title: Flow directionality, mountain barriers and functional traits determine diatom metacommunity structuring of high mountain streams.
abstract: Stream metacommunities are structured by a combination of local (environmental filtering) and regional (dispersal) processes. The unique characters of high mountain streams could potentially determine metacommunity structuring, which is currently poorly understood. Aiming at understanding how these characters influenced metacommunity structuring, we explored the relative importance of local environmental conditions and various dispersal processes, including through geographical (overland), topographical (across mountain barriers) and network (along flow direction) pathways in shaping benthic diatom communities. From a trait perspective, diatoms were categorized into high-profile, low-profile and motile guild to examine the roles of functional traits. Our results indicated that both environmental filtering and dispersal processes influenced metacommunity structuring, with dispersal contributing more than environmental processes. Among the three pathways, stream corridors were primary pathway. Deconstructive analysis suggested different responses to environmental and spatial factors for each of three ecological guilds. However, regardless of traits, dispersal among streams was limited by mountain barriers, while dispersal along stream was promoted by rushing flow in high mountain stream. Our results highlighted that directional processes had prevailing effects on metacommunity structuring in high mountain streams. Flow directionality, mountain barriers and ecological guilds contributed to a better understanding of the roles that mountains played in structuring metacommunity.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Fengzhi
authors.initials: F
authors.lastname: He
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Meiqin
authors.initials: M
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Haomiao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Tan
authors.affiliation: Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, China.|Collaborative Innovation Center for the Biodiversity in the Three Parallel Rivers of China, Dali, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Xiao
authors.affiliation: Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, China.|Collaborative Innovation Center for the Biodiversity in the Three Parallel Rivers of China, Dali, China.
authors.forename: Shuoran
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.|Collaborative Innovation Center for the Biodiversity in the Three Parallel Rivers of China, Dali, China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Cai
mesh_terms: D000531:Altitude; D017377:Diatoms / Q000502:physiology*; D017753:Ecosystem; D045483:Rivers; D014872:Water Movements