Study: Selective cutting to conserve genetic diversity in Finland’s forests

The valuable genetic resources of Norway spruce in the Lapinjärvi Gene Reserve Forest are conserved through management, in order to support natural regeneration. Regeneration is needed to maintain wide genetic variability. Lapinjärvi Gene Reserve Forest is an important part of a network of in situ conservation units on both national and European levels. Natural Resources Institute Finland, Luke, is responsible for conservation of forest tree genetic resources in Finland and the maintenance of national gene conservation units, namely the gene reserve forest.

The management plan has been modified according to discussions with WWF Finland, the Finnish Association for Nature Conservation and The Finnish Nature League, which strongly advocate leaving the forest completely unmanaged. During the participatory process the area to be managed was reduced to one third of the original plan and is now a total of 10 hectares, organized in several strips of forestland. The total area of the Lapinjärvi Gene Reserve Forest is 243 hectares. No clear-cutting will be done and all the dead wood will be left in the forest.

In situ conservation of genetic diversity is not focused on preserving specific genotypes, rather it is dependent on abundant regeneration yielding numerous genotypes. Halting forest management in Lapinjärvi would limit gene conservation achieved through promoting the dynamic processes which maintain genetic variability and enable adaptation to the changing environment. In an ideal situation a gene reserve forest contains all age classes, the adult trees are in good shape to flower and produce seed and there are plenty of seedlings for the next generation. Therefore, a typical old-growth forest is not ideal for gene conservation. Late-successional stage forests represent the outcome of natural selection from a long time ago and are therefore adapted to the past, and not necessarily the future, environment. In addition, old trees are often vulnerable to external threats such as extreme weather events. This is why gene conservation differs from traditional habitat conservation efforts regarding an optimal management strategy. In the agreed European minimum requirements for a gene reserve forest, active management is listed as one of the basic requirements.

The management plan in Lapinjärvi is based on positive experiences from silvicultural measures in the same forest in 2005, when thinning and creation of small openings proved useful in promoting natural regeneration and reducing insect damage. In Lapinjärvi, the average tree diameter is relatively large, but the trees are not remarkably old. The regular management practices in the forest have been continuously documented since 1933.  The present management area does not include any known nationally endangered or vulnerable species.

Lapinjärvi forest is administered by Metsähallitus, which is also responsible for the forest’s operational management, as commissioned by Natural Resources Institute Finland, with the common goal of preservation of this internationally valued genetic resource.


Source: Natural Resources Institute Finland