Vol.:(0123456789) 1 3 Trees DOI 10.1007/s00468-017-1614-7 ORIGINAL ARTICLE Estimating leaf biomass of pollarded lebanon oak in open silvopastoral systems using allometric equations Sima Shahabedini 1  · Loghman Ghahramany 2  · Fernando Pulido 3  · Sheyda Khosravi 4  · Gerardo Moreno 3   Received: 23 March 2017 / Accepted: 6 September 2017 © Springer-Verlag GmbH Germany 2017 indices as predictor variables for estimating dry weight of leaf biomass were used. Multiple linear regression based on CD and stem DBH produced the more parsimonious model. The results indicated that natural logarithmic transforma- tion of dry weight of leaf biomass improved the model’s goodness of ft. The moderate accuracy of the proposed allo- metric equation is explained by the scattered distribution of the trees and the strong modifcation 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. Keywords Fodder trees · Northern Zagros · Pollarding · Quercus libani Introduction Biomass of different parts of standing trees, which is dependent on site characteristics and tree attributes, is dif- fcult to predict (Lehtonen 2005). While there is abundant scientifc literature on the quick estimation of timber and wood biomass (i.e., the world’s most common forest prod- ucts), scientifc knowledge for the estimation of leaf biomass is still poor. Since direct measurement of leaf biomass is impractical, leaf biomass estimation using non-destructive techniques requires development of allometric equations based on predictor variables such as biometric indices which can be easily measured. Accurate estimates of leaf biomass are essential because it indicates the production capacity of forest per unit area or time and can be used as an indicator of site productivity, both biological and economic. Estimates of leaf biomass allow the quantifcation of forest resources such as availability of wood fuel and tree fodder. In addition, Abstract Key message Multiple linear regression based on the crown diameter (the most explicative biometric variable for pollarded trees) and diameter at breast height indices produced the more parsimonious model with moderate accuracy to estimate leaf biomass used to feed livestock in strongly seasonal silvopastures. Abstract The aim of this study is to develop allometric equation 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 diam- eter ≥5 cm) was conducted: collar diameter and diameter at breast height (DBH) of stem, tree height, trunk height, and crown diameters (CDs) were measured. At the time of pol- larding, the fresh weight of leafy branches resulting from pollarding of each tree was measured. Finally, dry weight of leaf biomass for entire crown was determined. Biometric Communicated by E. Priesack. Electronic supplementary material The online version of this article (doi:10.1007/s00468-017-1614-7) contains supplementary material, which is available to authorized users. * Loghman Ghahramany l.ghahramany@uok.ac.ir 1 Faculty of Natural Resources, University of Kurdistan, Sanandaj, Iran 2 Department of Forestry, The Center for Research and Development of Northern Zagros Forestry, University of Kurdistan, Sanandaj, Iran 3 Institute for Dehesa Research, University of Extremadura, Plasencia, Spain 4 Lorestan University, Khorramabad, Iran