西藏草地生态系统植被碳贮量及其空间分布格局

The vegetation carbon reserve and its spatial distribution configuration of grassland ecosystem in Tibet

在广泛收集资料的基础上,利用平均碳密度方法,估算了西藏高原草地生态系统17类草地植被的碳贮量,并分析了其空间分布格局。结果表明:(1)17类草地植被总面积为8205.194×104hm2,总碳贮量为189.367Tg(1TgC=1012g),平均碳密度为2307.895kgC/hm2,不同植被类型差异较大,在395.977～20471.161kgC/hm2之间波动;(2)从草地类型分布看,高寒草原和高寒草甸是西藏分布面积最大的2类草地,分布面积占西藏草地总面积的70.210%,又是西藏草地碳贮量的主要贮库,碳贮量占西藏草地总碳贮量的79.393%;(3)在空间分布格局上,随着自藏东南向西北的延伸,草地植被总碳密度逐次降低,这一水平分布格局与西藏独特的水热分布相一致;碳密度的垂直分布规律因地区而异,但各地区均以高寒草甸或高寒荒漠的低碳密度为终点,表现出"殊途同归"的特征。

Based on extensively collected data, we used average carbon density method to estimate 17 vegetations carbon reserve of alpine grassland ecosystem and analyzed its spatial distribution in Tibet. The results indicated that ： 1 ） the total area of all 17 grassland vegetation was 8205. 194 × 10^4hm^2, total carbon reserve was 189. 367 Tg （ 1TgC = 10^12g） , average carbon density was 2307. 895 kgC/hm：, there was significant variation between 395. 977 -20471. 161kgC/hm^2 among different grassland types. 2） In the view of grassland types, Alpine grassland and Alpine meadow took the biggest portion of 70. 210% all of Tibet grassland. They were also the main grassland carbon reserve in Tibet, and occupied 79. 393% of the total. 3 ） In the spatial configuration, the vegetation carbon density gradually decrease from southeast to northwest in Tibet, This distribution is in correspondence to the particular precipitation and temperature in Tibet. Vertical distribution was different according to regions, but alpine meadow or Alpine desert had the lowest carbon density and was characterized by reach the same goal by different routes＂