Afforestation of semi-arid regions of Mongolia: carbon sequestration in trees and increase of soil organic carbon

Abstract

This work examines the variation of carbon sequestration (considered as the sum of above- and below-ground plant biomass production added to soil organic carbon) occurring in two sites (named respectively BN and ER) characterized by a semi-arid climate after planting three tree species (Populus sibirica, Ulmus pumila, and Hippophae rhamnoides). Soil organic carbon (SOC) was analyzed at four different depths (from 0–60 cm). In these two sites, the three tree species contributed differently to carbon sequestration. We found that above-ground plant biomass (leaf, branch, stem) was higher at the BN site whereas at the ER site prevailed below-ground biomass. That is probably due to the low tree density in BN site and the higher soil moisture content present in ER site. Among the three tree species considered, P. sibirica showed the highest biomass value. The SOC values were highest in the topsoil layer (0-40 cm) and decreased with depth. This works clearly shows that in semi-arid lands carbon sequestration depends on the environmental factors that characterize the site, the tree density, and the tree species selected.

Keywords:

• afforestation
• semi-arid
• biomass
• soil organic carbon
• Mongolia

Acknowledgements

The authors gratefully thank the staff of the “Green Asia network” INGO and members of the Laboratory of Forest Genetics and Ecophysiology, at the National University of Mongolia for their assistance in the laboratory and field works.

Author contributions

BN-O and TA conceived the research project. BN-O provided primary funding. BN-O, S-OB, and TA developed the study plan. BN-O and S-OB dealt with the methodological approach and equally contributed to data interpretation. TA, S-OB, BG and BN-O were responsible for field excavation and data collection. S-OB and KS performed the data analysis. TA, S-OB and KS prepared the original draft. DC, GS and BN-O wrote the manuscript and dealt with the revision process and finalization. DC and BN-O edited and revised the manuscript. All authors contributed to the article and approved the submitted version.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Additional information

Funding

This work was financially supported by the Fellowship Grant by “Green Asia network” INGO.