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The main aim is to test the influence of anatomical structure (grain direction and elements size), wood hardness and machining conditions on wood surface roughness. 180 samples defect-free were obtained from beech, oak and pine and processed with different machining methods (planning, sanding with 60 grit or sanding with 180 grit). Roughness, hardness, and anatomical structure were analysed using international methodologies. An analysis of variance of the data from all the samples with the four factors in the experimental design were performed. Results showed that machining processes and species are the factors that significantly affect surface roughness, as opposed to grain direction (plane of section and stylus-grain angle), which was only shown to be significant in some subgroups. Roughness parameters of samples sanded with 180 grit were lower in contrast to samples planned or sanded with 60 grit. Hardness was found to be the property of the wood that most clearly affects its final roughness, and makes it difficult to achieve better roughness results as the hardness increases.

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a b s t r a c tBiomass growing stocks, harvesting productivity and costs of energy production, were studied in thinnings of Quercus pyrenaica.Eleven forest sites were selected in coppices located in Castilla y Leo´ n (Spain). Three systems were employed for harvesting: a mech-anised whole tree harvesting (WTH) system, which included chipping at landing; a fully mechanised cut-to-length (CTL) harvesting system for firewood; and a semi-mechanised CTL system with manual felling and bunching. Three WTH trials had a hauling off 34.7 e44.1 oven-dried tonnes (odt) ha À1 . In contrast, only 11.6e30.0 odt ha À1 were obtained in the other eight CTL trials.Biomass weight equations for stems and whole trees were fitted. Worker operations were time-studied using software designed by the authors. The WTH system reached maximum productivity rates of 3.9 oven-dried tonnes per productive hour (odt h À1 ) for the felling and bunching operation and 6.9 odt h À1 for the forwarding opera-tion. The mechanised CTL harvesting method achieved a productivity range of 1.3 e0.5 odt h À1 for the harvesting operation. Furthermore, the average forwarding produc-tivity was 7.3 odt h À1 . Motor-manual felling and crosscutting in the CTL system accom-plished a productivity range of 0.7e1.9 odt h À1 . Manual bunching resulted in similar values. The lowest firewood unit cost for trees with 10 cm of diameter at breast height (DBH) was 62.0 V odt À1 using a semi-mechanised CTL system. Under similar conditions, this cost was 85.2 V odt À1 for the mechanised CTL system. Finally, the cost corresponding to chips at landing from WTH sites (average DBH ¼ 10 cm) was 65.3 V odt À1 . IntroductionThe Spanish Renewable Energy Plan (2005e2010) [1] has finished. This plan tried to increase renewable energy (RE) production rate of total primary energy production (4.77 Â 10 12 MJ) from 6.3% in 2005 to 30% in 2010. Bioenergy was an important part of the plan's goal. Currently, there are only 648 MW generating capacity installed [2] in biomass power plants; however, the plan had aimed to reach 1317 MW by 2010. The objective remained unaccomplished despite government subsidies for electricity production from forest residuals (0.11 V kWh À1 ) and from forest woody crops (0.16 V kWh À1 ) [3]. According to the RE National Action Plan 2011e2020 [4], renewable energies accounted for 9.4% of primary energy consumption in 2010, 132,000 Mtep, whereas the goal for 2020 is 20.1%. Regarding electricity production, RE