HR: 13:30h
AN: NB13F-01 INVITED     [Abstracts]
TI: Modelling and Prediction of Trait Response and Functional Diversity of Stream Invertebrates: how to Deal With Fuzzy Coded Species Traits?
AU: Bady, P
EM: pierre.bady@univ-lyon1.fr
AF: UMR CNRS 5023 - UCB Lyon 1, Bƒt Forel Rdc 43 Bd du 11 novembre 1918, Villeurbanne, 69622 France
AU: * Dolédec, S
EM: sylvain@biomserv.univ-lyon1.fr
AF: UMR CNRS 5023 - UCB Lyon 1, Bƒt Forel Rdc 43 Bd du 11 novembre 1918, Villeurbanne, 69622 France
AB: Since the special session `Synthesizing long-term riverine research: new multivariate approaches to test ecological theory' at the 41th NABS Calgary meeting in 1993, several authors have continued the quantification of stream invertebrate biological traits using a flexible fuzzy coding technique. Fuzzy correspondence analysis was designed for the description of such information. However, the growing need for predictive models has urged scientists towards designing appropriate statistical tools. Here, we present a statistical approach based on Vector Generalized Linear Models suitable for multidimensional responses and preserving the conditional relationships among trait modalities. To investigate the potential of VGLM, we have used stream invertebrate sampling and associated habitat characteristics at 67 quasi-reference condition sites in 8 European rivers. Altitude and stream gradient were the most frequently selected variables in models associated to traits such as trophy or size. Temperature range participated in modelling traits associated to life cycles. Local hydraulics were essential to modelling body form. Finally, our model enabled the detection of human impacts on patterns in life cycle confirming a priori predictions. These results suggest the potential specific responses of traits to environmental conditions and the potential applicability of VGLM for elaborating a trait-based monitoring tool.
DE: 1803 Anthropogenic effects
DE: 1845 Limnology
DE: 1871 Surface water quality
DE: 3210 Modeling
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly