用不同高度树干直径建立并比较臭冷杉各器官生物量方程,分析林木竞争对臭冷杉地上、地下生物量分配的影响。结果表明: 臭冷杉不同高度树干直径中,胸径是预测各器官生物量的最可靠变量; 利用不同高度树干直径建立各器官生物量方程均会高估小个体样木(直径≤10 cm)的生物量,并且随着直径增大,预测误差也随之增大; 臭冷杉地上生物量与地下生物量的比值(T/R)与树木年龄、单株生物量、整株生物量年均生长率及树高年均生长率间均没有显著相关性(P>0.05); 随着竞争增强,臭冷杉树干生物量占单株生物量的比例逐渐减小,枝叶生物量比例逐渐增大,而粗根生物量比例则基本保持不变; 胸径年均生长率、树高年均生长率及单株生物量年均生长率均随着竞争强度增大逐渐减小,而T/R值并不受林木竞争的影响。
Allometric equations for different biomass components were developed using stem diameters at different tree heights (DBH; crown base, DC; 30 cm height, D30 and tree base, DB). The effects of tree competition on biomass partitioning was also analyzed. The results showed that DBH was a simple and reliable predictor for estimating above- and belowground biomass components. The allometric equations estimated with stem diameters at different tree heights all slightly overestimated biomeass components in the smaller stem diameter trees (diameter≤10 cm). The prediction errors increased with tree diameters. The aboveground to belowground biomass ratio (T/R) did not correlate with tree age, individual plant biomass, mean annual growth rate of individual plant biomass and mean annual growth rate of tree height (P>0.05). With increasing competition intensity, the relative proportion of stem biomass decreased, whereas, that of canopy biomass (i.e., living branch and needle biomass) increased. The coarse root biomass maintained virtually constant proportion. As expected, the mean annual growth rate of DBH, mean annual growth rate of tree height and mean annual growth rate of individual plant biomass were negatively affected by competition intensity while T/R almost kept constant and was free of the intensity.