Small-scale spatial variability in phylogenetic community structure during early plant succession depends on soil properties

Abstract

During early plant succession, the phylogenetic structure of a community changes in response to important environmental filters and emerging species interactions. We traced the development of temperate-zone plant communities during the first 7 years of primary succession on catchment soils to explore patterns of initial species assembly. We found pronounced small-scale differences in the phylogenetic composition of neighbouring plant assemblages and a large-scale trend towards phylogenetic evenness. This small-scale variability appears to be mediated by soil properties, particularly carbonate content. Therefore, abiotic environmental conditions might counteract or even supersede the effects of interspecific competition among closely related species, which are usually predicted to exhibit patterns of phylogenetic evenness. We conclude that theories on phylogenetic community composition need to incorporate effects of small-scale variability of environmental factors.Electronic supplementary materialThe online version of this article (doi:10.1007/s00442-014-2954-2) contains supplementary material, which is available to authorized users.

Site‐specific responses of foliar fungal microbiomes to nutrient addition and herbivory at different spatial scales

“…Contrary to our expectations, here, we found phylogenetic clustering of co‐occurring members within a community across all environment (i.e., control, fertilized and fenced) at leaf scale when summed across the region. These results were in parallel with other studies where phylogenetic clustering was more apparent at smaller scales, (e.g., Parmentier et al, ; Ulrich et al, ).…”

Species interactions and random dispersal rather than habitat filtering drive community assembly during early plant succession

“…Some theories of plant succession predict species richness to increase until a mid‐successional maximum is reached (Horn ). In our study system, such a maximum was not visible after seven years of succession (Ulrich et al , ). In line with major hypotheses on primary succession, we also predicted 1) an initial random pattern of species co‐occurrences as a consequence of spatially random external colonisation and germination from the soil seed bank (Hubbell , Baasch et al , del Moral ).…”

“…Only at the largest, whole‐catchment scale did co‐occurrences became increasingly segregated (Fig. and Zaplata et al ) through time, and this segregation was associated with the underlying large‐scale variation in substrate conditions (Ulrich et al ). Consequently our results demonstrate a temporal divergence in plant community structure at the catchment scale.…”

“…As soil conditions were also and inevitably autocorrelated in time, we hesitated to use a simple nested GLM design. Nevertheless, to account for this type of temporal pseudo‐replication we followed a similar approach to Ulrich et al () and restricted the degrees of freedom in the parametric t‐tests for all single predictors to the total number of 1‐m 2 plots (426 instead of > 1280) to minimize the inflation of the temporal degrees of freedom and the possible bias when estimating p‐values.…”

“…The study system and the specific sampling design allows for the first time a detailed analysis of the interplay between temporal community assembly, spatial patterns of co‐occurrences, and changes in competitive strength. Previously we used these data to detect a temporal progression towards large‐scale negative spatial species associations (Zaplata et al ) and towards increased utilization of plant trait space (Ulrich et al ). We further detected variability in phylogenetic community composition at small spatial scales that could be traced back to important soil attributes (Ulrich et al ).…”