The major forest types in lowland Thailand and its adjacent parts in Southeast Asia with the distinct dry season are the mixed deciduous forest (MDF), dry dipterocarp forest (DDF) and dry evergreen forest (DEF). We report the first comprehensive data set in leaf physiology of canopy trees in these three forest types and clarify adaptive functional differences of woody plants among three forests. Unlike temperate forests, the forest variations in leaf mass per area (LMA) were related to nutrient use strategies (less vs. more conservative) associated with soil nutrients rather than with leaf phenology (evergreen vs. deciduous). In the interspecific variations within each forest, A_max in MDF and DEF was limited by foliar phosphate, whereas that in DDF was limited by foliar nitrogen. The close association between leaf physiology and soil properties suggests that climate change and increasing human impacts will disrupt this association, leading to forest degradation and dysfunction.

In this study, we obtained the ecophysiological characteristics of top canopy leaves in almost all canopy tree species in three different forest types: including (1) mixed deciduous forest (MDF), (2) dry dipterocarp (deciduous) forest (DDF), and (3) dry evergreen forest (DEF), in Thailand. Here we obtained 21 physiological traits in the top/sunlit leaves of canopy trees in 107, 65 and 51 tree species in MDF, DEF and DDF, respectively. In this inventory, approximately 70%, 95% and 95% of canopy tree species which consist of MDF, DEF and DDF were covered, respectively.