Change Of Soil PH Value And Its Affecting Factors In Pinus Sylvestris Var.mongolica Plantation On Sandy Land

Construction of Pinus sylvestris var.mongolica plantation was an important measure to sandy land control,meanwhile afforestation generally changed soil p H,but the change in soil properties by the construction of Pinus sylvestris var.mongolica sand-fixing plantations have been not attracted attention.In this paper,20 plots of Pinus sylvestris var.mongolica forests at different growth stages(including young forest,middle-aged forest,mature forest and over-mature forest)in Zhanggutai were used as objects to study the change of soil p H values in 0-100 cm soil layers after afforestation.The results showed that the range of p H values of Pinus sylvestris var.mongolica forests changed from two levels(0-10 cm,0-20 cm,or 20-100 cm)expanded to three levels(0-10 cm,10-40 cm,40-60 cm or 60-100 cm)compared with control grass.With the increase of forest age,the p H values in 0-20 cm layer decreased significantly,in 20-40 cm soil layer was no significant change,and the p H values of young and mature forests were significantly increased than that of over-mature forests in40-100 cm soil layers,while there were no significant change between over-mature forest and control grass.There was a significant positive correlation between p H and TK,and the p H significantly negatively related to AP in 0-10 cm soil layer.There were significantly negative correlation between p H,AK and SOC and the p H positively correlated with SW in10-20 cm soil layer,and the p H were positively correlated with AN,TN and TP in 20-40 cm,40-60 cm,60-80 cm soil layer.In young forest,the p H values were positively correlated with C/P,AN,BD in 20-40 and 60-80 cm soil layer,and negatively correlated with N/P in80-100 cm soil layer.In middle-aged forest,the p H values was negatively correlated with C/P in 10-20 cm layer,and it was positively correlated with FS and TN in 20-40 cm and40-60 cm layer.In mature forest,the p H values in 0-10 cm soil layer were significantly positively correlated with BD and AP,and positively related to SW,AK and FS.The p H values were positively correlated with TN in 20-40 cm soil layer and negatively correlated with C/N in 60-100 cm soil layer.In over-mature forest,the p H values were positively correlated with AN in 0-10 cm soil layer,while negatively correlated with TK.There was positive correlation between TN and p H values in 10-20 cm soil layer.In short,the construction of Pinus sylvestris var.mongolica sand-fixation forest in Zhanggutai area significantly reduced the p H value of the soil in the 0-20 cm soil layers.The clarification of this issue will provide an important basis for the rational management and renewal of Pinus sylvestris var.mongolica sand-fixation forest in this area.The paper has 31 figures,8 tables,and 137 references.