Dataset for: Immediate and carry-over effects of late-spring frost and growing season drought on forest gross primary productivity capacity in the Northern Hemisphere

Forests are increasingly exposed to extreme global warming-induced
climatic events. However, the immediate and carry-over effects of extreme
events on forests are still poorly understood. Gross primary productivity
(GPP) capacity is regarded as a good proxy of the ecosystem’s functional
stability, reflecting its physiological response to its surroundings.
Using eddy covariance data from 34 forest sites in the Northern
Hemisphere, we analyzed the immediate and carry-over effects of
late-spring frost (LSF) and growing season drought on needle-leaf and
broadleaf forests. Path analysis was applied to reveal the plausible
reasons behind the varied responses of forests to extreme events. The
results show that LSF had clear immediate effects on the GPP capacity of
both needle-leaf and broadleaf forests. However, GPP capacity in
needle-leaf forests was more sensitive to drought than in broadleaf
forests. There was no interaction between LSF and drought in either
needle-leaf or broadleaf forests. Drought effects were still visible when
LSF and drought coexisted in needle-leaf forests. Path analysis further
showed that the response of GPP capacity to drought differed between
needle-leaf and broadleaf forests, mainly due to the difference in the
sensitivity of canopy conductance. Moreover, LSF had a more severe and
long-lasting carry-over effect on forests than drought. These results
enrich our understanding of the mechanisms of forest response to extreme
events across forest types.