The application of standard industrial simulation software for technical production in forestry is investigated. By strictly separating forestry activities, stand characteristics, and operating specifics in a simulation model, a multipurpose tool can be created. It can be used for planning, optimising and controlling technical activities, as well as for educational purposes. Some difficulties in the development process are discussed.

In 2019, the machine manufacturer HSM presented a forwarder prototype for timber hauling in cut-to-length processes fitted with a new 10-wheel triple-bogie (TB) setup approach aimed at promoting sustainable forest management by reducing the ecological impact of forest operations, especially under soft-soil working conditions. The purpose of our study was to assess the resulting soil-protection effect emerging from additional wheel-contact surface area. For this, the rut development under known cumulative weight, related to the soil conditions of shear strength and moisture content, was recorded for later comparison. Additional terrestrial laser scanning (TLS) was used to generate a multi-temporal digital terrain model (DTM) in order to enhance the data sample, assess data quality, and facilitate visualization of the impact of local disturbance factors. In all TB configurations, a rut depth of 10 cm (5.8–7.2 cm) was not exceeded after the hauling of a reference amount of 90 m3 of timber (average soil shear strength reference of 67 kPa, volumetric water content (VMC) 43%). Compared to a reference dataset, all observed configurations ranked in the lowest-impact machine categories on related soil stability classes, and the configuration without bogie tracks revealed the highest machine weight to weight distribution trade-off potential.

Forest roads are an important element in forest management as they provide infrastructure for different forest stakeholder groups. Over time, a variety of road assessment concepts for better planning were initiated. The monitoring of the surface cross-section profile of forest roads particularly offers the possibility to take early action in restoring a road segment and avoiding higher future costs. One vehicle-based monitoring system that relies on ultrasound sensors addresses this topic. With advantages in its dirt influence tolerance and high temporal resolution, but shortcomings in horizontal and vertical measuring accuracy, the system was tested against high resolution terrestrial laser scanner (TLS) data to find and assess working scenarios that fit the low- resolution measuring principle. In a related field test, we found low correct road geometry interpretation rates of 54.3% but rising to 91.2% under distinctive geometric properties. The further applied line- and segment-based method used to transform the TLS data to fit the road scanner measuring method allows the transfer of the road scanner evaluation principle to point-cloud or raster data of different origins.

Skyline planning: accuracy of singletree detection with dronegenerated aerial photos Information collected with drones has the potential to simplify the planning and marking of skylines. The prerequisite for this is that 1) the tree coordinates of potential intermediate support and anchor trees and 2) their diameter at breast height (DBH) can be determined with sufficient accuracy in the surface model obtained from the drone data. To analyse the achievable accuracies, two Swiss marteloscopes were surveyed with a senseFly eBee Classic drone at a height of 180 m and aerial photos were taken with a Sony camera with a resolution of 18.2 megapixels. In the resulting normalised surface model (nDOM) the local maxima (treetops) were determined with the single-tree detection software “FINT”. For these treetops the coordinates and the DBH were determined. The detection rate for both marteloscopes was 65%. On average, the coordinates deviated less than 1.4 m from the terrestrial reference tree coordinates. The predominant and dominant trees could be located even more precisely. The DBH was determined with an average accuracy of 5 cm. A practical test with nine skylines showed that the coordinates were accurate enough to use the support trees determined in the nDOM for the technical realisation of the skylines. However, an on-site inspection is still necessary to check the potential intermediate support trees for damages, invisible in the aerial view.