Estimation of Soil Carbon Sequestration Rate in Steppes (Case Study: Saveh Rudshur Steppes)

Since Renaissance, the natural ecosystems have fallen into a complete state of disarray due to the rise in the amount of carbon dioxide. Soil, the unsparing stuff, is one of the major sources of carbon storage, and plays a paramount role in the global equilibrium of carbon as well as carbon sequestration. Given that Iran is benefiting from vast steppes, the rate of carbon sequestration in them deserves attention. In order to estimate the soil carbon sequestration, the Saveh Rudshur steppes were selected and placed into three treatments: long-term exclosure, medium-term exclosure and grazing rangelands. The soil sampling was conducted at the depth of 0-30 cm under the plants and between the plants. As many as 60 soil samples on each area and 180 soil samples in total were taken. The sampled soils were dried out in the open air and sifted through a sieve of 2mm meshes in the laboratory. The soil organic carbon was measured using the Walkley-Black method. The findings indicated that there was a significant difference between the amount of the soil organic carbon under the plants and the carbon between the plants on each area separately (P0.05). The results also showed that the amount of organic carbon under the plants is greater than that between them in the treated exclosures while the grazing areas proved a different result. It can be seen from the mean of the total carbon sequestration that there is also a statistically significant difference between the medium-term exclosure with a mean of 22.45 ton/ha and the long-term exclosure with a mean of 17.76 ton/ha and the grazing rangelands with a mean of 18.50 ton/ha.