Leaf Venation Networks Link Climate to Plant Form and Function

Abstract

Within each leaf is an intricate network of veins. The geometry of this network shows large variation across species and environments, paralleling variation in species' functioning and geographic distributions. Here I develop theory that links leaf venation networks to 1) the worldwide leaf economics spectrum, enabling better understandings of the resource tradeoffs that are central to the terrestrial carbon and water cycles, and 2) atmospheric temperature and carbon dioxide concentrations, enabling better use of leaf fossils for paleoclimate reconstruction. I successfully test these theories across contemporary temperate and tropical sites, and apply them to paleo-sites spanning a 2Myr interval across the Cretaceous-Paleogene boundary. These theoretical and empirical results demonstrate that leaf venation networks can provide an integrative framework for understanding relationships between plant form, function, and environment.