Evidence for relationship between carbon storage and surface cover characteristics of soil in rangelands

Abstract

Carbon storage (CS) and consequently carbon sequestration by plants is the most natural and least expensive method for atmospheric CO2 mitigation. Areas with high CS potential should be identified, maintained and subject to investment. CS depends strongly on status of vegetation and soil surface cover characteristics. Therefore, the objectives of the present study was an assessment of the relationship between aridisols CS and characteristics of soil cover in some plant types in western rangelands of Isfahan in Iran. Three different plant types including Scariola orientalis-Astragalus gossypinus, Hordeum fragile-Astragalus gossypinus and Cousinia bachtiarica-Astragalus gossypinus were identified. Then, some sampling plots were placed along the four transects in each plant type, which were placed obliquely to the general and the lateral slope of the region. Plants' characteristics and soil surface characteristics were recorded. The soil samples were taken along transects at depths of 0–20 and 20–75 cm. Soil samples were transferred to the soil laboratory and analysed. The results demonstrated that the soil carbon storge (SCS) is different between three plant types. SCS in Sc. or-As. go, Ho.fr-As. go and Co. ba-As.go plant types were 340, 182 and 173 kg/ha, respectivly. Moreover, there was a positive and significant relationship (R2 = 0.88|0.42, p < 0.01) between coverage and density of shrubby species and soil surface gravel with amount of CS.