Foliar and litter nutrients, nutrient resorption, and decomposition in Hawaiian Metrosideros polymorpha

The native tree Metrosideros polymorpha dominates Hawaiian forests across a very wide range of soil fertility, including both sites where forest production is limited by nitrogen (N) and others where it is limited by phosphorus (P). Five long-term fertilization experiments have further broadened the range of nutrient availabilities experienced by Metrosideros. Adding P to P-limited sites increased foliar P concentrations threefold and litter P concentrations up to 10-fold; lignin concentrations decreased, and the decomposability of leaf litter increased from 32%-35% to 36%-46% mass loss in the first year. Adding N to N-limited sites increased leaf and litter N concentrations by only 15%-20%, with little or no effect on the decomposability of tissue.