20.500.12556/RUL-185218 Interannual variability of European beech spring phenology across elevation gradients derived from Sentinel-2 time series Spring phenology of temperate deciduous forests is highly sensitive to interannual temperature variability, particularly in mountainous regions where strong elevational gradients create pronounced spatial differences in thermal forcing. In this study, we use dense Sentinel-2 time series to quantify start-of-season (SOS) dynamics of European beech across Slovenia between 2018 and 2021 and compare satellite-derived phenology with in situ observations from the Slovenian National Phenological Network. Satellite-derived SOS estimates showed moderate agreement with in situ phenological observations. Spring onset showed a clear elevational gradient, with SOS delayed by approximately 2.5–2.8 days per 100 m increase in elevation, consistent with temperature-related differences in spring thermal accumulation across the mountain landscape. Interannual variability was substantial, with a 16.9-day difference in national mean SOS between 2018 and 2021. Spatial patterns of phenological shifts reflected contrasting spring thermal conditions, suggesting a close association between SOS variability and April temperature during the 2018–2021 study period. These results highlight the short-term temperature-associated variability of European beech spring phenology and demonstrate the potential of high-resolution satellite time series to quantify canopy-level phenological patterns in topographically complex landscapes. fagus sylvatica land surface phenology red-edge vegetation indices IRECI mountainous forests thermal forcing in situ observations fagus sylvatica fenologija kopenskega površja vegetacijski indeksi rdečega roba IRECI gorski gozdovi temperaturni vpliv opazovanja in situ true false true Angleški jezik Slovenski jezik Članek v reviji 2026-07-29 07:42:35 2026-07-29 07:42:45 2026-07-30 04:02:31 0000-00-00 00:00:00 2026 0 0 14 str. Vol. 97, art. 103934 Aug. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 551.506.8:581.54(497.4) 1878-0512 10.1016/j.ecoinf.2026.103934 286243843 Potocnik_Buhvald,_Ostir,_Skudnik-Interannual_variability_of_European_beech_spring_phenology_across_elevation_gradients_derived_from_Sentinel-2_time_series.pdf Potocnik_Buhvald,_Ostir,_Skudnik-Interannual_variability_of_European_beech_spring_phenology_across_elevation_gradients_derived_from_Sentinel-2_time_series.pdf 1 EAC2EEF6DF1FD8DC1FE66872C67B8069 682a54d3e0470518a99d77c2b4c45a7b020ef7e23b6a55bb0cb589ab742ef157 55a794a1-8b10-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=243529 https://www.sciencedirect.com/science/article/pii/S1574954126003419 1 0db91291-8b10-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=243527 Fakulteta za gradbeništvo in geodezijo 0 0 0