Freestone Amy L, Harrison Susan
Ecol Lett. 2006 Feb;9(2):95-102. doi: 10.1111/j.1461-0248.2005.00849.x.
Theory predicts that the effects of regional richness on the richness of local communities may depend on the productivity, resource availability, and/or heterogeneity of local sites. Using the wetland plant communities of 50 independent streams as 'regions', we tested whether: (1) local richness in 1-m(2) quadrats and 50-m stream segments was positively related to regional richness, even after environmental influences were considered; and (2) the effect of regional richness would interact with the effects of biomass, soil moisture, and/or heterogeneity on local richness. In models that explained up to 88% of variation in local richness, we found that richness at both local scales was positively related to regional richness, and that regional richness did not interact with any of the environmental gradients that also shaped local richness. We conclude that species availability from the regional pool may consistently enrich local communities, even while other constraints on local richness operate.
理论预测，区域物种丰富度对当地群落物种丰富度的影响可能取决于当地生境的生产力、资源可用性和/或异质性。我们以50条独立溪流的湿地植物群落作为“区域”，测试了以下两点：（1）即使考虑了环境影响，1平方米样方和50米溪流段的当地物种丰富度是否与区域物种丰富度呈正相关；（2）区域物种丰富度的影响是否会与生物量、土壤湿度和/或异质性对当地物种丰富度的影响相互作用。在解释了高达88%的当地物种丰富度变化的模型中，我们发现两个局部尺度的物种丰富度都与区域物种丰富度呈正相关，并且区域物种丰富度并未与任何也影响当地物种丰富度的环境梯度相互作用。我们得出结论，即使存在对当地物种丰富度的其他限制因素，区域物种库中的物种可用性可能会持续丰富当地群落。
