Characteristics of Biomass Carbon Density of Degraded Natural Grassland and Artificial Grassland in the "Three-River Headwaters" Region
Biomass carbon density is one of the important features of carbon sequestration ability in ecological system.To describe the characteristics of biomass carbon density in alpine grassland in the "Three-River Headwaters" region,above ground biomass,living root biomass,dead root biomass and their carbon content in black soil land and natural grassland were measured.The results showed that the aboveground biomass in black soil land was higher than the aboveground biomass in degraded artificial grassland and natural grassland;but the living root biomass and dead root biomass in black soil land were lower than the living root biomass in degraded artificial grassland and natural grassland.The total biomass carbon density in degraded artificial grassland,black soil land and natural grassland was 719.47,706.57 and 2 233.09 g/m2,respectively.Grassland degradation not only changed ecosystem biomass allocation,but also changed the carbon density distribution in aboveground vegetation,living roots and dead roots.Root carbon density in degraded artificial grassland and natural grassland accounted for more than 90% of the total biomass carbon density,while the roots carbon density in black soil land accounted for 79.41%.The variation of carbon density in living roots was greater than those in aboveground vegetation and dead roots among three types of grassland,therefore,we initially considered that living roots carbon density may be a sensitive indicator of grassland degradation.
"Three-river Headwaters" regiondegraded artificial grasslandblack soil landnatural grasslandbiomass carbon density