Characteristics Of Tvnical Plant Root Svstem Structure And Its Effect On Soil Permeabilitv In The Lower Reaches Of The Yellow River

The riparian vegetation buffer zone has important ecological service functions in terms of water conservation and soil and water conservation.Riparian ecosystems are located on both sides of the boundary where land and rivers intersect and are not affected by river water.They belong to the ecological transition zone between terrestrial ecosystems and aquatic ecosystems.The range is distributed between the high and low water levels of the river corridor and from the high water level of the river to the highland area affected by the flood.It has unique vegetation,soil,terrain,landform and hydrological characteristics that determine the uniqueness,complexity and dynamics of the riparian ecosystem.In recent years,due to a large number of human activities,the riparian zone and its vegetation and functions have been damaged,the soil and water loss has been serious.Therefore,it is urgent to restore the vegetation and prevent soil and water loss in the riparian zone of the Yellow River.In order to explore the relationship between the root structure characteristics and soil permeability of different plant types in the riparian zone,five single plants(reeds,cogongrass,bermuda grass,felon herb and juncellus serotinus)and four combinations were selected in the Zhengzhou section of the riparian zone in the lower Yellow River.Plants(cogongrass+reed?cogongrass+felon herb?cogongrass+bermuda grass and cogongrass+juncellus serotinus)were studied for soil permeability and root structure and structural characteristics.(If the root structure of the complete sample is not mentioned below,it is all divided into points.Layer sample root system parameters,no more detailed description)the comprehensive results are as follows:(1)The root structure of the complete samples of 5 kinds of single plants has the largest fractal dimension of bermuda grass root and the smallest fractal dimension of juncellus serotinus.The total root length,total root surface area,total root volume,root cross number,and root tip number exist.The correlation was extremely significant.The principal parameter analysis showed that the three parameters that had the greatest influence on the root architecture of the five herbaceous plants were total root volume,total root length,and total root surface area.(2)The soil permeability of 0-10 cm soil layers of 5 kinds of single plants are:bermuda grass>cogongrass>reed>felon herb>juncellus serotinus;the soil permeability of 10-20 and 20-30 cm soil layers are:cogongrass>reed>felon herb>bermuda grass>juncellus serotinus.The soil permeability of the four types of combined plants in the 0-10 cm soil layer is:cogongrass+bermuda grass>cogongrass+reed>cogongrass+felon herb>cogongrass+juncellus serotinus;the soil permeable size in the 10-20 cm soil layer is cogongrass+reed>cogongrass+bermuda grass>cogongrass+felon herb>cogongrass+juncellus serotinus;in the soil layer of 20-30 cm,the soil permeability is cogongrass+reed>cogongrass+felon herb>cogongrass+bermuda grass>cogongrass+juncellus serotinus(3)There is a large difference in soil permeability between different soil layers of the same or two types of plants,bermuda grass and juncellus serotinus gradually decrease from the upper layer to the lower layer,and cogongrass and reed decrease first and then increase,the major trend is that felon herb is gradually increasing;cogongrass+bermuda grass and cogongrass+juncellus serotinus are gradually decreasing from the upper layer to the lower layer,cogongrass+reed and cogongrass+felon herb show a trend of decreasing first and then increasing.(4)With the increase of root length density and root surface area density of different single plant types and combined plant types,indicators such as soil initial infiltration rate and infiltration rate have increased significantly,and the There is a clear correlation between root characteristic parameters(P<0.05),so root length density and root surface area of 0.5-5mm diameter root systems are very important for soil permeability.(5)There were extremely significant(P<0.01)or significant(P<0.05)correlations between soil initial permeability and steady permeability of 5 single plants and 4 combination plants and total porosity,non-capillary porosity,bulk density,clay,powder and organic matter.(6)The Kostiakov model is more suitable for the process of soil moisture infiltration in the riparian zone of the Yellow River,followed by the Horton model,and the Philip model has a worse fitting effect than the first two.Root length density and root surface area density have a greater effect on the parameters a and b of the Kostiakov model.As root length density and root surface area density increase,the parameter a,which describes the change of soil infiltration rate with time,,gradually decreases,which describes the infiltration of soil The parameter b of the average infiltration rate in the first period gradually increases.