Global patterns of plant form and function are strongly determined by evolutionary relationships

Plants display an incredible variety of forms and functions, which sustains a vast diversity of ecosystems on Earth. This diversity is the result of two forces: environmental filtering, the selection of phenotypes fit to a specific habitat; and evolutionary history, genetic constraints that determine the potential adaptations that species may evolve. To date, most studies have focused on describing macroecological patterns of trait variation, while the role of evolutionary history in determining these patterns has remained much less explored. Here, we combine a traits dataset including 4,213 vascular plant species with a phylogeny of the plant kingdom, to determine the influence of evolutionary history on the patterns of trait variation. Our results show that commonly used plant traits, such as plant height or leaf nitrogen, are strongly constrained by evolutionary history. Accounting for phylogenetic relationships changes the variance explained by the main axes of trait variation in the Plant Kindgom --the leaf economic spectrum and the plant size and organ axis continuum-- with the former explaining more variance than the latter. Moreover, we demonstrate that the plant size continuum is more influenced by evolutionary history than the leaf economics spectrum. These results highlight the influence of evolutionary history in shaping plant life history strategies and the importance of accounting for phylogeny in trait-based studies.