Elevated Concentrations of Carbon Dioxide (CO2) on the Harbechy Plateau (Moravian Karst) Reveal a Gas-Rich Soil Layer (GRSL)

• Authors: FAIMON Jiří; BALDÍK Vít; REZ Jiří; NOVOTNÝ Roman; HADACZ Roman; OCÁSKOVÁ Daniela; DOSTALÍK Martin; VŠIANSKÝ Dalibor; NEČAS Jiří; ŠTELCL Jindřich; KUDA František; KŘENOVSKÁ Iva; CHALUPKA Filip
• Year of publication: 2025
• Type: Article in Periodical
• Magazine / Source: APPLIED SCIENCES-BASEL
• MU Faculty or unit: Faculty of Science
• web: Full Text from Publisher
• Doi: https://doi.org/10.3390/app15168907
• Keywords: karst soils; carbon cycling; gas-rich soil layer; CO2 dynamics; SOM transport; ?13C isotopes; agricultural tillage impact
• Description: Precipitation leaches soil organic matter (SOM), transporting it downward where it accumulates at the soil–bedrock interface. Intensive agriculture, particularly tillage, accelerates this process. Microbial decomposition of SOM generates CO2, forming a gas-rich soil layer (GRSL)—a phenomenon long hypothesized but never directly confirmed until now. Drilling on the Harbechy Plateau (Moravian Karst) revealed a GRSL with a thickness of ~0.8 m, CO2 concentrations averaging 1.5–3 vol. % (peaks of 4–6 vol. %), and isotopic signatures (?13C) indicating a mix of biogenic (-25‰) and atmospheric (-8‰) CO2. These findings necessitate re-evaluation of carbon cycling models in karst agroecosystems.