The Vertical Distribution Of Soil Nutrients Of Plantations In The Windy Desert Areas Of Northwest Liaoning

The main objective of this study is to provide scientific afforestation measures for different cultivation targets and to achieve the sustainable development of forest ecosystem.The study compared contents of the soil organic carbon?SOC?,soil total phosphorus?TP?,soil total nitrogen?TN?and microbial biomass carbon?MBC?in five typical local artificial shelterbelt-Pinus sylvestris var.mongolica?PS?plantation,Populus × euramericana?PX?plantation,Pinus tabulaeformis Carr.?PC?,P.sylvestris var.mongolica-P.× euramericana mixed plantation?PS-PX?,P.sylvestris var.mongolica-P.tabulaeformis mixed plantation?PS-PC?in the Fujia Forest Farm,Northwest Liaoning.We analyzed whether SOC,TP,TN,MBC content was signinficantly by three factors:stand density,forest type,pure forest and mixed forest and study the spatial variability at different soil depths.The results showed that:?1?The difference of tree species not only affected the soil organic carbon,nutrient and microbial biomass carbon in 0-50cm soil profile,but also changed the vertical distribution of each index.The indexes of PS and PX were significantly decreased with the increase of soil depth?P<0.05?.But the soil organic carbon and total nitrogen content of PC showed different distribution characteristics.The 0-40cm soil profile decreased with the increase of soil depth,and the soil layer of 40-50cm increased significantly.The contents of soil organic carbon and total nitrogen in the soil layers of PS were the highest in 0-50cm soil profile,But the contents of soil total phosphorus and microbial biomass of PX were the highest.The accumulation of soil organic carbon and total nitrogen of the PS than PX,PC accounted for the dominant.?2?Due to differences of tree species composition in PS pure and mixed forest,Soil organic carbon,soil nutrient and soil microbial biomass carbon content were different,and showed different vertical distribution characteristics in 0-50cm soil profile.The soil organic carbon content decreased with the increase of soil depth?P<0.05?at 0-50cm vertical soil profile in the PS and PS-PX.The soil organic carbon and soil total nitrogen content were not significantly different in 0-40cm soil profile,and the soil profile in 40-50cm was significantly improved in the PS-PC.For soil microbial biomass carbon content,there was no significant difference between the PS and PS-PX,but the PS and PS-PX were higher than PS-PC?P<0.05?in 0-10 cm soil layer.?3?The difference of stand density was not affect the distribution of soil organic carbon,nutrient and microbial biomass carbon with the depth of soil layer,but it affected the content of each layer.The soil microbial biomass carbon content of PS I(183zhu·hm^-2)is the highest among the three densities of the forest at 0-50cm.Soil organic carbon,soil nutrient content of PS?(642 zhu·hm^-2)is the highest.soil organic carbon,soil nutrient content accumulation of PS? had a significant effect.