Effects of land use change on soil carbon sequestration and emissions (case study: arid rangelands of Eivanakei, Semnan province)

Due to the notable role of different land uses in carbon sequestration and emission، four treatments including rangeland as control، Haloxylon plantation area، Olea plantation (olive garden)، and Residential lands، were selected to study the effects of land use change on soil carbon sequestration and emissions in Eivanakei rangelands، Semnan province. Carbon stocks in vegetation and soil of each treatment were measured and the results showed that the conversion of rangelands to plant cultivation will increase the carbon stocks in vegetal parts of ecosystem. Residential Land soil carbon content is fewer than control، but olive garden and Haloxylon planted area is not significantly different from control. On the other hand، the highest annual carbon emission was observed in residential area (4526 kg/ ha/year) and the lowest in Haloxylon plantation (1606 kg/ ha/year). Most of the carbon emission from soil has occurred in August (3. 32 g C/m2/day) in residential areas and the lowest in February in Haloxylon plantation (0. 05 g C/m2/day). According to the results of carbon sequestration and emission in​​ the study area، it is recommended to exert minimal intervention and manipulation in natural regimes during the rehabilitation projects; also proportional to the rate of increase in carbon emissions resulting from change of rangelands to residential areas، establishment of permanent sustainable and indigenous vegetation should be prioritized