The chord distance is maximum when the species at two sites are completely different. In such a case, the normalized site vectors are at 90° from each other on the circumference of a 90° sector of a circle (when there are only two species), or on the surface of a segment of a hypersphere (for p species), and the distance between the two sites is 72 . This measure solves the problem caused by sites having different total abundances of species as well as the paradox explained above for Di. Indeed, with D3, the distances between pairs of sites for the numerical example are:
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