Biodiversity and Ecosystem Properties

Abstract

Because the goal of ecology is to understand the causes of patterns observed in the natural world, studies that document novel patterns in natural ecosystems are of central importance. The report "The influence of island area on ecosystem properties" by David A. Wardle et al. (29 Aug., p. 1296) is such a study. Some interpretations of data made by Wardle et al. illustrate the difficulty of ascribing causation on the basis of observation. In particular, their assertions "that ecosystem process rates were lowest on those islands with the greatest diversity" and that "this finding is in direct contrast to other studies which have shown elevated process rates in more diverse communities" are difficult to justify given their analyses and the data in the other studies (1-4).