Formation mechanism of taxonomic structures for forest communities in different successional stages in Changbai Mountains of northeastern China

ObjectiveTaxonomic structures are the intuitive reflection of the species compositions of communities and they can reflect the regulation of local processes, such as environmental filtering and interspecific competition.

MethodBased on the species composition data collected in three large forest observational field studies, the taxonomic structures of the communities were analyzed at different sampling scales. Random null model was used and the “standardized effect size” (SES) of taxonomic ratios was calculated.

ResultAs expected, the taxonomic ratios declined with increasing grain size in all plots. The quantitative relationship between genera/families and species, described by a linearized power function, showed a good fit. In the mixed conifer and broadleaved forest and Tilia sp.-Korean pine forest, the taxonomic ratios of the observed communities had significantly lower values than those of the simulated random community under the test of null model at almost all scales. But that was not the case for the secondary poplar-birch forest, SES was larger than 0.

ConclusionThe results suggest that the effect of abiotic filtering is greater than the effect of interspecific competition in shaping the local community for the mixed conifer and broadleaved forest and Tilia sp.-Korean pine forest. In the secondary poplar-birch forest, competition dominated the taxonomic structure of the community. Local processes do influence the taxonomic structure, but their combined effects may vary with scale and successional stages.