Silvilaser 2019 - Poster Presentations »
The use of very dense ULS and ALS point clouds in monitoring the effects of protective treatments carried out in Scots pine (Pinus sylvestris L.) stands in the National Park Bory Tucholskie, Poland.
Detection of changes taking place in stands and on individual trees in their 3D space has become possible with the appearance of very dense clouds of LiDAR points that can be achieved through the use of ULS (Unmanned Laser Scanning) platforms. The aim of the presented project was to compare parameters (solar energy reaching the ground under the canopy) and selected taxation features (number of trees, tree height, canopy cover and other) stands after applying active protection activities in the protected area in the Bory Tucholskie National Park. The research experiment consisted in thinning in pine stands (Pinus sylvestris L.) to ensure protection of lichens that require direct access to solar light. In 2018, a gyrocopter was used with a RIEGL VQ-580 scanner, thanks to which it was possible to obtain about 90 pts/m2 in the research area of about 13 ha. The flight was performed at 250 AGL with speed 28m/s and overlap 30% of 8 strips.The classified point clouds were used for generating altitude models and determining the number of trees and shortening stands. In 2019, after thinning, flights were made using the RICPOTER platform and the RIEGL VUX-1 scanner, reaching the average density of points at 300 pp / m2. Comparison of both sets of LiDAR data (Gyrocopter / ULS) allowed to calculate the change in the canopy cover parameter and the insolation reaching the ground. The results confirmed the performance of thinning works in stands (a canopy cover by about 30%). At the same time, for individual pines, the height increase reached an average of 27cm in the period from 08.2018-09.2019. Attempts have also been made to compare the number of tree trunk detection results based on ULS point clouds compared to TLS reference data. The experiment confirmed the right choice of the ULS platform, which with high precision (RMSE XYZ approx. 1-2 cm) achieved the acquisition of LiDAR point clouds with a density of approximately 300 pt / m2.