Peeking beneath the hood of the leaf economics spectrum

Commentary on a paper is this issue. In the paper in this issue of New Phytologist, Onoda et al. (pp. 1447–1463) empirically tackle several questions about those underlying mechanisms and, in so doing, help advance our understanding of the anatomical and physiological relationships underpinning the LES, while perhaps involuntarily, also raising important questions about what drives these trade-off relationships. What is most novel about their study is the bringing together of considerable data on rarely measured leaf traits, assessing both chemical (e.g. nitrogen (N) allocation) and diffusive (mesophyll conductance) constraints at the same time, and identifying a key role for cell-wall thickness in both of these.