The Process and Mechanisms of Plant Competition in the Great Basin Sagebrush-Dominated Ecosystem

这一多研究者研究项目将探讨植物竞争的机制及其与竞争过程和大流域鼠尾草主导的生态系统植物群落发展的联系。这项研究是基于对重复地块的操纵性实地研究，并将其延伸到景观背景。在四组假设中强调了地下竞争：(1)根渗漏和植物间水分转移的发生、程度和意义--涉及全植物气体交换、土壤湿度和时间域反射仪、稳定同位素和根系解剖的实验；(2)资源丰富的斑块的开发--涉及微尺度的根分布、菌根动态、双同位素标记和根系生理特性；(3)与竞争能力相关的根的特征--使用具有广泛种质资源的指示植物方法，以及(4)将竞争与植物健康成分，如种子产量和幼苗建立--联系起来--使用植物种群和竞争排除方法。此外，还将测试一组将这些概念扩展到景观情况的预测。总共提出了22个假设和4个预测，这些预测的范围从单个根和相关的菌根到群落水平的现象。这个项目的研究团队非常优秀，无疑将保持其PEST生产力。该机构为该项目的实地和实验室位置提供的设施都是一流的。可以预期会产生高水平的科学生产力。

This multi-investigator research project will address mechanisms of plant competition and their linkage with the process of competition and plant community development in the Great Basin sagebrush-dominated ecosystem. The research is based on manipulative field studies in replicated plots with extension to a landscape setting. Belowground competition is emphasized in four sets of hypotheses concerning (1) the occurrence, magnitude and significance of water leakage from roots and water transfer between plants -- experiments involving whole-plant gas exchange, soil psychrometry and time-domain reflectometry, stable isotopes, and root anatomy, (2) exploitation of resource-rich patches -- involving microscale root distributions, mycorrhizal dynamics, dual-isotope labeling, and root physiological properties, (3) characteristics of roots associated with competitive ability -- using indicator plant approaches with a broad germplasm resource, and (4) linking competition with plant fitness components such as seed output and seedling establishment -- using plant demographic and competition exclusion approaches. Additionally, a set of predictions extending these concepts to landscape situations will be tested. In all, 22 hypotheses and 4 predictions are posed and these range in scale from individual roots and associated mycorrhizae to community-level phenomena. The research team for this project is excellent and will undoubtedly maintain its pest productivity. Facilities provided by the institution for both field and laboratory positions of the project are first-class. A high level of scientific productivity can be expected to result.