EFFECTS OF FISH CONNECTIVITY AND DRYING REGIME ON STREAM ECOSYSTEM STRUCTURE AND FUNCTION: RESULTS FROM A MESOCOSM EXPERIMENT.
Prairie streams are home to diverse assemblages of organisms that live in harsh and unpredictable environments. Small prairie streams frequently dry, creating disconnected habitat patches throughout the landscape. Climate change is increasing the frequency and duration of drying events in streams, so there is a need to better understand how spatial and temporal patterns of drying influence stream ecosystem structure and function. We conducted a mesocosm experiment to study the effect of connectivity between intermittent habitats on food web and community dynamics. We mimicked a landscape of isolated stream pools using thirty mesocosms and experimentally manipulated fish connectivity by manually moving fish between tanks in connected treatments, and manipulated drying with three treatments: completely dry, no surface water but wet sediment, and a no drying control. To measure the ecosystem responses to the connectivity and drying treatments, we measured algae accrual and benthic invertebrate abundance weekly throughout the 11 week-long experiment, and at the end of the experiment we sampled fish stomach contents and determined food web structure using community-wide stable isotope analysis. Our results indicate that drying and connectivity in streams have important consequences for stream ecosystems.
Daniel Allen (Co-Presenter/Co-Author), University of Oklahoma, firstname.lastname@example.org;
Steven Bittner (Primary Presenter/Author), University of Oklahoma, email@example.com;