HR: 1330h
AN: NB33Q-05    [Abstracts]
TI: The Effects of Amphibian Extirpations on Foodweb Structure and Function in Panamanian Highland Streams.
AU: * Hunte-Brown, M E
EM: meh27@dreel.edu
AF: Drexel University, Dept of Bioscience and Biotechnology Drexel University, Philadelphia, Pa 19104 United States
AU: Kilham, S S
EM: kilhams@drexel.edu
AF: Drexel University, Dept of Bioscience and Biotechnology Drexel University, Philadelphia, Pa 19104 United States
AU: Whiles, M R
EM: mwhiles@zoology.siu.edu
AF: Southern Illinois University, Dept of Zoology Southern Illinois University, Carbondale, Il 62901 United States
AU: Lips, K
EM: klips@zoologu.siu.edu
AF: Southern Illinois University, Dept of Zoology Southern Illinois University, Carbondale, Il 62901 United States
AU: Pringle, C
EM: pringle@sparc.ecology.uga.edu
AF: University of Georgia, Institute of Ecology University of Georgia, Athens, Ga 30602
AU: Colon, C
EM: checo@siu.edu
AF: Southern Illinois University, Dept of Zoology Southern Illinois University, Carbondale, Il 62901 United States
AU: Brenes, R
EM: tadpole@siu.edu
AF: Southern Illinois University, Dept of Zoology Southern Illinois University, Carbondale, Il 62901 United States
AU: Connelly, S
EM: scottcon@@uga.edu
AF: University of Georgia, Institute of Ecology University of Georgia, Athens, Ga 30602
AB: Amphibian populations are declining globally in uplands. Stream-dwelling tadpoles are potentially important herbivores, and their loss is expected to cause significant changes in structure and function of lotic ecosystems. This study is part of a collaborative effort to measure changes in trophic structure associated with amphibian extirpations. We used stable isotopes to elucidate trends in Panamanian highland streams at two locations, El Cope and Fortuna, which are differentially affected by the declines. Generally, the nitrogen source in the Fortuna stream, where amphibians have already declined, is primarily atmospheric, whereas it is more recycled in El Cope where tadpoles are still abundant. FBOM is an important food resource in El Cope, and because of the recycled N from tadpole feces, the delta N15 values of the periphyton are higher in the pools than in the riffles in El Cope. Generally, the delta N15 signal of similar trophic groups is lower at Fortuna than at El Cope. The delta N15 signals also tend to fall with increased rainfall. Leaf packs are apparently under-utilized in these systems. Results allow for an assessment of trophic structure in highland neotropical streams and suggest that stream-breeding anuran extirpations may alter nutrient cycling and energy flow.
DE: 0399 General or miscellaneous
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly