Following the appointment of the new Cabinet, the Forest Sector now reports to the ministère des Ressources naturelles et des Forêts, while the Wildlife and Parks Sectors report to the ministère de l'Environnement, de la Lutte aux changements climatiques, de la Faune et des Parcs. Adjustments will be made to the website over time.

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Drought timing and local climate determine the sensitivity of eastern temperate forests to drought

Summary

Published in Global Change Biology 24(6): 2339-2351. doi.org/10.1111/gcb.14096

Projected changes in temperature and drought regime are likely to reduce carbon (C) storage in forests, thereby amplifying rates of climate change. While such reductions are often presumed to be greatest in semi-arid forests that experience widespread tree mortality, the consequences of drought may also be important in temperate mesic forests of Eastern North America (ENA) if tree growth is significantly curtailed by drought. Investigations of the environmental conditions that determine drought sensitivity are critically needed to accurately predict ecosystem feedbacks to climate change. We matched site factors with the growth responses to drought of 10,753 trees across mesic forests of ENA, representing 24 species and 346 stands, to determine the broad-scale drivers of drought sensitivity for the dominant trees in ENA. Here we show that two factors—the timing of drought, and the atmospheric demand for water (i.e., local potential evapotranspiration; PET)—are stronger drivers of drought sensitivity than soil and stand characteristics. Droughtinduced reductions in tree growth were greatest when the droughts occurred during early-season peaks in radial growth, especially for trees growing in the warmest, driest regions (i.e., highest PET). Further, mean species trait values (rooting depth and w50) were poor predictors of drought sensitivity, as intraspecific variation in sensitivity was equal to or greater than interspecific variation in 17 of 24 species. From a general circulation model ensemble, we find that future increases in earlyseason PET may exacerbate these effects, and potentially offset gains in C uptake and storage in ENA owing to other global change factors.

Sector(s): 

Forests

Categorie(s): 

Scientific Article

Theme(s): 

Ecosystems and Environment, Forest Ecology, Forest Growth and Yield Modelling, Forestry Research, Forests

Departmental author(s): 

Ouimet, Rock

Author(s)

D'ORANGEVILLE, L., MAXWELL, KNEESHAW, PEDERSON, DUCHESNE, LOGAN, HOULE, ARSENEAULT, BEIER, BISHOP, DRUCKENBROD, FRAVER, GIRARD, HALMAN. HANSEN, HART, HARTMANN, KAYE, LEBLANC, MANZONI, OUIMET, RAYBACK, ROLLINSON and PHILLIPS

Year of publication :

2018

Keywords :

dendrochoronologie, sécheresse, croissance, réseau, climat, écologie forestière, écosystèmes et environnement, modélisation de la croissance et du rendement des forêts, article scientifique de recherche forestière, ecosystems and environment, forest ecology, forest growth and yield modelling, dendrochronology, drought, growth, network, climate

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