MICROBIAL BIOMASS C AND N, AND MINERALIZABLE-N, IN LITTER AND MINERAL SOIL UNDER PINUS RADIATA ON A COASTAL SAND - INFLUENCE OF STAND AGE AND HARVEST MANAGEMENT

摘要

Microbial biomass C and N, and anaerobically mineralizable-N, were measured in the litter and mineral soil (0-10 cm and 10-20 cm depth) of Pinus radiata plantations in two trials on a nitrogen-deficient coastal sand. The trials comprised (a) stands of different age (1 to 33 years), with five of the seven stands studied being second rotation, and (b) a harvest-management trial, with stands established after different harvesting treatments of the first-rotation trees and understorey development controlled by manual weeding and chemical sprays. The harvest-management stands were sampled in the fifth year after the second-rotation establishment.