Wednesday, August 6, 2008 - 10:30 AM

COS 47-8: Among-habitat patterns in the taxonomic and functional composition of littoral benthic invertebrate communities

Katrina June Butkas, University of Wisconsin

Background/Question/Methods

The littoral zone of many lakes is heterogenous, consisting of a landscape of different patch types (e.g., macrophytes, bare substrate, cobble). It is largely unknown but often assumed that these differences in physical habitat structure correlate with differences in invertebrate community taxonomic and functional composition. If physical habitat descriptors are highly correlated with taxonomic or functional community similarity, then the pattern of physical habitat (e.g., the percent contribution of each habitat type to total littoral area) may play a large role in determining how the littoral zone contributes to ecosystem processes. I use benthic invertebrate data from 8 north temperate lakes to quantify the strength of the correlation between physical habitat characteristics and benthic invertebrate community similarity. I also synthesize the literature on this topic to determine how strong this linkage is across systems and across different studies.

Results/Conclusions

Preliminary results from nonmetric multidimensional scaling, mantel tests, and partial mantel tests indicate that physical habitat descriptors are significantly but only moderately correlated with the taxonomic similarity (Bray-Curtis) (mantel r = 0.16). In contrast, site, date, and depth were only weakly or nonsignificantly correlated with taxonomic similarity.