PARENT SESSION
Oral Session 4: Biodiversity I: Communities and Function.
Presiding: C Holzapfel and D Ellsworth
Monday, August 2, 8:00 AM to 11:30 AM, Meeting Room B 110.

Quantifying functional diversity: A new analytic method.

Cornwell, William^*,1, Schwilk, Dylan¹, Ackerly, David¹, ¹ Dept. of Biological Sciences, Stanford, CA, USA

ABSTRACT- The functional diversity of a community has often been quantified as the number of functional groups present, with the assignment of species to functional groups based on measures of the species' functional traits. However, functional traits are, with few exceptions, continuous and normally or log-normally distributed, and imposing bins on these distributions discards important information. Here, we present a new measure of functional diversity based on quantifying the volume (or hyper-volume) of trait space occupied by a group of species. This method is well-suited to the continuous and n-dimensional nature of functional trait data. Using this approach we examine the effects of trait correlations on functional diversity. We also show that the shape of the functional diversity-species richness relationship depends on the dimensionality of the trait space considered. In higher dimensional spaces, functional diversity shows an increasingly linear relationship with species richness. Finally, we present data from California woody plant communities, which show that communities display non-random patterns of functional diversity with respect to a null model.

Key words: functional diversity