Remote sensing for assessing peatland status two decades after rehabilitation: An Irish case study

Sammanfattning

Peatlands, covering only ~3% of Earth’s land area, are among the world’s most significant carbon sinks. In Ireland, peatlands account for about 23% of the land area and historically peat has been extracted for its energy potential or converted for other land uses. As a result, up to 84% of Irish peatlands have undergone land cover changes. This study assesses the status of a rehabilitated Atlantic blanket bog in western Ireland two decades after restoration, using open-access satellite imagery and terrain data. Vegetation greenness (NDVI) was derived using Landsat imagery combined with a Sentinel-2 land cover classification to map Sphagnum-associated vegetation and topographic metrics from a digital terrain model. The presence of Sphagnum is central to the rehabilitation target since it is the primary peat-forming moss and typically establishes only under persistently wet and waterlogged conditions. The study site shows an overall increase in NDVI between 2002 and 2024, and the land cover classification achieved good agreement with reference data (overall accuracy ~82%). Sphagnum-associated classes were situated in flatter topographic positions. Overall, the combination of Sentinel-2 land cover classification with NDVI and topographic data provides a useful, rough indication of Sphagnum presence and extent in the rehabilitated peatland. However, Sentinel-2 resolution is unable to capture fine-scale heterogeneity and small, scattered trees at the site. Future work should aim to evaluate the mapped Sphagnum extent in the field and evaluate hydrological properties of the site.