REU: Competitive Dominance at Two Soil Resource Levels: An Experimental Investigation of an Old-Field Community

施肥可以极大地改变草本植物群落的结构，而对土壤肥力水平的控制可以提供对自然界物种共存机制的洞察。这个项目将通过控制优势物种的存在和土壤资源的水平来实验测试竞争和土壤肥力之间的相互作用。试验将包括在低(对照)和高(肥沃)土壤肥力水平下，单独完全或部分移除两种优势物种--鸭茅和一枝黄花。对物种丰富度、多样性和其他群落属性的影响也将随之而来。在互补性实验中，不同数量的Dactylis种子将被播种在新犁的田地上，以测试优势物种的初始存在和丰度对群落发展的影响。这项研究将首次尝试调查与优势物种的竞争是否在高土壤资源水平上对群落结构产生不同于低土壤资源水平下的不同影响。这些实验的数据将检验一些主要的、以前未经检验的关于自然群落中植物共存基础的理论。

Fertilization can dramatically alter the structure of herbaceous plant communities, and the manipulation of soil fertility levels can offer insight into the mechanisms of species coexistence in nature. This project will experimentally test the interaction between competition and soil fertility in an old- field community by manipulating both the presence of dominant species and the level of soil resources. Experiments will consist of complete or partial removals of the 2 dominant species, Dactylis glomerata and Solidago altissima, alone together at low (control) and high (enriched) soil fertility levels. The effect on species richness, diversity, and other community properties will be followed. In complementary experiments, varying amounts of Dactylis seed will be sown in a newly plowed field to test the effects on community development of the initial presence and abundance of a dominant species. The study will be the first attempt to investigate whether competition with the dominant species has a different effect on community structure at high than at low soil resource levels. The data from these experiments will test a number of major, previously untested theories regarding the basis for coexistence among plants in natural communities.