PARENT SESSION
Session #10: Functional similarity and functional groups in ecological systems. Organized by: P. Morin and R. Zamora.
Tuesday, August 7, 2001. Lecture Hall
The measurement, prediction, and significance of functional similarity.
Morin, Peter1, 1
ABSTRACT- The controversy over the impact of biodiversity on ecosystem functioning stems partly from the problems involved in measuring the extent of functional similarity of different species. Logistic constraints limit direct experimental approaches to comparisons of small numbers of species, but a review of these comparisons shows that some species have virtually identical impacts on particular attributes, including prey species composition and secondary production. In some of these cases, taxonomic similarity appears to be a better predictor of functional similarity than broad trophic or physiological characterizations. The interpretation of indirect approaches based on levels of functioning versus the richness of species or functional groups remains problematic, partly because such patterns may arise from multiple processes. Another source of confusion is that there is currently little consensus about the criteria used to identify key functional groups. Possible standardized approaches to the identification of functional groups could employ criteria that incorporate information about taxonomic similarity, niche metrics, and position and linkage patterns within food webs. Examples from our recent work with aquatic microbial communities explore how conclusions about the significance of functional similarity depend on the function in question and the criteria used to define functional groups.
KEY WORDS: Biodiversity, Ecosystem, Functional group, Experiments