Analysis of changes in the timing of the growing season in the Europe using remote sensing data

The most reliable method for monitoring plant phenology and changes in vegetation development is ground observation (in-situ). However, this method is difficult to implement on a larger spatial scale. For that reason, remote sensing data have begun to be used to quantify vegetation phenology in recent decades. Information about phenology is derived from remote sensing data using ie. phenological metrics. In this study, we used 3 base metrics - the start of the growing season (SOS), the end of the growing season (EOS), and the length of the growing season (LGS) for evaluating changes in the phenology of four land covers (coniferous forest, broadleaf forest, field, and grassland) in the European region (approx. 30 countries). For their determination, Enhanced Vegetation Index2 (EVI2) was used based on images from The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Satellite images were obtained at a spatial resolution of 5 x 5 km in the time period from 2000 to 2022. For four land covers within the 22-year period, it was evaluated that the SOS significantly shifted to an earlier date in about half of the evaluated states. The EOS significantly shifted to a later date in almost all evaluated states. Based on these results, we evaluated the whole length of the growing season and found a significant shift to a later date also in almost all evaluated states.

Acknowledgement: This work was supported by an individual IGA project - Determination of vegetation time and its spatiotemporal variability using remote sensing of the Earth (AF-IGA2022-IP-067) and by SustES project – Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797), which provided essential data and software access.