Department of Biology and Environmental Science, University of New Haven, West Haven, Connecticut, United States of America.
PLoS One. 2013 Jun 12;8(6):e65823. doi: 10.1371/journal.pone.0065823. Print 2013.
We examined temporal changes in macrofaunal α- and β-diversity over several spatial scales (within patches, among patches, across landscapes and across regions) in Long Island Sound on the northeast USA coast. Regional ε-diversity was estimated at 144 taxa, however γ-diversity fluctuated over time as did α- and β-diversity components. Based on additive partitioning, patch- and region-scale β-diversity components generally had the highest contributions to γ-diversity; lower percentages were found at within-patch and landscape scales. Multiplicative diversity partitioning indicated highest species turnover at within- and among patch scales. For all partition results, within-patch and patch-scale β-diversity increased sharply when hypoxia impacted benthic communities. Spatial variation in diversity components can be attributed to the collection of different patch types at varying spatial scales and their associated habitats across the benthic landscapes, as well as gradients in depth and other estuarine-scale characteristics. Temporal variation in diversity components across spatial scales may be related to seasonal changes in habitat heterogeneity, species population dynamics, and seasonal disturbances. Rare species were significant and temporally consistent components of macrofaunal diversity patterns over different spatial scales. Our findings agree with other marine and terrestrial studies that show diversity components vary significantly over different spatial scales and the importance of habitat/landscape heterogeneity in supporting diversity. However, our results indicate that the relative contributions of scale-specific β-diversity components can also change significantly over time. Thus, studies of diversity patterns across patches and landscapes based on data collected at one time, or assembled into a single data set from different times, may not capture the full suite of diversity patterns that occur over varying spatial scales and any time-specific determinants of those patterns. Many factors that shape and maintain sedimentary communities vary temporally, and appear to play an important role in determining and maintaining macrofaunal diversity over different spatial scales.
我们检验了美国东北部长岛海峡的大型底栖动物α多样性和β多样性在多个空间尺度（斑块内、斑块间、景观间和区域间）随时间的变化。区域ε多样性估计为 144 个分类单元，但γ多样性随时间波动，α多样性和β多样性成分也是如此。基于加性分区，斑块和区域尺度的β多样性成分通常对γ多样性的贡献最大；在斑块内和景观尺度的贡献比例较低。乘法多样性分区表明，在斑块内和斑块间尺度上物种周转率最高。对于所有分区结果，当低氧影响底栖群落时，斑块内和斑块尺度的β多样性急剧增加。多样性成分的空间变化可归因于在不同空间尺度上收集不同的斑块类型及其在底栖景观中的相关栖息地，以及深度和其他河口尺度特征的梯度。跨空间尺度的多样性成分的时间变化可能与栖息地异质性、物种种群动态和季节性干扰的季节性变化有关。稀有物种是不同空间尺度上大型底栖动物多样性模式的重要且具有时间一致性的组成部分。我们的研究结果与其他海洋和陆地研究一致，表明多样性成分在不同空间尺度上差异显著，并且栖息地/景观异质性对多样性的支持作用很重要。然而，我们的研究结果表明，特定于尺度的β多样性成分的相对贡献也可能随时间显著变化。因此，基于在一个时间点收集的数据或从不同时间组装成一个数据集来研究斑块和景观之间的多样性模式，可能无法捕捉到在不同空间尺度上发生的所有多样性模式，以及这些模式的任何特定于时间的决定因素。塑造和维持沉积群落的许多因素随时间变化，并且似乎在确定和维持不同空间尺度上的大型底栖动物多样性方面起着重要作用。
