Tissue-level leaf toughness, but not lamina thickness, predicts sapling leaf lifespan and shade tolerance of tropical tree species
Article first published online: 10 MAR 2010
© The Authors (2010). Journal compilation © New Phytologist Trust (2010)
Volume 186, Issue 3, pages 708–721, May 2010
How to Cite
Kitajima, K. and Poorter, L. (2010), Tissue-level leaf toughness, but not lamina thickness, predicts sapling leaf lifespan and shade tolerance of tropical tree species. New Phytologist, 186: 708–721. doi: 10.1111/j.1469-8137.2010.03212.x
- Issue published online: 13 APR 2010
- Article first published online: 10 MAR 2010
- Received: 27 September 2009, Accepted: 12 January 2010
- leaf functional traits;
- leaf lifespan;
- leaf toughness;
- ontogenetic shifts;
- sapling shade tolerance;
- structural equation modeling;
- tropical trees
- •Leaf toughness is thought to enhance physical defense and leaf lifespan. Here, we evaluated the relative importance of tissue-level leaf traits vs lamina thickness, as well as their ontogenetic changes, for structure-level leaf toughness and regeneration ecology of 19 tropical tree species.
- •We measured the fracture toughness of the laminas and veins of sapling leaves with shearing tests, and used principal component analysis and structural equation modeling to evaluate the multivariate relationships among traits that contribute to leaf toughness and their links to ecological performance traits.
- •Tissue traits (density and fracture toughness of lamina and vein) were correlated positively with each other, but independent of lamina thickness. The tissue traits and lamina thickness contributed additively to the structure-level toughness (leaf mass per area and work-to-shear). Species with dense and tough leaves as saplings also had dense and tough leaves as seedlings and adults. The patterns of ontogenetic change in trait values differed between the seedling-to-sapling and sapling-to-adult transitions.
- •The fracture toughness and tissue density of laminas and veins, but not the lamina thickness, were correlated positively with leaf lifespan and sapling survival, and negatively with herbivory rate and sapling regeneration light requirements, indicating the importance of tissue-level leaf traits.