PARENT SESSION
Oral Session #65: Aquatic Ecology: Stream and Lake.
Presiding: C. Osenberg
Wednesday, August 7. 1:00 PM to 4:45 PM. Coconino Meeting Room, TCC.
Modeling linkages between terrestrial and aquatic ecosystems (Part 1).
Roth, Brian*,1, Kaplan, Isaac1, Sugden-Newbery, Anna1, Yannarell, Anthony1, Willis, Theodore1, Turner, Monica1, 1 University of Wisconsin-Madison, Madison, Wisconsin
ABSTRACT- This is the first of two presentations that examine the influence of coarse woody debris (CWD) inputs and removals on fish food webs. We developed two ecosystem models that separately address riparian forest and aquatic food web dynamics, but are linked through CWD dynamics. Here we describe the forest model, parameterized based on data collected in and around Little Rock Lake in northern Wisconsin. The model forest incorporates saplings, adult trees and standing snags. TIn addition, the forest undergoes succession from generic softwoods to hardwoods. CWD is created through mortality of adult trees or from falling snags. We simulated two disturbance scenarios: 1) a large wind event, and 2) lakeshore development by humans. In a control scenario, the model predicted steady state CWD density similar to that found in Little Rock Lake. Following the large wind event, CWD density increased sharply following the large wind event. However, the wind event blew down adult trees, creating a source deficit for CWD in following years. Softwood abundance increased for 36 years after the wind event and then declined. Lakeshore development caused declines in all trees and snags and led to a mix of hardwood and softwood trees. In addition, CWD declined 98.3% within 50 years following the onset of development. These results suggest that perturbations to the riparian forest may have drastic effects on CWD dynamics and as a result may cause changes in the aquatic food web.
KEY WORDS: coarse woody debris, riparian forest, aquatic and terrestrial linkages, modeling