EFFECTS OF SOIL NUTRIENT AVAILABILITY ON INVESTMENT IN ACQUISITION OF N AND P IN HAWAIIAN RAIN FORESTS
- Author(s): Treseder, Kathleen K
- Vitousek, Peter M
- et al.
Published Web Locationhttps://doi.org/10.1890/0012-9658(2001)082[0946:eosnao]2.0.co;2
We determined the influence of nutrient availability on the mechanisms used by plants to acquire nitrogen and phosphorus from the soil. Extracellular acid phosphatase production, mycorrhizal colonization, and N and P uptake capacities were measured in control, N-, and P-fertilized forests in three sites that varied in nutrient status from N limited to relatively fertile to P limited. Nitrogen fertilization increased extracellular phosphatase activity in all sites. Phosphorus additions consistently reduced phosphatase activity, mycorrhizal colonization, and P uptake capacity across sites. Our results indicate that these plants efficiently allocate resources to nutrient acquisition as suggested by an economic model. Investment in acquisition of a nutrient was greatest when that nutrient was limiting to growth, and plants appeared to allocate excess N to construction of extracellular phosphatases to acquire P. This increase in phosphatase production with N fertilization implies that even P-limited systems might respond to N deposition with greater productivity.