中文摘要：

采用树干解析法对六盘山华北落叶松（29a）和油松（30a）典型人工林的生长过程进行了研究,并利用树皮系数还原平均木各树龄的带皮胸径,根据生物量方程求得2个树种的净生产力,再结合各器官含碳量,得出林地的固碳速率。结果表明,华北落叶松与油松胸径优势木、平均木和劣势木的连年生长量趋势基本一致,二者胸径生长量分别在12a和10a后开始下降,在此期间可适当进行抚育间伐。2种林分均未进入成熟期,预计成熟年龄前者在30a以后,而后者35a左右。华北落叶松和油松人工林总固碳量分别是34.28t·hm-2和59.56t·hm-2。华北落叶松林整个生长阶段平均碳累积速率为1.18t·hm-2·a-1,12a后固碳速率比较稳定,平均为1.64t·hm-2·a-1;而油松林整个生长阶段平均碳累积速率为1.98t·hm-2·a-1,16a以后,碳累积量快速增加,平均为3.55t·hm-2·a-1。

英文摘要：

With the method of stem analysis,the growth characters of Larix principis-rupprechtii and Pinus tabulaeformis plantations in Liupan Mountains,Ningxia were studied.The diameter at breast height（DBH）with bark of the two conifers were reconstructed on the basis of bark coefficient,then the primary productivity and carbon sequestration rates were obtained according to biomass equations which existed or newly-established.As indicated by the analysis that the annual DBH increments of the dominant,average and suppressed trees showed a consistent trend within the two conifers.Their growth began to decline at the 12th and 10th year when intermediate thinning would be taken.These two forest stands were not in their maturation period and,we predicted that the mature age of L.principis-rupprechtii was 30aand P.tabulaeformis was 35a.The amounts of carbon fixation of L.principis-rupprechtii and P.tabulaeformis forests were 34.28tand 59.56tper hectare,respectively.The carbon sequestration rate of L.principis-rupprechtii was1.18t·hm-2·a-1,and from the 12th year,the rate kept a stable level of 1.64t·hm-2·a-1. But to the P.tabulaeformisforest,the average rate was 1.98t·hm-2·a-1 and the accumulation of carbon increased rapidly（3.55t·hm-2·a-1）from the 16th year.