title: Better environmental data may reverse conclusions about niche- and dispersal-based processes in community assembly.
abstract: Variation partitioning of species composition into components explained by environmental and spatial variables is often used to identify a signature of niche- and dispersal-based processes in community assembly. Such interpretation, however, strongly depends on the quality of the environmental data available. In recent studies conducted in forest dynamics plots, the environment was represented only by readily available topographical variables. Using data from a subtropical broad-leaved dynamics plot in Taiwan, we focus on the question of how would the conclusion about importance of niche- and dispersal-based processes change if soil variables are also included in the analysis. To gain further insight, we introduced multiscale decomposition of a pure spatial component [c] in variation partitioning. Our results indicate that, if only topography is included, dispersal-based processes prevail, while including soil variables reverses this conclusion in favor of niche-based processes. Multiscale decomposition of [c] shows that if only topography was included, broad-scaled spatial variation prevails in [c], indicating that other as yet unmeasured environmental variables can be important. However, after also including soil variables this pattern disappears, increasing importance of meso- and fine-scaled spatial patterns indicative of dispersal processes.
authors.affiliation: Institute of Ecology and Evolutionary Biology, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei 10617 Taiwan.
authors.forename: Li-Wan
authors.initials: LW
authors.lastname: Chang
authors.affiliation: Department of Botany and Zoology, Faculty of Sciences, Masaryk University, Kotlárská 2, Brno 61137 Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Zeleny
authors.affiliation: Department of Botany and Zoology, Faculty of Sciences, Masaryk University, Kotlárská 2, Brno 61137 Czech Republic.
authors.forename: Ching-Feng
authors.initials: CF
authors.lastname: Li
authors.affiliation: Institute of Ecology and Evolutionary Biology, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei 10617 Taiwan.
authors.forename: Shau-Ting
authors.initials: ST
authors.lastname: Chiu
authors.affiliation: Institute of Ecology and Evolutionary Biology, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei 10617 Taiwan.
authors.forename: Chang-Fu
authors.initials: CF
authors.lastname: Hsieh
mesh_terms: D000531:Altitude; D003710:Demography; D017753:Ecosystem; D008954:Models, Biological; D012987:Soil / Q000737:chemistry; D013045:Species Specificity; D013624:Taiwan; D014197:Trees
chemical_list: D012987:Soil