Capability of haloxylon in carbon sequestration in sand dunes of Sabzevar

Soil is known as a suitable reservoir for carbon sequestration. The objective of this study was to investigate the capability of haloxylon on sequestration of carbon in sand dunes of Yahya Abad, Sabzevar, in northeastern Iran. Eighty soil samples were taken from two depths of 0-5 and 5-10 cm under and between haloxylon trees. Eight soil profiles under and between haloxylon trees were described and sampled to explore subsurface variations of soil organic carbon (SOC). The results showed that SOC in 0-5 cm has increased from 0.18% in between trees to 0.79% under trees and similarly, in 5-10 cm has increased from 0.11 to 0.29%. SOC has decreased exponentially with increasing depth. A strong correlation was found between soil organic carbon and electrical conductivity in 0-10 cm depth due to accumulation of salts in haloxylon litters that has increased both SOC and electrical conductivity of surface soil. The SOC storage under and between haloxylon trees at 0-100 cm depth were estimated 27718 kg ha-1 and 14915 kg ha 1 respectively, that diferenemnce of these values represents carbon sequestration. The amount of carbon sequestration to depth of 10 and 40 cm was 5367 and 10155 kg ha-1 that is 36 and 68% of total carbon sequestration. The results of this study confirmed the importance of haloxylon in carbon sequestration in desert environments.