Predicting plant species climate preferences on the basis of mechanistic traits

Improved estimation of climate niches is critical, given climate change.
Plant adaptation to climate depends on their physiological traits and
their distributions, yet traits are rarely used to inform the estimation
of species climate niches, and the power of a trait-based approach has
been controversial, given the many ecological factors and methodological
issues that may result in decoupling of species’ traits from their native
climate. For 107 species across six ecosystems of California, we tested
the hypothesis that mechanistic leaf and wood traits can robustly predict
the mean of diverse species’ climate distributions, when combining
methodological improvements from previous studies, including standard
trait measurements and sampling plants growing together at few sites.
Further, we introduce an approach to quantify species’ trait-climate
mismatch. We demonstrate a strong power to predict species' mean
climate from traits. As hypothesized, the prediction of species' mean
climate is stronger (and mismatch lower) when traits are sampled for
individuals closer to species’ mean climates. Improved resolution of
species’ climate niches based on mechanistic traits can importantly inform
conservation of vulnerable species under the threat of climatic shifts in
upcoming decades.