Testing the limits of plant drought stress and subsequent recovery in four provenances of a widely distributed subtropical tree species

Abstract

Drought-induced tree mortality may increase with ongoing climate change. Unraveling the links between stem hydraulics and mortality thresholds, and the effects of intraspecific variation, remain important unresolved issues. We conducted a water manipulation experiment in a rain-out shelter, using four provenances of Schima superba originating from a gradient of annual precipitation (1124-1796 mm) and temperature (16.4-22.4°C). Seedlings were droughted to three levels of percentage loss of hydraulic conductivity (i.e., P 50 , P 88 and P 99) and subsequently rewatered to field capacity for 30 days; traits related to water and carbon relations were measured. The lethal water potential associated with incipient mortality was between P 50 and P 88 . Seedlings exhibited similar drought responses in xylem water potential, hydraulic conductivity and gas exchange. Upon rehydration, patterns of gas exchange differed among provenances but were not related to the climate at the origin. The four provenances exhibited a similar degree of stem hydraulic recovery, which was correlated with the magnitude of antecedent drought and stem soluble sugar at the end of the drought. Results suggest that there were intraspecific differences in the capacity of S. superba seedlings for carbon assimilation during recovery, indicating a decoupling between gas exchange recovery and stem hydraulics across provenances.

Embolism resistance explains mortality and recovery of five subtropical evergreen broadleaf trees to persistent drought

“…Third, studies involving repeated drought events showed that early exposure to water deficit could induce physiological or morphological changes that improved plant performance under later extreme droughts (Wang et al, 2017). Studies on multiple ecotypes or genotypes within the same species showed that the plasticity of physiological rates and hydraulic traits to drought could be adaptive (Challis et al, 2022; Duan et al, 2022). The existence of physiological acclimation and adaptation might help SEBFs to buffer the damage caused by severe droughts.…”

Predicting resilience through the lens of competing adjustments to vegetation function

“…More generally, reliance on species‐specific parameterizations of $${r}_{k}$$ would increase model complexity without always impacting hydraulic capacity and/or canopy fluxes. Meanwhile, there is mounting evidence of interconnected drought‐ and heat‐induced legacies on nonstructural carbohydrates (NSCs) and hydraulic function (Duan et al, 2022; Poyatos et al, 2013; Ruehr et al, 2019). The key to LSMs accounting for differentiated legacies from climate extremes (i.e., depending on species and/or location) might lie in a mechanistic link between NSCs and plant hydraulics.…”

Interactive effect of elevated CO2 and drought on physiological traits of Datura stramonium

“…Moreover, eCO 2 reduced the drought-induced damage in D. stramonium , with plant recovery being significant upon re-commencement of water and drought condition treatments. In previous work, it was noted that the degree of recovery depends upon species and drought duration ( Duan et al., 2022 ). Robredo et al.…”