title: Density-dependent effects of non-native brown trout Salmo trutta on the species-area relationship in stream fish assemblages.
abstract: The spatial scale and density-dependent effects of non-native brown trout Salmo trutta on species richness of fish assemblages were examined at 48 study sites in Mamachi Stream, a tributary of Chitose River, Hokkaido, Japan. The density of age ≥1 year S. trutta was high in the upstream side of the main stem of Mamachi Stream. Fish species richness increased with increasing area of study sites (habitat size), but the increasing magnitude of the species richness with area decreased with increasing age of ≥1 year S. trutta density. The relationships between age ≥1 year S. trutta, however, and presence-absence of each species seemed to be different among species. Species richness was also determined by location and physical environmental variables, i.e. it was high on the downstream side and in structurally complex environments.
authors: Hokkaido National Fisheries Research Institute, Japan Fisheries Research and Education Agency, Nakanoshima, Toyohira, Sapporo, Hokkaido, 062-0922, Japan.
authors: K
authors: K
authors: Hasegawa
authors: Aqua Restoration Research Center, Public Works Research Institute, Kawashima-Kasada Machi, Kakamigahara, Gifu, 501-6021, Japan.
authors: T
authors: T
authors: Mori
authors: Graduate School of Environmental Science, Hokkaido University, N10 W5, Kita, Sapporo, Hokkaido, 060-0810, Japan.
authors: C
authors: C
authors: Yamazaki
mesh_terms: D063147:Animal Distribution; D000818:Animals; D017753:Ecosystem; D058865:Introduced Species; D007564:Japan; D011156:Population Density; D045483:Rivers; D014337:Trout / Q000502:physiology*
keywords: biodiversity; interspecific interaction; salmonids; species richness