PARENT SESSION
Monday, August 7, 8:00-11:30 am
COS 14 - Amphibian and reptile ecology and decline
Plantation Room, Cook Convention Center
Presiders: D Nelson
Trophic basis of production and energy flow associated with emergence among assemblages of larval ambystomatid salamanders in forested ponds in southern Illinois.
Regester, Kurt*,1, Lips, Karen1, Whiles, Matt1, 1 Southern Illinois University, Carbondale, IL, USA
ABSTRACT- Larval amphibians transfer energy from freshwater to terrestrial ecosystems during seasonal emergences, but larval production and energy flow to adjacent systems are rarely quantified. During 2003-2004, we derived prey-specific assimilation efficiencies, conducted gut analyses, and intensively sampled ambystomatid salamander assemblages in four forested ponds to quantify energy flow associated with larval consumption and assess the importance of major prey types to production and emergence. We estimated that 2.5-17.2 g AFDM m-2 yr-1 of prey production was required to account for larval salamander production, which ranged from 0.8-5.3 g AFDM m-2 yr-1 among assemblages. Energetically important prey types varied among populations and ponds, with up to 88.5% of A. opacum production attributed to zooplankton, 84.2% of A. maculatum production attributed to aquatic insects, and 79.3% of A. tigrinum production attributed to amphibian prey. Overall, zooplankton accounted for 60.4-88.5% of salamander production in temporary ponds whereas aquatic insects accounted for 19.9-84.2% of production in permanent ponds. Emergences associated with larval assemblages represented 3.3%, 4.8%, and 8.2% of consumption and 9.9% 15.8%, and 26.4% of production at three ponds that did not dry during larval development. Our study demonstrates that emergences of larval amphibians represent a significant pathway for energy flow from freshwater to terrestrial food webs. Quantifying the ecological roles of amphibians is important in light of amphibian declines, as this information furthers our understanding of the ecological consequences of these losses.
Key words: energy flow, amphibian, forest ponds