Determination of carbon sequestration potential in different range planting methods in different geographical areas of country

     This research was conducted to evaluate the potential of different rangeland planting practices for carbon sequestration in various climatic and geographical regions of the country. For this purpose, the key sites of rangeland planting practices were selected in the Lorestan, Fars, Kermanshah, Khorasan Razavi, Mazandaran, Kordestan, Kerman, Markazi, and Esfahan. Then, the characteristics of the sites selected were recorded and sampling of soil, aerial biomass, and root was performed in a random-systematic manner. The results showed that rangeland planting practices in the semi-arid forests of central Zagros slopes had the highest carbon sequestration capacity. The seeding and pit-seeding of perennial legumes and grasses such as festuca, alfalfa, sainfoin and onobrichis could sequester up to 17.4 to 80 tons of carbon per hectare. The contribution of soil in carbon sequestration was at least 93 percent of the total carbon stock of the study area. Rangeland planting practices together with exclosure caused to increased carbon sequestration up to two times. In these areas, pit-seeding was more successful than the other practices. In the Hyrcanian regions, the seeding of perennial legumes and grasses could sequester 18 tons carbon, ranked second after range planting practices in the central Zagros slopes. Rangeland planting practices in arid and semi-arid areas of the central and the eastern part of the country showed little effect on increasing the carbon sequestration capacity compared to other areas mentioned above. The highest carbon sequestration was recorded to be 5.63 and 6.51 tons carbon per hectare for the exclosure rangelands in Kardeh and Shamsabad watershed, respectively. Land use change from dry farming to rangeland in Kardeh watershed resulted in carbon sequestration of 4.7 tons per hectare.