祁连山杜鹃灌丛草地地下生物量特征及其对休牧的响应

he alpine Rhododendron shrubland in Qilian Mountains exist for its important ecological services function and pasture of rare white yak and other herbivores, unreasonable utilization lead to degradation and retreating of alpine shrubland. In this paper, the belowground biomass responses of Rhododendron shrubland to different grazing rest modes were studied. The results show that: compared with the traditional summer grazing and grazing of heavy grazing (RG-0), underground biomass of live roots and underground storage organs biomass increased significantly, for the two whole growing season grazing rest modes (winter period heavy grazing: RG-1 and winter period light grazing: RG-2); the underground living roots biomass increased with soil depth, and decreased rapidly for Necromass; with increasing grazing pressure, living roots to emerged trend to deep soil layer; higher shrub coverage area (RG-2m) have a higher underground phytomass than the corresponding sparse zone; from June, August to October, the living roots biomass of the surface soil layer were slowly increase, dead roots biomass increased and then decreased, the total amount of underground phytomass have a slow decline after a sharp drop.