How Important are Regional Processes in Determining the Local Species Richness of Marine Communities

本研究调查了11个地理区域（10 ′ ~ 1 W km空间尺度）中固着表生无脊椎动物物种数与当地群落（1 ~ 10 ′ m空间尺度）中固着表生无脊椎动物物种数之间的关系。要测试的主要预测是：如果当地社区仅仅是一个水槽从地理（区域）物种池，那么当地的物种丰富度将是积极的，线性相关的区域物种丰富度在广泛的多样性。或者，如果生态相互作用限制了当地栖息地共存的物种数量，那么当地丰富度对区域丰富度的回归将趋于平稳或饱和。我们建议通过定量摄影技术对不同地理区域的表生动物群落的物种丰富度进行采样来检验这些假设。将从35 mm照片样方（0.25 m）中对局部多样性进行量化，这些样方是沿水平放置在潮下带岩壁上约10 m深度处的沿着随机位置拍摄的。将分析样方照片，直到每个位置的物种累积数量渐近线，这将包括我们对当地物种丰富度的测量。区域物种丰富度将根据公布的物种清单并通过咨询每个地点的当地专家进行估计。本文开发回归技术以测试区域影响与局部饱和度的预测。此外，本文还将探讨四个相关问题，以加深我们对以下问题的理解：1）身体与语言的关系（或群体）大小和局部物种丰富度2）幼虫扩散模式解释局部丰富度的区域影响程度的能力，3）物种密度之间的关系，地方物种丰富度和区域物种丰富度以及4）地方和区域丰富度之间的关系的性质如何在不同类群之间变化。 保护生物多样性是本世纪和下世纪最紧迫的环境问题之一。要准确查明对地球生物多样性的威胁的性质，并设计和实施健全的保护战略，就需要了解形成生物多样性时空格局的力量。拟议的研究结果将大大提高我们的能力，以批判性地评估区域过程的重要性，在结构化浅海硬底质社区。

This study investigates the relationship between the number of species in biogeographic regions (spatial scale of 10' to 1W kms ) and the number occurring in local communities (spatial scale of 1 to 10'm's) of sessile epifaunal invertebrates from 11 biogeographic regions comprising at least 33 local sites. The main predictions to be tested are: if local communities are simply a sink from the biogeographic (regional) species pool, then local species richness will be positively and linearly related to regional species richness over a broad range of diversities. Alternatively, if ecological interactions limit the number of species coexisting in local habitats, then regressions of local richness on regional richness will level off or saturate. We propose to test these hypotheses by sampling the species richness of epifaunal communities in different biogeographic regions with quantitative photographic techniques. Local diversity will be quantified from 35 mm photo quadrats (0.25m ) taken at random locations along transects placed horizontally across subtidal rock walls at approximately 10 m depth. Quadrat photos will be analyzed until a plot of the cumulative number of species at each location asymptotes, which will comprise our measure of local species richness. Regional species richness will be estimated from published species lists and by consulting local experts at each site. Regression techniques are developed herein to test the predictions of regional influence vs. local saturation. In addition, four related questions will be investigated to increase our understanding of 1) the relationship between body (or colony) size and local species richness 2) the ability of larval dispersal mode to explain the degree of regional influence an local richness, 3) the relation between species density, local species richness and regional species richness and 4) how the nature of the relationship between local and regional richness varies among different taxa. The preservation of biological diversity is one of the most pressing environmental issues of the present and next century. Accurately identifying the nature of threats to Earth's biotic diversity and designing and implementing sound conservation strategies requires an understanding of the forces that shape spatio temporal patterns of biodiversity. The results of the proposed research will greatly enhance our ability to critically assess the importance of regional processes in structuring shallow marine hard substrate communities.