Soil Ecological And Environmental Characteristics And Its Evaluation With Different Water Conservation Forest Models In Mountain Area Of Southern Ningxia

In this paper,seven pure water conservation forest models in the camel forest watershed of Liupan Mountain in Ningxia were taken as the research object,and the wasteland was used as a control.Combined with field tests and laboratory experiments,the effects of seven pure forest models on intercepted rainfall,soil physical and chemical properties,soil enzyme activity,and microbial diversity were studied.Finally,the analytic hierarchy process was used to comprehensively evaluate the soil ecological functions of seven pure water conservation forest models,and the pure forest model of most suitable for the local ecological environment was selected.It is expected to provide a scientific reference for constructing a suitable water conservation forest model for local and similar watersheds and promoting regional ecological restoration.The main conclusions are as follows:(1)The effect of water conservation forests on rainfall is closely related to interception rainfall characteristics and forest types.Robinia pseudoacacia has a strong interception capacity for short-duration and low-intensity rainfall,while Larix principis-rupprechtii and Pinus tabulaeformis have stronger interception capacity for longer-duration and stronger rainfall than Robinia pseudoacacia.Regardless of the period of the rain,the Robinia pseudoacacia had a stronger effect on intercepting the rain than the Larix principis-rupprechtii and Pinus tabulaeformis in the early rain.The three water conservation forest models 0?100cm vertical soil profile moisture content and coefficient of variation of the water are generally shown as:"S"-shaped change characteristics,0?50cm soil layer soil moisture change is relatively active,50?100cm water variation is relatively stable.(2)Compared with the wasteland,the construction of water conservation forest increases the soil capillary porosity and thus affects the water holding capacity of the forest soil,and this adjustment effect gradually increases with the increase of vegetation restoration years.Robinia pseudoacacia 15a and Hippophae rhamnoides 7a significantly increased soil nutrient content.The analysis of Alpha diversity of soil bacteria and fungi showed that water conservation forests can significantly increase soil bacterial and fungal microbial diversity compared to the wasteland.With the increase:of vegetation restoration years,the microbial diversity of soil fungi and bacteria in Robinia pseudoacacia and Pinus tabulaeformis samples increased significantly,and the microbial diversity of soil fungi and bacteria in Larix principis-rupprechtii samples decreased to some extent.(3)The principal component analysis showed that the five principal components explained a total of 82.02%of the various characteristics of the soil ecological environment.The first main component is soil enzyme activity;the second main component is soil nutrients;the third main component is soil microbial diversity;the fourth main component is soil microbial biomass;the fifth main component is soil moisture.(4)Through the analytic hierarchy process,the soil ecological environment functions of seven pure water conservation forest models are comprehensively evaluated and ranked as Pinus tabulaeformis 15a>Larix principis?rupprechtii 15a>Robinia pseudoacacia 15a>Robinia pseudoacacia 7a>Hippophae rhamnoides 7a>Larix principis?rupprechtii 7a>Pinus tabulaeformis 7a>wasteland.In the end,it was considered that Pinus tabulaeformis was the most suitable water conservation forest model for the pure forest in the camel forest watershed.