EXPLORING THE INFLUENCE OF BENTHIC SUBSTRATE ON BIOFILM GROWTH IN EXPERIMENTAL STREAMS AT ND-LEEF
Stream biofilms colonize benthic surfaces of all types and are well studied in the context of biogeochemistry, but the interplay between substrate, hydraulics, and patterns in biofilm colonization remain understudied. We explored the interaction between substrate composition and biofilms over two summers in four 50m experimental streams with contrasting substrate composition at the Notre Dame Linked Experimental Ecosystem Facility (ND-LEEF). The four streams varied only in substrate lining each channel, representing varying size (gravel vs. cobble) and heterogeneity (alternating sizes vs. well-mixed). We used repeated sampling over time to examine biofilm accumulation at two different timescales: in 2015 we sampled 6 times over 158d of growth, and in 2016 we sampled over 32d. During both summers, we found that biofilm colonization was substrate-specific, but spatially and temporally heterogeneous. While biofilm biomass generally increased over time in all streams, even over short time scales, biofilm accumulation also included significant reach-scale patchiness. These results suggest a strong linkage between biofilm character and underlying substrate, and should be considered when exploring the impact of the physical environment on the ecology of natural streams.
Nicole Gorman (Primary Presenter/Author), University of Notre Dame, firstname.lastname@example.org;
Arial Shogren ( Co-Presenter/Co-Author), University of Notre Dame, email@example.com;
Jennifer L. Tank ( Co-Presenter/Co-Author), University of Notre Dame, firstname.lastname@example.org;
Elizabeth Berg ( Co-Presenter/Co-Author), University of Notre Dame, Elizabeth.M.Berg.email@example.com;
Brittany Hanrahan ( Co-Presenter/Co-Author), University of Notre Dame, firstname.lastname@example.org;