A global meta‐analysis of the relative extent of intraspecific trait variation in plant communities

“…If the spatial patterns observed in our study are indicative of temporal responses 13,37 , climate change will likely shift trait distributions towards increased plant height, leaf area and seed mass, as has already been observed at some sites 38,39 , and for plant height at the tundra biome scale 13 . Contrary to our expectations, the contribution of withinspecies trait variation in the tundra was lower than global estimates 21 . Our findings support previous studies indicating that the relative importance of within-species variation decreases with increasing environmental stress 25 , leading to wide functional divergence between species, as found for resource economic traits 33,40 .…”

“…In alpine communities, species turnover explained community changes in size-related traits (i.e., plant height, leaf dry mass and leaf area), whereas intraspecific trait variation was responsible for changes in leaf economic traits (i.e., SLA, LDMC and leaf thickness). These results contradict other studies showing the contributions of intraspecific trait variation are expected to be higher in whole plant traits involving multiple plant organs rather than organ-level traits, such as leaf area or SLA involving a single, isolated plant structure (Siefert et al 2015). In contrast, in sub-alpine communities, species turnover only dominated for LDMC, while intraspecific trait variation dominated for all other traits.…”

“…These results contradict other studies showing the contributions of intraspecific trait variation are expected to be higher in whole plant traits involving multiple plant organs rather than organ‐level traits, such as leaf area or SLA involving a single, isolated plant structure (Siefert et al. 2015). In contrast, in sub‐alpine communities, species turnover only dominated for LDMC, while intraspecific trait variation dominated for all other traits.…”

“…For CWM, ITV spanned from being the main driver of trait variation for height and root depth, to being of similar importance as interspecific trait variation for SLA, PC1, and PC2, and only playing a minor role for R:S ratio. In contrast to previous results (Siefert et al 2015, Jónsdóttir et al 2023), size‐related traits (i.e. height and root depth) showed large proportions of trait variability explained by ITV, with the exception of R:S ratio.…”