Use of high Multi-temporal ground resolution model by Portable Laser Scanner and Physical parameters sampling to assess soils disturbance caused by logging operation.

Forest operations may lead to negative consequences in terms of compaction and rutting, which may result in soil degradation processes such as erosion, mudflow and landslides. The damage depends on type of vehicle, number of passes, ground morphology, soil properties and slope. The aim of this research was to investigate the impact on soil caused by logging operations through ground survey and terrestrial portable laser scanner (PLS). Samplings were carried out in two trails that differed for the numbers of machine passes and slope. The data collection where performed before and after logging to analyze the impact on soil of forest operations. The specific objectives were: (i) to analyze how forest operations have influenced soil compaction and rutting; (ii) to assess soil compaction with traditional techniques; iii) to determine logging caused rutting with high-resolution ground surface models generated by PLS scans; iv) to assess the differences in the soil disturbances in two different trials. Significant impacts were detected with both investigation methods, i.e. physical parameters and multi-temporal analysis of high resolution ground surface models derived by PLS. Therefore, in order to limit the damage to the soil, it is important to apply extraction methods and machines in relation with the specific site conditions, especially when a high mechanization level is used. We demonstrated that PLS technology can produce a fast, precise and accurate measurement of the impact of forest operations on soil.