Study On Soil Characteristic Evolution Of Pinus Sylvestris Var.mongolica Fixed Sand Forest Regeneration Slash Of Vegetation Reconstruction

Through field investigation and laboratory analysis method of combined determination,studied on soil characteristic evolution of Pinus sylvestris var.mongolica fixed sand forest regeneration slash of vegetation reconstruction after 13 years,and studied forest species diversity and water holding capacity,and used improved Nemero formula for a comprehensive evaluation of soil fertility quality.The results showed that soil characteristics evolution towards positive direction after revegetation,main results of the study were as follows:(1)After Pinus sylvestris var.mongolica fixed sand forest regeneration slash of vegetation reconstruction,herb species diversity changed significantly,the number of rare species increased,Leymus chinensis(Trin.)Tzvel.and Chenopodium acuminatum and Artemisia capillaries were common forest plant species in the region,Leymus chinensis(Trin.)Tzvel.and Chenopodium acuminatum and Eragrostis pilosa were the first dominant species in plantation after vegetation reconstruction.Research on litter layer of water-holding capacity showed that the maximum water holding rate,maximum water holding capacity,the effective rate and effective storing storing deep,the top three of seven kinds of stands were Populus×xiaozhuanica cv.?Zangwu?>Hemiptelea davidii(Hance)Planch.>Prunus sibirica L.(2)Integrated 0-10 cm and 10-20 cm soil layer,soil bulk density declined,and field capacity increased,and saturated hydraulic conductivity declined after vegetation reconstruction.Different types of vegetation on soil amelioration significant difference,in which Populus×xiaozhuanica cv.?Zangwu? on soil physical properties of the integrated ability the most obvious improvement,followed by Pinus densiflora var zhanguensis and Acer mono Maxim.After vegetation reconstruction 13 years,compared with logged slash,soil pH was reduced,and the content of other chemical properties were improved.Revegetation of different types were very different effect on improving soil chemical properties,and the best improvement effect on soil chemical properties was Populus×xiaozhuanica cv.?Zangwu?,followed by Acer mono Maxim.and Hemiptelea davidii(Hance)Planch..The number of soil microorganism increased obviously after the vegetation reconstruction,bacteria and actinomycetes and fungi comparatively speaking,compared to slash the largest increase was fungi,each stand fungi was more than 256 times the logged sites.Different types of revegetation total microbial population rate of increase significantly different,the number of microorganisms maximum in Syringa oblata var.alba,followed by Acer mono Maxim.and Hemiptelea davidii(Hance)Planch..(3)Physical and chemical properties of the soil,except bulk density no significant variation in the upper and lower soil,saturated hydraulic conductivity and pH in the upper soil were lowerthan the lower soil,other features were showed the upper levels higher than the lower content.Combined different soil characteristics,excepted three groups of microorganisms,the biggest increase was phosphorus content,followed by CEC.(4)The average soil fertility quality of the soil in the 0-20 cm soil layer of the 7 vegetation reconstruction types was: Populus×xiaozhuanica cv.?Zangwu?(0.88)>Acer mono Maxim.(0.87)> Prunus sibirica L.(0.84)> Syringa oblata var.alba(0.83)> Pinus densiflora var zhanguensis(0.77)> Hemiptelea davidii(Hance)Planch.(0.73)> Pinus sylvestris var.mongolica(0.72).