With a replicated N, P, and K fertilization
trial at different elevations and a N tracer experiment, we tested
the following hypotheses that fine root growth in pre-montane
rainforest (e1000 m asl) is limited primarily by low P availability,
whereas low N supply restricts root growth in upper montane
rainforest (e3000 m asl), and that the N uptake capacity of fine
roots decreases with increasing elevation due to decreased soil
temperatures