Specific location: southern Finland (Isojärvi research area, Kuhmoinen) and east-central Finland (Ruunaa research area, Lieksa) 

Which ecosystem type: Forests    

Title/name of the NbS: Disturbance-Based Forest management 

Summary: A large-scale and long-term research and development project Forest management inspired by natural disturbance dynamics (DISTDYN) was initiated in Finland in 2009. The aim is to examine how variation in spatial and temporal scales of felling affects forest structure and biota. Harvesting methods applied in this project include selection, gap, partial and clear felling with variable retention. Rehabilitation is also applied as dead wood is intentionally increased while harvesting. The motivation of the project lies in the growing interest in using natural disturbances as an inspiration of forest-ecosystem management and in the recognition that mid- to small-scale disturbances are a characteristic feature of unmanaged Fennoscandian forests. The effects of felling methods are studied at the stand scale. However, a unique aspect of the project is the focus on landscape-scale impacts of different harvesting alternatives by comparing ca. 150-ha landscape units with varying harvesting regimes. Overall, the project aims at creating a long-lasting multidisciplinary research infrastructure. It also addresses core issues of forest-ecosystem management, including ecological, timber-production, economic and socio-cultural performances of alternative harvesting practices. 

Contact: Prof. Koivula Matti (LUKE), Natural Resources Institute Finland, matti.koivula@luke.fi 

Relevant links to documentation: Forest management inspired by natural disturbance dynamics (DISTDYN) – a long-term research and deve (tandfonline.com) 

Specific location: Municipality of Oslo 

Which ecosystem type: Forest 

Title/ name of the NbS: Multifunctional forestry 

Summary: The municipality of Oslo aims to do economically profitable forestry that also protects biodiversity values, allows for versatile outdoor recreation possibilities, as well as contributes to climate change mitigation both through carbon sequestration in the forest ecosystem and through providing wood biomass for substitution of fossil-based materials. While the dominant harvest form in Norway is clear-cutting, the municipality of Oslo applies continuous-cover forestry where site conditions are appropriate for it. Clear-cutting is applied in sites not well suited for continuous-cover forestry. Nitrogen fertilizer is not used in forestry because of the uncertainty of its impacts on biodiversity. Much of the regeneration is natural, but planting is done in clear-cut sites and is also used to complement natural regeneration. The forests in Oslo municipality are currently in a transition phase from clear-cutting dominance to a larger share of continuous-cover forestry, as it takes time to convert traditionally managed forests into forests with greater variation in both structure, age and tree species. 

Contact: Esben Kirk Hansen, esben.kirk.hansen@bym.oslo.kommune.no, Lisa Näsholm, lisa.naesholm@bym.oslo.kommune.no, Knut Johansson, knut.johansson@bym.oslo.kommune.no, Bymiljøetaten, municipality of Oslo 

Relevant links to documentation: Inkludering-av-klimahensyn-i-Oslo-kommunes-skoger.pdf 

Specific location: Municipality of Eidskog 

Which ecosystem type: Forest 

Title/name of the NbS: Variable retention forestry 

Summary: The municipality forest of Eidskog aims to carry out active forestry and at the same time facilitate for higher biodiversity. Their approach, the so-called Eidskog-method, represents variable retention forestry that they implement in all kinds of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) stands.  

Before logging, employees in the municipality forest manually mark all the future retention trees in each stand. They select the retention trees so that they are scattered all over the stand, which is in considerable contrast to traditional clear-cuts, where the retention trees are most often set aside in groups and clusters. On-site individual selection of the future retention trees enables targeting the largest and most vital trees in the stand. In addition, they set aside a minimum of one extra (relative to the requirement of the Norwegian PEFC forest standard) retention tree per 1000 m2, so that stands harvested using the Eidskog-method contain at least two living retention trees per 1000 m2. All dead trees are also retained. As an additional contribution to maintain forest biodiversity in some of the stands, they set aside small areas with particularly high biological value. For instance, areas with extraordinary old and/or big trees, humid microclimate as well as parts that considerably deviate from the rest of the stand, for example areas with big stones and boulders which affects tree species composition and their age structure.    

After the first three years of implementing the Eidskog-method, the harvested stands differ visually considerably from traditional clear-cuts, the amounts of dead wood have increased substantially and the retention trees are remarkably stable. So far only a small fraction of the >1500 retention trees set aside have fallen down because of heavy wind or snow.  

Contact: John Wirkola Dirksen, the municipality of Eidskog, jwd@eidskog.kommune.no 

Relevant links to documentation: https://www.eidskog.kommune.no/tjenester/teknikk-plan-og-naring/skog-og-landbruk/skogbruk/kommuneskogen/