Effects Of Grazing Seasons On The Vegetation And Soil Of The Typical Steppe In Inner Mongolia:An Study

Grazing different grassland areas with the season changes is one of the key component of the traditional grazing managment in pastoral Inner Mongolia,and is also a key aspect for developing modern and sustainable grassland management regimes.However,there is little research on this aspect.To better understand the impact of grazing in different seasons on grassland plants and soil,we conducted a grazing experiment in the typical steppe region of Inner Mongolia to examine the effects of sheep grazing in four seasons,i.e.,autumn(SF),winter(SW),spring(SS)and summer(G),on grassland vegetation and soil properties.We used 20 grassland plots of 50 m × 50 m to arrange the five grazing treatments(four grazing season + no-grazing control),replicated four times.We measured traits of dominant plants,plant community composition,diversity and biomass,standing dead and litter mass,and soil physicalproperties in spring and plant peak biomass season in two years.We aim to understand the divergent effects of the grazing in different seasons on vegetation and soil systems.The results showed that:1.Senescent plant biomass cover can promote snow water storage in winter and prevent surface evapotranspiration in spring,and increase soil moisture available to plants in spring.In early spring,higher spring soil moisture significantly promotes plant height,density,and biomass(P <0.05),which is beneficial to grassland community biomass accumulation.2.In early spring,seasonal grazing will inhibit the accumulation and growth of grassland dominant species and community biomass.Grazing in spring is beneficial to the accumulation of grassland community productivity and the growth of tall dominant species.3.Seasonal grazing improves the diversity and richness of plant communities,and grazing in summer and autumn tends to decrease grassland uniformity.4.Grazing has the greatest impact on the surface root biomass of the soil,and grazing in spring has the lowest surface root biomass.5.Grazing in summer has a greater impact on plant nutrient content and soil properties.