Responses of vegetation and soil of alpine meadows on the Qinghai-Tibet Plateau to short-term grazing prohibition
Because of the harsh climate and high altitude of the Qinghai-Tibetan Plateau (QTP),the Alpine Meadow,the dominant vegetation of the plateau,could easily degenerate due to overgrazing.This research study aimed to investigate the responses of vegetation and top-soil (0-10cm) to short-term grazing prohibition.We collected samples from a winter pasture enclosed for two years (short-time grazing prohibition) at the Zoige Wetland Ecosystem Research Station,Chinese Academy of Sciences,in Hongyuan County of the northeastern margin of QTP.The sample sites were randomly selected in the field,the community coverage was recorded,and the above ground (shoots) and below ground (roots) parts of the grass were collected and cut at the root collar.We weighed the shoot and root biomass;determined the root-shoot ratio (R/S);and measured the concentrations of total carbon (C),total nitrogen (N),and total phosphorus (P) of the vegetation and top-soil.In addition,the ecological stoichiometric linkages of the main nutrients (C,N and P) were analyzed.The main results were as follows.1) Grazing prohibition significantly changed the vegetation coverage,aboveground biomass,R/S,P concentration in both vegetation and soil,and N ∶P of the vegetation.However,it had no significant effect on the below ground biomass,C and N concentration,C ∶N and C ∶P of the vegetation and soil,or N ∶P of the soil.2) There was asignificant relationship between the C concentration of the soil and that of the shoots under grazing prohibition conditions,and between the C and N concentration of the soil and those of the roots under grazing conditions.The results suggested that grassland management measures would change the distribution and balance of vegetation and soil nutrients of the Alpine Meadow,and the linkages of the main nutrients contents between the vegetation and top-soil in the Alpine Meadow exists in specific parts of the plant organs.
国家科技期刊平台
NSTL
万方数据
维普
