Tree Community-Level Phenological Monitoring Using MODIS, Sentinel-2 and PlanetScope in Himalayan Foothills, India
摘要
Remote sensing-derived phenology is a powerful tool for monitoring vegetation dynamics across large landscapes and offers critical insights into ecological responses to climate change. However, most studies focus on broad-scale assessments, often overlooking community-level phenology, which is essential for conservation planning and adaptive forest management. This study investigated land surface phenology (LSP) in the Nandhaur Landscape, a tropical forest ecosystem situated in the Himalayan foothills of India, using MODIS, Sentinel-2, and PlanetScope satellite datasets. By evaluating the effectiveness of these sensors in capturing phenological dynamics across tree communities, this study highlights the trade-offs between spatial resolution, temporal frequency, and statistical reliability.
The findings revealed significant phenological variability among tree communities, with deciduous forests exhibiting greater fluctuations in the start (SOS) and end (EOS) of the growing season than evergreen forests. Sentinel-2 emerged as the most suitable sensor for capturing community-level variations owing to its balance between spatial detail and reliability, whereas MODIS remains advantageous for broad-scale monitoring. Despite its high spatial resolution, PlanetScope introduces increased variability. By analysing Sentinel-2 NDVI time series data from 2018 to 2024, this study identified interannual variations in phenology driven by topography and climate dynamics. These findings emphasise the need for long-term phenological monitoring to assess the resilience of different tree communities. Future research should integrate ground-based observations with remote sensing and explore sensor fusion techniques to improve the accuracy of phenological assessments, ultimately supporting evidence-based conservation and forest-management strategies.