Shuitu Baochi Xuebao (Aug 2024)
Preliminary Estimation of Soil Carbon Sequestration Benefits of Terrace Construction on the Loess Plateau In the Past Nearly 40 Years
Abstract
[Objective] The aim of this study is to reveal the spatiotemporal patterns of soil organic carbon (SOC) content in terraced fields on the Loess Plateau and investigate the spatiotemporal distribution characteristics of soil carbon sequestration in these terraced fields. [Methods] Using the META analysis method, the variations characteristics of SOC content in terraced soil with soil depth and years of terraced construction were studied, and analyzed the spatiotemporal distribution features of soil carbon sequestration in terraced fields across different regions of the Loess Plateau. [Results] (1) SOC content and carbon sequeering benefits decreased with the increase of soil depth, SOC content in the 80-100 cm soil layer was 60.74% of that in 0-20 cm soil layer, carbon sequeering benefit in the 0-20 cm layer was 23.1% and that in 80-100 cm soil layer was 5.7%. (2) The carbon sequestration benefits of terrace increased nonlinearly with the construction years. The carbon sequestration benefits of 0-20 cm soil layer of terrace gradually increased from -8.29% in the first year of construction to 34% in the 24th year, and then remained stable. (3) During 1979 to 2023, the total carbon sequestration of terraces on the Loess Plateau was approximately 38.29 Mt C, and the average carbon sequestration was 38.49 t C/(km2·a). The Jinghe River upper and middle reaches exhibited the highest average sequestration rate at 50.14 t C/(km2·a), while the Helong interval showed the lowest at 29.04 t C/(km2·a). [Conclusion] Terraced field construction on the Loess Plateau can enhance SOC content, and terraced field carbon sequestration was a relatively lengthy process that requires scientific design and management to maximize its carbon sequestration benefits. Conducting terraced field construction, along with proper planning, design, and scientific management, proved to be an effective measure to enhance regional soil carbon sequestration benefits. The research findings can offer theoretical and methodological support for assessing the carbon sequestration benefits of soil and water conservation in the Loess Plateau region.
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