Research On The Effect Of Grassland Enclosure In Inner Mongolia

In order to explore the impact of enclosures on grassland vegetation and soil in Inner Mongolia,this thesis selects two typical areas of Xilingol grassland and Hulunbuir grassland as the research objects.Comparative analysis of the changes in plant species composition,community quantity characteristics,biomass and soil physicochemical properties within and outside the enclosure 4a,7a,10 a,and 13 a after the implementation of fences in the Beijing-Tianjin sandstorm source project area,and selected typical samples.The grassland health index before and after the enclosure was calculated,and the grassland health status after 13 years of enclosure was evaluated,aiming to provide a theoretical basis for the restoration of degraded grassland ecosystems.The research results show that:(1)After the grassland was enclosed,the community structure was obviously optimized.It is shown that the number of fine forage plants such as Gramineae,Liliaceae and Legumes increases,and the proportion of weeds decreases.Compared with the grazing area,the average height,coverage and aboveground biomass of vegetation increased significantly,and the corresponding average increases were 56.88%,45.90%,and 172.83%.With the increase of enclosure years,the characteristics of grassland plant community showed an overall increasing trend.It shows that the enclosure has a certain role in promoting the growth of grassland vegetation.(2)After the grassland was enclosed,the soil bulk density and the maximum field water holding capacity were better than those in the grazing area.Compared with the grazing area,the soil bulk density decreased by 16.54%,and the field water holding capacity increased by 73.75%.Soil bulk density and maximum field water holding capacity continued to improve with the increase of enclosure years,and reached a better state after enclosure for 10 years.(3)Enclosure has a significant effect on soil chemical properties.The p H value was weakened,and the contents of soil organic matter,available nitrogen,available phosphorus and available potassium were higher than those in the grazing area.With the extension of the enclosure period,the overall change trend shows an increasing trend.Among them,compared with the grazing area,the maximum growth rate of organic matter is 35.94%,the maximum growth rate of available nitrogen is 48.92%,the maximum growth rate of available phosphorus is 49.16%,and the maximum growth rate of available potassium is 67.52%.On the whole,the implementation of engineering measures has a certain improvement effect on grassland soil.(4)After the grassland enclosure project,the grassland health index value of Xianghuang Banner increased from 53 to 84,and the grassland health index value of Chenbaerhu Banner increased from 41 to 88.The grassland health status in the two regions changed from sub-health to healthy.