宁夏天然草地植被碳储量特征及构成

以宁夏广泛分布的温性草甸草原、温性草原、温性草原化荒漠和温性荒漠草原为研究对象,采用实地调查采样的方法,研究了宁夏天然草地植被总碳储量。结果表明: 宁夏天然草地地上植被、地下根系及主要灌木平均含碳率为0.40,枯落物平均含碳率为0.39。草甸草原、温性草原、草原化荒漠和荒漠草原的植被总碳储量分别为470.26、192.23、117.17和83.36 g·m^-2,其中,地上植被碳储量分别为87.35、68.50、59.32和40.05 g·m^-2,地下根系碳储量分别为344.29、108.83、50.65和30.29 g·m^-2,枯落物碳储量分别为38.62、14.91、7.19和13.03 g·m^-2,且均表现为草甸草原＞温性草原＞草原化荒漠＞荒漠草原。地下根系碳储量是构成草甸草原和温性草原植被总碳储量的主体,地上植被碳储量是构成草原化荒漠和荒漠草原植被总碳储量的主体,且地下根系碳储量均随土层深度加深而递减。宁夏天然草地植被总碳储量空间分布呈现草甸草原和温性草原分布的南部区域碳储量明显高于荒漠草原和草原化荒漠分布的中北部区域。

Characteristics and composition of vegetation carbon storage in natural grassland in Ning-xia,China.

We measured the total vegetation carbon stock in the widely distributed natural grassland of meadow steppe (MS), warm steppe (WS), steppe desert (SD) and desert steppe (DS)] in Ningxia, using survey and sampling method. The results showed that the average carbon rate of vege-tation, shrubs and root were 0.40, and that of litter was 0.39. The total vegetation carbon density of meadow steppe, warm steppe, steppe desert and desert steppe (including aboveground vegetation, litter and roots) was 470.26, 192.23, 117.17 and 83.36 g·m^-2, while that of aboveground vegetation was 87.35, 68.50, 59.32 and 40.05 g·m^-2, and that of roots was 344.29, 108.83, 50.65 and 30.29 g·m^-2, litter carbon storage was 38.62,14.91, 7.19 and 13.03 g·m^-2, respectively. The order of those grassland types ranked as MS＞WS＞SD＞DS. Root carbon storage contributed the most to carbon storage in meadow steppe and warm steppe, and aboveground vegetation carbon storage contributed the most to steppe desert and desert steppe. Root carbon storage showed a decreasing trend with the increases of soil depth within 40 cm soil layer. For the spatial distribution of total carbon stock, the southern part of meadow steppe and temperate steppe had obviously higher carbon stock than the middle and north part of desert steppe and steppe desert.