青藏高原高寒草甸生态系统碳增汇潜力

The potential of carbon sink in alpine meadow ecosystem on the Qinghai-Tibetan Plateau

为了揭示青藏高原高寒草甸生态系统植被变化对碳储量的影响,以原生矮嵩草草甸、退化草甸、人工草地以及农田为研究对象,对比分析了该4种不同土地格局下生态系统的有机碳现状。以原生矮嵩草草甸土壤碳储量为基准对不同类型高寒生态系统的碳增汇潜力进行了估算。结果表明:不同类型生态系统的碳储量和碳增汇潜力有很大差异,在0—40cm土层中,(1)原生草甸碳储量最高,达到17098 g C/m2,退化草甸、人工草地和农田的有机碳汇增加潜力分别为:5637、3823、1567 g C/m2。(2)对于退化草甸和人工草地,土壤有机碳含量和密度明显低于原生草甸和农田。(3)地下生物量碳储量主要集中在0—20cm,且原生草甸地下生物量的碳储量比其他3个植被类型高3.6—5倍。总体上,青藏高原草地生态系统存在巨大的碳增汇潜力。

To evaluate the potential effects of vegetation change on soil carbon storage on the Qinghai-Tibetan Plateau.We examined the soil organic carbon content of natural alpine meadow,degraded meadow,artificial pasture and farmland,and estimated the potential of carbon sequestration of the latter three types based on former natural alpine meadow.The results showed that the four vegetation types have a great difference in potential of carbon storage of 0—40 cm soil layer：（1） the carbon storage in natural alpine meadow was the highest with 17098 g C/m2,and were 5637,3823 and 1567 g C/m2 for degraded meadow,artificial pasture and farmland,respectively;（2） soil organic carbon content and density in degraded meadow and artificial pasture were significant lower than those in natural meadow and farmland;（3） root carbon storage mainly concentrated in the 0—20 cm topsoil,and the natural alpine meadow was 3.6—5 times higher than other three vegetation types.The results suggested that,there is a huge potential of carbon sink in alpine ecosystem on the Qinghai-Tibetan Plateau.