Silvilaser 2019 - Poster Presentations »
Long time series of ground based laser scanning measurements of single trees and forest stands – 4D LiDAR monitoring.
The precise ground based laser scanning measurements (TLS, MLS, HLS, WLS) conducted regularly allow to describe dynamics of changes happening in horizontal and vertical structure of the single tree and forest stands. The volumetric changes of selected tree parts and whole forest stand (biomass) taking place over time enable conducting the so called 4-D monitoring. In the presented paper case studies are presented: 1- the single tree monitoring; 2- the old-growth forest stand observations; 3-Norway spruce stand in forest decay stage and 4- secondary forest succession on the abandoned land. The aim of the case study no.1 was the monitoring based on multi-temporal comparison of point clouds captured with Terrestrial Laser Scanning (TLS) and Hand-Held systems. First TLS point clouds were collected during the Leaf-OFF (04.2013) and in Leaf-ON period (07.2013) using FARO FOCUS 3D. Additionally the RIEGL VZ-400, Leica C10 and RevScan (HandyScan) were used to collect point clouds. The height (H) of the oak tree differed approx. 0.41 cm using altimeter Vertex (Haglöf; H = 29.31 m) and TLS point cloud (28.49 m). Trunk circumference (L) was 9.80 m much shorter then adjacent along the shape of bark (LT = 13.70 m). The TLS point cloud-based measurements showed 9.97 m and Hand-Held RevScan 13.54 m. The study no. 2 was the old growth forest located in the Niepolomice Primeval Forest on the research area TR2. The first TLS point cloud was collected in 2006 and the last one in 2019 using FARO LS 880 and RIEGL VZ400i respectively. Throughout the 13 year analyzed period different scanners like: FARO, ZEB1, Leica, RevSca, Robin GEOSLAM (Wearable Laser scanning) equipped with RIEGL VUX-1 were used. The case study no. 3 was located in Gorce National Park in total reserve zone where the forest decay of Norway spruce stand is observed since last two decades. The 4-station TLS scanning was performed in years 2012, 2016 and 2018 as well. The high dynamic changes were observed like broken of dead trees, falling of logs and destruction of the wood. In the same time we observed the natural regeneration of the forest resulted as the inflow of a significant amount of sun light. Very high dynamics of secondary forest succession is observed in the last years (2012-2016-2018) in Poland on the on a high-mountain meadow where sheep grazing was stopped. Thanks to the precise TLS point cloud (FARO) you can follow the dynamics of the appearance of spruce individuals and their growth in height and width and closing of the tree cover. Conducted research demonstrates usefulness of TLS technology application in observation of natural processes taking place in natural forests ecosystems.