MCA: A Meta-analytic approach to resolving mechanisms of plant-soil-herbivore interactions

植物及其相关土壤是一种密切的双向关系，这种关系受到食草动物等以植物为食的生物的影响。食草动物的觅食可能会影响生态系统中存在的植物的数量和种类。然而，食草动物的觅食与土壤群落的组成或功能之间的一致关系尚未得到描述。这一悖论的解决是一个令人着迷的生态学问题，因为生物之间的间接影响很难解决，但从人类的角度来看，这也很重要，因为它对土壤性质有潜在的影响。例如，土壤功能的变化可能会影响农业的成功或减缓气候变化的碳储存。此外，人类人口模式和土地利用的变化明显改变了野生食草动物和牲畜的分布，使这一问题变得更加紧迫。因此，确定草食动物在土壤中的作用及其功能的必要性是深远的。这项研究将梳理并确定草食动物在不同环境中发生时对土壤群落组成和功能的影响。草食动物、植物和土壤之间的相互作用是由生物和非生物的多变量因素的梯度驱动的，建立可控和可重复的实验来捕捉这些因素是昂贵和具有挑战性的。来自以前的操纵性和观察性食草动物实验的现代和多样化的数据集是丰富的。然而，当单独考虑时，个别实验通常显示出土壤中不一致和微弱的反应。这项研究将汇编和分析大量的实验和观测数据集，从而揭示草食动物对土壤的生物和非生物影响的完整连续体。具体地说，这些方法将包括基于回归的多变量荟萃分析方法。在这样做的过程中，将解决以下研究目标：第一，元分析回归将捕捉草食对土壤功能的非线性或间接影响。其次，将从非生物环境变量和群落水平的相互作用变量，即通过粪便、践踏或种子传播的营养通量，来探索多变量的草食动物效应。这项研究将与一位世界荟萃分析专家合作，收集不同的数据集，以解决解释草食与土壤生态系统功能之间联系的最难以捉摸的机制。这项工作的结果将是一个大量的和公开可用的数据库，以及学生培训和大量的科学出版物和报告。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。

Plants and their associated soils are in a close bidirectional relationship, and this relationship is affected by organisms such as herbivores that consume plants. Feeding by herbivores may influence the numbers and species of plants present in the ecosystem. However, consistent relationships between feeding by herbivores does and the composition or functioning of the soil community have not yet been described. The resolution of this paradox is a fascinating ecological question because indirect effects among organisms are tricky to resolve, but it is also important from a human perspective due to the potential implications to soil properties. For example, changes in soil functioning can influence agricultural success or carbon storage for climate mitigation. In addition, human demographic patterns and shifts in land use have markedly changed the distribution of wild herbivores and livestock, making this a more urgent problem. Therefore, the need to define the role of herbivory on soils and their functioning is profound. This research will tease apart and define the effect of herbivory on soil community composition and functioning as it occurs across varied environments. Interactions among herbivores, plants, and soils are driven by gradients of multi-variate factors, both biotic and abiotic, and establishing controlled and repeatable experiments to capture these factors is expensive and challenging. Modern and diverse data sets from prior manipulative and observational herbivore experiments are abundant. However, when considered in isolation, individual experiments typically reveal inconsistent and weak responses in the soil. This research will compile and analyze a large number of experimental and observational data sets, thus revealing the full continuum of biotic and abiotic influences of herbivores on the soil. Specifically, the methods will include a regression based and multi-variate meta-analytic approach. In so doing, the following research goals will be addressed: First, meta-analytic regression will capture non-linear or indirect effects of herbivory on soil functioning. Second, multivariate herbivore effects will be explored with respect to both abiotic environmental variables and community level interaction variables, i.e. nutrient flux via dung, trampling or seed dispersal. In partnership with a world expert in meta-analysis, this research will gather diverse data sets to resolve the most elusive mechanisms explaining the link between herbivory and soil ecosystem functioning. The outcome of this work will be a substantial and publicly available database in addition to student training and numerous scientific publications and presentations.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.