Enhancing peatland monitoring through multisource remote sensing: optical and radar data applications

Peatlands play a pivotal role in global carbon cycling and the conservation of biodiversity even though they cover a small fraction of the Earth's terrestrial surface. These ecosystems are, however, increasingly vulnerable due to climate change impacts and anthropogenic activities, leading to significant degradation in many areas. This review compiles and analyses various studies that employ remote sensing for comprehensive peatland mapping and monitoring. Remote sensing offers detailed insights into critical peatland features, including the classification of peatland vegetation, assessment of water table dynamics, mapping of vegetation condition and diversity and the estimation of carbon stocks. Furthermore, the review delineates the utility of remote sensing in monitoring the recovery processes of restored peatlands, highlighting the scarcity of long-term studies. It also emphasizes the potential of integrating hyperspectral, multispectral and SAR data as well as cross-scale analyses. Concluding with future directions, the review underscores the necessity for enhanced upscaling techniques, integration of multi-sensor data and the application of modelling to enrich our understanding and management of peatland ecosystems.