Procedures for CO2 Fluxes Measurements with Portable Flux-Meters in Critical Zone Observatories (Bio-Geochemical Flux Laboratory, IGG-CNR).

This report updates the previous Italian version of the procedures for CO2 fluxes measurements with portable flux-meters in Critical Zone Observatories (CZOs) published in the CZO community of IGG-CNR on the Zenodo repository (https://zenodo.org/records/7544045). We present a full description of the procedures applied for the punctual measurements of CO2 fluxes in grasslands. Specifically, procedures are referred to data acquired by portable flux-meters by the IGG-CNR personnel. Data are in general acquired during field campaigns aimed to measure CO2 flux exchanges between soil, vegetation, and atmosphere at the IGG-CNR Critical Zone (CZ) observatories. Although these procedures are applied during field campaigns, sharing this information in the new-born Critical Zone Virtual Research Environment is essential in the spirit of creating shareable and FAIR data and results. In general, these procedures can be adapted to the measurements of other fluxes (e.g., CH4, H 2 O, and total VOC) and in other natural environments.