The plants eye view: disentangling plant-plant, plant-herbivore, and plant-soil interactions

我的研究项目调查植物和土壤群落多样性之间的因果联系。我最近的工作集中在植物-植物之间的相互作用，特别是入侵物种取代本地物种、构建植物和土壤群落的负面相互作用。在这个授予周期中，我将扩大我的计划范围，研究草食对植物-土壤相互作用的影响。众所周知，草食动物-植物-土壤之间的联系很难解开，因为植物-土壤反馈的强度和方向受到植物物种和非生物条件之间多方面相互作用的影响。虽然我们知道，这些机制可以单独成为构建植物群落和土壤群落多样性和功能的重要力量，但这些机制的相对重要性在单个自然群落中很少被研究。我在这个授予周期的具体目标是：1.测量放牧对羊茅草原植物和土壤群落结构的长期影响；2.评估放牧引起的根系生物量分配和根系分泌物剖面变化的相对重要性；3.研究植物入侵的已知长期影响是如何产生的，这些影响是由入侵时草食动物-植物-土壤的短期过程引起的。我的研究计划很重要，因为虽然大型哺乳动物草食被认为是构建植物-土壤关系的基础，但很少有研究试图将植物与植物的直接相互作用和非生物条件与草食的影响分开。我的研究计划将是第一批研究食草动物如何与植物和环境驱动因素相互作用来构建植物-土壤相互作用的项目之一。从一般的植物-土壤过程转移到特定的植物-土壤过程，我的计划将是第一批直接观察植物入侵时刻细微尺度地下动态的程序之一。这项工作的重点物种光滑雀麦是草原草原上最有问题的入侵物种之一。推动雀麦入侵的更广泛的生态系统过程和后果是众所周知的，但对个别雀麦植物与被雀麦取代的已建立的本地植物之间的相互作用知之甚少。因此，我的工作将是从植物的视角研究植物入侵的第一批人之一，研究地上和地下过程如何通过入侵过程实时相互作用。

My research program investigates the causal linkages between plant and soil community diversity. My most recent work focuses on how plant-plant interactions, particularly the negative interactions where an invasive species replaces a native species, structure plant and soil communities. In this granting cycle, I will expand my program scope to examine herbivory impacts on plant-soil interactions. Herbivore-plant-soil linkages have historically been notoriously difficult to disentangle because the strength and direction of plant-soil feedbacks are modified by multi-way interactions among the plant species and abiotic conditions. While we know that these mechanisms can separately be important forces structuring plant and soil community diversity and function, the relative importance of these mechanisms have rarely been investigated in a single natural community. My specific objectives for this granting cycle are to: 1.measure the long-term impacts of cattle grazing on fescue grassland plant and soil community structure, 2.evaluate the relative importance of grazing induced changes in root biomass allocation and root exudate profiles, 3.examine how the known long-term impacts of plant invasion arise from short-term herbivore-plant-soil processes operating at the moment of invasion. My research program is important because, while large mammal herbivory is known to structure plant-soil relationships, few studies have by attempted to disentangle the roles of direct plant-plant interactions and abiotic conditions from herbivory impacts. My research program will be among the first to investigate how herbivory interacts with plant-plant and environmental drivers to structure plant-soil interactions. Moving from the general to specific plant-soil processes, my program will be among the first to directly observe the fine-scale belowground dynamics at the moment of a plant invasion. The focal species for this work, Smooth Brome, is one of the most problematic invasive species in prairie grasslands. The broader ecosystem processes and consequences driving Brome invasion are well understood, yet little is known about the interactions between individual Brome plants and the established native plants that Brome displaces. My work will thus be among the first to study a plant invasion from the plants eye view, examining how aboveground and belowground processes interact through the invasion process in real time.