SPATIAL AND TEMPORAL VARIATION IN INSECT EMERGENCE FROM FOUR BACKWATERS OF THE MISSOURI RIVER
Consumer response to resource subsidies is constrained by the spatial and temporal dynamics of those subsidies, but these dynamics are not well-described. To quantify spatiotemporal variation in an aquatic-terrestrial subsidy, we measured emerging aquatic insects from four backwaters along the Missouri River from June through September of 2016. This study yielded two key findings: First, only two sites experienced distinct peaks, but in different months. Emergence in one site peaked in June and declined 78% in July through September. Emergence in the second site peaked in July, when it was 1.5 to 2.5 fold higher than any other month. The remaining sites experienced comparatively low but stable rates of emergence through all months. Second, the greatest disparity in total emergence—a 6-fold difference (208 insects/m2 versus 35 total insects/m2)—occurred between two adjacent sites separated by a beaver dam. These results demonstrate the potential for significant spatial and temporal variation to occur even amongst characteristically similar sites. Such asynchronous patterns of emergence may prolong the availability of the subsidy to consumers, thereby supporting a greater number of consumers than if emergence were synchronous.
Erika Oddy (Primary Presenter/Author), University of South Dakota, Erika.Oddy@coyotes.usd.edu;
Lisa Yager ( Co-Presenter/Co-Author), National Park Service, firstname.lastname@example.org ;
Jeff Wesner ( Co-Presenter/Co-Author), University of South Dakota, Jeff.Wesner@usd.edu;