Short Rotation Forestry - Growth Productivity of Four Cutting Cycles

According to a study by the Austrian Energy Agency the demand of forest products for energy purposes increases year by year. In 2007 the demand will nearly touch the range of 20 mill solid m³ per year. To deliver according to the needs of the Austrian as well as the European forest industry, several researches in timber mobilization were conducted. An emerging alternative might be the timber - respectively biomass production in short-rotation plantations. In 1987 a series of field trials were established in Austria to determine optimal biomass production on short-rotation poplar plantations. The objective was to gain the increment of five different poplar clones, planted at different spacings and harvested at several cutting cycles. Cutting dates were 1991, 1998, 2001 and 2006. The space layout was 0.8 x 0.8, 1.1 x 1.1, 1.4 x 1.4 to 1.7 x 1.7 m. For each combination a repetition was installed. Altogether 40 sample plots were applied. As the most favorable combination the poplar clone J 104 in a five year rotation at spacing of 1.4 x 1.4 m turned out. Overall sample plots and over all clones the average productivity was 9.86 odt/ha/year.