Effect of exclusion on carbon sequestration potential of Halocnemum strobilaceum and Halostachys caspica (Case study: Gomishan rangelands)

Range management to develop the shrub species in arid and semi arid rangelands is one of the inexpensive and multi-purpose methods to decrease CO2. Rangelands exclusion is one of the most simple and inexpensive methods of range management. In this study، in order to investigate the effect of exclusion in rangelands on carbon sequestration potential of shrub species، two key areas were selected within and outside in the excluded area in Gomishan rangelands. After determining the key area، dominant species of halophyte shrubs Halocnemum strobilaceum and Halostachys caspica in both excluded and control area were selected. In both areas، the amount of aboveground and underground biomass of the species were estimated by determining the weight of stand biomass. Ash method was used to determine carbon sequestration coefficient of the studied species. Comparing amount of carbon sequestration in biomass of studied species in excluded area with their same biomass in control area showed no significant difference between carbon sequestration of same biomass (p<0. 05). Moreover the comparison of carbon sequestration of studied species in the unit of the measuring surface in both excluded and control areas showed the difference of this ability between two areas (p<0. 01). The result of this research shows that in spite of the different responses of carbon sequestration of the studied species to the exclusion، in general، there is no significant difference between carbon sequestration in the unit of the measuring surface by standing biomass of studied species in excluded rangeland with the average of 49. 142 kg/ha and control area with the average of 49. 194 kg/ha.