Effects Of Different Improvement Measures On Plant Community And Soil Characteristics In Mowing Pasture Of Leymus Chinensis Meadow Steppe

As a storage warehouse for feed required by livestock in winter,mowing the grass plays a vital role in solving the imbalance of the season of grass and livestock,ensuring the safe wintering of livestock,and the sustainable development of grassland animal husbandry Due to the long-term mowing,the input and output of nutrients in the grassland ecosystem have become unbalanced,and the productivity of grassland has seriously declined.This study relied on the fertilization control experiment of Hulunbeier Leymus chinensis grassland in Inner Mongolia from 2014 to 2017,taking plant functional traits,functional groups,communities and soil as the research objects,from plant functional traits,populations,functional groups to various organizational levels of the community.Combined with multiple indicators of soil nutrients and stoichiometry,to explain the response characteristics and changes of the plant community and soil characteristics,to provide for the improvement and restoration of degraded grassland technical support and theoretical guidance and policy reference.The main findings are as follows,1.The plant height is the sensitive trait of Leymus chinensis under the measures of root-cutting+chemical fertilizer improvement.The high-concentration of root cutting+chemical fertilizer can increase the stem length and height of Leymus chinensis,and the increase of stem length is the main factor for the growth of Leymus chinensis plant height.As the year increased,the effect of the improvement measures of root-cutting+medium-concentration organic fertilizer on the growth of Leymus chinensis plant height,stem length and stem weight of Leymus chinensis shows year by year.2.Root-cutting+high-concentration chemical fertilizer and root-cutting+medium-concentration organic fertilizer measures are beneficial to increase the aboveground biomass of Leymus chinensis population.The important value of perennial rhizome grass functional group increased with the increase of root-cutting+chemical fertilizer concentration,and the proportion of biomass in community biomass also gradually increases,but the proportion of perennial forbs functional group biomass decreased.3.With the increase of the experiment year,the community richness decreased year by year under different improvement measures.The community biomass of the root-cutting+high-concentration fertilizer treatment is the highest.Root-cutting+medium concentration organic fertilizer treatment is more conducive to improving RFV of the community.4.The contents of soil available nitrogen and available phosphorus in different experimental treatments increased year by year,and root-cutting+high concentration organic fertilizer were more conducive to the increase of soil available nitrogen and available phosphorus.The root-cut+medium-concentration organic fertilizer soil has the highest total carbon and total nitrogen content of 0-10cm.5.Leymus chinensis population,plant community and soil stoichiometric ratio all showed that the growth of Leymus chinensis grassland was inhibited by nitrogen;root-cutting+chemical fertilizer and root-cutting+organic fertilizer could improve the degree of nitrogen suppression from short-term and long-term,respectively.6.In the process of vegetation restoration of Leymus chinen sis mowing grassland,the experimental treatment of root-cutting+high-concentration chemical fertilizer is beneficial to short-term vegetation restoration of Leymus chinensis mowing grassland,and the experimental treatment of root-cutting+medium-concentration organic fertilizer is beneficial to long-term vegetation restoration of Leymus chinensis mowing grassland.The quantitative characteristics of Leymus chinensis in the colony determine the community function,and solving the soil nitrogen limitation is the key to vegetation restoration.