Seeds and Seedlings for Forest Regeneration in the Nordic Forestry
In the Nordic countries, forests have always played an important role. Forests provide wood and bioenergy, protection against wind and erosion, support biodiversity and act as carbon dioxide sinks, as well as important areas for outdoor recreation and human health. When it comes to climate change, the forest is especially important because it binds carbon dioxide throughout its lifetime. In addition, timber can replace other materials that give large emissions when produced.
For all these purposes, it is important to keep a healthy and resilient forest, with sufficient genetic diversity for adaptation to climate change. Sufficient regeneration with the proper seed and plant material is crucial.
Forest regeneration after harvest may be executed differently in the Nordic countries, and for the various species, either by natural regeneration using seed-trees, by direct sowing or by planting of seedlings. For the main commercial species, planting of seedlings based on genetically improved seeds are used when such seeds are available.
This report aims at giving an overview of the use of seeds and seedlings in the Nordic countries, with key statistics from Denmark, Finland, Iceland, Norway and Sweden.
For all these purposes, it is important to keep a healthy and resilient forest, with sufficient genetic diversity for adaptation to climate change.
NordGen Forest
NordGen Forest is a Nordic body dedicated to forest regeneration, plants, seeds and genetic resources. Our main goal is to contribute to the establishment of the best possible Nordic forests for the future, through knowledge exchange and dialogue.
NordGen Forest is supported by two networks, the NordGen Forest Regeneration Council and the NordGen Forest Working Group on Genetic Resources, each with members from all the Nordic countries.
NordGen – the Nordic Genetic Resource Center – is a Nordic organization dedicated to safeguarding and sustainable use of cultivated plants, farm animals and forest trees.
Overview of the Most Important Species in Each Country
Choice of species for forest production varies across the Nordic region based on which tree species are naturally occurring and which thrive and produce under different climatic conditions. This, and the fact that available statistics vary among the countries, makes comparisons challenging across countries. Therefore, not all statistics are presented for all countries and species.
Seedlings in Sweden, Finland, and Norway
As an overview of the most important species in the production chain for the different countries the amount of seedlings delivered to the forestry in 2021 is shown below (Figure 1-4). In Finland, Sweden and Norway the two conifers Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) make up most of the plant production for forestry. Norway spruce makes the biggest share for commercial production of these two due to the large extent of natural regeneration and direct seeding of pine. Sweden has the largest forest area while Norway has the smallest among these three countries.
Top photo: Michael Angeloff/NIBIO.
Sweden
452.000.000 seedlings in total
Figure 1
Figure 1-3 shows rounded percentage of seedlings delivered to Swedish, Finnish and Norwegian forestry in different species categories in 2021. The total amount is rounded to thousand seedlings.
Finland
152.088.000 seedlings in total
Figure 2
In the category "Other" the percentage is 0,2 percent.
Norway
45.502.000 seedlings in total
Figure 3
In the category "Other" the percentage is 0,5 percent.
Flowering spruce (Picea abies). Photo: Arne Steffenrem Skogfröverket/NIBIO.
Seedlings in Iceland
The main species used for afforestation in Iceland is the native birch (Betula pubescens). Silver birch (Betula pendula) may be an alternative in lowland areas with increasing temperatures. Seeds are collected in the wild or from planted trees. Other important species in Iceland include Larix sibirica, Larix decidua and the hybrid Larix sibirica x Larix decidua, Populus trichocarpa, Pinus contorta, Picea sitchensis, Picea glauca and Abies lasiocarpa (Christmas trees).
Iceland
5.319.000 seedlings in total
Figure 4
Percentage of seedlings delivered to Icelandic forestry in different species categories in 2021.
Afforestation in Iceland
The first official National Forest Plan for Iceland was published in August 2022 by the Ministry of Food, Agriculture and Fisheries. After years of cutbacks due to the economic recession from 2008, the afforestation budget in Iceland has started to increase again, especially due to the efforts to reach the goals of the Paris Agreement on Climate change and the system of carbon credits causing an increased interest from the private sector and foreign companies to invest in afforestation in Iceland. In the next ten years about 15.000 hectares will be planted and 350.000 hectares of land will be restored by birch forest with natural methods. In 2022 Iceland reached 2 percent cover of forest and woodland. Another milestone this year was that the tallest tree in Iceland, a sitka spruce planted in 1949 at Kirkjubæjarklaustur, reached 30 meters height.
