Data from: Drought and heat-induced mortality of conifer trees is explained by leaf and growth legacies

An increased frequency and severity of droughts and heatwaves have
resulted in increased tree mortality and forest dieback across the world
but underlying mechanisms are poorly understood. We used a common garden
experiment with 20 conifer tree species to quantify mortality after three
consecutive hot, dry summers and tested whether mortality could be
explained by putative underlying mechanisms, such as stem hydraulics and
legacies affected by leaf lifespan and stem growth responses to previous
droughts. Mortality varied from 0-79% across species and was,
surprisingly, not affected by hydraulic traits. Mortality increased with
the species’ leaf lifespan, probably because leaf damage caused crown
dieback and contributed to carbon depletion and sensitivity to bark beetle
damage. Mortality also increased with lower growth resilience, which may
exacerbate the contribution of carbon depletion and bark beetle
sensitivity to tree mortality. Our study highlights how ecological
legacies at different time scales can explain tree mortality in response
to hot, dry periods and climate change.