Studies On The Suitable Site Conditions Of Quercus Mongolica In Eastern Liaoning

This paper took natural secondary Quercus mongolica forest in eastern Liaoning province as the research object.68 temporary standard plots of Quercus mongolica with different ages,different slope directions and different slope positions were selected in 7 state-owned forest farms of Qingyuan Manchu Autonomous County,Fushun City,Liaoning province.Tree growth indicators and site conditions were investigated.A dominant tree was selected in representative sample plots for trunk analysis,a total of 28 dominant trees were selected and the biomass of different organs were measured.Quantitative method was used to study the relationship between growth and site factors of Quercus mongolica.At the same time,the biomass equation of Quercus mongolica was constructed by model fitting,and the biomass productivity of different site types was compared according to different forest ages.The main results were as follows:1.Quantitative theory I was used to fit the model,the regression equation betwee n height,DBH and slope position(X1i),slope gradient(X2i),slope direction(X3i),soil A layer thickness(X4i)and age(a)of Quercus mongolica dominant wood was constr ucted.Regression model of DBH growth:DBH=8.846+1.737X11+0.604X12+0.576X21-2.942X22+5.003X31-3.633X32+1.240X41+2.294X42+0.252A(R2=0.957),regression model of tree height growth:H=10.692+0.765X1l11.041X12-0.174X21-0.715X22-1.370X31+0.765X32-0.489X41+0.862X42+0.135A(R2=0.854).The effects on the growth of natural secondary Quercus mongolica forest was slope gradient>slope direction>slope position>soil A layer thickness,and the dominant factor was slope gradient.2.The theoretical height growth equation of Quercus mongolica was H=22.0241(l-Exp(-0.0348A))1.1678(R2=0.997),and the index age was determined to be 50 years.3.The natural secondary Quercus mongolica forest in eastern Liaoning province was divided into 3 site type groups and 40 site types.The most suitable site conditions for the growth of Quercus mongolica in eastern Liaoning province was gentle slope,upper slope,sunny slope and thicker soil A layer below 150.4.The established equation of trunk biomass,branch biomass,leaf biomass,and total biomass of Quercus mongolica was respectively:W ?=0.034D1.658H1.263(R2=0.759),W ?=0.056D1.764H0.769(R2=0.845),W ?=0.006D1.628H0.855(R2=0.806),W ?=0.063D1.792H0.982(R2=0.899).The established biomass equation has high accuracy and could better predi ct the biomass of Quercus mongolica in eastern Liaoning province.5.By comparing the biomass productivity of natural secondary Quercus mongolica forest under different site types at different forest age stages,it was concluded that in the natural secondary Quercus mongolica forest in eastern Liaoning province,the best site types of aboveground biomass productivity of young forest were steep slope,semi-shady and semi-sunny slope,middle slope,thick soil.The best site types of middle-aged forest were steep slope,sunny slope,upper slope and thick soil.The best site types of near-mature forest were steep slope,shady slope,downhill position and middle soil.It can be seen that the biomass productivity of Quercus mongolica was higher under site conditions with medium soil thickness or above.