Carbon dioxide flux, meteo-climatic and vegetation data in the subarctic ecosystem at the Folafotur Peninsula, Westfjord (Iceland)

This dataset presents georeferenced measurements collected at the Folafotur Peninsula, Westfjord (Iceland). The measurements were taken from 12/07/2025 to 15/07/2025. The dataset includes: carbon dioxide (CO2) fluxes, namely the Net Ecosystem Exchange (NEE) and Ecosystem Respiration (ER) meteo-climatic variables, namely air and soil temperature (Tair and Tsoil, in Celsius degree), air relative humidity (RH, in %), soil volumetric water content (VWC, in %), atmospheric pressure (Press, in hPa) and solar irradiance (Rad, in W m-2) vegetation assembly characteristics, plant height (h, in cm) and green fractional cover (GFC, between 0-1) To estimate NEE and ER, we used a customized portable non-steady-state dynamic flux chamber, paired with an InfraRed Gas Analyzer (IRGA). We measured the temporal variation of CO2 concentration inside the chamber at 20 points, and NEE and ER values were estimated from the slope of the linear regression of CO2 concentration over time (ppm s-1) using a laboratory calibration curve. The sign convention for the fluxes is: a negative value indicates a CO2 flux from the atmosphere to the ecosystem, while a positive value represents a CO2 flux from the soil/ecosystem to the atmosphere. Consequently, ER values are positive, while NEE values can be positive or negative. The units for NEE and ER fluxes are μmolCO2 m-2 second-1. Meteo-climatic variables were measured with a portable weather station at 1.5 m above the ground. Plant height is the mean value of three random plant ramets within the collar. The grean fractional cover was estimated from zenital pictures took at each measurement point following the procedure proposed in Meyer & Neto (2008). Measurements were taken in three contrasting associations of geological substrate and plant community: heathland on volcanic substrate (HV), wetland on sedimentary substracte (WS) and meadows on marine terraces (MM). Two replicate plots were selected for each of these associations, with FO1 and FO3 corresponding to HV, FO2 and FO4 to WS, and FO5 and FO6 to MM. The dataset is provided in a comma-separated text file (.csv) format. Each record corresponds to a single measurement, with semicolons used as separators. The first values in each record of the dataset indicate the observation details (sampling date, site, etc.), followed by the corresponding measured or calculated variables. References: Meyer, G. E., & Neto, J. C. (2008). Verification of color vegetation indices for automated crop imaging applications. Computers and Electronics in Agriculture, 63(2), 282–293.