Using an portable gas analayzer to monitoring soil respiration in Mediterranean garrigues with extensive livestock system

Soil respiration, the release of carbon dioxide in terrestrial ecosystems, is second only to plant respiration and plays a crucial role. Grazing significantly impacts soil carbon cycling in grasslands, as well as abandonment or burning. Accurate measurement of CO
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fluxes is vital for understanding ecosystem health. In this study, we used a portable gas analyzer to assess diurnal and seasonal variations in soil CO
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fluxes in grazing, non-grazing, and burned areas followed by a 5 year of spontaneous evolution in Central Italy’s mountain region. Soil characteristics included a silty loam texture, with slightly more clay in the non-grazed area and no significant calcium carbonate content. Soil organic carbon (SOC) showed moderate variability between the sites, with no statistically significant differences within each site. Total nitrogen (TN) was significantly lower in the non-grazed area compared to the grazed area. We measured also soil temperature, and moisture in the spring-rainy and summer-dry seasons. Measurements were made two consecutive times: a month twice a day from 10:00 to 12:00 and from 16:00 to 18.00, with an infrared gas analyzer and a closed dynamic chamber (LI-COR LI-7810 CH4/CO2/H2O Trace Gas Analyzer). Soil moisture varied daily, with higher levels in the morning in grazed and abandoned areas, reversing in the burned area. Temperature patterns were consistent, with lower morning temperatures in grazed and burned areas and the opposite in the abandoned area, and these patterns were statistically significant. CO
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fluxes were measured, with the grazed area showing significantly higher flux compared to the non-grazed and burned areas, which did not significantly differ from each other. Additionally, CO
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fluxes generally peaked in the afternoon, with significant differences observed in grazed and non-grazed areas, but not in the burned area.