PARENT SESSION
Oral Session #2: Riparian Ecology.
Presiding: M. Dixon
Monday, August 5. 8:00 AM to 11:30 AM. Greenlee Meeting Room, TCC.

Developing a dynamic model linking riparian area forests with littoral zone coarse woody structure in a temperate lake.

Achuff, Brian^*,1, Bozek, Michael¹, Cook, James², Newbrey, Michael¹, ¹ Wisconsin Cooperative Fishery Research Unit, Stevens Point, WI² College of Natural Resources, Stevens Point, WI

ABSTRACT- North temperate lakes and riparian areas are closely linked ecosystems. Riparian forests provide habitat for numerous species of birds, mammals, amphibians, etc, and create aquatic habitat when trees recruit into the littoral zones of lakes. The objectives of this study were to 1) link characteristics of littoral zone coarse woody structure (CWS) with riparian forest characteristics, 2) determine current and historical rates of CWS recruitment, 3) quantify decomposition rates of CWS, and 4) quantify fish use of CWS as it structurally decomposes. We surveyed the riparian area and littoral zone of Katherine Lake, WI to collect data on riparian forest conditions (e.g. species, basal area, slope, etc), coarse woody structure (e.g. branching complexity, diameter, length etc.), and fish use of CWS in the littoral zone. Dendrochronological techniques were used to assess stand age, woody structure age, and decay rates. Multiple regression and canonical correlation analyses found riparian area characteristics (stand composition, slope, and others) correlated with submerged CWS characteristics. Submerged woody structure recruitment has fluctuated since logging and settlement circa 1900. Fish richness and abundance declined as CWS decomposed at each site. We are developing a dynamic model that integrates riparian forest stand dynamics with the recruitment of wood to the lake, the rate of wood decay, and use of wood by fish in this lake to elucidate ecosystem processes and the sustainability of land use.

KEY WORDS: riparian, fish habitat, coarse woody debris, dendrochronology