TY - JOUR
T1 - Assessing Ecological Responses to Catastrophic Amphibian Declines
T2 - Patterns of Macroinvertebrate Production and Food Web Structure in Upland Panamanian Streams
AU - Colón-Gaud, Checo
AU - Whiles, Matt R.
AU - Kilham, Susan S.
AU - Lips, Karen R.
AU - Pringle, Cathy M.
AU - Connelly, Scott
AU - Peterson, Scot D.
N1 - Enter your email address below. If your address has been previously registered, you will receive an email with instructions on how to reset your password. If you don't receive an email, you should register as a new user
PY - 2009/1
Y1 - 2009/1
N2 - As part of the Tropical Amphibian Declines in Streams (TADS) project, we estimated macroinvertebrate production and constructed quantitative food webs for four headwater stream reaches in the Panamanian uplands: two that had experienced massive amphibian declines and two with unaffected amphibian populations. As expected for forested headwaters, allochthonous materials were the dominant energy source. Total macroinvertebrate biomass and production ranged from 231 to 360 mg ash‐free dry mass m−2 and from 3.1 to 4.4 g ash‐free dry mass m−2 yr−1, respectively, and did not appear influenced by the presence or absence of amphibians. However, macroinvertebrate functional structure differed between pre‐ and post‐decline sites, with shredder production significantly higher in pre‐decline sites and scrapers significantly higher in post‐decline sites. Taxonomic differences between pre‐ and post‐decline sites were also evident. There was a shift in scrapers from smaller‐bodied taxa (e.g., Psephenus) in pre‐decline sites to larger‐bodied groups (e.g., Petrophila) in post‐decline sites. Detrital pathways were dominant in these systems, with shredders and collectors accounting for most energy flow. However, scrapers were well‐represented and they were food‐limited in these systems, particularly in the presence of larval amphibians at pre‐decline sites. Ecological effects of catastrophic amphibian declines ranged from subtle shifts in taxonomic composition and functional structure of remaining consumers to changes in the availability and relative importance of autochthonous energy sources.
AB - As part of the Tropical Amphibian Declines in Streams (TADS) project, we estimated macroinvertebrate production and constructed quantitative food webs for four headwater stream reaches in the Panamanian uplands: two that had experienced massive amphibian declines and two with unaffected amphibian populations. As expected for forested headwaters, allochthonous materials were the dominant energy source. Total macroinvertebrate biomass and production ranged from 231 to 360 mg ash‐free dry mass m−2 and from 3.1 to 4.4 g ash‐free dry mass m−2 yr−1, respectively, and did not appear influenced by the presence or absence of amphibians. However, macroinvertebrate functional structure differed between pre‐ and post‐decline sites, with shredder production significantly higher in pre‐decline sites and scrapers significantly higher in post‐decline sites. Taxonomic differences between pre‐ and post‐decline sites were also evident. There was a shift in scrapers from smaller‐bodied taxa (e.g., Psephenus) in pre‐decline sites to larger‐bodied groups (e.g., Petrophila) in post‐decline sites. Detrital pathways were dominant in these systems, with shredders and collectors accounting for most energy flow. However, scrapers were well‐represented and they were food‐limited in these systems, particularly in the presence of larval amphibians at pre‐decline sites. Ecological effects of catastrophic amphibian declines ranged from subtle shifts in taxonomic composition and functional structure of remaining consumers to changes in the availability and relative importance of autochthonous energy sources.
KW - Catastrophic amphibian declines
KW - Ecological responses
KW - Food web structure
KW - Macroinvertebrate production
KW - Upland Panamanian streams
UR - https://doi.org/10.4319/lo.2009.54.1.0331
U2 - 10.4319/lo.2009.54.1.0331
DO - 10.4319/lo.2009.54.1.0331
M3 - Article
SN - 0024-3590
VL - 54
JO - Limnology and Oceanography
JF - Limnology and Oceanography
ER -