مشخصات پژوهش

عنوان	Estimating Leaf Biomass of Pollarded Lebanon Oak in open Silvopastoral Systems Using Allometric Equations
نوع پژوهش	مقاله چاپ‌شده در مجلات علمی
کلیدواژه‌ها	Fodder trees, northern Zagros, pollarding, Quercus libani
چکیده	The aim of this study is to develop allometric equations to estimate leaf biomass of pollarded Lebanon oak trees, a species used as fodder tree in western Iran. A pollarded stand (6.6 ha in area including 560 Lebanon oak trees) was selected. Full callipering of all trees (collar diameter ≤ 5 cm) was conducted: collar diameter and diameter at breast height of stem, tree height, trunk height, and crown diameters were measured. At the time of pollarding, the crowns were divided into three layers (i.e. upper, middle and lower) and the fresh weight of leafy branches resulting from pollarding of each layer was measured separately. Finally, dry weight of leaf biomass for different crown layers was determined. Biometric indices as predictor variables for estimating dry weight of leaf biomass were used. Multiple linear regression based on the crown diameter and diameter at breast height produced the more parsimonious models. The results indicated that natural logarithmic transformation of dry weight of leaf biomass improved the model’s goodness of fit. Providing separate equations to estimate leaf biomass of crown layers does not improve the results. The moderate accuracy of the proposed allometric equation is explained by the scattered distribution of the trees and the strong modification of canopy structure through periodical pollarding. Leaf biomass estimate is used to evaluate the impact of pollarding on nutrient cycling and carbon sequestration in forest.
پژوهشگران	ژراردو مورنو (نفر پنجم)، شیدا خسروی (نفر چهارم)، فرناندو پولیدو (نفر سوم)، لقمان قهرمانی (نفر دوم)، سیما شهاب الدینی (نفر اول)