Munoz F., Couteron Pierre, Ramesh B. R., Etienne R. S. (2007). Estimating parameters of neutral communities : From one single large to several small samples. Ecology, 88 (10), p. 2482-2488. ISSN 0012-9658.
Titre du document
Estimating parameters of neutral communities : From one single large to several small samples
Munoz F., Couteron Pierre, Ramesh B. R., Etienne R. S.
Source
Ecology, 2007,
88 (10), p. 2482-2488 ISSN 0012-9658
The neutral theory of S. P. Hubbell postulates a two-scale hierarchical framework consisting of a metacommunity following the speciation - drift equilibrium characterized by the "biodiversity number' theta, and local communities following the migration - drift equilibrium characterized by the "migration rate' m ( or the "fundamental dispersal number' I). While Etienne's sampling formula allows simultaneous estimation of h and m from a single sample of a local community, its applicability to a network of ( rather small) samples is questionable. We de. ne here an alternative two-stage approach estimating h from an adequate subset of the individuals sampled in the field ( using Ewens' sampling formula) and m from community samples ( using Etienne's sampling formula). We compare its results with the simultaneous estimation of theta and m ( one-stage estimation), for simulated neutral samples and for 50 1-ha plots of evergreen forest in South India. The one-stage approach exhibits problems of bias and of poor differentiability between high-theta, low-m and low-theta, high-m solution domains. Conversely, the two-stage approach yielded reasonable estimates and is to be preferred when several small, scattered plots are available instead of a single large one.
Plan de classement
Sciences du milieu [021]
;
Etudes, transformation, conservation du milieu naturel [082]
