Division of Biology, Kansas State University, Manhattan, Kansas 66506 USA.
Am J Bot. 2001 Sep;88(9):1634-42.
Assessing the various mechanisms by which plants revegetate disturbances is important for understanding the effects of disturbances on plant population dynamics, plant community structure, community assembly processes, and ecosystem function. We initiated a 2-yr experiment examining temporal vegetation dynamics and mechanisms of recolonization on different-sized soil disturbances created to simulate pocket gopher mounds in North American tallgrass prairie. Treatments were designed to assess potential contributions of the seed rain, soil seed bank, clonal propagation from the edges of a soil mound, and regrowth of buried plants. Small mounds were more rapidly recolonized than large mounds. Vegetative regrowth strategies were the dominant recolonization mechanisms, while the seed rain was considerably less important in maintaining the diversity of forbs and annuals than previously believed. All recolonization mechanisms influenced plant succession, but stem densities and plant mass on soil mounds remained significantly lower than undisturbed controls after two growing seasons. Because natural pocket gopher mounds are indistinguishable from undisturbed areas after two seasons, these results suggest that multiple modes of recruitment concurrently, albeit differentially, contribute to the recolonization of soil disturbances and influence tallgrass prairie plant community structure and successional dynamics.
评估植物对干扰进行植被恢复的各种机制对于理解干扰对植物种群动态、植物群落结构、群落组装过程和生态系统功能的影响非常重要。我们启动了一项为期 2 年的实验，研究了不同大小的土壤干扰（模拟北美高草草原中的囊鼠丘）上的植被动态和再定居机制。处理设计旨在评估种子雨、土壤种子库、来自土壤丘边缘的克隆繁殖以及埋藏植物的再生等潜在贡献。小土丘比大土丘更快地被重新定居。营养繁殖策略是主要的再定居机制，而种子雨在维持草本植物和一年生植物的多样性方面的重要性远低于先前的认识。所有的再定居机制都影响着植物演替，但两个生长季后，土丘上的茎密度和植物质量仍然明显低于未受干扰的对照。由于在两个季节后，天然囊鼠丘与未受干扰的区域难以区分，因此这些结果表明，多种招募模式同时但不同程度地促进了土壤干扰的再定居，并影响了高草草原的植物群落结构和演替动态。
