We investigated how spatial distance among peat domes and environmental difference within a dome interact to produce the observed plant communities by analyzing phylogenetic diversity of seven peat domes in SE Asia.

We found a common tendency to the domes for phylogenetic diversity to decrease as peat depth increased. Higher phylogenetic diversity in the forest zone closest to the river could be attributed to competitive exclusion in a relatively benign peatland environment, whilst lower phylogenetic diversity further from the river could be attributed to the filtering effect of a more stressful environment.

We conducted cluster analyses to classify the plant communities. When we do not consider phylogenetic distance among the communities, each cluster was composed by communities belonging to a dome. On the other hand, when we conduct cluster analysis by considering phylogenetic diversity, each cluster was composed by plant communities which possess similar position on domes (i.e. edge or centre).

These results indicates, plant communities on each peat dome keep its phylogenetic structures regardless of spatial distinctness and have similar history of community assemblage.