Wood biomass production potential on agricultural lands in Northern Europe – achieving the goals of energy policy

Abstract

Short rotation forestry for bioenergy is an important means of meeting renewable energy targets for the shift towards a more sustainable energy model. This research focuses on the production and expansion of short rotation willow coppice on agricultural land in Northern Europe, based on empirical data from a large sample of commercially managed plantations. The thesis reviews six manuscripts concerning: the current yields of willow plantations in Sweden, for first, second and third cutting cycles (Paper I), the yield trends for the first cutting cycle during the period 1986-2000 (Paper II), the use of remote sensing in order to assess productivity from willow plantations (Paper III), the geographical spread of willow cultivation in Sweden (Paper IV) and the effect of policy incentives on the expansion of willow cultivation in Sweden during the period 1986-2006 (Paper V). The final paper presents estimates of productivity potential from willow plantations on agricultural land on six EU countries in Northern Europe (Paper VI). The results of the analysis of yield performance (Paper I) show a great variability between growers, which suggests the importance of proper management in the establishment and tending of the plantations. Although the average yields of the first established plantations were significantly lower than previous estimates, the results show a clear trend of yield improvement over time (Paper II). During the period studied, the average productivity of the plantations increased each year by 0.20 odt ha-1 yr-1, and in the best managed plantations 0.27 odt ha-1 yr-1, possibly due to the release of improved willow clones and management practices. In addition to regional estimates, the thesis also provides tools for the assessment of yield at plantation level using remote sensed images, with reasonable levels of accuracy (Paper III). The research stressed the role of policy incentives as an important tool for the spread of short rotation forestry (Paper IV), which significantly affects the adoption of willow cultivation by local farmers (Paper V). The thesis offers methodological tools to analyse and measure these effects, confirming the importance of consumers that can guarantee a long-term demand for willow chips. Finally, the models performed during the study serve as a basis for yield projections for Finland, Denmark, Estonia, Latvia, Lithuania and Sweden, assuming different scenarios of productivity (Paper VI). The final conclusions of this thesis show that the conditions for a successful development of the sector include the spread of know-how based on research, skilled growers, existence of an infrastructure and favourable policies. The yield estimates and projections not based on empirical data can significantly over-estimate the actual production of new biomass cultivations. Finally, the models and tools provided can be useful for energy management and planning, and are a starting point for further research on the topic and for management and economic considerations.