Comparison of Quantitative, Qualitative and Soil of Chestnut-leaved Oak and Loblolly Pine plantations of Shen-Rood Watershed No: 25 of Guilan Province

Investigating the growth and production of afforestation's is effective to improve the management of these stands and the prosperity of the future afforestation's. Natural forests' rest plan has attracted the attention of forest specialists and beneficiary's towards the forest plantations. The present study carried out in order to investigate the specification of 32-year-old loblolly pine (Pinus taeda L.) and Chestnut-leaved oak (Quercus castaneifolia C. A. Mey.) plantations in Shen-Rood Watershed No: 25 of Guilan province. In each region, 5 sample plots with 4r area in the form of systematic method with 100×500m Network Dimensions conducted in the study area. Then trees diameter, total height, trunk height and some qualitative characteristics of the trees, including the crown symmetry, forking and curvature of the trunk were recorded in each plot. Also, five soil samples were taken from four quadrants and center of each plot from 0 to 30 cm depth, then combined and transferred to the laboratory in order to investigate the properties of the soil. The results indicated insignificant difference between the quantitative characteristics of two stands, such as mean height, basal area, volume and slenderness coefficient. However, the mean length of the branchless trunk of loblolly pine stand (11.33 m) was higher than Caucasian oak (6.6 m). Also, it was no significant differences between two stands in terms of symmetry. However, the pine stand trees had a less curvature (14%) and forking (16%) than it in Chestnut-leaved oak stand (35% and 37% respectively). Investigation of soil samples showed that there is no significant difference between two stands in about sand, particle and bulk density and carbon percentage but clay and silt (42.28% and 26.29%), Microbial respiration (1.86 gram carbon dioxide in soil per day), pH (5.71), porosity (21%) and Soil saturated water content (37.95%) had a significant difference with the Chestnut-leaved oak mass (25.09, 48.70, 2/79, 29, 6.31 and 18.33). Finally, considering the similarity of other conditions, soil texture reported as the main limiting factor of loblolly pine growth. Therefore, planting of the Pinus taeda species is recommended in order to gain more volume production in moderate, lightweight and appropriate drainage areas and planting the Quercus castaneifolia is recommended for revitalization of damaged and ruined areas.