Inferring Regional-Scale Species Diversity from Small-Plot Censuses

Abstract

Estimation of the number of species at spatial scales too large to census directly is a long- standing ecological challenge. A recent comprehensive census of tropical arthropods and trees in Panama provides a unique opportunity to apply an inference procedure for up-scal- ing species richness and thereby make progress toward that goal. Confidence in the under- lying theory is first established by showing that the method accurately predicts the species abundance distribution for trees and arthropods, and in particular accurately captures the rare tail of the observed distributions. The rare tail is emphasized because the shape of the species-area relationship is especially influenced by the numbers of rare species. The infer- OPEN ACCESS ence procedure is then applied to estimate the total number of arthropod and tree species at Citation: Harte J, Kitzes J (2015) Inferring Regional- spatial scales ranging from a 6000 ha forest reserve to all of Panama, with input data only Scale Species Diversity from Small-Plot Censuses. from censuses in 0.04 ha plots. The analysis suggests that at the scale of the reserve there PLoS ONE 10(2): e0117527. doi:10.1371/journal. are roughly twice as many arthropod species as previously estimated. For the entirety of pone.0117527 Panama, inferred tree species richness agrees with an accepted empirical estimate, while Academic Editor: Maura (Gee) Geraldine Chapman, inferred arthropod species richness is significantly below a previous published estimate that University of Sydney, AUSTRALIA has been criticized as too high. An extension of the procedure to estimate species richness Received: August 21, 2014 at continental scale is proposed. Accepted: December 29, 2014 Published: February 23, 2015 Copyright: © 2015 Harte, Kitzes. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any