Drought-induced tree mortality is projected to increase due to climate change, which will have manifold ecological and societal impacts including the potential to weaken or reverse the terrestrial carbon sink. Predictions of tree mortality remain limited, in large part because within-species variations in ecophysiology due to plasticity or adaptation and ecosystem adjustments could buffer mortality in dry locations. Here, we conduct a meta-analysis of 50 studies spanning >100 woody plant species globally to quantify how populations within species vary in vulnerability to drought mortality and whether functional traits or climate mediate mortality patterns. We find that mortality predominantly occurs in drier populations and this pattern is more pronounced in species with xylem that can tolerate highly negative water potentials, typically considered to be an adaptive trait for dry regions, and species that experience higher variability in water stress. Our results indicate that climate stress has exceeded physiological and ecosystem-level tolerance or compensating mechanisms by triggering extensive mortality at dry range edges and provides a foundation for future mortality projections in empirical distribution and mechanistic vegetation models.
1.Univ Utah, Sch Biol Sci, Salt Lake City, UT 84112 USA 2.Carnegie Inst Sci, Dept Global Ecol, Stanford, CA USA 3.Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA 4.Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 USA
Recommended Citation:
Anderegg, William R. L.,Anderegg, Leander D. L.,Kerr, Kelly L.,et al. Widespread drought-induced tree mortality at dry range edges indicates that climate stress exceeds species' compensating mechanisms[J]. GLOBAL CHANGE BIOLOGY,2019-01-01