title: Isotopic evidence for the spatial heterogeneity of the planktonic food webs in the transition zone between river and lake ecosystems.
abstract: Resources and organisms in food webs are distributed patchily. The spatial structure of food webs is important and critical to understanding their overall structure. However, there is little available information about the small-scale spatial structure of food webs. We investigated the spatial structure of food webs in a lake ecosystem at the littoral transition zone between an inflowing river and a lake. We measured the carbon isotope ratios of zooplankton and particulate organic matter (POM; predominantly phytoplankton) in the littoral zone of a saline lake. Parallel changes in the δ (13)C values of zooplankton and their respective POMs indicated that there is spatial heterogeneity of the food web in this study area. Lake ecosystems are usually classified at the landscape level as either pelagic or littoral habitats. However, we showed small-scale spatial heterogeneity among planktonic food webs along an environmental gradient. Stable isotope data is useful for detecting spatial heterogeneity of habitats, populations, communities, and ecosystems.
authors.affiliation: Graduate School of Life Sciences, Tohoku University , Katahira, Aoba-ku, Sendai , Japan ; Institute for Sustainable Sciences and Development, Hiroshima University , Kagamiyama, Higashi-Hiroshima , Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Doi
authors.affiliation: Institute of Animal Systematics and Ecology, Siberian Branch of Russian Academy Sciences , Novosibirsk , Russia.
authors.forename: Elena I
authors.initials: EI
authors.lastname: Zuykova
authors.affiliation: Center for Northeast Asian Studies, Tohoku University , Kawauchi, Aoba-ku, Sendai , Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Shikano
authors.affiliation: Environmental Education Center, Miyagi University of Education , Aramaki-Aoba, Aoba-ku, Sendai , Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Kikuchi
authors.affiliation: Center for the Advancement of Higher Education, Tohoku University , Kawauchi, Aoba-ku, Sendai , Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ota
authors.affiliation: Institute of Animal Systematics and Ecology, Siberian Branch of Russian Academy Sciences , Novosibirsk , Russia.
authors.forename: Natalia I
authors.initials: NI
authors.lastname: Yurlova
authors.affiliation: Institute of Animal Systematics and Ecology, Siberian Branch of Russian Academy Sciences , Novosibirsk , Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Yadrenkina
keywords: Carbon; Food web; Heterogeneity; Isotope; Lake; Phytoplankton; Plankton; Spatial scale; Zooplankton