Manipulation of local environment produces different diversity outcomes depending on location within a river network

被引:13
作者
Tornwall, Brett M. [1 ]
Swan, Christopher M. [2 ]
Brown, Bryan L. [1 ]
机构
[1] Virginia Tech, Dept Biol Sci, Derring Hall,Room 2125,1405 Perry St, Blacksburg, VA 24061 USA
[2] Univ Maryland Baltimore Cty, Dept Geog & Environm Syst, Baltimore, MD 21250 USA
基金
美国国家科学基金会;
关键词
Dendritic; Stream; Macroinvertebrate; Metacommunity; Dispersal; HABITAT HETEROGENEITY; SPATIAL HETEROGENEITY; TEMPORAL VARIABILITY; HEADWATER STREAMS; DYNAMICS; CONNECTIVITY; BIODIVERSITY; PATTERNS; RESTORATION; DETRITUS;
D O I
10.1007/s00442-017-3891-7
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 ; 0713 ;
摘要
Ecologists have long been interested in mechanisms governing community composition and assembly. Spatial connectivity is one potential mechanism that can have a large influence on community processes. In accordance with network metrics such as closeness and betweenness, headwater streams are more isolated than mainstem streams. Theory and observational studies predict that community structure in isolated locations of dispersal networks should respond more strongly to manipulations of local conditions, whereas well-connected communities subject to high levels of dispersal should not respond strongly to local manipulations. We experimentally investigated this prediction by manipulating habitat complexity in headwaters and mainstem streams while monitoring macroinvertebrate communities through time. As predicted, the manipulation of local habitat had a stronger influence in headwaters than mainstreams. Both taxon richness and community similarity showed strong responses to alterations in habitat complexity in headwaters, but not in mainstem streams. These findings support the hypothesis that location within a dispersal network affects the relative importance of local and regional factors in structuring the local communities within a spatially structured metacommunity. In addition, our results suggest that conservation strategies need to account for the possibility that the relative importance of local and regional drivers of community composition and assembly can vary spatially.
引用
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页码:663 / 674
页数:12
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