Can evolutionary history predict plant plastic responses to climate change?

Plant plastic responses are critical to the adaptation and survival of species under climate change, but whether they are constrained by evolutionary history (phylogeny) is largely unclear. Plant leaf traits are key in determining plants’ performance in different environments, and if these traits and their variation are phylogenetically dependent, predictions could be made to identify species vulnerable to climate change.

We compiled data on three leaf traits (photosynthetic rate, specific leaf area, and leaf nitrogen content) of 434 species and their variation under four environmental change scenarios (warming, drought, elevated CO2, or nitrogen addition) from 210 manipulation experiments.

We found phylogenetic signal in the three traits but not in their variation under the four scenarios. This indicates that closely related species show similar traits but that their plastic responses could not be predicted from species relatedness under environmental change. Meanwhile, phylogeny weakened but did not change directions of conventional pairwise trait relationships, suggesting the co-evolved leaf trait pairs have consistent responses across contrasting environmental conditions.

Phylogeny can identify lineages rich in species showing similar traits and predict their relationships under climate change, but the degree of plant phenotypic variation does not vary consistently across evolutionary clades.