Estimation of soil carbon sequestration in steppic rangelands (Case study: steppe rangeland Rudshur, Saveh)

Increasing disorder in natural ecosystems has increased from growing the amount of carbon dioxide since the industrial revolution until now. Soil, is one of the main sources of stored carbon in hemisphere, and has an important role for balancing and sequestration of carbon dioxide. Considering the vast steppic areas of Iran, studying of carbon sequestration rate is important in these ecosystems. The steppic rangelands of Rudshur were selected as study area. Three treatments including long-term exclosure, medium-term exclosure, and grazed area were selected. Soil sampling was carried out from 0-30 cm depth of plant baseline and inter-distance between plants. Sixty soil samples were collected in each site. Soil samples were air dried and sieved (2 mm).. Measuring of inorganic carbon was done using Walkley-Black method. The results showed that the amount of carbon sequestration in plants vicinity and plants parts had significant differences (P<0.05). The results indicated that inorganic carbon around plants was more than bare soil area between plants in exclosures but it was reverse in the grazed sites. The average carbon sequestration in the medium-term exclosure was 22.45 ton/ha and it had significant differences with long-term exclosure (17.76 ton/ha) and grazed area (18.5 ton/ha) sites.