Biomass and nutrient distribution in relation Pine in relation to previous land use I. Biomass

Above-ground biomass data are compared for 21-year-old radiata pine stands on three sites which had different types of land use prior to plantation establishment. The three sites, previously under native forest, grazed pasture and a pasture site subsequently used for crop production (cultivated) formed a continuous section of plantation in the 1968 age class. Biomass equations were developed for each tree component in relation to stem diameter for each site. There were no significant differences between sites in the coefficients for stemwood and bark, but different coefficients were required to relate stem diameter to the biomass of branches in the dead crown and foliage in the lower live crown. Stands on previously cultivated pasture (pasture followed by crops) accumulated 362,745 kg ha^?1 in the above-ground biomass; 40% and 13% more than the ex-native forest (259,183 kg ha^?1) and ex-pasture (320,055 kg ha^?1) sites, respectively. Trees on the previously cultivated pasture allocated a larger proportion of the total biomass to branches (17.4%) compared with the ex-native forest and ex-pasture trees (11.1%). This is attributed to reduced stocking and enriched soil resulting from different previous land use practices. The high frequency of multi-leadered trees in the ex-cultivated pasture increased the non-merchantable components to 26.7% of the total biomass.