Study On Soilwaterholding Characteristicsand Water Holding Capacity Under Different Vegetation Types In Xarxili Nature Reserve

As an important part of water resources,soil water is also the link between terrestrial water and biological earth cycle.It is also the main source of water resources required by plants.Due to the difference between vegetation types,soil water holding capacity varies greatly.Exploring the water-holding performance of soils under different vegetation is particularly important for the coordinated development of ecosystems in the region.The vertical landscape zone of the Xarxili Nature Reserve is obvious.A study on soil water holding capacity under different vegetation types is carried out in this area to establish the background value of soil water holding capacity related indicators in the natural state to fill the soil water holding capacity of the area.Capacity gaps.Based on the combination of field surveys and indoor experiments,13 representative soil sampling sites were selected under different vegetation types in the study area.A total of 220 soil samples were collected on the soil sampling sites with a ring knife to determine the soil bulk density and natural water content.Rate,saturated water content,total porosity,capillary porosity,non-capillary porosity,organic matter,early water content,maximum water holding capacity,capillary water holding capacity,non-capillary water holding capacity,effective storage capacity,storage precipitation capacity The content of indicators,the physical properties and hydrological characteristics of soils under different vegetation types were analyzed by statistical methods,and the soil water holding capacity under different vegetation types by principal component analysis.The main results are as follows:(1)The soil bulk density content under the grassland is generally 0—10cm <10—20cm <20—30cm at different depths at the same point.At the same soil depth,the content generally decreases with increasing altitude,and the changes in total porosity and capillary porosity are opposite;At different soil depths,the soil bulk density content under the shrubs showed a trend of decreasing first and then increasing with increasing altitude.The total porosity and capillary porosity were at G2 sample soil depth at 20—30cm,and G3 sample soil depth 30—40cm have the maximum value appeared;the change in soil bulk density under the forest was the same as that under the grassland,and the minimum value appeared at the soil depth of S4 sample point at 0—10cm.The values all appear in the S4 plot,and the minimum values appear in the S1 plot.(2)The indexes of soil water holding capacity in the study area weresignificantly different at the same soil depth(P <0.05).The maximum water holding capacity of the soil under the grassland and the capillary water holding capacity decreased with increasing soil depth,and the maximum values were 68.64 mm and67.27 mm,respectively.The water content of the soil under the shrubs and the capillary water holding capacity followed the soil at different points.As the depth increases,the content decreases first and then increases.The soil moisture content,maximum water holding capacity,and capillary water holding capacity of the soil under the forest are generally consistent in different plots,all of which decrease with the increase of soil depth.,The maximum values appear in the soil depth of S4 plot of 0 — 10 cm,and the effective culvert and culvert precipitation have the same increase and decrease law under different vegetation types.(3)The water holding capacity of the soil under the grassland at different depths at each sample site is in the order of 0—10cm> 10—20cm> 20—30cm in descending order.The main contributing factor affecting the soil water holding capacity index under the grassland is total pores.Degree,capillary porosity,maximum water holding capacity,and capillary water holding capacity;with the increase of soil depth at each sample point of the soil under the shrub,the water holding capacity generally increased first and then weakened,and the soil depth at the G3 sample point was 20—30 cm.The strongest,G1 sample soil depth of 10—20cm is the weakest water holding capacity.The main contributing factors affecting the soil water holding capacity index under shrubs are total porosity,capillary porosity,and non-capillary water holding capacity.Different points and great differences in different depths,S5 sample soil depth of 0—10cm has the strongest water holding capacity.The main contributing factors affecting the soil water holding capacity index under the forest are total porosity,capillary porosity,and non-capillary water holding capacity.From the overall perspective of the soil water holding capacity of the study area,as the altitude of the sample points increased,the soil water holding capacity generally showed a gradual increase trend.The S4 sample point had the strongest water holding capacity,and the C1 sample point had the weakest water holding capacity.The main contributing factors affecting soil water holding capacity in the study area are total porosity,capillary porosity,maximum water holding capacity,and capillary water holding capacity.