A Geomorphic–Trophic Model for Landscape Control of Arctic Lake Food Webs

Abstract

trophic structure is a result of complex interactions among consumers and their resources. Algal productivity is channeled to higher trophic levels, which in turn structure planktonic consumer food webs and control algal biomass through cascading trophic interactions (Shapiro 1980, Carpenter et al. 1985). Top predators also affect benthic food web structure (Bronmark et al. 1992). However, cascading effects in benthic food webs are confounded by habitat complexity in the littoral zone and accumulation of organic matter in lake sediments (Crowder and Cooper 1982, Gilinsky 1984, Hershey 1985, 1992, Carpenter and Lodge 1986). Thus, benthic-pelagic coupling is not well integrated into the current understanding of lake trophic dynamics. However, because arctic lake food webs are dominated by benthic-pelagic interactions, a model that focuses on planktonic food webs does not describe them well.