title: Wood traits related to size and life history of trees in a Panamanian rainforest.
abstract: Wood structure differs widely among tree species and species with faster growth, higher mortality and larger maximum size have been reported to have fewer but larger vessels and higher hydraulic conductivity (Kh). However, previous studies compiled data from various sources, often failed to control tree size and rarely controlled variation in other traits. We measured wood density, tree size and vessel traits for 325 species from a wet forest in Panama, and compared wood and leaf traits to demographic traits using species-level data and phylogenetically independent contrasts. Wood traits showed strong phylogenetic signal whereas pairwise relationships between traits were mostly phylogenetically independent. Trees with larger vessels had a lower fraction of the cross-sectional area occupied by vessel lumina, suggesting that the hydraulic efficiency of large vessels permits trees to dedicate a larger proportion of the wood to functions other than water transport. Vessel traits were more strongly correlated with the size of individual trees than with maximal size of a species. When individual tree size was included in models, Kh scaled positively with maximal size and was the best predictor for both diameter and biomass growth rates, but was unrelated to mortality.
authors.affiliation: Institute of Botany, University of Natural Resources and Life Sciences, Gregor Mendel-Straße 33, 1180 Vienna, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Hietz
authors.affiliation: Institute of Botany, University of Natural Resources and Life Sciences, Gregor Mendel-Straße 33, 1180 Vienna, Austria.
authors.forename: Sabine
authors.initials: S
authors.lastname: Rosner
authors.affiliation: Institute of Botany, University of Natural Resources and Life Sciences, Gregor Mendel-Straße 33, 1180 Vienna, Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Hietz-Seifert
authors.affiliation: Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancón, Republic of Panama.
authors.forename: S Joseph
authors.initials: SJ
authors.lastname: Wright
mesh_terms: D010176:Panama; D010802:Phylogeny; D025341:Principal Component Analysis; D019655:Quantitative Trait, Heritable; D065947:Rainforest; D012044:Regression Analysis; D013045:Species Specificity; D014197:Trees / Q000033:anatomy & histology / Q000254:growth & development*; D014934:Wood / Q000502:physiology*
keywords: growth rate; hydraulic conductivity; mortality; rainforest; tree size; wood density; wood functional traits; xylem vessels