Comparison of agroforestry species for woody biomass production

Abstract

The use of woody biomass is increasing in North America as the economics of fossil fuels change and concerns about climate change grow. Salix spp. and Populus spp. have been considered to be best for biomass production in temperate regions because of their fast growth. However, there exists little information about other temperate tree and shrub species, including those that are commonly used in western Canada for agroforestry. To determine the potential of such species for biomass production, eighteen commonly used agroforestry species were studied, including Salix and Populus clones for comparison. Characteristics that were analyzed included leaf and shade development, drought and cold tolerance, timing of growth, ability to regenerate after coppice and the frequency of harvest. Nine of the most promising species were further studied in 2010 for photosynthetic rate, light interception and carbon partitioning. This work was conducted by Camille Herouard as a Master's project for the �cole Sup�rieure d'Agriculture of Angers, France. Results will be presented, with a particular focus on the most promising species. For example, red elder (Sambucus racemosa) was found to re-grow very quickly in the year after coppice, with aboveground biomass production comparable to acute willow (Salix acutifolia). However, biomass growth was less in the second year, partly due to heavy fruit production, suggesting annual coppicing would be advisable. Buffaloberry (Shepherdia argentea) and pincherry (Prunus pensylvanica) also performed well when harvested at longer intervals. It was not the purpose of this work to identify the fastest-crowing species, as it is clear that willows and poplars have the greatest potential for dedicated woody biomass plantations. Rather, the purpose was to understand the productivity of adapted native, multi-purpose woody species, with a view to developing recommendations for their sustainable use as woody biomass sources in agroforestry systems.