Riparian forests are fundamental for regulating ecological processes in headwater stream networks and are often considered of high conservation value. Because riparian delineation methods including fixed-width buffers, topography-based methods, and field surveys, strongly influence buffer extent, remote sensing—particularly LiDAR—offers a more automated and time-efficient approach, especially in mountainous headwater systems. We applied a LiDAR-based, function-oriented method using canopy height along stream-perpendicular transects to derive variable riparian widths and assessed riparian forest composition, temporal continuity, and structural dynamics using bi-temporal LiDAR data (2013−2023). We tested whether persistent riparian forests—defined as areas with continuous forest cover and no land-use change over the study period—exhibit greater canopy height and distinct species composition compared to non-persistent forests—i.e. areas with non-continuous forest cover, typically representing recently established forests on former agricultural land. Using our approach, we delineated nearly 40 km 2 of riparian zones, representing 9% of the study area. Persistent and non-persistent riparian forests differed significantly in species composition, with persistent forests dominated by silver fir and non-persistent forests characterized by higher proportions of alder and beech. Across all riparian forests, mean canopy height increased by nearly 2 m over the study period and was consistently greater in persistent than in non-persistent forests (15.6 m vs. 12.2 m), with these differences being statistically significant and observed across all analyzed tree species. LiDAR point cloud profiles further revealed species- and persistence-specific structural trajectories in riparian forests, ranging from gradual canopy development to pronounced management-related change. These structural dynamics have direct implications for headwater stream functioning, as riparian forest structure regulates light availability, and consequently, stream temperature and nutrient processing through biotic uptake in both the terrestrial and aquatic environments. Overall, the proposed approach provides a transferable and management-relevant framework for improving riparian buffer delineation in managed forests and informing climate-smart forest management in mountainous headwater systems. • LiDAR enabled delineation of canopy-influenced riparian zones. • Riparian zones cover nearly 40 km 2 (9% of the study area). • Persistent riparian forests showed higher canopy height than non-persistent. • Species composition differed between persistent and non-persistent forests. • Bi-temporal LiDAR revealed distinct structural trajectories in riparian forests.
Grabska et al. (Thu,) studied this question.