Five measures are treated in this study: (1) the clustering coefficient, (2) the betweenness centrality, (3) the assortativity coefficient, (4) the modularity and (5) the number of chordless cycles. The weighted mean of within—habitat species diversities constitutes a measure of the average niche overlap among the c habitats examined. A method of standardizing them is proposed. However, there are (at least) two challenges considering a useful and interpretable quantification of H-niche overlap. 93 A variety of approaches and metrics have been used to measure niche overlap (e.g., Horn, 1966; 94 MacArthur & Levins, 1967; Schoener, 1970; Colwell & Futuyma, 1971; May & Arthur, 1972; 95 Pianka, 1980). By measuring the niche overlap on the discriminant variable the multivariate problem is reduced to a univariate problem while preserving the relevant multivariate information. A method of standardizing them is proposed. & Graham, C. H. (2012). However, quantifying each of these components is difficult because it is not always possible to identify or measure relevant environmental gradients (niche axes) along which species might partition or compete for niche space. measure niche overlap (e.g. First, how to measure overlap of H-niches in one dimension and second, how to extend the concept to multi-dimensional situations? The first technique uses the MacArthur-Levins (Amer. Global Ecology and Biogeography, 21(4), 481-497. Horn, 1966; MacArthur & Levins, 1967; Schoener, 1970; Colwell & Futuyma, 1971; May & Arthur, 1972; Pianka, 1980). The measures are of actual, realized niche widths and niche overlaps and are therefore inevitably affected by the relative abundances of the species and the habitats. constitutes a measure of the average niche overlap among the c habitats examined. Niche availability, niche overlap and competitive ability are key determinants of the distribution and abundance of species. food-webs and niche-overlap graphs are considered as complex systems. ... applies kernel smoothers to densities of species occurrence in gridded environmental space to calculate metrics of niche overlap and test hypotheses regarding niche conservatism. The measures are of actual, realized niche widths and niche overlaps and are therefore inevitably affected by the relative abundances of the species and the habitats. Natur. The main purpose of this work is to compare the topology of 15 real niche-overlap graphs with random ones. Measuring ecological niche overlap from occurrence and spatial environmental data. Measuring ecological niche overlap from occurrence and spatial environmental data. The niche overlap is then calculated by two different techniques. Generally, these methods date to the period in which competition was widely believed to be the primary mechanism structuring ecological communities and measures of niche overlap were developed to quantify differences due to competition (Chase & …