Effect of Site on Soil Properties and Carbon Sequestration in Populus deltoids Stand in Sari

Climate change and global warming is one of the major challenges in the context of sustainable development, which is due to increasing concentrations of greenhouse gases, especially carbon dioxide. Afforestation is one of the practical and simple ways to reduce atmospheric carbon dioxide and increase carbon uptake in the soil. Therefore, the purpose of this study was to investigate the trend of soil carbon sequestration in Populus deltoides plantation located on different elevation classes.

Three sites (Mahdasht, Pahnekola and NaghibdehMazde) were selected at elevations between 150 to 1200 m in Sari city. Quantitative variables including diameter at breast height, total height, basal area of all trees with a diameter more than 7.5 cm were recorded (full inventory method). Ten soil samples were taken at a depth of 0-10 cm in each site using the core method in order to study soil physical (moisture, texture and bulk density) and chemical properties (pH, EC, nitrogen, phosphorus, potassium and organic carbon).

The highest diameter (27.83 cm), height (21.13 m), basal area (0.046 m2) and volume (2.11 m3) was observed in Mahdasht and the lowest values ​​were observed in Pahnekola. The lowest amount of pH (6.26±0.04), EC (0.3±0.01 ds/m), total nitrogen (0.11±0.01 %), potassium (169.49±25.00 mg/kg) and organic carbon (1.43±0.06 %) were observed in NaghibdehMazde (highest altitude). The highest and lowest rate of carbon sequestration was observed in Mahdasht (lowest altitude) and NaghibdehMazde (highest altitude), respectively. In general, in lower altitudes, poplar trees had a much better diameter growth than higher altitudes.

According to results, it can be stated that planting Populus deltoides in lower altitudes can be a suitable approach to reduce the concentration of atmospheric carbon dioxid.