Impact of Post-Wisconsinan Range Expansions on Community Structure of North American Endemic Earthworms

蚯蚓是大多数陆地生物的重要组成部分， 生态系统，并对土壤结构产生重大影响， 有机物分解过程。 该提案使用一个 重大历史事件集中在蚯蚓在接口 生态学和地理学。 冰后期差异北移 据推测，扩散引起了生物多样性的变化， 群落结构由南向北。 分层方法 用于定义与景观扩散相关的假设 特征、生殖生物学和生态因素。 现代 物种分布的气候限制，竞争性迁移 由外来物种，和社区的互动结构是 作为替代品提出。 四南采集方案 从威斯康星州的冰川避难所向北的横断面 冰川边缘和边缘以南的高程断面 将获得关于长期的生物群落结构、 扩散率的估计，以及地理因素的影响 不同生态类型的扩散障碍 蚯蚓 测量短期扩散率的实验， 测试单亲繁殖的可能性， 提出了替代模型。 一种植物地理学和分类学 将建立数据库。

Earthworms are important constituents of most terrestrial ecosystems and have a major influence on soil structure and organic matter decomposition processes. This proposal uses a major historical event to focus on earthworms at the interface of ecology and biogeography. Differential post-glacial northward dispersal is hypothesized to have caused variation in earthworm community structure from south to north. A hierarchical approach is used to define hypotheses relating dispersal to landscape features, reproductive biology, and ecological factors. Modern climatic limitation of species ranges, competitive displacement by exotic species, and interactive structuring of communities are proposed as alternatives. A program of collecting on four south to north transects from glacial refugia across Wisconsinan glacial margins and on elevational transects south of the margins will obtain data on earthworm community structures, long-term estimates of dispersal rates, and the influence of geographic barriers on dispersal of different ecological categories of earthworms. Experiments measuring short-term dispersal rates and testing the possibility of uniparental reproduction and alternative models are proposed. A biogeographic and taxonomic data base will be created.