Functional traits and the growth-mortality trade-off in tropical trees

Abstract

A trade-off between growth and mortality rates characterizes tree species in closed canopy forests. This trade-off is maintained by inherent differences among species and spatial variation in light availability caused by canopy-opening disturbances. We evaluated conditions under which the trade-off is expressed and relationships with four key functional traits for 103 tree species from Barro Colorado Island, Panama. The trade-off is strongest for saplings for growth rates of the fastest growing individuals and mortality rates of the slowest growing individuals (r(2) = 0.69), intermediate for saplings for average growth rates and overall mortality rates (r(2) = 0.46), and much weaker for large trees (r(2) 80% of the explained variation and, after WD was included, LMA and H-max made insignificant contributions. Virtually the full range of values of SM, LMA, and H-max occurred at all positions on the growth-mortality trade-off. Although WD provides a promising start, a successful trait-based ecology of tropical forest trees will require consideration of additional traits.