My research addresses the ecological and evolutionary processes that shape the functional diversity of terrestrial plants, with a particular focus on the California flora. I approach this broad topic from many perspectives, drawing on ecophysiology, population biology, community ecology and phylogenetics. Lab projects range from in depth physiological research testing the adaptive significance of traits such as stem hydraulics, to broad comparative studies that integrate large-scale ecological databases with recent advances in seed plant phylogeny. Current research is focused on three areas. i) The study of plant ecological strategies, based on comparative ecophysiological studies in groups of coexisting and/or closely related species. Variation and correlations among functional traits are frequently examined in closely related species, using methods such as phylogenetic independent contrasts, to test for replicated patterns of evolutionary divergence along climatic and edaphic gradients. ii) The processes shaping functional diversity, from local to regional scales. Projects range from analyses of leaf and seed trait variation in local communities, to the functional diversity of the woody plants of California in the context of their diverse biogeographic history. iii) Macro-evolutionary studies of ecological trait diversity, based on the synthesis of ecological data, recent advances in phylogenetics, and the development of comparative phylogenetic methods. For example, a recent comparative study demonstrated that leaf traits of many chaparral shrubs are ancestral traits of the respective lineages, suggesting a strong role for species sorting in the assembly of this community, rather than in situ convergent evolution. Current collaborative projects are aimed at analyzing large global trait databases using phylogenetic comparative methods to obtain insights into the major factors influencing trait evolution during diversification of the seed plants and the assembly of regional floras.