Investigation of Basal Area, Volume and Carbon Sequestration Allometric Models according to independent variable of Age in Populus deltoides Plantation

Populus deltuides is one of the most important economically (wood production), environmentally (biomass production and carbon sequestration) and fast growing species in plantations. Therefore, the purpose of this study was to investigate basal arae, volume and carbon sequestration allometric models according to the age using stem analysis method in ۹ parcel of poplar plantations in Shaft County, Guilan province. Measurement features included diameter at breast height and total height of all trees in two ۱-hectare plots area. Then, ۳۰ trees were randomly selected in different diameter classes, fell down and the discs were obtained in order to stem analysis. The annual rings of discs counted, age at different tree heights obtained, and the annual rings diameter were measured to determine annual diameter and volume growth. Carbon measurement, volume measurement of wood, volume conversion to weight ratio were calculated. Finally, regression analysis performed by the relationship between volume and basal area by age based on the highest coefficient of determination and minimum standard error. The results showed that the highest stands volume occurred in ۲۹ years, the highest annual volume increment at ۹ years and the highest carbon storage at ۲۹ years in the stand with ۱۴۵ trees per hectare, respectively. The model of basal area was BA = abtxo with adjusted coefficient of determination of ۰.۹۹ (R۲=۰.۹۹) and SD= ۰.۱۷, the model of volume was V = atbt۶, (R۲=۰.۹۹) and SD= ۴.۰۶ and carbon sequestration model was C = abft with adjusted coefficient ۱+ct+dt۲ of determination of ۰.۹۹ and SD= ۰.۵۴. The nonlinear models were able to show the highest coefficient of determination (R۲۰.۹۹) and the least standard error of the relationship between these characteristics.

کلیدواژه ها:

Allometric models ، Carbon storage ، Plantation ، Populus deltoides ، Stem analysis