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Community Persistence and the Pattern of Community Variability Over Time: A Test Using Fossil Assemblages From Four Marine Transgressions in the Breathitt Formation......

群落持久性和群落随时间变化的模式：使用来自 Breathitt 地层四次海洋海侵的化石组合进行的测试......

基本信息

批准号：
9105469
负责人：
Richard Bambach
金额：
$ 6.1万
依托单位：
Virginia Polytechnic Institute and State University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1991
资助国家：
美国
起止时间：
1991-08-01 至 1994-01-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9105469&HistoricalAwards=false
关键词：
Community Persistence Pattern Variability Over

项目摘要

This study will use the fossil record of four separate marine inundations of eastern Kentucky to test for community persistence on a time scale of 10 - 10 years. Each marine inundation resulted in the establishment of benthic habitats that were colonized by the same or similar species of marine invertebrates and preserved as layers of fossiliferous shale. Four marine units will be sampled with replication at multiple locations to obtain complete fossil species abundances for each sample. The lithological and microfaunal characteristics of each sample will be used to determine which samples formed in comparable habitats. Samples from comparable habitats will be statistically compared. Replicate samples will provide an estimate of variation due to sampling that will form the basis for judging the significance of variation between localities within a marine unit. Statistical tests comparing multiple localities within a marine unit will demonstrate the geographic pattern of variation in community structure that existed during each marine inundation. The variation in species abundances seen within each marine unit will, in turn, provide a basis for judging whether the same community structure was reassembled after major disruptions and persisted through some or all of the marine inundations. The project is designed to rigorously test (a) whether fossil assemblages represent communities in a more highly structured sense than just the coincidental co-occurrence of component species, and (b) whether fossil communities (as represented by fossil assemblages from particular habitats) persist through time despite major disruptions.

这项研究将利用肯塔基州东部四次独立海洋淹没的化石记录来测试群落在 10 - 10 年时间尺度上的持久性。每次海洋淹没都会导致底栖栖息地的建立，这些栖息地被相同或相似物种的海洋无脊椎动物殖民，并以含化石页岩层的形式保存下来。将在多个地点对四个海洋单元进行重复采样，以获得每个样本的完整化石物种丰度。每个样本的岩性和微型动物特征将用于确定哪些样本是在可比较的栖息地中形成的。来自可比栖息地的样本将进行统计比较。重复样本将提供因采样而产生的变化的估计，这将构成判断海洋单元内地点之间变化的显着性的基础。比较海洋单位内多个地点的统计测试将证明每次海洋淹没期间存在的群落结构变化的地理模式。反过来，每个海洋单元内物种丰度的变化将为判断相同的群落结构是否在重大破坏后重新组装并在部分或全部海洋洪水中持续存在提供基础。该项目旨在严格测试（a）化石组合是否在更高度结构化的意义上代表群落，而不仅仅是组成物种的巧合共现；以及（b）化石群落（以来自特定栖息地的化石组合为代表）是否在遭受重大破坏的情况下持续存在。