On the species abundance distribution in applied ecology and biodiversity management

Abstract

The species abundance distribution (SAD) is an important concept in ecology, and much work has focused on the SAD in a theoretical context. However, less focus has been placed on the utility of SADs in applied ecology and biodiversity management, which therefore forms the focus of the present article. We illustrate that study of the SAD allows inferences beyond those that flow from many simple diversity indices, enabling workers to identify patterns in the commonness and rarity of species in a community. First, we discuss how incorporating SAD analyses into the study of ecological communities can generate useful information for the management of biodiversity. In particular, we argue that deconstructing ecological assemblages into various subsets and analysing how each subset contributes to the overall SAD can reveal patterns of interest to managers. Secondly, we review the many applications of SADs in applied ecological fields, including disturbance ecology, conservation planning and conservation biological control. Using examples we show that the SAD can be useful in applied ecology as it is visually intuitive, easy to implement in a broad variety of ecological contexts, and does not require substantial species-specific data. We provide a summary of the various methods available for plotting the SAD and illustrate how each method provides information of value for applied ecologists. Using empirical and simulated data, we show that the SAD can provide early warning of the effects of disturbance on ecological communities and that a number of SAD models represent useful tools for comparing communities in a management context. Synthesis and applications. Applied ecologists require tools that allow for relatively quick assessments of ecosystem health and/or the success of management prescriptions aimed at ameliorating the effects of disturbance. We demonstrate that that the methods reviewed herein provide such tools and that the species abundance distribution (SAD) has additional applied uses beyond traditional applications in disturbance ecology. We hope that this synthesis will provide a catalyst for advancing a more utilitarian SAD research agenda.