4.3 Stronger provenance effects in fast vs. slow growth species
Provenance trials are highly resource-intensive (Sork et al. 2013), often restricting investigations to a single species. However,
local adaptation can be highly species- and context-dependent, which
limits the broad applicability of climate-matching provenance strategies
in tropical systems with high species diversity. We differentiated
between species that generally grow slower, live longer, and invest more
resources into defences than those that grow fast and have a more rapid
lifecycle using the fundamental plant trait wood density (Poorteret al. 2008, Wright et al. 2010). We found that
species-level wood density was negatively associated with the mean
performance of provenances grown in sympatry vs those grown for survival
and growth (height increment). This supports our hypothesis that
faster-growing species with shorter generation times are more likely to
exhibit local adaptation, with slower-growing species potentially more
likely to be maladapted. However, this was not the case for inherent
growth rate. It is likely that after only 1.5 years of measurements,
provenance variation is observable primarily in faster-growing species
or at sites where resource limitations do not obscure growth potential,
and so it remains unclear whether the observed provenance differences
are due to higher rates of molecular evolution in faster-growing species
(Smith & Donoghue 2008).