 The study evaluated the detectability of LAI and biomass patterns in northern boreal fens using multi-temporal and multi-source remote sensing data, including hyperspectral drone data. The results suggest that fine-scale spatial patterns of peatland LAI and biomass can be detected with multi-source remote sensing data, vegetation mapping should include both spectral and topographic predictors at sub-meter level spatial resolution, and hyperspectral imagery gives only slight benefits. This article was authored by Alexei Razanen, Sari Jutunen, Margaret Kalakska, and others.