Alley Coppice : an innovative agroforestry system that combines timber and energy wood production

International audienceThe push to combat climate change and greenhouse gas emissions and reduce our dependency on non-renewable energy sources has never been more topical. One aspect of this is the need to decrease human pressure on natural forests, which poses questions as to how timber, food, and bioenergy production on agricultural land can best be obtained. Agroforestry and Short Rotation Coppice (SRC) are recognised as separate economically viable and sustainable cropping systems. But little is known about the agricultural and ecological interactions if the two are combined. This mixed approach, which we call alley coppice, has potential advantages, including: (i) regular income guaranteed from the SRC component; (ii) improved stem formation of timber trees and reduced pruning intensity in mixed systems, because of competition for light between species; (iii) planting of timber trees at final density, avoiding expensive thinning costs; (iv) reduced wind and storm damage to timber trees during the initial years of tree growth, due to the protection provided by the SRC component, and; (v) improved ecological impacts, such as increased biodiversity, reduced spread of diseases, reduced soil erosion, and reduced soil nutrient depletion. This approach is being assessed within the European AGROCOP project (Woodwisdom-Eranet EUPF7; http://www.agrocop.com/) and involves seven research institutes from five countries: France, Germany, Ireland, Italy, and the United Kingdom. One of our research objectives is to evaluate the yield of alley coppice system in comparison to monocultural systems, using the Land Equivalent Ratio (LER). We also focus on water, nutrient and light competition. Results presented were obtained in a seven-year old experimental field, located in Northern Italy. This has Pyrus and Sorbus as timber trees, and poplar SRC grown in a two-year rotation cycle. We analysed the yield and survival rate of SRC poplars, and the leaf phenology and stem form of timber trees