Effect of Fungal Endophyte Infection on the Structure of Experimental Grasslands

粘土 97 27116 生物相互作用长期以来一直是生态学中相当感兴趣的问题，特别是考虑到它们在影响生态系统过程中与多样性的相互作用。 这种相互作用中更广泛和潜在重要的一种是生活在其细胞内的草和真菌之间发生的共生。 在这个项目中，PI，基思粘土，将利用内生真菌和高羊茅，高羊茅，一种常见于草原的物种之间的联系。 这种特殊的关联在高羊茅中是不寻常的，发生在有或没有真菌内生菌的菌株中。 这项研究将操纵这两种形式的实验测试的潜在利益的共生体，这种草的物种。 调查将评估真菌内生菌感染如何影响高羊茅草地的多样性和生产。 他们还将评估对草食动物和压力的抗性影响内生菌感染的草的优势的程度。 一系列的地块将种植内生菌和非内生菌感染的草株的种子，以检查它们对植物多样性和生产的影响。 围栏和杀虫剂的应用将被用来改变草食动物的水平和感染和未感染的草株生存的相对比例将被量化。 植物边缘的地点也将种植这两个菌株以及其他四个牛毛草品种，以检查他们的整体成功率。 这项工作的最终目标是研究微生物共生在植物群落结构和功能中的一般作用。 这项工作将提供重要的实用信息，因为高羊茅是美国东部草原的优势物种之一。

Clay 97 27116 Biotic interactions have long been of considerable interest in ecology particularly in light of their interactions with diversity in influencing ecosystem processes. One of the more widespread and potentially important of such interactions is the symbiosis occurring between grasses and fungi that live within their cells. In this project, the PI, Keith Clay, will take advantage of an association between endophytic fungi and tall fescue, Festuca arundinacea, a species that occurs commonly in grasslands. This particular association is unusual in Festuca arundinacea occurs in strains that do or do not have fungal endophytes. This research will manipulate these two forms in experimental tests of the potential benefits of the symbionts for this grass species. Investigations will evaluate how fungal endophyte infections influence the diversity and production of Festuca arundinacea grasslands. They will also evaluate the degree to which resistance to herbivory and stress influence the dominance of endophyte-infected grasses. A series of plots will be planted with seeds of endophyte- and non-endophyte infected grass strains to examine their effects on plant diversity and production. Fencing and insecticide applications will be used to vary the levels of herbivory and the relative proportions of infected and noninfected grass strains that survive will be quantified. Ecologically marginal sites will also be planted with the two strains as well as four other fescue species to examine their overall success rates. The ultimate goal of this work will be to examine general role of microbial symbiosis in the structure and function of plant communities. This work will provide important practical information because tall fescue is one of the dominant species across the eastern US in grasslands.