Effects Of Root Cutting And Fertilization On Plant Community Characteristics And Soil In Moderate Degraded Meadow Steppe Due To Overgrazing

Grazing is one of the main ways of grassland utilization,over the years,grassland degradation due to overgrazing has become a common phenomenon.This study was conducted from 2017 to 2019.It takes the moderately degraded meadow grasslands caused by grazing in West Ujimqin Banner,Xilin Gol League,Xilin Gol League,Inner Mongolia as the research subject.Four categories of sample processing were first performed including root cutting,organic fertilizer(fermented dung),root cutting combined with organic fertilizer and blank control group.The characteristics of plant community,community diversity,functional traits of dominant species,carbon and nitrogen content,and physical and chemical properties of the soil were then studied.The effects of different measures on the recovery of degraded meadow steppe were finally explored.The main conclusions are as follows:1.The combination of root cutting and fertilization is beneficial to the restoration and improvement of community height,density and aboveground biomass.2.The combination of root cutting and fertilization is beneficial to the restoration and improvement of community species diversity and evenness.Fertilization,root cutting,root cutting with fertilization can increase the community species.Root cutting can reduce Shannon-Wiener diversity,Pielou evenness,Simpson dominance and Margalef richness,but the four diversity indexes increased under the combined measure of root cutting and fertilization.3.The root cutting treatment is beneficial to the restoration and improvement of the basic functional characters of the dominant species.Root cutting treatment can increase the leaf length,stem length,stem diameter and plant height of the P.tanacetifolia.It can also increase the leaf length,leaf area,plant height and cluster width of the C.squarrosa.It can moreover increase the leaf length,leaf thickness,stem length,stem diameter,leaf area,plant height and clump width of the S.baicalensis.4.Fertilization treatment is beneficial to the recovery of carbon and nitrogen content of the dominant species.Fertilization treatment can increase the carbon content and carbon-nitrogen ratio of the P.tanacetifolia,the nitrogen content and carbon-nitrogen ratio of the S.baicalensis and the carbon-nitrogen content of the C.squarrosa.Root cutting treatment can increase the nitrogen content of the P.tanacetifolia.The combined treatment of root cutting and fertilization can reduce the carbon and nitrogen content and carbon-nitrogen ratio of the S.baicalensis.It can also increase the carbon and nitrogen content and reduce the carbon-nitrogen ratio of the C.squarrosa.fertilization is beneficial to the recovery of carbon and nitrogen content of the dominant species.5.The three measures of root cutting,fertilization,root cutting and fertilization are beneficial to the improvement of soil physical and chemical characteristics to some extent.Root cutting treatment can reduce the soil bulk density and the compactness of soil.It also can increase the moisture content,the content of carbon,nitrogen and phosphorus in the shallow layer of soil.Fertilization treatment can reduce the soil bulk density and increase the content of carbon,nitrogen and phosphorus in the shallow layer of soil.The combined treatment of root cutting and fertilization can increase the content of nitrate nitrogen and ammonium nitrogen in the soil.