Soil Infiltration Capacity And Its Influencing Factors Of Different Plant Communities In The Xilamuren Grassland

In order to investigate the mechanism of soil infiltration in grassland of Xilamuren and its relationship with local plant communities,effectively maintain the stability of grassland community structure,reduce soil erosion,and prevent degradation of natural grassland,the paper studied the soil and Based on the trend of vegetation change,soil infiltration rate and infiltration water distribution regularity of different plant communities in the study area were measured by the double ring method,ring knife method and field dyeing tracer method.Soil permeability and soil were also analyzed.The relationship between vegetation and other environmental factors leads to the following main conclusions:(1)The process of soil infiltration in the six community types in the study area can be roughly divided into three stages.That is,the soil infiltration rate shows a rapid decline from 0 to 10 min after infiltration begins,and the rate of decline from 10 to 20min significantly slows down and increases.After stabilization,it reached a stable state after 30 minutes.There were great differences in soil infiltration performance among different community types,of which the community of the grasses performed the best,and the silver and gray flowers were the worst.(2)Overall,With the increase of soil depth,the soil infiltration rate of other vegetation communities decreased with the increase of soil depth.Among them,the soil infiltration rate of Koeleria asiatica was the most different among different soil layers,and its stable infiltration rate varied from 0.83mm/min to 2.71mm/min.The difference of Allium mongolicum was the smallest,and its stable seepage rate varied from 0.74 to 0.92mm/min.(3)The soil infiltration water distribution of Stipa breviflora,Stipa grandis,and Convolvulus ammannii communities in six communities was relatively uniform;There are obvious continuous or discontinuous branch structures and preferential channels of infiltration in Allium mongolicum,Koeleria asiatica and Leymus chinensis community.There was a polynomial relationship between the depth of soil wetting front and the infiltration rate of each community,and the correlation between the depth of soil wetting front and the initial infiltration rate was the strongest(R~2=0.87).(4)The soil physicochemical properties and plant root characteristics in the study area were significantly correlated with the soil infiltration rate.The soil bulk density in the soil properties and the root volume density in the vegetation root index correlated strongly with the soil infiltration rate.Soil bulk density is the most direct factor affecting soil infiltration rate,and other influencing factors indirectly affect soil infiltration rate by changing soil bulk density.(5)By using the Kostiakov,Honton,Philip and general empirical formula,the infiltration data were simulated and found that the Horton model is most suitable for describing the change of soil infiltration rate with time in the study area.