Soil physico-chemical properties 20 years after plantation in the Iranian northern ‎forests (Emphasizing on carbon and nitrogen stocks in plantation with broadleaved and ‎coniferous species)‎

This study was conducted to determine carbon and soil nitrogen stocks in five plantations with broadleaved stands including oak, alder, maple and poplar species and a cypress conifer stand in Tajan watershed in Mazandaran province (Sari city). In order to study soil physico-chemical properties, soil samples were taken at a depth of 10 cm in each stand. Soil characteristics including texture, soil acidity, bulk density, electrical conductivity, total nitrogen, organic carbon was measured. The results showed that tree species affect the physicochemical properties of the soil. The highest carbon storage was observed in alder (64/61 ton/ha) and the lowest carbon storage in poplar (26/76 ton/ha). Nitrogen stock had the highest (2/68 ton/ha) and the lowest (1/17 ton/ha) in alder stand. Overall, the results showed that carbon and soil nitrogen storage are as an added value with other values ​​and benefits of forest ecosystems and as an indicator for assessing ecosystem sustainability. Based on plantation and reforestation must be done with broadleaf species that have high potential for atmospheric carbon storage.