LTREB: Effects of Recent Environmental Change on the Pinyon-Herbivore-Mycorrhizal Community of Sunset Crater

9615313 Whitham对自然扰动的研究有助于理解植物如何在生态和/或进化上对气候变化做出反应。自从大约公元1300年日落陨石坑喷发以来，殖民植物只有几百年的时间来适应这种更热、更干燥、营养更差的煤渣环境。这项LTREB项目是对这些环境压力如何影响松树及其依赖的社区成员的15年研究的继续。与生长在低应力沙壤土中的树木相比，生长在煤渣中的树木产生的防御性树脂较少，遭受长期的昆虫暴发，菌根互助体、生长和球果产量也相应下降。这反过来又会影响依赖松子生存的鸟类和哺乳动物。树木遗传学的相关变化表明，这种新环境施加的选择压力导致了植物种群的遗传调整。依赖菌根、节肢动物和脊椎动物的分布映射到植物种群的潜在遗传结构上。由于自有记录以来，西南部经历了普遍的变暖，目前正在遭受百年一遇的干旱记录，通过将日落陨石坑与邻近压力较小的控制点进行对比，PI可以解决这样一个问题，“日落陨石坑与全球气候变化相似吗？如果是，它如何被用来预测持续变暖趋势对生态和进化的影响？”继续对个别树木进行长期监测以及相关的长期实验将为这一重要问题提供明确的答案。

9615313 Whitham Studies of natural perturbations help understand how plants ecologically and/or evolutionarily respond to climate change. Since the eruption of the Sunset Crater in about 1300AD, colonizing plants have had only a few hundred years to adapt to this hotter, dryer, and nutrient poor cinder environment. This LTREB project represents a continuation of a 15 year study on how these environmental stresses have affected pinyon pine and its dependent community members. Compared to trees growing in low stress sandy-loam soils, trees growing in cinders produce less defensive resin, suffer chronic insect outbreaks, and suffer corresponding declines in mycorrhizal mutualists, growth and cone production. This in turn affects birds and mammals dependent upon pinyon seeds for their survival. Associated changes in tree genetics suggest that the selection pressures imposed by this new environment have resulted in genetic adjustments in the plant population. The distributions of dependent mycorrhiza, arthropods, and vertebrates map onto the underlying genetic structure of the plant population. Because the southwest has experienced general warming since the beginning of record keeping and is currently suffering a 100-year record drought, by contrasting Sunset Crater with adjacent less stressed control sites, the PI's can address the question, "Is Sunset Crater an analogue to global climate change and if so, how can it be used to predict the ecological and evolutionary impacts of continuing warming trends?" The continuation of long-term monitoring of individual tress and the associated long-term experiments will provide a clear answer to this important question.