秦岭天然华山松林碳素空间分布规律及其动态变化

基于野外调查和实验室仪器分析数据,研究了秦岭天然华山松林生物量、碳密度、碳储量的空间分布及其随龄级、海拔变化的规律。结果表明:碳在华山松各器官中的分配以树干所占比例最大,其次为树枝,树皮最小;不同器官含碳率波动在0.488 6～0.519 8之间,顺序为叶>根>干>枝>皮;华山松林生态系统的生物量碳密度为133.59t/hm~2,其中地下部分(0～80cm)约占2/3,地上部分约占1/3;华山松林生态系统的生物量碳密度在海拔1 800～1 900m最大,达142.73t/hm~2,海拔低于1 700m和超过2 300m,都较小,分别为120.81t/hm~2和107.21t/hm~2;6个龄级的天然华山松林的生物量碳密度以平均树龄20a为最小,60a为最大;通过两期清查数据对比可知,其生物量增加了2.17t/hm~2,生物量碳密度增加了0.64t/hm~2。

Distribution and Dynamics of Carbon in Pinus armandi Forest Ecosystem in Qinling Mountains

Based on field investigation and laboratory data,spatial distribution and temporal variations of biomass carbon density(BCD) in Pinus armandi forest ecosystem in Qinling Mountains were studied in this paper.The results showed:1) the organ distribution of BCD was 47.91% for trunk,22.80% for branch and 6.20% for bark,and BCD of different Pinus armandi organ ranged from 0.4916 to 0.5298, with the order as follows:barks>leaf>branch>trunk>root;2) the total BCD in Pinus armandi eco- system was 183.26 t·hm~(-2),about 2/3 of which was stored in the plant(including root) and 1/3 in the soil;3) the highest BCD values,70.48 t·hm~(-2),occurred at the elevation ranging from 1 700 m to 1 800m;below the elevation of 1 500m or above the elevation of 1 900m the BCD values were 50.26 t·hm~(-2) and 46.57 t·hm~(-2) respectively;4) the highest and lowest BCD values were found in 50a and 20a respectively among the five age grades;and 5) comparing data of the two periods,biomass of forest Pinus armandi and BCD for 5 years increased by 3.12 t·hm~(-2) and 1.61t·hm~(-2) respectively.