CAREER: Microclimate Amelioration Underlying Biodiversity-Ecosystem Functioning Research

该奖项全部或部分由2021年美国救援计划法案（公法117- 2）资助。许多物种目前面临灭绝的威胁。这种灭绝危机对生态系统的功能有重要影响。特别是，物种的丧失可能导致数千年来一直存在的生物缓冲区的丧失。这些缓冲的丧失可能使系统更容易受到干旱等压力因素的影响。了解生物多样性如何帮助缓冲我们的生态系统免受环境压力的影响是预测未来保护后果的重要下一步。这种理解也将帮助我们理解生态系统如何可能在更少的物种下保持功能。该项目研究了不同种类的植物如何改变周围的微气候，例如降低温度，增加湿度和增加土壤湿度。微气候的改变可能是多种物种共存的重要机制，是生物多样性的关键。该项目还为研究生和本科生提供研究机会和教育。该项目测试微气候改变效应在确定生物多样性和生态系统功能之间关系方面的作用。该方法是设计一系列的生物多样性小气候加湿实验，无论是在温室设置和在整个洛杉矶县，加州的网站网络。实验中使用了几种原产于加州的草，因为它们对变化的湿度条件非常敏感。该项目从三个重要方面审查了小气候改变的影响：（1）利用生物多样性实验来检验小气候改善的强度，以及它是否可以解释自然干旱条件下生物多样性-生态系统功能的正相关关系，（2）利用仔细的生理测量来评估小气候改善是否由植物功能性状驱动（如生根深度或水分利用效率），整个群落结构（例如，冠层复杂性和边界层条件），或仅仅创建物理遮阳屏障，以及（3）研究城市干旱生态系统中高等植物多样性群落小气候改善的作用。该奖项反映了NSF的法定使命，通过使用基金会的知识价值和更广泛的影响审查标准进行评价，认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117- 2).Many species are currently threatened with extinction. This extinction crisis has important implications for how ecosystems function. In particular, loss of species may lead to loss of biological buffers that have been in place for thousands of years. The loss of these buffers could make systems more vulnerable to stressors such as drought. Understanding how biodiversity helps buffer our ecosystems from environmental stressors is an essential next step to predicting the consequences of future extinctions. This understanding will also help us understand how ecosystems can possibly retain function with fewer species. This project examines how different species of plants can modify the microclimate around them, such as decreased temperatures, increased humidity and increased soil moisture. The modification of microclimate may be one important mechanism allowing many species to coexist, which is a key to biodiversity. This project also provides research opportunities and education to graduate students and undergraduate students.This project tests the role of microclimate modification effects in determining relationships between biodiversity and ecosystem function. The approach is to design a series of biodiversity microclimate humidification experiments both in a greenhouse setting and in a network of sites across Los Angeles County, California. Several species of grasses native to California are used in the experiments because they are very sensitive to changing moisture conditions. This project examines microclimate modification effects in three important ways: (1) using a biodiversity experiment to examine the strength of microclimate amelioration and whether it can explain positive biodiversity-ecosystem function relationships under natural drought conditions, (2) using careful physiological measurements to assess whether microclimate amelioration is driven by plant functional traits (e.g. rooting depth or water use efficiency), whole community structure (e.g. canopy complexity and boundary layer conditions), or merely creating a physical shade barrier, and (3) examining the role of microclimate amelioration in higher plant diversity communities in an urban arid ecosystem.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.