Eucalypt functional trait dataset of plants grown under common garden conditions

Understanding the role of site climate in driving geographic trait
variation and revealing the relative contributions of adaptation and
plasticity are key goals in plant sciences. We tested mechanistic
hypotheses for trait–climate relationships for mature eucalypt trees grown
in common garden and in situ field conditions, quantifying joint and
individual effects of mean annual precipitation (MAP) and temperature
(MAT) on eight functionally important traits. Trait–MAP relationships were
particularly strong, with all but one trait consistently related to
precipitation in both growth conditions. Trait–MAT relationships were
notably weaker, but where relationships existed, most traits responded to
low temperature in the same direction as to low rainfall, as predicted.
Comparing cross-species trait–climate relationships in situ with
trait–climate-of-origin relationships in the common garden indicated
substantial contributions from both adaptation and plasticity, with
plasticity contributing more to variation in photosynthetic traits than in
leaf structural or wood traits. Two key advances were (1) teasing
apart the roles of site temperature and rainfall on trait variation, which
are often confounded; and (2) inferring the contributions of adaptation
and plasticity to observed trait patterns. The relative importance of
these processes may determine the timescales over which plant traits shift
with climate change.