Estimation of stem biomass of Pupulus. caspica and Pupulus. alba 57.58 seedlings based on allometric relations (Case study: Chamestan, Noor)

Today, the use of allometric relations for easy, non-destructive, low cost and fast estimation of tree biomass is widely used. The aim of this study was to estimate the stem biomass of Pupulus. caspica and Pupulus. alba 57.58 seedlings. First, 45 cuttings from both fast-growing tree species were selected and planted in a randomized complete block design with three replications in the lands of Chamestan Forest Research and Rangeland Research Station. At the end of the growing season, stem height, collar diameter and stem weight of each rootstock were measured and then, allometric relations were calculated using regression models including power, logarithmic, exponential and linear models. The significance of allometric models was evaluated by regression analyses of variance and among the significant models, the model with higher determination coefficient (R2) was selected. The results showed that the collar diameter presents significant models with high coefficient of determination, but models based on height variable were not significant. For Pupulus. caspica species, logarithmic model based on collar diameter variable (R2=0.99) and for Pupulus. alba 57/57 species, power model based on collar diameter variable (R2=1) were recognized as the best models. The results showed that diameter is an appropriate estimator in terms of determination coefficient for estimating biomass of small-diameter trees in two studied species.