An investigation on Picea abies (L) Karst growth rate in Guilan afforestations.

Abstract

Norway spruce (Piceae abies L. Karst.) has been planted on a wide range of world. It is generally pyramidal in shape and can grow to 40 m in height and to 1-1.5 m in diameter. Norway spruce has apoor reputation for wind firmness. It is a shallow rooting species on sites with a high fluctuating ground water table or on soils where the effective rooting depth is limited. This study was carried out during 2001-2002 in four sites of Guilan Forests. These sites were Aroston, Rec, Picehson and Shenrud. The primary distance between the trees was 2×2 m. The stands age in Shenrud and the other sites was 17 and 27 years, respectively. The investigated growth parameters were; Survival %, mean height, mean D.B.H., density per hectar, basal area per hectar, annual growth rate of diameter, annual growth rate of height, dominant height, number of diameter classes per hectar, annual growth rate of tree volume, stand volume per hectar, volume table (tarif), form factor (f), relationship between quantitative parameters (diameter to height and diameter to volume) and stand qualitative parameters (natural pruning, stem condition and branch angle). The wood mechanical characteristics (density and fibre length) and the stand pests and diseases were investigated as well. In order to study the effects of Picea plantation on soil characteristics, soil samples were tested physicaly and chemicaly and the data of the two sites were compared. The results showed that Aroston site was the best one due to its greatest survival (70%), growth rate (basal area: 37 m2, Volume: 301.25 m3/ha, annual volume growth; 11.1 m3/ha) and wood quality (tracheid length: 2.89 mm and specific gravity: 0.36 g/cm')

Keywords

• Norway spruce
• growth
• afforestation
• Guilan