A new HSM 904Z 6WD skidder of a large size was tested in a 140-year-old beech stand in northern Poland. The aim of the study was to analyse machine productivity and impact on the soil (bulk density and cone penetrometer test) and the remaining natural regeneration caused by skidding. Trees were cut by chainsaw and, if possible, felled into the direction of the skidroads. After delimbing, logs with a top diameter of a minimum 7 cm over the bark were prepared. The average skidding operational productivity including piling was 21.0 m³·h^-1. At the same time, the level of damage in natural regeneration was: 18% (38% due to both: felling and skidding). An analysis of the soil after skidding showed that the density had grown by 15-30 g·cm^-3. Increase of penetration resistance was up to 2.77 MPa as the biggest.

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