青藏高原高寒草原碳增贮潜力的初步研究

The Response of Potential Carbon Sequestration Capacity to Different Land Use Patterns in Alpine Rangeland

青海省西部地区的高寒草原分为高寒草甸草原、高寒草原化草甸和高寒草原3种类型;按照草地利用现状,分为原生草地、退化草地和人工草地3种土地利用格局。以原生草地为参照,通过比较不同草地类型和土地利用格局草地碳贮现状,探索其碳的增贮潜力。结果表明:原生高寒草原、退化高寒草原、高寒草原化草甸、退化草原化草甸、高寒草甸草原、退化草甸草原和人工草地的土壤-植物系统中总有机碳贮量分别为45.07±0.68,30.41±0.5,84.21±0.61,66.11±0.62,98.85±0.11,80.02±0.22,43.77±0.16tC.hm-2,其中原生高寒草原与高寒草原化草甸、高寒草甸草原、退化高寒草原有机碳储量差异显著。对退化草地进行人工恢复,具有显著的碳增贮潜力,高寒草甸草原、高寒草原化草甸、高寒草原和人工草地的理论碳增贮潜力分别为18.82±0.51,18.15±0.15,14.65±0.78,1.29±0.21tC.hm-2。气候变化导致的青藏高原干暖化,对高寒草原有机碳贮量的影响主要体现在由高寒草甸草原和高寒草原化草甸向高寒草原的演替上。

There are three steppe classifications of land-use patterns in Qinghai province： native,degraded steppe and pastureland.Dynamic changes of organic soil carbon storage are analyzed to estimate the potentially increasing carbon sequestration of each land-use type based on the natural alpine steppe.Result show that the carbon stock of native,degraded steppe,prata stepposa,degraded prata stepposa,meadow prata,degraded meadow prata and pastureland is 45.07±0.68,30.41±0.5,84.21±0.61,66.11±0.62,98.85±0.11,80.02±0.22 and 43.77±0.16 t C·hm-2,respectively.Both plant organic carbon and soil organic carbon are remarkably influenced by land use.The degraded steppe after recovering could get a huge carbon sequestration.The content of carbon sequestration potential from high to low is degraded prata stepposa（18.82±0.51 t C·hm-2）,degraded meadow prata（18.15±0.15 t C·hm-2）,degraded steppe（14.65±0.78 t C·hm-2）and pastureland（1.29±0.21 t C·hm-2）.The influence of climate change on organic carbon sequestration is mainly reflected in the succession from prata stepposa to meadow prata.