Forests facing drought and heat-waves: the need of a physiological-based forestry to increase plantations adaptability to climate change

FERNÁNDEZ M.E.; MONTEOLIVA S; BAROTTO JA; BULFE, N.; SERGENT AS; GÁNDARA J.; GATICA, G.; MARTINEZ-MEIER A; GYENGE JE

Rosario

Congreso; XXXIV Meeting of the Argentinean Society of Plant Physiology; 2023

Soc. Argentina de Fisiología Vegetal

CHARLA INVITADA EN SIMPOSIO FORESTALIncreased tree mortality is a phenomenon widely reported over the last decades in different species and forests around the world. About 70% of the global drought-induced tree die-offs have been related to the combined effects of drought and heat waves (i.e. “hotter-drought” events) mainly associated with global warming. The hydraulic disfunction of the trees has been proposed as the main physiological driver of tree death. In forest plantations intensively managed to feed different industries this kind of event is rarely reported. However, they are not immune to extreme climate events, as was shown in a recent mortality event occurred in Corrientes province, Argentina, due to the combination of prolonged extreme drought and heat waves. In this sense, even when mortality events might not be observed, decreased productivity due to abiotic stress (alone or in combination with biotic agents), may represent a serious threat for their sustainability. New paradigms are needed to face climate change impacts posed on planted forests since most of the strategies applied until now has been oriented to increase productivity (and sometimes, also for wood quality). However, due to functional relationships and constraints, these objectives are sometimes compromised with abiotic stress resistance. In this talk, three major strategies are discussed and exemplified with study cases of Pinus spp and Eucalyptus spp, aiming to show possibilities and current limitations to develop a climate-smart forestry: a) species and genotype selection as well as genetic improvement oriented to abiotic stress resistance (and the potential trade-offs with growth and wood quality traits); b) planting site selection at landscape level to decrease mortality risks; and c) silvicultural management to reduce climate sensitivity and increase resistance and/or resilience to extreme climatic events.