Estimating Carbon Storage in Tree Stem Biomass of Mixed Boreal Forest Using UAV LiDAR Data

The inventory of carbon stocks in forests and the assessment of their spatio-temporal variability is a crucial task in the context of climate change and the search for adaptation strategies, as noted at both international and national levels. Since 2022, Russia has been implementing the project “Rhythm of Carbon”, one of the main goals of which is the assessment of carbon stocks in forests on permanent sites, which should be further upscaled using remote methods. We conducted the assessment of carbon stocks in tree stem biomass in a mixed boreal forest at the “Mukhrino” field station (West Siberia) using a comprehensive approach based on UAV LiDAR surveys and ground verification. Allometric models based on an ensemble approach and stochastic modeling were used to assess the relationship between ground-determined wood biomass stocks and tree height obtained via LiDAR. We obtained sufficient agreement between ground-based and remote assessments of tree heights, their number, and carbon stocks, which averaged 54 ± 11 t/ha. However, the LiDAR assessment conducted from a flight altitude of 120 meters does not account for understory trees due to the high canopy closure and systematically underestimates the number of overstory trees, which was compensated for using a correction factor.