title: Developmentally based scaling of leaf venation architecture explains global ecological patterns.
abstract: Leaf size and venation show remarkable diversity across dicotyledons, and are key determinants of plant adaptation in ecosystems past and present. Here we present global scaling relationships of venation traits with leaf size. Across a new database for 485 globally distributed species, larger leaves had major veins of larger diameter, but lower length per leaf area, whereas minor vein traits were independent of leaf size. These scaling relationships allow estimation of intact leaf size from fragments, to improve hindcasting of past climate and biodiversity from fossil remains. The vein scaling relationships can be explained by a uniquely synthetic model for leaf anatomy and development derived from published data for numerous species. Vein scaling relationships can explain the global biogeographical trend for smaller leaves in drier areas, the greater construction cost of larger leaves and the ability of angiosperms to develop larger and more densely vascularised lamina to outcompete earlier-evolved plant lineages.
authors.affiliation: Department of Ecology and Evolution, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, California 90095, USA. lawrensack@ucla.edu
authors.forename: Lawren
authors.initials: L
authors.lastname: Sack
authors.forename: Christine
authors.initials: C
authors.lastname: Scoffoni
authors.forename: Athena D
authors.initials: AD
authors.lastname: McKown
authors.forename: Kristen
authors.initials: K
authors.lastname: Frole
authors.forename: Michael
authors.initials: M
authors.lastname: Rawls
authors.forename: J Christopher
authors.initials: JC
authors.lastname: Havran
authors.forename: Huy
authors.initials: H
authors.lastname: Tran
authors.forename: Thusuong
authors.initials: T
authors.lastname: Tran
mesh_terms: D005075:Biological Evolution; D017753:Ecosystem; D019684:Magnoliopsida / Q000033:anatomy & histology / Q000737:chemistry / Q000235:genetics / Q000254:growth & development*; D018515:Plant Leaves / Q000033:anatomy & histology / Q000737:chemistry / Q000235:genetics / Q000254:growth & development*; D058526:Plant Vascular Bundle / Q000033:anatomy & histology / Q000737:chemistry* / Q000254:growth & development