Effects Of Different Cutting Time On Community And Stability Of Xilin Gol Meadow Grassland

Taking Xilingole meadow grassland as the research object,four different cutting time treatment plots were set up in May 2017,including no cutting,cutting on July 20,cutting on August 15 and cutting on September 10.Before July 20,2018-2020,investigate the plant community characteristics,species diversity and biomass of four sample plots,measure the soil physical properties indoors,analyze the community stability through the community density model and Gordon stability model,and explore the reasonable cutting time in autumn,so as to provide a theoretical basis for the sustainable utilization of Xilingol meadow grassland.The main results are as follows:1.In the three-year cutting experiment,different cutting time reduced the height and coverage of plant community and increased the community density.Among them,the density of cutting treatment on July 20 was the highest,which was 17.41% higher than that of non cutting control treatment;The height and density of the community decreased with the later cutting time.2.Cutting can reduce the status of dominant species in plant community.With the later cutting time,the important values of Gramineae and Cyperaceae in plant community show a downward trend;Cutting can increase the community α Diversity,plant community under cutting treatment on September 10 α The diversity value is the highest.3.The aboveground biomass of plant community showed a downward trend with the backward movement of cutting time,and the aboveground biomass of excellent forage showed a trend consistent with the total aboveground biomass;Cutting increased the underground biomass and root shoot ratio of plant community.The underground biomass and root shoot ratio under cutting treatment on July 20 were the maximum among different treatments in the same year;The underground biomass and root shoot ratio of plant community decreased with the increase of cutting years.4.Cutting increased the soil bulk density,and with the increase of cutting years and the backward movement of cutting time,the soil bulk density generally showed an increasing trend;The trend of soil moisture content is opposite.5.Compared with other cutting time,the similarity between plant community under cutting treatment and no cutting on August 15 was the highest;Among the four treatments,the density based stability and Gordon stability of the community were the highest under the cutting treatment on August 15;There was a positive correlation between community diversity and stability under different cutting times.6.Different cutting time had different effects on community structure,diversity,biomass and stability.Cutting on July 20 was the most beneficial to community structure and biomass;Cutting on August 15 showed the highest community stability;Communities cut on September 10 α The diversity is the highest.