Estimating species richness in tropical forest: the missing species extrapolation technique

Abstract

A new technique for estimation of tree species richness in tropical forests was developed and tested in this study. The missing species extrapolation technique is based on the assumption that the rate of accumulation of new species with increasing area is the same within sampled and unsampled areas of similar habitat within a region. This new technique was tested on four 1-ha sites of subtropical moist forest in Rio Bravo, Belize for which complete species counts of trees ≥10cm dbh are available. Estimates given by the technique are 115, 98, 93 and 106% of the actual species counts within the four sites. The accuracy of these estimates was found to be equal to or better than most others obtained by using existing methods of extrapolation. The missing species extrapolation technique was also applied to a 21-ha riparian forest patch in the Mountain Pine Ridge, Belize, where it was used to obtain an estimate of the number of tree species ≥10cm dbh in the entire patch.

Comparing species richness among assemblages using sample units: why not use extrapolation methods to standardize different sample sizes?

“…Solow and Polasky (1999) presented an estimator to be used when sample size is expressed as number of individuals. Tackaberry et al (1997) suggested a simple extrapolation technique using sampling units, but based on the knowledge of the physical location of each sampling unit. When large and structurally similar data sets are available, a promising extrapolation technique is presented by Plotkin et al (2000).…”

“…The parameters obtained in the adjusted equation using the species accumulation curve of the less sampled assemblage, are used to extrapolate to a larger sample size. Although simple, only a few models in a small number of papers have evaluated the closeness of estimates in relation to a priori known actual richness (Arrhenius 1923, Palmer 1990, Tackaberry et al 1997, Keating et al 1998).…”

Bromeliaceae da Ilha Grande, RJ: revisão da lista de espécies

“…Tackaberry et al (1997) e Plotkin et al (2000) sugeriram que a modelagem de curvas espécie-área pode não somente estimar a riqueza de uma área, mas também extrapolá-la, desde que a estrutura das áreas analisadas e das espécies seja levada em consideração.…”

An assessment of sample-based estimators of tree species richness in two wet tropical forest compartments in Panama and India

“…A long history of research on estimation of the number of species in an area (Arrhenius 1921, Evans et al 1955, Fisher et al 1943) has provided us with a plethora of estimators and estimation procedures (for examples, Chao and Bunge 2002, Chazdon et al 1998, Dorazio and Royle 2003, Skov and Lawesson 2000, Tackaberry et al 1997, and Walther and Morand 1998. Each estimator rests on a set of assumptions about the population and the sampling protocol (Bunge and Fitzpatrick 1993).…”

“…An index of species similarity between a pair of plots was cast as a non-linear function of inter-plot distances and used in a plug-in formula for the speciesarea relationship. Excellent summaries of techniques and methods for assessing species richness have been given by, for examples, Chazdon et al (1998), Condit (1998, Condit et al (1996) and Tackaberry et al (1997). It is well known that only an intensive survey of a population can generate an accurate estimate of richness (for example Gimaret-Carpentier et al 1998).…”