title: Growth parameters of Pinus nigra J.F. Arnold and Picea abies (L.) H. Karst. plantations and their impact on understory woody plants in above-timberline mountain areas in the north of Iran
abstract: We investigated the growth parameters of 20-year-old plantations of Pinus nigra J.F. Arnold and Picea abies (Linnaeus) H. Karsten and their impact on understory woody plants and we compared them with a natural stand in above-timberline mountain areas. 30 sample plots (each of 400 m2 in area) were systematically established on each site. Tree height, DBH, collar diameter, crown diameter and crown length of all trees were measured in each sample plot. The results of the diameter growth analysis of
journal: Journal of Forest Science