Sonja Canger

Tree Improvement Station, The National Forest and Nature Agency, 3050 Humlebæk, Denmark

The Norway spruce area in Denmark covers 135 000 ha corresponding to 32% of the total forested area. Norway spruce is by far the most important exotic species in Danish forestry.

Norway spruce was introduced into Denmark in the last half of the 18th C and the first imports of seed presumably originated from Germany (Harz and Thüringer Wald). Large quantities of seed were harvested from the first plantings. A good part of the existing Danish Norway spruce stands are probably third or fourth generation from the first imports.

It is assumed that natural selection and domestication activities have led to the formation of landraces, which are especially well adapted to Danish conditions.

During the 19th C and the beginning of the 20th C the Danish seed production was supplemented by new imports, primarily from Germany but also from Finland and Sweden. Seed imports during the last 50 years have been of various origin, mainly from Middle and Eastern Europe.

Norway spruce is one of the 75 tree and shrub species included in the 1994 Danish strategy for conservation of forest genetic resources. It is the aim of the strategy to select and conserve two or three Norway spruce stands adapted to climate and growth conditions west of the glacial stagnation line and two or three stands adapted to climate and growth conditions east of the glacial stagnation line. It is also the aim of the strategy to regenerate, for conservation purposes, particularly healthy and vigorous material that currently is being substituted by improved material.

The strategy for conservation of forest genetic resources is planned to be implemented within the next 10 years. However, no stands have so far been identified/demarcated for gene-conservation purposes.

The Norway spruce genetic resources will be conserved in evolutionary conservation stands where the species will be allowed to adapt to prevailing environmental conditions and their change with time.

The conservation method to be applied in the case of establishing Norway spruce conservation stands in Denmark can be considered as a `transitional' method between, respectively, in situ and ex situ, as the species is assumed to have developed landraces.

The abovementioned conservation activities will be supplemented by long-term conservation of selected seedlots and current ex situ conservation measures that have already been undertaken in the context of tree-improvement activities.

Some existing tree-seed production areas and breeding populations also serve as ex situ conservation areas. A number of genotypes are conserved in clone and family banks and additional tested genotypes can be retrieved from existing clone and progeny tests (see Table 1).

Genetic resources of Norway spruce in Denmark are not considered as being immediately threatened or endangered. However, unless protective measures are taken the genetic variation of Norway spruce will be influenced and possibly reduced in the medium to long term by more intensive use of genetically improved material.

There is a risk that the increased use of genetically improved material will supersede landrace material. This development may result in an unfortunate situation where it will be impossible to retrieve useful basic material for breeding purposes.

Norway spruce genetic resources will be protected as described above.

Table 1. Existing tree seed production areas, clonal banks and breeding populations that also serve as ex situ conservation areas. Up to 90% of the material in the trials is available.

Research concerning forest genetic resources in Denmark has so far been focused on indigenous species. However, there is a need for research on the important exotic species, i.e. scientific verification of whether evolvement of landraces actually has taken place and how the genepool has been affected by strong selection under the environmental conditions in Denmark. Further, significant genetic variation in fertility has been observed and there is a need for information on causes as well as the long-term consequences of this phenomenon.

Intensive breeding activities and provenance trials have contributed greatly to the current knowledge about Norway spruce.

Finally, much research regarding forest dieback is currently being carried out in Denmark, and Norway spruce plays an important role in this research since it is one of the species that is most threatened by forest dieback.

Generally the public awareness of the importance of conservation of forest ecosystems as a whole is very large and it has grown over the last few decades. The public interest in forests has led to various government initiatives, e.g. a strategy for conservation of natural forests and other forest types of high conservation value in Denmark.

The overall objective of the strategy is to conserve the biodiversity of the Danish forests, including the forest genetic resources. The preparation and implementation of the strategy has been covered by the news media and followed closely by all major Danish NGOs interested in environmental issues.

However, conservation of genetic resources of trees probably has lower priority among the public than conservation of forest ecosystems.

As Norway spruce is not a native species in Denmark, the conservation activities in the species' natural distribution area are obviously regarded as very important.

It follows from this view that information on specific conservation activities concerning Norway spruce in other European countries is very important from Denmark's perspective.

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