Background The Arnsberger Wald forest forms part of the Nordsauerländer uplands. It is located between the Möhne River and reservoir in the north and the Ruhr valley in the south. This large, continuous forest features a network of small and medium size streams. Because of changes in forestry policy beginning in the 19th Century, there are today uniform spruce populations on about half of the sites that would be typical for beech, oak and alder. The project area contains four Natura 2000 sites: the "Arnsberger Wald" (DE- 4514-302), Heveoberlauf (DE-4515-302), "Kleine Schmalenau und Hevesee" (DE-4514-304) and "Hamorsbruch und Quellbache" (DE-4515301). The proposed project would allow the development of natural habitat types in the streams and stream valleys of the four sites. The size of the project area was 1 300 hectares, 71 ha of which were not included in Natura 2000 but would be designated at the end of the project. Objectives The overall objectives of the project were to: Develop near natural habitat types in the stream valleys; Create of a near natural water regime in the stream valleys; Establish near natural stream dynamics; Increase the structural diversity of the streams; Restore the linear connectivity in the streams; and Improve the water regime of bog woodland. Results The ‘Bachtäler Arnsberger Wald’ project transformed spruce forest into oak and alder forests on 123 ha. It planted around 3 500 alders and 1 000 oaks to support the development of native alluvial vegetation. Furthermore 1 200 sampling trees were protected against damage by roe, red and sika deer. Spruce rejuvenation was removed on 34 ha, particularly in valleys. This action was followed by river restoration measures to increase the ground and surface water levels. Such hydrological actions included the extension of river courses, the creation of side channels and restoration of old river arms, the insertion of dead wood, closing of drainage ditches and the removal of migration barriers. In total, 9.5 km stream courses were restored to a near natural condition. The river courses were extended by 3 760 m (more than the 3 000 planned), side channels were created on 1 090 m (750 m was planned), and 130 trees were brought into the rivers to increase the deadwood share. During the project, it became apparent that it would be necessary to construct a ramp over the River Heve in order to stabilise the bed. Furthermore, in the wetland Harmorsbruch the hydrologic water regime was restored on 8.5 ha through the closure of 2 060 m of drainage ditches. A further 1 690 m of ditches were filled in in the river valleys within the Arnsberger Wald. Seven obstructed road crossing structures were replaced with new ones. The restoration methods of the project were based on available best practices. One innovative practice, however, was the use of cable cranes in sensitive floodplain areas in order to protect the alluvial forest structures and the sensitive soil. The long-term impacts on biodiversity (fishes, birds and vegetation) will only be visible several years after the project end. However, protected aquatic species, such as Cottus gobio and Lampetra planeri, are believed to have benefited from the LIFE project, along with the bird species, Alcedo atthis and Ciconia nigra. Other species living in streams and wetlands that were improved by the project and are thus expected to have also benefited are the golden-ringed dragonflies Cordulegaster boltonii and Cordulegaster bidentata and the very rare carabid beetle (Carabus nodulosus). The After-LIFE Conservation Plan will ensure the continuation of the project’s aims. The plan details specific actions that are necessary as well as specifying which project participant is responsible. As a result of the project, 200 ha of land were nominated as Natura 2000 sites. Moreover, the project had an economic impact on the area, benefiting local small enterprise that provided services for more than €690 000. In particular, it engaged forestry enterprises and building companies. Furthermore, awareness raising measures promoted the aims of the LIFE project and the Arnsberger Wald region in general. The Arnsberger Wald Nature Park was a key partner in the project and it now more attractive as a tourist spot, offering numerous information points, brochures, leaflets and two nature trails. The LIFE project cooperated as well with social institutions, such as international youth camps and agencies for the long-term unemployed. The project participants BS Hochsauerlandkreis and ABU Soest engaged a high number of volunteers that supported the project. Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).