藏北高寒草地植被的碳密度与碳贮量

Carbon density and reserve of alpine grassland vegetation in northern Tibet

采用实地调查与查阅文献相结合的方法估算藏北高寒草地植被碳密度和碳贮量。结果表明:1)藏北高寒草地总面积约39.059×106 hm2,植被地上平均碳密度12.158±4.7 g.m-2,植被地下平均碳密度84.458±20.38 g.m-2,植被地上部碳贮量5.171±0.95 Tg,植被地下部碳贮量25.223±2.96 Tg,植被总碳贮量为30.394±3.91 Tg;2)不同草地组间植被碳密度和碳贮量差异显著。其中不同草地组间植被碳密度以丛生禾草组碳密度值最低,地上和地下碳密度分别为6.13±1.51 g.m-2和26.04±5.8 g.m-2,具灌木的半灌木组碳密度最高,地上和地下碳密度分别为31±3.4 g.m-2和244.59±6.9 g.m-2;而不同草地组间,草地植被碳贮量以小莎草组最大,植被地上和地下碳贮量分别为2.24±0.32 Tg和9.52±0.89 Tg,半灌木组碳贮量最小,其地上和地下碳贮量分别为0.012 4±0.002 Tg和0.098 1±0.002 Tg。3)藏北高寒草地分布各县(区)碳密度和碳贮量的分布也存在显著差异。从碳密度来看,革吉县、札达县、噶尔县和措勤县碳密度较高,植被平均碳密度分别相当于藏北平均植被碳密度的1.76,1.47,1.11和1.06倍,从碳贮量来看,碳贮量集中分布于双湖特别区、札达、尼玛、日土、革吉和改则6县(区),六县(区)草地植被碳贮量为25.2±2.31 Tg,占藏北总植被碳量的82.89%。

In this paper, the alpine grassland carbon density and carbon reserve in northern Tibet was calculated by field investigation and reference review. The results showed that, 1） The total area of alpine grassland in northern Tibet was about 39.059× 10^6 hm^2, The carbon density of aboveground and belowground vegetation were 12.158±4.7 g·m^2 and 84.458±20.38 g·m^-2, the carbon reserve of aboveground and belowground vegetation were 5.171±0.95 Tg and 25.223±2.96 Tg, the total carbon reserve of alpine grassland was 30.394±3.91 Tg. 2）These distributions were different in different grassland groups, the lowest carbon density was Gramineae group and its carbon density of aboveground and belowground vegetation were 6.13±1.51 g·m^-2 and 26.04±5.8 g·m^2, the highest aboveground and belowground vegetation carbon density was shrub with hypo-shrub group were 31±3.4 g·m^2 and 244.59±6.9 g·m^-2. The highest aboveground and belowground vegetation carbon reserve was Cyperaceae and the amount were 2.24±0.32 Tg and 9.52±0.89 Tg, the lowest carbon reserve was hypo-shrub and were 0.012 ±0.002 Tg and 0.0981 ± 0.002 Tg. 3）this diversity was also observed in all of counties and boroughs, higher carbon density counties were Geji, Zhada, Geer, Cuoqin, the vegetation carbon density respective was 1.76, 1.47, 1.11 and 1.06 times in average northern Tibet carbon density, and the carbon reserve concentrate in Shuanghu, Zhada, Nima, Rim, Geji, Gaize, in this area total carbon reserve was 25.2±2.31 Tg, which consists about 82.95 of carbon reserve in Northern Tibet.