Classification Of Forest Site Types And Evaluation Of Ecological Function Importance In Ningxia Hui Autonomous Region

Forest geology is the science that explores the environmental conditions of forest growth and its differentiation.It is of great practical significance to carry out the classification of site types and evaluate the versatility of forest land to promote sustainable forest management.This paper takes the Ningxia Hui Autonomous Region as the research area,and based on the collection of meteorological,soil,topographic and other related data,combined with the expert consultation method,established the dominant factor of the site classification,and used ArcGIS to superimpose and analyze the main factors to complete the Ningxia region.According to the status of ecological function in the study area,the site type classification is carried out to evaluate the multi-functional importance of forest land,and it is clear that different site types should play various functions.The research results areas follows:(1)Choose the terrain,altitude,vegetation type,land use type,vegetation cover,soil salt content,soil type as the leading factor of the area of Ningxia.(2)Ningxia Hui Autonomous Region is divided into five sites,namely Helan Mountain,Ningxia Plain,Central Hilly and Sandy Area,Southern Loess Hilly Area,Liupanshan Earthstone Mountain Area,18 site groups and 45 site types.(3)According to the current ecological environment of Ningxia,the importance evaluation of water conservation function,the importance evaluation of soil and water conservation function,the importance evaluation of biodiversity conservation,and the importance evaluation of wind and sand fixation function.Each ecological function importance level is divided into 4 levels:generally important,more important,medium important,and extremely important.The evaluation of the importance of water conservation is of great importance and medium importance.The main distribution areas are the source of rivers such as Liupanshan Mountain and Helan Mountain.The area of general important area is 36900 km2,accounting for 71.3%;the area of relatively important area is 14100 km2,accounting for 27.3%;the medium important area is 736 km2,accounting for 1.42%;the area of extremely important area is only 64 km2.The importance of soil and water conservation is based on the sensitivity of soil erosion.The medium-sized area covers an area of 25,100 km2,accounting for 48.47%.The most important area is only 1900 km2,accounting for 3.55%.The area of general important area is 9100 km2,accounting for 17.59%;the area of relatively important area is 15700 km2,accounting for 30.39%.Among the evaluation results of the importance of biodiversity conservation,the medium-sized area is 24,200 km2,which accounts for the largest proportion of the four importance levels,followed by the general important area of 24,000 km2,and the area of the more important and extremely important areas is smaller.The most important area of the wind and sand fixation function is 22,800 km2,which is the largest area,followed by the general important area of 12,116 km2,and the medium and important areas are 8,925 km2 and 7957 km2.(4)The main functions and other auxiliary functions of forest land in each site type are calculated by sub-region,and the appropriate forest development strategy is proposed.In areas where the water conservation function is more important,such as the dark ash brown soil site type in the middle and high mountain forests of Liupan Mountain,the water source conservation forest should be the main type;in areas with important soil and water conservation functions,such as the deciduous broad-leaved forest site type,the water and soil should be strengthened.Maintaining the construction of forests;in the site types with better vegetation resources,such as high-altitude plain temperate deciduous shrub site types should be based on biodiversity conservation,strengthen the protection of forest resources;important sites in the middle and above of wind and sand fixation function Types such as sandy desert wind and sand soil site types should be based on forest development strategies that focus on wind-fixing and sand-fixing forests.