Smartphone-based measurements of Scots pine trunk diameters in Kostroma region, Russia

In the study, the use of a smartphone equipped with a LiDAR sensor for forest stand inventory was analyzed. The accuracy of determining diameter at breast height (DBH), basal area, and stand volume was investigated by comparing the Arboreal Forest app with traditional forest inventory methods. Data from pure Scots pine stands across four temporary sample plots in the Kostroma region (Russia) were examined. Metrics such as RMSE, MBE, MAE, MAPE, and R² were determined based on statistical analysis and graphical evaluations. A high agreement between DBH and basal area values obtained via the Arboreal Forest app and manual caliper measurements was established, with mean DBH deviations not exceeding ±1.6%. The alignment of diameter class distributions, confirmed by the Kolmogorov-Smirnov test ( p = 0.05), was validated across all plots. Permissible deviations in stand basal area and volume (±3.2%) were identified, meeting Russian forest inventory standards. Directions for improving mobile LiDAR-based technologies to enhance forest assessment efficiency were proposed. The potential for scaling this methodology to other forest types was substantiated. Overall, the results demonstrate smartphones’ viability as rapid, accurate tools for forest inventory, maintaining compliance with regulatory precision requirements.