Claret C., Marmonier P., Dole-Olivier M-J. Creuzé Des Chatelliers M., Boulton A.J. and Castella E. 1999.

A functional classification of interstitial invertebrates: supplementing measures of biodiversity using species traits and habitat affinities

Archiv Für Hydrobiologie 145/4, 385-403.

Abstract

Although functional classifications have been successfully used in terrestrial and marine ecosystems to generate ecological hypotheses, compare local and regional environments, and supplement studies of biodiversity, they rarely have been applied to aquatic ecosystems, especially interstitial ones. We present two complementary classifications of interstitial invertebrates, and demonstrate their utility as a supplement for conventional measurements of biodiversity, as "common currency" for regional and global comparisons, as a tool for generating hypotheses, and as indictors of ecological variation in space and time. The first classification uses three species traits: diet, locomotion, and body size. Although mode of reproduction and extent of parental care were originally explored, these traits were less useful for prediction and explanation. The second classification reflects the degree of affinity for different subsurface habitats. Invertebrates can be classified as stygoxenes, stygophiles and stygobites. Changes in conditions in subsurface habitats (e.g. through groundwater extraction, sedimentation) can alter the proportions of these categories, providing a useful biological indicator of subsurface dynamics. Presently, use of these functional classifications is limited by a lack of autecological data for many interstitial species. However, as our knowledge increases and these data are obtained, there is great potential for large-scale ecological hypothesis-testing, prediction of the effects of human and natural disturbances, and global comparisons of interstitial assemblages and biodiversity.