Evaluation of Enclosure Effects on Soil Carbon Storage (Case Study: Rangeland of Shahtappeh-Chah Mahmood and Chiro in Semnan Province)

Abstract

Livestock grazing is one of the most important kinds of land usage that has a high potential to decrease or increase carbon storage in rangeland ecosystem. This research was investigated the effects of enclosure on soil carbon storage in a rangeland with dominant plants of Artemisia aucheri. Hence, two rangelands of enclosure (Shahtappeh-Chah Mahmood) and no enclosure (Chiro) were chosen in Semnan province, Iran. For soil sampling, 20 plots of 1x1 m2 along with two vertical transects with 100 m length were used in each region. Then, two profiles were dug in 0-15 and 15-30 cm depths in soil of baseline and inter-path of plants in each plot. Data were collected for pH, EC, CaCO3, saturation moisture, soil texture, organic carbon (OC%) and s organic matter (OM%), Soil bulk density and Soil carbon storage and the mean was compared by t-test. The results showed that there was a significant difference (P<0.05) between OC% and OM% of baseline in enclosure and no enclosure rangeland. Soil OC% and OM% in baseline in the first depth was more than the second depth in two study areas. There was a significant difference (P<0.05) between soil OC% and OM% in baseline and inter-path of plants in two depths of enclosure and no enclosure rangelands. Soil bulk density (gr/ha) in baseline and inter-path of plants in 15-30 cm was more than 0-15 cm. In enclosure and no enclosure rangelands, grazing had no significant effects on soil organic carbon storage of baseline in each depth. So, the total carbon in 0-30 cm in each region was 47.46 and 40.85 ton/ha, respectively. There was a significant difference between carbon storage of baseline and inter-path of plants (P<0.05) in two depths in enclosure and control rangelands. It was concluded that higher carbon sequestration occurs in the soil, the soil biological and mechanical activities can increase.