This thesis is based on the research, comissioned by Finnish Forest Center Pirkanmaa in Tampere. The research was carried out in the areas of Hämeenkyrö and Kangasala municipalities. This is a case study based thesis. The purpose of the thesis was to find out how the immediate surroundings of brooks and rivulets protected by the Forest Act section 10 have been preserved in regeneration felling areas in Hämeenkyrö and Kangasala municipalities. On the basis of this research a feedback is given to the harvesting implementers. The research paid attention to the buffer zones widths, quantity of decomposed wood, windblown trees, the realization of insect destruction law, trenching, soil preparation and logging road location. The basis of the research was the publication of the Finnish Forestry Centre Assessment: Guide 2014 the nature management quality assessment of commercial forests.

There were 20 field subjects in this thesis. In all of them a regeneration felling had been done in the immediate proximity of a brook or a rivulet. The choice of the 24 subjects was made of the forest use notifications and by using the Forestry Centre Aarni programme. The final number of 20 was based on field surveys.

On the basis of the results of the thesis it can be noted that brook and rivulet buffer zone boundaries vary considerably depending on different sites and felling parties. Guidance for the buffer zone boundaries protecting the brooks and rivulets should be clarified in order to maintain the characteristics of the brooks and rivulets, and to standardize logging practices.