The additive partitioning of species diversity: recent revival of an old idea

Abstract

Ecologists have traditionally viewed the total species diversity within a set of communities as the product of the average diversity within a community (alpha) and the diversity among the communities (beta). This multiplicative concept of species diversity contrasts with the lesser known idea that α‐ and β‐diversities sum to give the total diversity. This additive partitioning of species diversity is nearly as old as the multiplicative concept, yet ecologists are just now beginning to use additive partitioning to examine patterns of species diversity. In this review we discuss why additive partitioning remained “hidden” until just a few years ago. The rediscovery of additive partitioning has expanded the way in which ecologists define and measure β‐diversity. Beta diversity is no longer relegated to describing change only along an environmental gradient. Through additive partitioning, β‐diversity is explicitly an average amount of diversity just as is α‐diversity. We believe that the additive partitioning of diversity into α and β components will continue to become more widely used because it allows for a direct comparison of α‐ and β‐diversities. It also has particular relevance for testing ecological theory concerned with the determinants of species diversity at multiple spatial scales and potential applications in conservation biology.

Community structure and microhabitat preferences of harpacticoid copepods in a tropical reef lagoon (Zanzibar Island, Tanzania)

“…Calculated indicator values were tested for significant values using a Monte Carlo test (Dufrêne & Legendre, 1997). The additive partitioning of species diversity into measures of a-and b-diversity (Veech et al, 2002;Crist et al, 2003) was conducted with PARTITION software.…”

Study of biological communities subject to imperfect detection: bias and precision of communityN‐mixture abundance models in small‐sample situations

“…Because the number of detected species throughout the survey (r) was always ‡35, we used 40 augmented species in the analysis. The mean site-level detection-naı¨ve species richness is the observed a diversity; hence, we obtained the detection-naı¨ve b diversity estimate by subtracting the mean of the a diversity from c diversity, i.e., b = c À mean (a) (Veech et al 2002;Crist et al 2003). We calculated the site-level Shannon index (a diversity of Shannon index) using the maximum count (over the four visits) of each species and used the overall Shannon index as a measure of c diversity by summing these maximum counts for each species across the sites.…”

“…Simulation experiment 3: partitioning c diversity into a and b diversity subject to imperfect detection We used additive partitioning (Veech et al 2002;Crist et al 2003) in the community abundance models for those scenarios of the sampling design where community abundance models achieved good performance (see ''Results''): n site = 40, n visit = 4, and mean abundance ð k ¼ expðl b 0 Þ) = 0.5. We only varied the mean detection probability ðp), which will affect the observed sitelevel species richness, at the three levels of 0.1, 0.2, and0.5.…”

“…Second, community abundance models are able to estimate local (site-specific) species richness (a diversity) as well as overall species richness (c diversity) and the size of the regional species pool; c diversity can be greatly smaller than the size of regional species pool depending on the total area of the sampling plots used. Turnover of community composition among sites (b diversity) can be calculated by subtracting the mean a diversity from c diversity using the framework of additive partitioning (Veech et al 2002;Crist et al 2003) or by computing indices such as the Jaccard index that are based on pairwise comparisons of species occurrence (Dorazio and Royle 2005;Dorazio et al 2010;Ke´ry and Royle 2016).…”

Dung beetle communities: a neotropical-north temperate comparison

“…Betadiversity, originally proposed as a measure of diversity along a gradient, has been generalized to a measure of species differences and turnover rates across geographical locations (Veech et al 2002). Spector (2002) measured dung beetle beta-diversity across sites in Parque Nacional Noel Kempff Mercado where he found 143 species, but on average, only 29.4 species were present at any single site.…”