Data from: Drought legacies are short, prevail in dry conifer forests and depend on growth variability.

The negative impacts of drought on forest growth and productivity last for
several years generating legacies, although the factors that determine why
such legacies vary across sites and tree species remain unclear. We used
an extensive network of tree-ring width (RWI, ring-width index) records of
16 tree species from 567 forests, and high-resolution climate and NDVI
datasets across Spain during the common period 1982‒2008 to test the
hypothesis that climate conditions and growth features modulate legacy
effects of drought on forests. Legacy effects of drought were calculated
as the differences between detrended-only RWI and NDVI series (i.e. after
removing long-term growth trends) and pre-whitened RWI and NDVI series
predicted by a model including drought intensity. Superposed epoch
analysis (SEA) was used to estimate whether legacy effects differed from
random. Finally, legacy effects were related to water balance, growth
persistence and variability, and tree species identity. We found a
widespread occurrence of drought legacy effects in both RWI and NDVI, but
they were seldom significant. According to SEA, first-year drought
legacies were negative and different from random in 9% and 5% of the RWI
and NDVI series, respectively. The number of significant second- and
third-year legacies was substantially lower. Differences between RWI and
NDVI legacies indicate that canopy greenness and radial-growth responses
to drought are decoupled. We found variations in legacies between tree
species with gymnosperms presenting larger first-year drought legacies
than angiosperms, which were exposed to less severe droughts. Greater
growth variability can explain the presence of first-year RWI legacies in
gymnosperms from dry sites despite the relationship between growth
variability and legacies was complex. “Synthesis” Accounting for species
and site responses to drought provides a better understanding of the
magnitude and duration of drought legacies on forest growth and
productivity. Despite the widespread occurrence of growth reductions in
the years during and after drought occurrence, significant legacies were
not very common, mostly lasted one year and were more widespread in
gymnosperms. These are relevant factors to be considered in the future
when studying the consequences of drought on forest productivity and tree
growth.