Effects of reach-scale canopy cover on trophic pathways of caddisfly larvae in a Japanese mountain stream
Hideyuki Doi A B F , Yasuhiro Takemon C , Taichi Ohta D , Yuko Ishida D and Eisuke Kikuchi EA Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
B Present address: School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195, USA.
C Water Resources Research Center, Disaster Prevention Research Institute, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
D Graduate School of Engineering, Kyoto University, Katura, Nishikyo-ku, Kyoto 615-8530, Japan.
E Center for Northeast Asian Studies, Tohoku University, Kawauchi, Aoba-ku, Sendai 980-8576, Japan.
F Corresponding author. Email: hdoi@u.washington.edu
Marine and Freshwater Research 58(9) 811-817 https://doi.org/10.1071/MF07067
Submitted: 2 April 2007 Accepted: 1 August 2007 Published: 21 September 2007
Abstract
Differences in trophic pathways between reaches with and without tree canopy cover above the channel were assessed using stable isotopes in a 1.4-km stretch of the Kamo River, Japan. The trophic pathways of two larval trichopteran species, a grazer (Goera joponica, Goeridae) inhabiting stone surfaces and a net-spinning filter-feeder (Stenopsyche marmorata, Stenopsychidae) inhabiting interstices of the stony stream bottom, were estimated using carbon and nitrogen isotopes in reaches with and without canopy cover in winter. The δ13C values of G. japonica were similar to those of periphyton at each station, suggesting that G. japonica is a grazer on periphyton. A significant positive correlation between carbon isotope values of S. marmorata and benthic particulate organic matter (BPOM) indicated that BPOM varied in composition according to the amount of solar energy within a reach. In addition, there was a significant positive correlation between carbon isotope values of filter-feeders and the periphytic algal contribution to BPOM using an isotope mixing model, indicating that the main food source of the filter feeders was derived from the in situ periphytic algae in open reaches and from a terrestrial source in canopy-covered reaches.
Additional keywords: filter-feeder, food webs, grazer, spatial scale, stable isotope.
Acknowledgements
We thank Dr K. Itoh, Department of Agriculture, Tohoku University, for her permission to use the stable isotope analytical facilities in her laboratory. We thank Mr T. Tanaka, of the Graduate School of Engineering at Kyoto University, for his help with field work. This study was supported in part by Grant-in-Aid for Scientific Research (A2) from Japan Society for the Promotion of Science (No.15206058) and by CREST, JST.
Behmer, D. J. , and Hawkins, C. P. (1986). Effects of overhead canopy on macroinvertebrate production in a Utah USA stream. Freshwater Biology 16, 287–300.
| Crossref | GoogleScholarGoogle Scholar |
Takemon, Y. (2005). Life-type concept and functional feeding groups of benthos communities as indicators of lotic ecosystem conditions. Japanese Journal of Ecology 55, 189–197.[In Japanese]
Tanida, K. , Mitsuhashi, H. , and Fujitani, T. (1999). A simple acrylate fiber sampler for stream periphyton. Japanese Journal of Limnology 60, 619–624.
Thorp, J. H. , and Delong, M. D. (1994). The riverine productivity model: an heuristic view of carbon sources and organic processing in large river ecosystems. Oikos 70, 305–308.
| Crossref | GoogleScholarGoogle Scholar |
Thorp, J. H. , Delong, M. D. , Greenwood, K. S. , and Casper, A. F. (1998). Isotopic analysis of three food web theories in constricted and floodplain regions of a large river. Oecologia 117, 551–563.
| Crossref | GoogleScholarGoogle Scholar |
Trudeau, V. , and Rasmussen, J. B. (2003). The effect of water velocity on stable carbon and nitrogen isotope signatures of periphyton. Limnology and Oceanography 48, 2194–2199.
Vannote, R. L. , Minshall, G. W. , Cummins, K. W. , Sedell, J. R. , and Cushing, C. E. (1980). The River continuum concept. Canadian Journal of Fisheries and Aquatic Sciences 37, 130–137.
Wallace, J. B. , Eggert, S. L. , Meyer, J. L. , and Webster, J. R. (1997). Multiple trophic levels of a forest stream linked to terrestrial litter inputs. Science 277, 102–104.
| Crossref | GoogleScholarGoogle Scholar |
Woodward, G. , and Hildrew, A. G. (2002). Food web structures in riverine landscapes. Freshwater Biology 47, 777–798.
| Crossref | GoogleScholarGoogle Scholar |
