Evaluation of methods for estimating macroinvertebrate species richness using individual stones in tropical streams

Abstract

1. The most straightforward way to assess diversity in a site is the species count. However, a relatively large sample is needed for a reliable result because of the presence of many rare species in rich assemblages. The use of richness estimation methods is suggested by many authors as a solution for this problem in many cases. 2. We examined the performance of 13 methods for estimating richness of stream macroinvertebrates inhabiting riffles both at local (stream) and regional (catchment) scales. The evaluation was based on (1) the smallest sub‐sample size needed to estimate total richness in the sample, (2) constancy of this size, (3) lack of erratic behaviour in curve shape and (4) similarity in curve shape through different data sets. Samples were from three single stream sites (local) and three from several streams within the same catchment basin (regional). All collections were made from protected forest areas in south‐east Brazil. 3. All estimation methods were dependent on sub‐sample size, producing higher estimates when using larger sub‐sample sizes. The Stout and Vandermeer method estimated total richness in the samples with the smallest sub‐sample size, but showed some erratic behaviour at small sub‐sample sizes, and the estimated curves were not similar among the six samples. The Bootstrap method was the best estimator in relation to constancy of sub‐sample sizes, but needed an unacceptably large sub‐sample to estimate total richness in the samples. The second order Jackknife method was the second best estimator both for minimum sub‐sample size and constancy of this size and we suggest its use in future studies of diversity in tropical streams. Despite the inferior performance of several other methods, some produced acceptable results. Comments are made on the utility of using these estimators for predicting species richness in an area and for comparative purposes in diversity studies.

Assessment of richness estimation methods on macroinvertebrate communities of mountain ponds in Castilla y León (Spain)

“…These approaches include measures of bias and accuracy of the estimated richness in relation to the true richness using an a priori chosen sub-sample size. However, the estimated richness is strongly dependent on sample size (Colwell and Coddington, 1994;Melo and Froehlich, 2001;Petersen and Meier, 2003) and different sub-samples sizes will produce different bias and accuracy values (Hellmann and Fowler, 1999). In addition, these approaches require data for maximum species numbers for their calculation, so they cannot be used here.…”

“…Therefore, richness measures are becoming valuable tools for a number of scientific applications as well as a means to assess environmental degradation. The assessment of richness in a given area requires a count of observed species or taxa (Melo and Froehlich, 2001) but, unfortunately, in biological and ecological sciences, the compilation of complete species census and inventories is costly or even impossible (Foggo et al, 2003;Hortal et al, 2006). In addition, biodiversity data suffer from heterogeneity in sampling strategies and/or sample size: the larger the sampling effort, the larger will be the number of observed taxon (Walther et al, 1995).…”

“…Taxon richness estimation techniques have been developed, mainly in the past 20 years, and are emerging as a powerful tool for providing a cost-effective method of assessing richness in an area without the need for full inventories. These estimation methods have been the subject of a growing body of literature (Colwell and Coddington, 1994;Hammond, 1994;Gotelli and Colwell, 2001), with validation of the methods for a variety of taxa and habitats remaining a priority (Colwell and Coddington, 1994;Melo and Froehlich, 2001;Brose et al, 2003). Richness estimation models are based on different mathematical approaches and can be classified as either species accumulation curves or nonparametric estimators (Gotelli and Colwell, 2001;Brose et al, 2003).…”

“…However, in freshwaters their use has mostly been restricted to stream invertebrates (Melo and Froehlich, 2001) and lake zooplankton (Dumont and Segers, 1996;Arnott et al, 1998). Few researches of this kind have been undertaken in ponds (Foggo et al, 2003), but none in mountain ponds.…”

Use of the BEAST model for biomonitoring water quality in a neotropical basin

“…The scientific community has recently developed and extended biomonitoring programs Passy, 2007). Aquatic macroinvertebrate assemblages are frequently used as indicators of environmental quality, allowing the detection and evaluation of ecosystem impacts (Melo & Froehlich, 2001;Roque et al, 2003;Moreno & Callisto, 2006).…”