Fractional land cover maps for the European Alps

This repository contains annual fractional land cover maps for the European Alps covering the period 1986–2023. The dataset is organized by land cover class. For each class, one multi-band raster is provided, where each band corresponds to one year in the time series and stores the fractional land cover of that class for the respective year. The three classes included are tree cover, grassland, and bare ground, with values ranging from 0 to 100%. The dataset is derived from dense Earth observation time series based on Landsat 4–8 and Sentinel-2A/B imagery. It provides continuous sub-pixel estimates of land cover composition and is designed to capture gradual changes in vegetation and land surface composition over time. This makes it particularly useful for studying long-term vegetation dynamics, forest disturbance and recovery, and land cover change in heterogeneous mountain landscapes such as the European Alps. These fractional land cover maps were used in the analysis presented in Mandl et al. (2024), Remote Sensing of Environment, 308, 114194 (https://doi.org/10.1016/j.rse.2024.114194), titled “Unmixing-based forest recovery indicators for predicting long-term recovery success” and Mandl et al. (2026), Agricultural and Forest Meteorology 378 (https://doi.org/10.1016/j.agrformet.2026.111016, titled "The role of thermal constraints in post-disturbance forest recovery across the European Alps – a large-scale remote sensing study" The studies uses fractional cover maps derived from spectral unmixing as the basis for ecologically interpretable indicators of forest recovery.