Testing how interactions between plants and soil microbes influence plant community structure along a climatic gradient

所有的植物都生活在数量庞大、种类繁多的微生物中，这些微生物被称为微生物。一些植物通过提供营养来帮助植物，而另一些则会产生负面影响，比如引起疾病。生态学家现在相信，土壤中的一些微生物可以决定哪些植物物种可以在特定的地方生长，以及这些植物能变得多普遍。因此，微生物可能是一种无形的力量，决定着许多植物的健康，包括那些我们赖以为生的植物。几乎所有的微生物都对环境的变化很敏感。这一点很重要，因为天气的变化——例如降雨减少——可能会极大地影响土壤中哪些微生物茁壮成长，从而影响植物的丰度和分布。反过来，植物可能决定土壤中某些微生物的存在与否，从而造成植物和微生物相互影响的复杂局面。这种“植物-土壤反馈”的想法是一种相对较新的思考植物需要什么以及它们与微生物的生活安排的方式。这项研究将测试土壤微生物对土壤湿度的敏感程度，以及这种敏感性如何影响植物。研究人员将比较沿着德克萨斯州降雨梯度的植物和微生物群落，并将探索本地和非本地植物物种在与沿着该梯度的微生物相互作用方面的差异。这项工作的结果将直接应用于预测和减轻干旱对经济和文化重要生态系统德克萨斯草原的影响。这项研究还将为下一代科学家提供培训机会，包括来自休斯顿大学（一所西班牙裔服务机构）代表性不足群体的学生。调查员将与服务不足的公立学校的孩子们分享她的经验，并将通过当地非营利机构领导教育研讨会。这个项目有三个主要组成部分。首先，温室实验将测试水分有效性如何影响原生和非原生植物物种之间的植物-土壤反馈。该实验将与根显微镜和DNA测序相结合，以确定潜在的植物-土壤反馈效应的候选微生物类群，这是推广植物-土壤反馈反应的关键但往往缺乏的一步。其次，通过田间降水调控试验，首次验证不同降水处理下植物-土壤反馈的变化能否预测植物群落组成的变化。第三，反向土壤移植实验将测试德克萨斯州自然降水梯度中植物-土壤反馈反应的普遍性，这将为植物-土壤对气候的反馈反应是否依赖于历史气候遗产提供见解。鉴于植物-土壤反馈理论成功地将植物-微生物相互作用整合到植物群落生态学的框架中，对影响植物-土壤反馈的因素的更深入的了解可能会改变我们对植物群落结构和植物多样性维持方式的理解。该奖项反映了美国国家科学基金会的法定使命，并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估，被认为值得支持。

All plants live with a huge number and diversity of tiny organisms, called microbes. Some help plants by providing nutrients, whereas others can have negative effects like causing disease. Ecologists now believe that some microbes in the soil can determine which plant species can grow in a particular place and how common those plants can become. Thus, microbes may be an invisible force determining the health of many plants, including those we depend on for food. Practically all microbes are sensitive to changes in the environment. This is important because changes in weather -- decreased rainfall, for example -- could greatly affect which microbes thrive in the soil and therefore the abundance and distribution of plants. Plants, in turn, may determine the presence or absence of certain microbes in the soil, thereby creating a complicated situation in which plants and microbes affect each other's success. This idea of "plant-soil feedback" is a relatively new way of thinking about what plants need and their living arrangements with microbes. This research will test how sensitive soil microbes are to soil moisture and, in turn, how that sensitivity may impact plants. The investigator will compare plant and microbial communities along a gradient of rainfall in Texas and will explore how native and non-native plant species differ in their interactions with microbes along that gradient. Results of this work will have direct applications for predicting and mitigating the effects of drought on an economically and culturally important ecosystem, Texas grasslands. This research will also provide training opportunities for the next generation of scientists, including students from underrepresented groups at the University of Houston, a Hispanic Serving Institution. The investigator will share her experiences with children in under-served public schools and will lead educational workshops through local non-profit agencies.This project has three major components. First, a greenhouse experiment will test how water availability influences plant-soil feedback among native and non-native plant species. The experiment will be paired with root microscopy and DNA sequencing to identify candidate microbial taxa underlying plant-soil feedback effects, a critical, but often lacking step in generalizing plant-soil feedback responses. Second, a precipitation-manipulation experiment in the field will test, for the first time, whether changes in plant-soil feedback can predict changes in plant community composition in the different precipitation treatments. Third, a reciprocal soil transplant experiment will test for generality in plant-soil feedback responses across a natural precipitation gradient in Texas, which will provide insights into whether plant-soil feedback responses to climate may depend on historical climate legacies. Given plant-soil feedback theory's success at integrating plant-microbe interactions into the framework of plant community ecology, deeper insights into the factors that influence plant-soil feedback may transform our understanding of how plant communities are structured and plant diversity is maintained.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.