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

FERNÁNDEZ, MARÍA ELENA; MONTEOLIVA, SILVIA; BAROTTO, ANTONIO JOSÉ; BULFE, NADIA; GIANA, FABIÁN; SERGENT, ANNE SOPHIE; MARTINEZ-MEIER, ALEJANDRO; GATICA, MARIO GABRIEL; GYENGE, JAVIER

Congreso; XXXIV Argentinian Meeting of Plant Physiology; 2023

Increased tree mortality is a phenomenon widelyreported over the last decades in different species and forests around theworld. About 70% of the global drought-induced tree die-offs have been relatedto the combined effects of drought and heat waves (i.e. “hotter-drought”events) mainly associated with global warming. The hydraulic disfunction of thetrees has been proposed as the main physiological driver of tree death. Thiskind of event is, however, rarely reported in mature forest plantations,intensively managed to feed different industries. However, they are not immuneto extreme climate events, as was shown in a recent mortality event occurred inCorrientes province, Argentina, due to the combination of prolonged extremedrought and heat waves. Moreover, in commercial plantations, even whenmortality events might not be observed, decreased productivity due to abioticstress (alone or in combination with biotic agents), may represent a seriousthreat for their sustainability. New paradigms are needed to face climatechange impacts posed on planted forests since most of the strategies applieduntil now has been oriented to increase productivity and wood quality. However,due to functional relationships and constraints, these objectives are sometimescompromised with abiotic stress resistance. In this talk, three majorstrategies are discussed and exemplified with study cases of Pinus sppand Eucalyptus spp, aiming to show possibilities and current limitationsto develop a climate-smart forestry: a) genetic improvement oriented to abioticstress resistance (and the potential trade-offs with growth and wood qualitytraits); b) planting site selection at landscape level to decrease mortalityrisks; and c) silvicultural management to reduce climate sensitivity andincrease resistance and/or resilience to extreme climatic events.