Assessment of Soil Organic Carbon and Nutrient Stocks Along a Degradation Gradient in Semi-Arid Grasslands

DOI

10.2991/978-94-6463-837-0_6How to use a DOI?

Keywords

carbon stock; nitrogen stock; available stock; degradation level; dry steppe

Abstract

The dry steppe region of Mongolia, characterized by semi-arid climate and sparse vegetation, plays a crucial role in regional carbon cycling and ecosystem resilience. Despite its vast extent, limited data are available on soil organic carbon (SOC) dynamics and the carbon-to-nitrogen (C:N) ratio as indicators of soil health and nutrient status. This study assesses spatial variability in soil organic carbon (SOC) and nutrient stocks and C:N ratios across representative dry steppe grassland dominated by Stipa grandis and Stipa baicalensis in eastern Mongolia. This study examined the vertical distribution of soil pH, soil organic carbon (SOC), total nitrogen (TN), available phosphorus, bulk density (BD), soil moisture, and associated carbon, nitrogen and available stocks across five representative dry steppe sites. Results reveal that SOC and total nitrogen stocks in the upper 30 cm of soil range from 11.2 to 65.6 t C ha⁻1, and from 1.02 to 6.01 t C ha⁻1 with higher values associated with finer-textured soils and better vegetative cover. The C:N ratio varied from 6.43 to 18.8, reflecting differnet stages of organic matter decomposition and nitrogen availability. Sites experiencing moderate grazing pressure maintained relatively stable SOC levels and balanced C:N ratios, while heavily grazed areas showed reduced carbon stocks and narrower C:N ratios, suggesting nitrogen enrichment through biomass degradation. These findings highlight the importance of grazing management and land-use practices in maintaining soil carbon pools in dry steppe ecosystems. The C:N ratio serves as a useful metric for assessing soil organic matter quality and potential for carbon sequestration. Understanding these dynamics is critical for regional climate mitigation strategies and sustainable rangeland management in semi-arid landscapes.

Copyright

© 2025 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Khulan Nyamsanjaa
AU  - Tuvshintogtokh Indree
AU  - Batzaya Gachmaa
AU  - Lyankhua Bayasgalankhuu
AU  - Nyambayar Nyamjantsan
AU  - Sukhbat Altangerel
AU  - Buyan-Undrakh Battushig
PY  - 2025
DA  - 2025/09/17
TI  - Assessment of Soil Organic Carbon and Nutrient Stocks Along a Degradation Gradient in Semi-Arid Grasslands
BT  - Proceedings of the International Biological Conference in Mongolia 2025 (IBCM 2025)
PB  - Atlantis Press
SP  - 77
EP  - 90
SN  - 2468-5747
UR  - https://doi.org/10.2991/978-94-6463-837-0_6
DO  - 10.2991/978-94-6463-837-0_6
ID  - Nyamsanjaa2025
ER  -