There has been little study investigating whether individual tree species in forest communities tend to be accumulators or repellers of phylogenetic diversity or whether species accumulators and repellers have non-random distributions on the phylogenetic tree itself.
To address the issue, Prof. CAO Min and his team of Xishuangbanna Tropical Botanical Garden (XTBG) proposed a framework for utilizing individual species and phylogenetic information to study tree-tree interactions across scales within forests. In the study, they first quantified the individual species-area relationship (ISAR) in nine temperate and tropical forest dynamics forest plots across latitude and then put the result into a phylogenetic context. The second way they integrated the ISAR and phylogenies was to quantify whether species accumulators and repellers had non-random distributions on community phylogenies.
The researchers asked: (1) what was the phylogenetic diversity of the neighborhoods of accumulator, repeller and neutral species and was it any different from a random expectation?; and (2) what was the distribution of accumulator, repeller and neutral species on the phylogenetic tree?
Their results suggested that biotic interactions on individual-level distributions in communities were strongest at spatial scales r<30 m in the nine tropical and temperate forests and that the phylogenetic diversity surrounding the individuals of species was generally only non-random on very local scales. In particular, the distribution of species accumulators and repellers was non-random on the community phylogenies suggesting the presence of phylogenetic signal in the ISAR across latitude.
The study entitled “A Phylogenetic Perspective on the Individual Species-Area Relationship in Temperate and Tropical Tree Communities” has been published in PLoS ONE 8(5): e63192. doi:10.1371/journal.pone.0063192
Xishuangbanna tropical forest dynamics plot, one of the nine studied plots (Image by LIN Luxiang)