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

所有的植物都与数量庞大、种类繁多的微生物生活在一起，这些微生物被称为微生物。一些通过提供营养来帮助植物，而另一些则会产生负面影响，比如导致疾病。生态学家现在认为，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，以及这些植物可以变得多常见。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，包括那些我们赖以生存的食物。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，降雨量的减少--可能会极大地影响哪些微生物在土壤中茁壮成长，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或不存在，从而造成植物和微生物相互影响的复杂情况。这种“植物-土壤反馈”的想法是一种相对较新的方式来思考植物需要什么以及它们与微生物的生活安排。这项研究将测试土壤微生物对土壤水分的敏感度，进而测试这种敏感度对植物的影响。研究人员将沿着德克萨斯州的降雨梯度比较植物和微生物群落，并将探索本地和非本地植物物种在与微生物沿梯度相互作用方面的不同之处。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上重要的生态系统--德克萨斯州草原的影响。这项研究还将为下一代科学家提供培训机会，包括来自西语裔服务机构休斯顿大学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儿童分享她的经验，并将通过当地非营利性机构领导教育讲习班。该项目包括三个主要部分。首先，温室实验将测试水的可用性如何影响本地和非本地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，田间降水控制实验将首次检验植物-土壤反馈的变化是否可以预测不同降水处理下植物群落组成的变化。第三，一个相互的土壤移植实验将测试德克萨斯州自然降水梯度上植物-土壤反馈反应的共性，这将为植物-土壤对气候的反馈反应是否可能取决于历史气候遗产提供见解。鉴于植物-土壤反馈理论在将植物-微生物相互作用整合到植物群落生态学框架中的成功，对影响植物-土壤反馈的因素的更深入的洞察可能会改变我们对植物群落是如何构建和维持植物多样性的理解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.