Nutrient Use Efficiency in Three Fast-Growing Tropical Trees

摘要

We measured nutrient use efficiency (NPPutrient uptake) in three species of tropical trees, Hyeronima alchorneoides, Cedrela odorata, and Cordia alliodora. We tested the prediction that on fertile soils species with very different biomass and nutrient allocation and turnover would converge on a common value of nutrient use efficiency. Due to high soil fertility, nutrient use efficiencies of the species studied were low (95-150 and 433-962 for N and P use efficiency, respectively). Nutrient use efficiency was examined in terms of its components, nutrient productivity and the mean residence time of nutrients. Although the species converged on the same nitrogen (but not phosphorus) use efficiency, differences in nutrient productivity and nutrient residence time may confer varying abilities to deal with nitrogen limitation. A combination of high nutrient productivity and longer nutrient retention (e.g., Hyeronima) signals an ability to prosper on infertile sites, whereas high nutrient productivity in the absence of long nutrient retention (e.g., Cedrela) indicates a capacity for high productivity, but only on fertile soil. Nutrient use efficiency and its components help explain species' distributions in natural communities and can be important criteria in selecting perennial plants for human use.