Regional and Local Influences on Species Richness in Coral Communities Across a Pacific Diversity Gradient

太平洋多样性梯度上的区域和地方对珊瑚群落物种丰富度的影响

• 批准号: 0095108
• 负责人: Howard Cornell
• 金额: $ 24.55万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0095108&HistoricalAwards=false
• 关键词: Regional; Local; Influences; Species; Richness

Species richness in coral communities has traditionally been explained in terms of processes operating within the local community over relatively short periods of time. Recent studies of other assemblages have made it clear that communities can be organized by a variety of processes operating at different spatial and temporal scales. Since coral communities are imbedded in larger geographic regions, regional/historical phenomena and local processes may jointly influence local richness and should be analyzed simultaneously. This study will sample corals in six island groups along a gradient of increasing regional species richness across the Pacific Ocean and in three different habitats at local sites to quantitatively evaluate the relative influence of regional and local processes on local richness. The Pacific Ocean gradient is the best possible choice for this test because of the large unequivocal trend in regional richness. Traveling from west to east, regional richness drops from over 450 species in the Philippines and Indonesia to fewer than 100 species in eastern French Polynesia. A hierarchical sampling design will be employed to measure variation in species richness, composition, and relative abundance at four spatial scales spanning 5-6 orders of magnitude (among replicate samples at a site, among sites on an island, among islands in a region, among regions). Data will be collected on species presence and relative abundance as well as on habitat breadth and depth range of selected species. This information will be used to test the effects of the increasing regional pool on local richness, evenness, habitat compression and habitat overlap at different scales. Percent cover of colonizable substrate will also be quantified and used to test the effects of the "openness" of local assemblages on their sensitivity to regional influences. The hierarchical design will provide a powerful framework for quantifying the proportion of total variation among samples that is attributable to each spatial scale and thus will permit a rigorous estimate of scale-dependency in patterns of diversity and abundance. This synthesis of regional and local perspectives will have relevance not only for basic studies of community ecology but also for applied problems associated with species extinctions, habitat loss and fragmentation, and ecological restoration.

珊瑚群落中的物种丰富度传统上被解释为在相对较短的时间内在当地社区内运作的过程。最近对其他群落的研究表明，群落可以通过在不同空间和时间尺度上运作的各种过程来组织。由于珊瑚群落分布在较大的地理区域，区域/历史现象和当地进程可能共同影响当地的丰富程度，因此应同时进行分析。这项研究将沿着整个太平洋区域物种丰富度不断增加的梯度，在六个岛屿群和当地三个不同生境对珊瑚进行取样，以定量评价区域和当地进程对当地丰富度的相对影响。太平洋梯度是这一测试的最佳可能选择，因为区域丰富度的大的明确趋势。从西到东，区域丰富度从菲律宾和印度尼西亚的450多个物种下降到法属波利尼西亚东部的不到100个物种。将采用分层抽样设计，在跨越5-6个数量级的四个空间尺度上（在一个地点的重复样本之间、在一个岛屿上的地点之间、在一个区域的岛屿之间、在区域之间）测量物种丰富度、组成和相对丰度的变化。将收集有关物种存在和相对丰度以及选定物种栖息地宽度和深度范围的数据。这些信息将被用来测试的影响，不断增加的区域池对当地的丰富度，均匀度，栖息地压缩和栖息地重叠在不同的尺度。还将量化可定殖基质的覆盖百分比，并用于测试当地组合的“开放性”对区域影响的敏感性的影响。分层设计将提供一个强有力的框架，用于量化样本之间归因于每个空间尺度的总变异的比例，从而允许对多样性和丰度模式的尺度依赖性进行严格估计。这种区域和地方观点的综合不仅与群落生态学的基础研究有关，而且与物种保护、生境丧失和破碎化以及生态恢复有关的应用问题有关。