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Flow directionality, mountain barriers and functional traits determine diatom metacommunity structuring of high mountain streams.

Dong X, Li B, He F, Gu Y, Sun M, Zhang H, Tan L, Xiao W, Liu S, Cai Q - Sci Rep (2016)

Bottom Line: Our results indicated that both environmental filtering and dispersal processes influenced metacommunity structuring, with dispersal contributing more than environmental processes.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.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.

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.

No MeSH data available.


Related in: MedlinePlus

Map of the study area and the distribution of sampling sites in the Cangshan Erhai National Nature Reserve, Yunnan Province, Southwestern China.Green dots represent sampling sites (S1–1 represents the site most upstream in stream 1, and S1–6 represents the site most downstream in stream 1); blue lines and polygon depict the streams and the Erhai Lake. The map is based on a digital elevation model at 30 m resolution and created using ArcGIS 10.0 software (http://www.esri.com/software/arcgis).
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f1: Map of the study area and the distribution of sampling sites in the Cangshan Erhai National Nature Reserve, Yunnan Province, Southwestern China.Green dots represent sampling sites (S1–1 represents the site most upstream in stream 1, and S1–6 represents the site most downstream in stream 1); blue lines and polygon depict the streams and the Erhai Lake. The map is based on a digital elevation model at 30 m resolution and created using ArcGIS 10.0 software (http://www.esri.com/software/arcgis).

Mentions: In this study, we investigated 63 sites in high mountain streams (elevation ranges from 1600 to 2900 m a.s.l.), across a small spatial extent in Southwestern China (<500 km2, Fig. 1). Benthic diatoms were selected to study metacommunity structuring in high mountain streams for the following reasons: (1) benthic diatoms are dominant primary producers, and one of the most important and ubiquitous assemblages in streams, however, to our knowledge, metacommunity study on benthic diatoms is still scarce up to now, especially those considering the dispersal ability or some other ecological traits when comparing with macroinvertebrates1139 (but see4041); (2) diatoms are widely regarded as ubiquitously distributed organisms42, but recent studies suggested that dispersal limitation also played an important role in structuring benthic diatom metacommunities in streams at a large scale303943; (3) whether dispersal limitation occurs in high mountains at a small scale remains unknown; and (4) it is relatively easy to study the traits related to dispersal and habitat affinities of benthic diatoms44.


Flow directionality, mountain barriers and functional traits determine diatom metacommunity structuring of high mountain streams.

Dong X, Li B, He F, Gu Y, Sun M, Zhang H, Tan L, Xiao W, Liu S, Cai Q - Sci Rep (2016)

Map of the study area and the distribution of sampling sites in the Cangshan Erhai National Nature Reserve, Yunnan Province, Southwestern China.Green dots represent sampling sites (S1–1 represents the site most upstream in stream 1, and S1–6 represents the site most downstream in stream 1); blue lines and polygon depict the streams and the Erhai Lake. The map is based on a digital elevation model at 30 m resolution and created using ArcGIS 10.0 software (http://www.esri.com/software/arcgis).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835781&req=5

f1: Map of the study area and the distribution of sampling sites in the Cangshan Erhai National Nature Reserve, Yunnan Province, Southwestern China.Green dots represent sampling sites (S1–1 represents the site most upstream in stream 1, and S1–6 represents the site most downstream in stream 1); blue lines and polygon depict the streams and the Erhai Lake. The map is based on a digital elevation model at 30 m resolution and created using ArcGIS 10.0 software (http://www.esri.com/software/arcgis).
Mentions: In this study, we investigated 63 sites in high mountain streams (elevation ranges from 1600 to 2900 m a.s.l.), across a small spatial extent in Southwestern China (<500 km2, Fig. 1). Benthic diatoms were selected to study metacommunity structuring in high mountain streams for the following reasons: (1) benthic diatoms are dominant primary producers, and one of the most important and ubiquitous assemblages in streams, however, to our knowledge, metacommunity study on benthic diatoms is still scarce up to now, especially those considering the dispersal ability or some other ecological traits when comparing with macroinvertebrates1139 (but see4041); (2) diatoms are widely regarded as ubiquitously distributed organisms42, but recent studies suggested that dispersal limitation also played an important role in structuring benthic diatom metacommunities in streams at a large scale303943; (3) whether dispersal limitation occurs in high mountains at a small scale remains unknown; and (4) it is relatively easy to study the traits related to dispersal and habitat affinities of benthic diatoms44.

Bottom Line: Our results indicated that both environmental filtering and dispersal processes influenced metacommunity structuring, with dispersal contributing more than environmental processes.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.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.

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.

No MeSH data available.


Related in: MedlinePlus