Here are included two files related to the vegetation survey: González- García, V., Fernández- Pascual, E., Font, X. & Jiménez- Alfaro, B. (2024) Forest habitat diversity in the Cantabrian Mixed Forests ecoregion (NW Iberian Peninsula), a climatic refugium in western Europe. Applied Vegetation Science, 27, e12793. Available from: https://doi.org/10.1111/avsc.12793 forests_header.csv includes all the relevés classified during this research: original SIVIM code, coordinates in UTM grid cells of 10x10, 1x1km and decimal degrees, original elevation of the relevés, plants cover (%), aspect, slope, the area (m2), syntaxa originally associate to each relevé, year of publication and accuracy of the decimal degrees coordinates. iberoatlantic.rar includes the shapefile of the ecoregion, as redesign for this research, using as base the "ibero-atlantic territories" proposed by Fernández Prieto et al. 2023.