Print PageThe leaf economics spectrum describes leaf-level functional trade-offs that relate to whole-plant functioning and ecosystem processes. Despite the ecological importance of this spectrum, its origin remains uncertain. We hypothesize that a leaf’s venation network imposes strong biomechanical constraints on multiple leaf functional traits, and that variation in the geometry of the venation network generates the multiple economic strategies and forms found in leaves worldwide. Here we ask if venation networks control the leaf economics spectrum.
Results/Conclusions
We develop a novel quantitative model that uses venation traits to model leaf-level physiology, and show that selection to optimize the venation network predicts mean global trait–trait scaling relationships across 2548 species from the GLOPNET database. Furthermore, using empirical venation data for 25 Arizona plant species, we test our model by predicting four key leaf functional traits related to leaf economics: net carbon assimilation rate, life span, leaf mass per area ratio and nitrogen content. Observed/predicted relationships for all traits are significant and positive. Together, these results indicate that selection on venation geometry is a fundamental basis for understanding the diversity of leaf form and function, and the carbon balance of leaves.
