Changes Of Soil Enzyme Activities And Influencing Factors Of Pinus Sylvestris Var. Mongolica Plantation In Sandy Land

The growth of Pinus sylvestris var.mongolica plantation in sandy land affects the change of soil enzyme activity.In order to reveal the change of soil enzyme activity and its influencing factors,the temporal-spatial alternation method was used to study the soil enzyme activity and other soil characteristic factors of 10-60 years old Pinus sylvestris var.mongolica plantation in Zhanggutai area of Liaoning Province.In addition,the innovation of this paper lies in the systematic analysis of the change of soil enzyme activity and the change of soil enzyme comprehensive evaluation index.And the influencing factors of soil enzyme activity were found out through the application of mathematical model.The results are as follows.(1)The activities of sucrase and protease in the soil of Pinus sylvestris var.mongolica plantation increased in the range of 10-60 years.The activities of soil phosphatase and catalase increased first and then decreased at 10-60 years,and reached the maximum at 30 years.Soil urease activity decreased first and then remained stable in the 10-60 years.In addition,the activity of five soil enzymes decreased with the deepening of soil layer.The comprehensive index of five soil enzymes increased first and then decreased during the whole growth cycle of Pinus sylvestris var.mongolica,indicating that the comprehensive effect of five soil enzymes on soil was the strongest at the middle forest age.On the soil layer,the five enzymes in the surface layer had the strongest comprehensive effect on the soil,and gradually weakened with the deepening of the soil layer.Last but not least,there was no significant difference in soil enzyme activities between different distances from standard tree trunks.(2)The main influencing factors of different soil enzyme activities were different,and the main influencing factors of sucrose enzyme are organic matter,clay,available phosphorus and pH.The main influencing factors of protease were alkali-hydrolyzed nitrogen,available potassium and water content.The main influencing factors of phosphatase are total phosphorus,available potassium and powder.The main influencing factors of catalase are pH,bulk density,total phosphorus and total potassium.The main influencing factors of urease were pH,clay,total nitrogen and water content.In conclusion,there is a significant interaction between soil enzyme activities and physical and chemical factors in this study area.The soil enzyme activity index can be used to measure the soil fertility of Pinus sylvestris var.mongolica plantation in Zhanggutai sandy land.