放牧对内蒙古草原温室气体排放的影响

Research of grazing effects on greenhouse gas emission in Inner Mongolian grasslands

静态箱-气相色谱法用于测定内蒙古典型草原温室气体排放.禁牧草原及放牧草原吸收CH4、排放N2O和CO2各自有其相对固定的季节变化形式,草原和大气交换温室气体通量的季节变化形式主要受年度气候变化所控制,而土壤、植被类型、降雨量等禁牧因素和放牧强度等人为因素仅影响排放强度.与禁牧草原相比,自由放牧降低了羊草草原对CH4的吸收和对N2O的排放,但大大增加了CO2的排放量.随着放牧强度的增加,草原温室气体排放强度呈线性迅速增长.

Static closed chamber/GC technique was used to measure the grassland greenhouse gas emission in the typical grassland of Inner Mongolia. CH4 uptake, N2O and CO2 emission, have their own relatively fixed seasonal variation patterns in the ungrazed and the grazed grasslands. This variation pattern of the greenhouse gas emission interchanged between grassland and atmosphere are mainly controlled by yearly variation of climate; while the nature factors of soil, vegetation type and precipitation and the anthropogenic factors of grazing intensity, could influence only the intensity of emission. Compared with the ungrazed, grazed land decreases CH4 uptake and N2O emissions of lyemus chinense grassland, but increases the CO2 emission amount greatly. The emission intensity of grassland greenhouse gases appears increase linear rapidly with the increase of grazing intensity.