events typically are short events that challenge species beyond their ability to acclimate. In California the heatwave season is expected to increase by up to thirteen weeks, yet it remains unclear whether it will start earlier or end later. These two possibilities will have different effects on plants because sudden heat in the cool, wet spring should affect plants differently than extreme heat at the end of the dry summer, when plants have acclimated to high temperatures but soil water availability is low. Moreover, the responses of species may be different across their ranges because of climatic differences across California, where coastal sites are buffered from high temperatures and their annual climate is more stable than inland sites. If plants found in climatically stable sites are adapted to stable climates, they may be disproportionately harmed by increases in climatic extremes. We will determine if variation in response to heatwaves is greater within a population, between inland and coastal populations, or between distant populations. We will create artificial heatwaves and measure performance and stress in seedlings before and after these events and we will study the effect of naturally occurring heatwaves on adult plants.Heatwaves pose a grave threat to biodiversity. To determine the magnitude of threats, and to provide a strong scientific basis for conservation and management strategies, we must forecast responses to climate change. The proposed research is some of the first to examine the influence of local genetic pools on responses to heatwaves. One proposed human adaptation to climate change is assisted migration. Our data will provide valuable insight into the consequences of moving native seed out of its home climate. This project will directly involve undergraduates from the diverse population at UC Berkeley and the scientific process from this project will be disseminated to the public through the Flat Stanley @ Cal Project which pairs a paper doll sent in by a student with a scientist who writes about the "adventure" online.