The paper presents the assessment of compaction grade caused by machinery used in forest biomass for energy harvesting. The main aim was to determinate unaff ected soil conditions, the compaction grade exactly a er harvesting activities, the return of soil a er couple of years and compaction grade in stands, which were not harvested but aff ected by skidding and seed collection activities. Therefore four diff erent compaction grades were evaluated. To ensure as much as possible uniform soil conditions also soil samples were evaluated. Soil samples were collected using Kopecky physical metal rings and followed characteristics of soil were determined i.e. moisture content, bulk density and porosity, respectively. In San Rossore national park 24 plots were identifi ed of which 8 were harvested in 2011 year (H2011), 8 were harvested in 2005 year (H2005), 7 were not harvested but were aff ected by other activities (NH) and 1 was unaff ected (U). On each plot 50 repetition of measurement were carried out. The results display both: signifi cantly diff erent compaction grade of soil and return of the soil towards the original conditions a er 6 years.

An assessment of soil compaction caused by machinery used in stump and/or logging residue extraction for energy on soils typical of Ireland. We determined unaff ected soil conditions and to fi nd the compaction grade after timber harvesting and bundling activities, and to compare those results with stands where timber harvesting was followed by stump extraction for energy. Th e investigation was carried out in Ireland on three diff erent locations which had a slightly diff erent proportion of stones in their soils. Two of the soils were purely mineral soils, and the third was a mineral soil aff ected by anthropogenic activities. To ensure comparable results as much as possible, the moisture content of the soil on wet basis was investigated. Each location was purposely treated. Th erefore, on each location plots were identifi ed as follows: plots unaff ected by operation (reference area), plots after timber harvesting, plots after timber harvesting and bundling operation, and plots after timber harvesting and stump extraction operation. According to the experimental design 40 repetitions on each of the three diff erent treatments were set. Th e results showed that the compaction of soil occurred on plots after timber harvesting, but there was not a signifi cant diff erence between compaction grades with and without logging residue bundling operation. However, once the site was extracted of stumps, the soil became too loose and no signifi cant diff erence was found compared to unaff ected soil.