Department of Biology, Utah State University, Logan, UT 84322, USA.
Ecol Lett. 2013 Sep;16(9):1177-85. doi: 10.1111/ele.12154. Epub 2013 Jul 15.
The species abundance distribution (SAD) is one of the most intensively studied distributions in ecology and its hollow-curve shape is one of ecology's most general patterns. We examine the SAD in the context of all possible forms having the same richness (S) and total abundance (N), i.e. the feasible set. We find that feasible sets are dominated by similarly shaped hollow curves, most of which are highly correlated with empirical SADs (most R(2) values > 75%), revealing a strong influence of N and S on the form of the SAD and an a priori explanation for the ubiquitous hollow curve. Empirical SADs are often more hollow and less variable than the majority of the feasible set, revealing exceptional unevenness and relatively low natural variability among ecological communities. We discuss the importance of the feasible set in understanding how general constraints determine observable variation and influence the forms of predicted and empirical patterns.
物种丰富度分布（SAD）是生态学中研究最广泛的分布之一，其空心曲线形状是生态学中最普遍的模式之一。我们在具有相同丰富度（S）和总丰度（N）的所有可能形式的背景下研究 SAD，即可行集。我们发现可行集主要由形状相似的空心曲线主导，其中大多数与经验 SAD 高度相关（大多数 R²值>75%），这揭示了 N 和 S 对 SAD 形式的强烈影响，并为空心曲线的普遍存在提供了一个先验解释。经验 SAD 通常比可行集的大多数更空心且变化更小，这表明生态群落之间存在异常的不均匀性和相对较低的自然变异性。我们讨论了可行集在理解一般约束如何确定可观察到的变化以及影响预测和经验模式的形式方面的重要性。
