Estimating biomass of loblolly pine (Pinus taeda L.) using allometric equations (Case study: plantations of Chobar-Shaft, Guilan)

The aim of this study was to estimate the biomas of loblolly pine (Pinus taeda L.) using allometry method in compartment 10 of Chobar-Shaft plantation with an area of 61 ha. For this purpose, 30 circular sample plots, each 500 m2 were established. In each sample plot, the diameter of the stump, diameter at breast height (D.B.H), crown width and height of all trees were measured. Totally, 12 trees in different diameter classes were selected and cut about 10 cm above the ground. Fresh weight of different sections of trees was measured. Samples of each section were transferred to the laboratory and get dried in oven and percentage of dry weight was calculated. Modeling of biomass and independent variables was performed using non-linear regression. Normal distribution of data was assessed by Kolmogorov-Smirnov test. For accessing the best result, several models were tested. The results showed that the model of E(YT) = 0/045D2 H0/864 was the best model for estimation of total tree biomass (R2 = 0.952). Results of our research confirmed the value of allometric equations for estimating of stand biomass.