The first topic discussed in the thesis is biomass production. A customer focused approach has been chosen, in which we discuss the entire production chain Ž from forest to customer. In contrast to more established roundwood chains, the production of chips is more demanding as the price of chips is influenced by several factors. We have used a model to compare different technologies suitable for biomass production with focus on early thinnings. The inputs into the model are literature review and case studies of different technologies. The focus of the experimental work was new cut-to-length technology that has been introduced to Slovenian conditions. The model has delivered answers to questions regarding the economy of such biomass technologies as presented in the model. It has been shown that, although using new and adapted technologies that are highly mechanized, the income for the contractor is low. A big problem for the sector is the absence of market for some high value roundwood assortments as well as green chips in Slovenia. We have also conducted surveys of stand and soil damage on all case study objects. We have developed and adapted two methods; one for determining stand damages using plots on a grid, and the second one for the determination of rut depth on profiles that were set up along the skid trail. Using these methods, we have shown that stand damages are smaller using cut-to-length technology than when skidder and chain saw are applied. Concerning soil damage we have shown that when using the cut-to-length technology in dry weather, soil compaction and rutting are not problematic and are not causing irreversible changes to forest soils. Economic and ecological data from the case studies have been applied to a model of a comprehensive evaluation of technologies. In this model we have evaluated technologies from an economic and ecological point of view in an attempt to present a more complete view of the subject.