Related Experiment Video
Updated: Jun 30, 2026

Reconstructing Terrestrial Paleoclimate and Paleoecology with Fossil Leaves Using Digital Leaf Physiognomy and Leaf Mass Per Area
Published on: October 25, 2024
Leaf size, sapling allometry, and Corner's rules: phylogeny and correlated evolution in maples (Acer)
1Harvard University Herbaria, Cambridge, Massachusetts 02138, USA.
Abstract:
We studied the evolution of leaf size, sapling canopy allometry, and related traits in 17 Acer species growing in the understory of temperate deciduous forests, using parsimony methods, randomization tests, and independent contrasts calculated on a phylogeny inferred from nuclear ribosomal internal transcribed spacer (ITS) sequences. Bivariate correlations and multivariate analyses indicated two independent suites of coevolving traits, and the results were robust over a range of alternative phylogenies. The first suite consisted of strong positive correlations among twig thickness, leaf size, inflorescence length, and branch spacing (Corner's rules). Seed size and mature height were also weakly correlated with these traits. The second suite reflected aspects of sapling crown allometry, including crown size, stem diameter, and total leaf area, which appear to be related to shade tolerance. There was a weak negative correlation between sapling crown size and mature height, but no correlation with leaf or seed size. Most correlations were similar in magnitude for ahistorical and independent contrasts analyses, and discrepancies between these two measures were greater in traits with lower levels of convergent evolution. The evolutionary correlations among twig, leaf, seed, inflorescence, and canopy dimensions emphasize the need for integrated theories of evolution and function of these disparate traits.
Related Concept Videos
Phylogenetic Trees
Phylogenetic Trees
Light Acquisition
Phylogeny
Basic Plant Anatomy: Roots, Stems, and Leaves
Primary and Secondary Growth in Roots and Shoots

