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).