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| A species abundance distribution (SAD) characterises patterns in the commonness and rarity of
all species within an ecological community. As such, the SAD provides the theoretical foundation
for a number of other biogeographical and macroecological patterns, such as the species–
area relationship, as well as being an interesting pattern in its own right. While there has been
resurgence in the study of SADs in the last decade, less focus has been placed on methodology in
SAD research, and few attempts have been made to synthesise the vast array of methods which
have been employed in SAD model evaluation. As such, our review has two aims. First, we provide a general overview of SADs, including descriptions of the commonly used distributions, plotting
methods and issues with evaluating SAD models. Second, we review a number of recent advances
in SAD model fitting and comparison. We conclude by providing a list of recommendations for
fitting and evaluating SAD models. We argue that it is time for SAD studies to move away from
many of the traditional methods available for fitting and evaluating models, such as sole reliance
on the visual examination of plots, and embrace statistically rigorous techniques. In particular, we
recommend the use of both goodness-of-fit tests and model-comparison analyses because each
provides unique information which one can use to draw inferences. | |
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