Drought tolerance traits of leaves of 20 tree species in temperate forest of Northeast China

Abstract

The increases in frequency and intensity of drought worldwide has seriously affected tree growth, and even led to widespread forest mortality. Leaf traits estimated from pressure-volume (PV) curve provide key leaf physiological information that reflects the drought tolerance of trees. However, it is uncertain that which PV parameter performs the best at local scale. Here, we measured five PV traits (including TLP, π0, ε, Cleaf, and RWCtlp) and two leaf structural traits (specific leaf area and leaf density) in 20 tree species (16 angiosperms and 4 gymnosperms) in a temperate mixed forest at the Maoershan Forest Ecosystem Research Station, Northeast China. The objectives of this study were to search the best indicators of leaf drought tolerance at local scale, and to explore the correlation between PV traits and leaf structural traits. We found that angiosperms had significantly greater RWCtlp and lower Cleaf than gymnosperms, indicating that RWCtlp and Cleaf might be the good indicators of leaf drought tolerance in temperate mixed forest in Northeast China. Within angiosperm species, TLP and π0 were significantly and negatively correlated with leaf density, but positively correlated with specific leaf area; while ε was negatively correlated with specific leaf area. However, the opposite trends between PV traits and leaf structural traits were observed between gymnosperms and angiosperms, which might be attributed to their differences in drought response and adaptation strategies.