Study on Aboveground Biomass and Model of Rosa omeiensi in Dry Valley of the Minjiang River

Vegetation restoration is very difficult in the dry valley of the Minjiang River. Research on the biomass and model of Rosa omeiensis can provide scientific theoretical basis for vegetation protection and restoration in the dry valley of the Minjiang River. The results showed that: (1) Regardless of the slopes, the biomass distribution of different organs of Rosa omeiensis with different diameters was in the order: dry biomass > branch biomass > bark biomass > leaf biomass. The main stem with the largest proportion contributed greatly to the total aboveground biomass. (2) The ratio of aboveground biomass to fresh weight of Rosa omeiensis plants in the middle slope position was the lowest, which indicated that the growth of Rosa omeiensis plants was affected by the low soil moisture content in the middle slope position in this area, and the degree of lignification was low. Under the same fresh weight, the aboveground biomass was significantly lower than other slope positions. (3) The crown width (C), basal diameter (D) and tree height (H) were all independent variables closely related to shrub biomass. The screening results of Rosa omeiensis biomass estimation model showed that both power function model and triple polynomial model had satisfactory correlation coefficient values. The optimal model was mostly the cubic polynomial, because the R² value of cubic polynomial model was higher. Considering the different shrub morphology, the independent variable factors should be selected according to the actual conditions.