Identifying Carbon Sequestration Hotspots in Semiarid Rangelands (Case Study: Baghbazm Region of Bardsir City, Kerman Province)

Carbon sequestration in rangeland ecosystems has been identified as a suitable strategy to offset greenhouse gas emissions and information on carbon sequestration hotspots is a good tool to improve rangeland management. Objectives for this study were to assessment potential carbon sequestration in various rangeland types, to identify carbon sequestration hotspots and to study the effective factor on hotspots in semiarid rangeland of Kerman province. The content of above and underground biomass and litter carbon by Ash method and soil carbon by Walcky-Black method were determined in 300 plots 2m×2m scattered randomly in rangeland types in 2014. Results showed that rangeland types had significant effect on carbon sequestration as Zygophyllum eurypterum-Artemisia sieberi, Artemisia sieberi-Pteropyrum aucheri, Astragalus microcephalus –Stipa barbata, Artemisa sieberi and Artemisia sieberi- Salsola brachiata respectively with 65.84, 53.92, 43.32, 33.17 and 24.77 (T/ha) regarding the highest and lowest carbon sequestration amounts. Carbon sequestration hotspots and coldspots were mapped by using hotspots analysis. Zygophyllum eurypterum-Artemisia sieberi and small parts of both types Artemisia sieberi-Pteropyrum aucheri and Astragalus microcephalus–Stipa barbata with 65.34 (T/ha) were carbon sequestration hotspots. Majority of Artemisia sieberi-Salsola brachiata and small parts of Artemisa sieberi with 23.78 (T/ha) included carbon sequestration coldspots. PCA analysis also showed that life form, clay and vegetation cover were the most important factors influencing on the hotspots. It was concluded that soil characters also play effective roles to stock carbon in semiarid rangeland ecosystems although rangeland types demined with Phanerophyte species had a greater probability of being identified as carbon sequestration hotspots.