Soil carbon sequestration compression in plantations with different species in Makhmalkooh forest park. khoramabad-Lorestan

The aim of this study is to investigate and to compare soil carbon sequestration in broad leaves and needle leaves afforestation stands in Makhmalkooh forest park in Khoramabad. Soil samples were taken from depth 0-5 and 5-15 cm in each type and some soil properties such as pH, organic carbon, and texture were analyzed. In each depth, soil organic carbon were measured and the amount of carbon sequestration were computed and compared for each types. The results showed that broad leaves species, ash, redbuds, olive, Persian oak resulted to more soil carbon sequestration compared to needle leaves, Turkish red pine, Mediterranean cypress. Also in unplanted area close to plantation the amount of soil carbon sequestration was significantly higher than other plantation types in the 0-5 cm depth and in the 5-15 cm depth, Persian oak and Turkish red pine had the highest and lowest amount of carbon sequestration respectively. While it is expected that needle leaves with higher growth rate and leaf area, result to more soil carbon sequestration, in short time the slow rate of coniferous litter decomposition result to less soil carbon sequestration in needle leaves stands compared to broad leaves stands. The pattern of organic carbon sequestration in afforested stands less than 20 years is decreasing, while after 20 years it follows an increasing trend. It is concluded that broad leaves trees show more effects on soil organic carbon than needle leaves trees but more effects on soil organic carbon can be seen at older stands.