Brualdi Richard A, Sanderson James G
Mathematics Department, University of Wisconsin, Madison, WI 53706-1313, USA, , , , , , US.
Department of Wildlife Ecology and Conservation, PO Box 110430, University of Florida, Gainesville, FL 32611-0430, USA, , , , , , US.
Oecologia. 1999 May;119(2):256-264. doi: 10.1007/s004420050784.
The nested-subset hypothesis of Patterson and Atmar states that species composition on islands with less species richness is a proper subset of those on islands with greater species richness. The sum of species absences, referred to as gaps, was suggested as a metric for nestedness, and null models have been used to test whether or not island species exhibited nestedness. Simberloff and Martin stated that finding examples of non-nested faunas was difficult. We revisit previous analyses of nested faunas and introduce a new metric we call "discrepancy" which we recommend as a measure for nestedness. We also recommend that the sample spaces conserve both row sums (number of species per site) and column sums (number of sites per species) derived from the incidence matrix. We compare our results to previous analyses.
帕特森和阿特马尔的嵌套子集假说指出，物种丰富度较低岛屿上的物种组成是物种丰富度较高岛屿上物种组成的一个恰当子集。物种缺失的总和，即所谓的间隙，被提议作为嵌套性的一个度量指标，并且已使用零模型来检验岛屿物种是否表现出嵌套性。辛伯洛夫和马丁指出，找到非嵌套动物区系的例子很困难。我们重新审视了之前对嵌套动物区系的分析，并引入了一种我们称之为“差异”的新度量指标，我们推荐将其作为嵌套性的一种度量方法。我们还建议样本空间保留从发生率矩阵得出的行总和（每个地点的物种数量）和列总和（每个物种的地点数量）。我们将我们的结果与之前的分析进行比较。
