An algebraic derivation of Chao’s estimator of the number of species in a community highlights the condition allowing Chao to deliver centered estimates. - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue International Scholarly Research Notices Année : 2014

An algebraic derivation of Chao’s estimator of the number of species in a community highlights the condition allowing Chao to deliver centered estimates.

Résumé

Anne Chao proposed a very popular, nonparametric estimator of the species richness of a community, on the basis of a limited size sampling of this community. This expression was originally derived on a statistical basis as a lower-bound estimate of the number of missing species in the sample and provides accordingly a minimal threshold for the estimation of the total species richness of the community. Hereafter, we propose an alternative, algebraic derivation of Chao’s estimator, demonstrating thereby that Chao’s formulation may also provide centered estimates (and not only a lower bound threshold), provided that the sampled communities satisfy a specific type of SAD (species abundance distribution). This particular SAD corresponds to the case when the number of unrecorded species in the sample tends to decrease exponentially with increasing sampling size. It turns out that the shape of this “ideal” SAD often conforms approximately to the usually recorded types in nature, such as “log-normal” or “broken-stick.”. Accordingly, this may explain why Chao’s formulation is generally recognized as a particularly satisfying nonparametric estimator.

Domaines

Biodiversité

Dates et versions

hal-01101415 , version 1 (08-01-2015)

Identifiants

Citer

Jean Béguinot. An algebraic derivation of Chao’s estimator of the number of species in a community highlights the condition allowing Chao to deliver centered estimates.. International Scholarly Research Notices, 2014, 2014, pp.847328. ⟨10.1155/2014/847328⟩. ⟨hal-01101415⟩
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