Seedlings in Denmark
Seedling statistics for Denmark is not available. As an overview of the most important species in the Danish forestry, the proportions of the total forest area covered by each species are presented in the pie chart below. It is important to note that the conifers are planted and introduced species, whereas for instance beech (Fagus sylvatica) and sycamore (Acer pseudoplatanus) often are regenerated naturally. Furthermore, the yearly use of seedlings is higher for short-rotation Christmas trees (e.g. Abies species) than for typical long-rotation species such as oak (Quercus spp).
Denmark
640.835 hectares in total
Figure 5
Area of the 10 most common tree species in Denmark. References: Nord-Larsen, T., Johannsen, V. K., Riis-Nielsen, T., Thomsen, I. M., Bentsen, N. S., & Jørgensen, B. B. (2023). Skovstatistik 2021.
Forest Areas Are Set Aside for the Benefit of Nature
With the goal of a total of 75,000 hectares of untouched forest, approximately 12 percent of the forest area in Denmark would be left untouched. The majority of the forests becoming untouched are state-owned.
In 2022 an important milestone in the work of setting aside areas was reached as 28.000 hectares of state-owned forest was selected for this purpose. With this latest setting a side of areas the goal of a total of 75.000 ha of untouched forest is almost reached.
A common thing for the untouched forests – regardless of where they are located – is the stop of commercial forestry, and that dead trees and fallen trunks are left in the forests for the benefit of biodiversity.
In the implementation of the untouched forests there will be a restoration period, where different processes are initiated through a number of restoration activities. These restoration activities include for instance felling of mainly non-native conifer species. Also, the hydrology of the areas is restored by closing of ditches and drains, so small lakes, bogs and mires again become an integrated part of the forests. Veteranization of trees will assure higher levels of standing and laying dead wood in the untouched forests.
Cutting of hardwood tree species will gradually be phased out, in order to ensure the accessibility of certified wood during a transitional period to the Danish sawmills.
Time Series for Plant Deliverance
The deliverance of seedlings to forestry is presented below for the years 2006-2021 for Norway, Sweden, Iceland and Finland.
Picea abies
Figure 6
Figure 6-14 shows the number of million seedlings to the forestry planted in each country and year.
Pinus sylvestris
Figure 7
The low numbers of pine seedlings in Norway is due to the fact that pine traditionally has been regenerated naturally.
Abies spp.
Figure 8
Data for Norway not available for the years before 2021.
Iceland
For the past decades forest seedlings have been stored outside over the winter time in Iceland. There is a growing interest in using freezers to store seedlings during the winter, as this method eases the transportation of seedlings and can better guarantee their quality.
A PhD project, carried out by Rakel J. Jónsdóttir, compares survival, growth and autumn freezing tolerance for seedlings stored in freezers and in an outdoor storage. After planting the seedlings at various dates in early spring and summer. The result will help to deal with increasing production and planting of seedlings.
Betula spp.
Figure 9
The category Betula spp. (birch) contains aggregated numbers for all species of birch where data were available.
Larix spp.
Figure 10
Data for Sweden not available for the years before 2019.
Pinus contorta
Figure 11
Data for Sweden not available for the years before 2011.
Sweden
In 2021, 452 million seedlings were delivered in Sweden, which is an increase by 11 percent since 2020. Scots pine has increased since 2013 and is now the most common species to be planted in Sweden. Also the amount of spruce seedlings has increased since 2020, but on a lower level than Scots pine. After several years of decrease, Lodgepole pine (Pinus contorta) has increased in the two last years, to an annual delivery of 10 million seedlings. The most common broadleaved tree species sold in Sweden is birch, with 1.8 million seedlings delivered in 2021.
Popolus spp.
Figure 12
Aspen forest, photo: Lars Sandved Dalen/NIBIO.
Other conifers
Figure 13
Data for Sweden not available for the years before 2019.
Other broadleaves
Figure 14
Data for Norway and Sweden not available for the years before 2021.
Forest for Climate Mitigation in Norway
In 2016 NOK 33 mill was allocated to climate mitigation measures within the forest sector in Norway. The funds were divided into three different uses; denser planting of forest, fertilization and breeding. There was a shortage of spruce seedlings in Norway the same year. Political aim and increased funding for climate mitigation measures, including denser planting of forest, caused a growing demand for seedlings.