Data from: Meta-analysis reveals that hydraulic traits explain cross-species patterns of drought-induced tree mortality across the globe

Drought-induced tree mortality has been observed globally and is expected
to increase under climate change scenarios, with large potential
consequences for the terrestrial carbon sink. Predicting mortality across
species is crucial for assessing the effects of climate extremes on forest
community biodiversity, composition, and carbon sequestration. However,
the physiological traits associated with elevated risk of mortality in
diverse ecosystems remain unknown, although these traits could greatly
improve understanding and prediction of tree mortality in forests. We
performed a meta-analysis on species’ mortality rates across 475 species
from 33 studies around the globe to assess which traits determine a
species’ mortality risk. We found that species-specific mortality
anomalies from community mortality rate in a given drought were associated
with plant hydraulic traits. Across all species, mortality was best
predicted by a low hydraulic safety margin—the difference between typical
minimum xylem water potential and that causing xylem dysfunction—and xylem
vulnerability to embolism. Angiosperms and gymnosperms experienced roughly
equal mortality risks. Our results provide broad support for the
hypothesis that hydraulic traits capture key mechanisms determining tree
death and highlight that physiological traits can improve vegetation model
prediction of tree mortality during climate extremes.