OPUS: CRS Predicting establishment, competitive interactions, and mortality in desert shrub populations based on spatial structure and intrinsic water-use efficiencies

在过去的四十年里，美国西部莫哈韦沙漠内的温度和降水量的变化影响了生活在这种沙漠环境中的灌木。气温越来越高，该地区越来越干燥。在这项研究中，将综合39年的干旱落叶灌木种群和生理观测（约265，000个数据点），以促进我们对干旱和厄尔尼诺事件的结合沿着灌木生理学差异如何塑造西部沙漠植物种群结构的理解。这些信息是重要的土地管理人员，资源专家和生态学家，因为他们寻求更好地管理美国西部广泛的干旱地区，并了解未来的气候变化将如何影响这些干旱的土地生态系统。在这项研究中合成的概念使用的数据，已经收集到的，并将空间格局的植物建立和生存与环境变量和内在差异的水利用效率不同的沙漠灌木物种。这项研究旨在了解植物与植物和植物与环境的相互作用如何构建沙漠植物种群，以及气候变化如何影响这些模式。综合的重点是在三个关键的生活史阶段，人口结构受到影响时，导致预测结构的意见：建立，成年人之间的竞争，和人口下降突然和极端干旱。如果未来的气候趋势遵循过去39年的干湿模式，或者如果上个世纪的长期干湿循环回归，这种综合也将产生关于人口结构的生态生理方面将如何变化的预测。这一综合将提供一个框架，以了解荒漠植物中植物生理学的变化如何在种群和种间水平上影响荒漠植物种群的结构，以及这些模式如何受到已经发生的环境变化的影响。该奖项反映了NSF的法定使命，并被认为值得通过利用基金会的智力价值和更广泛的影响进行评估来支持审查标准。

Over the past four decades, changes in both temperature and precipitation within the Mojave Desert of the western United States have impacted shrubs living in this desert environment. Temperatures are increasingly warmer and the region is getting progressively drier. In this study, 39 years of drought-deciduous shrub population and physiological observations (some 265,000 data points) will be synthesized to advance our understanding of how the combination of drought and El Niño events along with differences in shrub physiologies have shaped plant population structure in western deserts. Such information is important for land managers, resource specialists, and ecologists as they seek to better manage extensive arid regions of the western United States and to understand how future changes in climate will impact these arid land ecosystems. The concepts synthesized in this study use data that has already been collected and will link spatial patterns of plant establishment and survival with environmental variables and intrinsic differences in the efficiency of water use by different desert shrub species. This research aims to understand how plant-plant and plant-environment interactions structure desert plant populations and how changes in climate affect these patterns. The focus of the synthesis is on observations leading to predictive constructs at three key life-history stages when population structure is affected: establishment, competition among adult individuals, and population decline under abrupt and extreme droughts. This synthesis will also generate predictions about how ecophysiological aspects of population structure will change if future climate trends follow the wet-dry pattern of the last 39 years or if the long term wet-dry cycles of the last century return. This synthesis will provide a framework for understanding how variation in plant physiology among desert plants operate at both the population and interspecific levels to affect structure of desert plant populations and how these patterns will be affected by the environmental variability already occurring.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.