Conclusion
We found that anatomical traits related to xylem and stomata played a more prominent role than commonly used soft traits (e.g., SLA, wood density) in explaining the drought response of tree seedlings from seasonally wet humid forests of south Asia. These anatomical traits are directly involved in water movement and gas exchange (Brodribb & Holbrook 2003, Brodribb et al. 2003, Sterling 2005)⁠, which highlights the need to link hydraulic performance and whole-plant response of tree seedlings to drought in field conditions. Drought conditions equalized performance differences seen in well-watered conditions or advantaged some species. Species from more seasonal or drier region may also induce carbon starvation by reduce photosynthetic activity to survive drought (McDowell et al. 2008). The ability to tolerate drought may thus influence tree species’ regeneration and alter species composition in humid tropical forests if global environmental change increases the frequency of intra-seasonal droughts or severity of the dry season (Chou et al. 2013)⁠.