Background Logging residues such as small trees, branches and tree tops can be used as biofuel, but removing them means that important elements are lost from forest ecosystems. At the same time, however, the increasing combustion of wood fuels leads to an increased production of wood-fuel ash, which can be spread back in the forests to return key nutrients and improve the acid-buffering capacity of soils. Since 1998, the Swedish Forest Agency has recommended ash recycling after extraction and in 2001 it produced “Recommendations for the extraction of forest fuel and compensating fertilising”. At the start of the project, the annual production of wood ash had reached 300,000 tons in Sweden and 100,000 tons in Finland alone. However, ash recycling was only taking place in a small part of the area from which wood fuels were extracted; most of it was deposited in landfills. Despite positive experiences of ash recycling in the whole bio-energy chain, the main obstacles to regular recycling were identified as a lack of knowledge, regulation and training materials. Objectives The ‘Recash’ project aimed to demonstrate the effective implementation of ash-recycling methods and thus create the conditions for the regular recycling of wood ash to forestland. This aimed to be in line with the EU’s Sixth Environment Action Programme objective of ensuring "the consumption of renewable and non-renewable resources and the associated impacts do not exceed the carrying capacity of the environment”. It sought to carry out an ash classification study to produce recommendations for maximum and minimum contents of various elements - including both nutrients and hazardous elements - and a minimum level of stabilisation for recyclable wood and wood/peat ashes. The project intended to gather and analyse existing knowledge on ash recycling in Northern Europe and to select and develop the best methods of ash recycling. The testing of at least two ash-recycling systems - one in Sweden and one in Finland – was planned in complete full-scale demonstrations to verify their successful application. This would enable the project to gather, demonstrate and spread knowledge about how regular recycling of wood ash is organised with respect to ecological, technical, economic, logistic and administrative aspects. This would achieve the aim of increasing the sustainability of wood fuel combustion and decreasing the amount of wood ash left in landfill sites. Results The project successfully implemented two case studies on ash-recycling systems in Sweden and Finland. It managed to reduce the amount of ash dumped in landfills – often to zero levels - and was able to recycle ash either as forest fertiliser or to cover old landfill sites to enable reuse of the land. In the Finnish case, the existing ash-recycling chain was improved. It worked to find the optimum balance of peat ash and wood ash for forest fertiliser, on combining sludge and ash recycling, to develop an efficient logistics system for ash recycling, and linking the ash handling of smaller heating plants with existing pioneer systems. In Sweden, a new system was developed covering the entire chain from biofuel extraction, to ash production and ash recycling. It worked with relevant agencies to study the system, localise problem areas and test possible improvements. The two working ash-recycling systems developed partial systems for all stages - including ash storage, production of hardened products, transport, forest owner and authority contacts, spreading, and documentation - and demonstrated how these could be combined into a single chain. The project also produced an ash classification study to increase understanding of different types of ash An ash recycling handbook was published to distribute the knowledge gathered and analysed about potential technical, logistic and administrative solutions for regular ash recycling. It describes the techniques, laws, costs and environmental benefits. The project held regional, national and European-level field demonstrations of ash recycling and seminars on the subject to increase awareness and understanding amongst stakeholders of the economic and environmental costs and benefits of different systems. Forest owners, entrepreneurs and other companies involved in the chain were engaged in organising and conducting the systems to maximise the chances of the new ways of working being implemented into the future. As the new systems do not depend on high technology, it is expected that the methods will be widely transferable to other countries in an affordable manner.