Experimental Analysis of Species Percolation Through Communities

9207376 Glenn群落的物种多样性部分是本地迁移和灭绝动态的产物。移民障碍可能导致主导地位的转变，并影响社区结构和功能。渗透理论提供了一种机制来发展关于生物在环境中运动的假设。草原的群落结构类似于一个渗透网络，但是，渗透网络的适用性，但是，渗透理论对植物群落结构的适用性尚未得到评价。本文将通过野外实验和模拟模型对一系列假设进行验证，以确定渗透理论在预测草地植被优势度和多样性空间格局中的适用性。以前的研究表明，草地在短时间内的小空间尺度上具有高度的动态。从渗流网络中克隆生长刺激模型的初步结果表明，物种多样性受到移动障碍的影响。超过临界阈值后，物种多样性呈下降趋势，优势竞争者占据可利用空间。在此基础上，建立了一系列草地植被的实验渗透网络，并监测了多年生物种的克隆生长、本地迁移和灭绝模式、物种多样性和空间格局。田间试验将通过模拟不同传播速率和竞争能力的无性系植物的渗透来补充。本研究将有助于确定渗透理论在草地植被小尺度植物群落动态中的实用性。​​​!!!F (Times New Roman Symbol & Arial " h C抽象伊丽莎白M.贝伦斯伊丽莎白M.贝伦斯

9207376 Glenn Species diversity in a community is partially a product of the dynamics of local immigration and extinction. Barriers to immigration may result in shifts in dominance and affect community structure and function. Percolation theory provides a mechanism for developing hypotheses regarding movement of organisms through the environment. Community structure in grasslands resembles a percolation network, however, the applicability of percolation network, however, the applicability of percolation theory to plant community structure has not been evaluated. A series of hypotheses will be tested using field experiments and simulation modeling to determine the applicability of percolation theory to predicting spatial patterns of dominance and diversity in grassland vegetation. Previous studies have shown grasslands to be highly dynamic at small spatial scales over short periods. Preliminary results from stimulation models of clonal growth in percolation networks suggests that species diversity is affected by barriers to movement. Above a critical threshold, species diversity declined in these models as superior competitors dominated available space. A series of experimental percolation networks in grassland vegetation will be created and clonal growth of prennial species, local patterns of immigration and extinction, species diversity, and spatial pattern will be monitored. Field experiments will be supplemented by modelling percolation of clonal plants with different rates of spread and competitive abilities. This study will help to determine the utility of percolation theory to small-scale plant comm unity dynamics in grassland vegetation. ! ! ! F ( Times New Roman Symbol & Arial " h Y C abstract Elizabeth M. Behrens Elizabeth M. Behrens