期刊
AMERICAN NATURALIST
卷 177, 期 6, 页码 800-811出版社
UNIV CHICAGO PRESS
DOI: 10.1086/659963
关键词
functional traits; leaf toughness; defense; phylogenetically independent contrasts; shade tolerance; life-history trade-offs
资金
- F. H. Levinson Fund
- National Science Foundation
- MacArthur Foundation
Slow-growing juveniles of shade-tolerant plant species are predicted to have tough leaves because of the high cost of leaf replacement in shade relative to potential carbon gain. We assessed the degree of correlated evolution among eight traits associated with leaf toughness and the relationships of those traits with the growth and mortality rates of 197 tree and shrub species from the understory of the 50-ha forest dynamics plot on Barro Colorado Island, Panama. Path analysis with phylogenetically independent contrasts revealed that leaves attained material toughness (resistance to fracture per unit fracture area) through increases in tissue density, percent cellulose per unit dry mass, and vein fracture toughness. Lamina density and cellulose content evolved independently and thus represent different paths to material toughness. Structural toughness (resistance to fracture per unit fracture length) depended on material toughness and lamina thickness. Mortality rates of individuals 1-10 cm in stem diameter were negatively correlated with material toughness and lamina density but were independent of structural toughness and cell wall fiber contents. Leaf toughness traits were uncorrelated with relative growth rates. Results imply that material toughness enhances resistance to natural enemies, which increases survival and offsets the biomass allocation cost of producing tough leaves in the shaded understory.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据