Climatic changes are expected to alter timing and intensity of drought period, which might significantly impact the drought tolerance mechanisms of TDF trees. Therefore, it is important to understand the composition of drought survival strategies and resilience capacity of tree species in these forests.
In a study published in Forest Ecology & Management, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) and Banaras Hindu University reported that the tree species experiencing drought conditions, maintained their physiological functions by three strategies, i.e., drought avoidance, drought resistance, and drought tolerance.
The researchers found that the drought avoiding species tend to avoid drought period by shedding their leaves at the start of dry period, while drought tolerant as well as drought resistant species had ability to tolerate water stress to greater extent, and they are able to sustain foliage for longer period.
They selected five forest fragments or study sites in Vindhyan highlands (21？29′ – 25？11′ N; 78？15′ – 84？15′ E), situated in Sonebhadra district of Uttar Pradesh, India.
They selected 12 FTs associated with plant water use strategies, viz., canopy cover intensity (CC), wood specific gravity (WSG), saturated stem water content (QWsat), leaf size or leaf area (LA), specific leaf area (SLA), relative water content (RWC), leaf dry matter content (LDMC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), maximum saturated stomatal conductance (Gsmax), maximum saturated photosynthetic rate (Amax), and intrinsic water use efficiency (WUEi).
The study showed the dominance of drought tolerant functional guilds (DTFG) in the study region in terms of greater species richness, stand biomass, as well as biomass accumulation capacity (BAC). The important functional traits (FTs) for greater productivity and storage of biomass for DTFG were Amax, WSG, LA and SLA, whereas LDMC was responsible for greater LA and CC for DTFG.
“Our findings could help forest managers in restoration and conservation of TDFs,” said R.K. Chaturvedi of XTBG.
R.K. Chaturvedi Ph.D
Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China