MCA: Plant-soil feedbacks and population dynamics of two arid system shrubs with contrasting spatial distributions and life histories

植物-土壤相互作用代表了生态学研究的一个新兴和有影响的领域，它正在提高对物种内和物种之间的植物-植物相互作用的理解，以及对群落结构的控制。这项研究中包含的互补专业知识为将植物-土壤反馈与植物种群增长相结合提供了一种新的合作方式。这种整合促进了对上下文相关的种群调控的理解，并有望推动未来的生态学研究。这项研究的结果将在种群水平上提供对植物微生物反馈的重要理解，并允许对这些反馈进行长期评估，由于美国西南部干旱的发生和严重程度的持续变化，这些反馈变得越来越重要。一个综合外展部分将支持正在进行的努力，以改善对生态和环境生物学的不同参与。通过从一个研究身份认同和生态教育之间关系的现有项目中招募代表性不足的学生参与者，当前的项目提供了一个独特的机会，通过处理文化对学生留存的影响的前沿研究和教育学来评估学生的实地经验。这一综合为这两项研究工作增加了价值。该项目检查了两个常见植物物种之间的反馈，以及一个研究得很好的干旱植物系统的土壤微生物群落。这些反馈将在美国西南部两个优势种的不同生活史阶段进行研究，这两个物种是：白背天牛(Ambrosia umosa(A.Gray)Payne Asteraceae)和三齿海鞘Larrea tridentata(DC.)鸡冠花科、杂果油灌木。这项研究将在约书亚树国家公园的一个现场进行，在那里，一个永久绘制的地块中收集了超过35年的空间显式人口数据。将对微生物呼吸、微生物多样性和微生物组成进行观测和实验研究，以响应1)植物种类、2)植物大小和3)植物密度，并将结果用于预测未来的种群增长。研究人员将使用专门的种群模型来衡量种群轨迹的差异，这些差异包括1)排除微生物活动，2)包括微生物呼吸但不包括多样性或组成，3)包括微生物多样性和组成但不包括呼吸，以及4)包括微生物呼吸、组成和多样性。通过包括土壤微生物群对植物生长和生存的影响，该项目提高了了解植物静止和可变生境条件如何相互作用以控制种群和社区的空间结构和动态的能力。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。

Plant-soil interactions represent a burgeoning and impactful area of ecological inquiry that is improving understanding of plant-plant interactions within and between species, and controls on community structure. The complementary expertise included in this study offers a novel collaboration to integrate plant-soil feedbacks with plant population growth. This integration advances understanding of context-dependent population regulation and promises to advance future ecological research. Outcomes from this research will provide important understanding of plant-microbial feedbacks at the population level and permit long-term assessment of these feedbacks, which is increasingly important due to ongoing changes in the occurrence and severity of drought in the US Southwest. An integrated outreach component will support ongoing efforts to improve diverse participation in ecology and environmental biology. By recruiting underrepresented student participants from an existing project that examines the relationship between identity and ecology education, the current project provides a unique opportunity to assess student field experiences with cutting edge research that treats cultural influences on student retention, and pedagogy. This synthesis adds value to both research efforts.The project examines feedbacks between two common plant species and the soil microbial community of a well-studied arid plant system. These feedbacks will be studied at different life history stages of two dominant species in the US Southwest, Ambrosia dumosa (A. Gray) Payne Asteraceae, white bur-sage, and Larrea tridentata (DC.) Coville Zygophyllaceae, creosote bush. The study will occur in a field site at Joshua Tree National Park where more than 35 years of spatially-explicit demographic data have been collected within a permanently mapped plot. Observational and experimental studies of microbial respiration, microbial diversity, and microbial composition in response to 1) plant species, 2) plant size and 3) plant density will be conducted, and outcomes will be used to project future population growth. The researchers will use specialized population models to measure differences in population trajectories that differ by 1) exclusion of microbial activity, 2) inclusion of microbial respiration but not diversity or composition, 3) inclusion of microbial diversity and composition but not respiration, and 4) inclusion of microbial respiration, composition, and diversity. By including the influence of the soil microbiome on plant growth and survival, this project advances the ability to understand how plant immobility and variable habitat conditions interact to control the spatial structure and dynamics of populations and communities.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.