Study On Plant Community Characteristics And Soil Physicochemical Properties Of Aerial Seeding Afforestation Area In Northeastern Tengger Desert

Aerial seeding afforestation is an important measure to quickly and effectively realize the vegetation reconstruction and restoration of barren hills or sandy land,and is widely used in desertification control projects.It is of great significance for the protection and utilization of plant diversity in sandy areas and the management of sandy land to study and explore the characteristics of plants and soil after vegetation reconstruction in sandy areas under artificial aerial seeding afforestation,and to analyze the effects of artificial vegetation reconstruction measures on plant species diversity restoration and sandy soil properties.In this thesis,the 1992 sowing area(A),2001 sowing area(B)and 2004 sowing area(C)of Calligonum mongolicum,Hedysarum scoparium and Artemisia sphaerocephala in the northeastern margin of Tengger Desert were taken as the research object.Through the method of field sample survey and indoor analysis,the characteristics of community species composition,height,coverage,density,species diversity,soil water content,bulk density,organic matter,p H,available and total nitrogen,phosphorus and potassium after aerial seeding were analyzed compared with the control,and the quantitative characteristics,community diversity characteristics and soil physical and chemical properties after vegetation restoration in aerial seeding afforestation area were explored.The main conclusions are as follows :1.In 1992,there were 7 species of plants belonging to 5 families and 7 genera,mainly Chenopodiaceae plants.There were 11 species of plants in 2001,belonging to 5families and 10 genera,and there were more plants in Chenopodiaceae and Asteraceae.In2004,there were 14 species belonging to 6 families and 14 genera in the sowing area.Compositae plants were the most,followed by Leguminosae and Chenopodiaceae.2.The height,coverage and density of vegetation in 1992,2001 and 2004 were significantly higher than those in the control,and the coverage of aerial seeding area increased by 58 %,49 % and 45 % respectively.The total coverage of vegetation in1992,2001 and 2004 was 63.92 %,54.02 % and 48.20 % respectively.3.The composition of vegetation community structure in different sowing areas was different.Among them,the dominant species of the plant community in the sowing area in 1992 were Hedysarum scoparium and Calligonum mongolicum,the dominant species of the plant community in the sowing area in 2001 were Hedysarum scoparium and the second dominant species were Artemisia sacrorum,and the dominant species of the plant community in the sowing area in 2004 were Calligonum mongolicum and the second dominant species were Hedysarum scoparium and Artemisia sphaerocephala.The richness index of herbaceous layer was greater than that of shrub layer,and the dominance and evenness index of shrub plants were greater than those of herbaceous plants.The dominant position of shrub plants in the community is more prominent.4.The soil water content of each soil layer in the aerial seeding area decreased to different degrees compared with the moving sandy land,and the soil bulk density decreased to varying degrees compared with the moving sandy land.The recovery period of the 1992 seeding area was the longest,and the soil bulk density decreased most obviously.5.The soil organic matter in the aerial seeding area was improved compared with the control,and the most obvious was in 1992.The content of nitrogen,phosphorus and potassium in soil increased significantly compared with the control.