Dynamic Model Study Of Caragana Korshinskii Biomass Based On The Influence Of Ground Factors

The biomass prediction of afforestation trees in the arid and semi-arid areas of northwest China is mainly shrubs,and its biomass prediction is of great significance for evaluating the total primary productivity and carbon storage of forests.As the main afforestation tree species in arid and semi-arid areas,Caragana korshinskii has strong stress tolerance to cope with harsh natural environments.In this study,26 part of 15× 15m Caragana korshinskii plots were set up to investigate the biomass and growth years of each part of the sample,and the three standing factors of slope,aspect and altitude were recorded.Based on the R boxplot function,the box plot was drawn to analyze the influence of site conditions on the biomass of each part,and the nonparametric multivariate ANOVA was selected to determine that the site conditions with significant influence on the biomass of each part were dumb variables,and the logistic equation was used to construct a regression model to describe the dynamic change of total biomass under the influence of site factors and their interactions.The study yielded the following results:(1)The biomass of each part of the Caragana korshinskii strip decreases when the slope increases,the biomass of the shady slope is greater than that of the sunny slope,and the biomass of each part decreases when the altitude increases.(2)The basic model was based on the highest fitting accuracy of total biomass(adj-R2=0.8258)and the lowest fitting accuracy of leaf biomass(adj-R2=0.4).(3)The results of nonparametric multivariate ANOVA showed that slope and aspect had significant effects on the biomass of all parts of the lemon strip(P<0.05),while the influence of altitude on the biomass of each part was not significant(P>0.05).(4)The interaction between slope,aspect and slope aspect affected the three dumb variables to establish a dumb variable model,and the non-convergent model was eliminated,the total biomass dumb variable model performed best with equation t9(adj-R2=0.8875),the aboveground biomass dumb variable model performed best with equation a9(adj-R2=0.8783),and the stem biomass dumb variable model performed best with equation s10(adj-R2=0.8805),The root biomass dumb variable model performed best with equation r8(adj-R2=0.8432),and leaf biomass with equation f4(adj-R2=0.5166).In this study,the dynamic model of site factors and their interactions was established,which could provide a basis for predicting the biomass of lemon shrubs in this area.