The Impact of Some Environmental Factors on the Seed Productivity of Stone Pine (Pinus pinea L.) in Different Forest Sites in Northwest Syria

Abstract

The study was carried out in 5 different forest sites in terms of age and environmental conditions in northweste Syria: Mohambel, Maryameen, Wadi Haj Khaled, Ain Jroun, Sheikh Sayyah, in successive ages (35, 19, 34, 47,25) years, Density: 400, 467, 200, 288, 517 trees/ha, with the aim of identifying the factors affecting the productivity of pine tree from seed pulp. The productivity of the tree reached 96.97, 75.02, 78.85, 41.53, 35.37 gr. in those sites respectively, and the productivity of the hectare reached 38.8, 35.1, 15.8, 21.5, 10.2 kg respectively. It was found that productivity is related to the type of soil, as the loamy clay soils with high organic material and potassium content and low calcium carbonate content (Mohambel and Maryameen) are the most suitable for the growth and productivity of the stone pine. As for the climate, the tree gives abundant yields in the semi-humid fresh bioclimatic structures as in the Mohambel site (P=561.7 mm), and the seed yield is affected by the tree density of the site, which was directly proportional to it, which reached 400 trees/ha as in the Mohambel site, provided that the soil is suitable for growth. It was found that there is a close relationship between pulp productivity and the average crown diameter, as this was clear in the site of Mohambel with an average crown diameter of 6.21 m, followed by the site of Maryameen with 4.88 m, then the site of Wadi Haj Khaled with 4.63 m. As for the two least productive sites (Sheikh Sayyah, Ain Jroun), the average crown diameter for them was 3.91 m and 3.59 m, respectively