Regeneration and regeneration fellings

In natural regeneration, pine and silver birch (Betula pendula) seedlings grow from the seeds of seed trees left in the regeneration area or the surrounding stand. Natural regeneration is suitable for pine in nutrient-poor and dry habitats where surface vegetation does not hinder seedling development. Especially in Northern Finland, natural regeneration felling should be carried out in good seed years. 

Throughout Finland, the natural regeneration of spruce requires good seedling emergence before the actual regeneration felling. Natural regeneration is often slower and seedlings become more uneven in density than when cultivated. Soil preparation speeds up and ensures seedling growth.

In the cultivation process, the forest is regenerated either by seeding or planting. The planting is suitable for regeneration of all tree species. Before planting the seedlings, the soil is prepared. The preparation method is selected on the basis of the place of growth, tree species and soil type, taking into account water protection and landscape values. The recommended planting density varies by tree species and is usually about 1,600 to 2,500 seedlings per hectare. Seeding is usually done mechanically during harrowing or scalping to make it cost effective. By seeding you can regenerate pine and silver birch stands. Broad-leaved tree seedlings naturally grown from seeds complement conifer seedlings and make the forest species-richer and healthier.  

Seeds or seedlings of breeding origin can be used in cultivation and the benefits of forest breeding can be exploited. Cultivation is also a good choice in forests where there is an abundance of Annosum root rot or resin‐top disease. Cultivated seedlings are healthy, unlike local underbush. Cultivation also allows for the change of tree species. 

After the regeneration, it is good to monitor seedling emergence and the growth of seedlings. Weed control is often necessary on eutrophic sites, that is, in mesic heath forests and on more eutrophic heath soil sites. Eutrophic peatlands and fertile mires are also easily grassed. Weed control is usually done mechanically by stamping or mowing the harmful vegetation around the seedlings. It is also possible to control weed growth with various chemical substances.  

The timing of regeneration is influenced by a number of factors. The timing of regeneration is often a compromise between economic and biological factors as well as the goals of the forest owner. It is economically viable to regenerate a stand when value growth falls below the set yield requirement. Regeneration felling is the most economically profitable felling method in forest management.   

In even-aged silviculture, the regeneration felling method is influenced by whether the forest is regenerated naturally or by cultivation. Clear cutting is done when the forest is regenerated by cultivation. Clear cutting is suitable for all tree species and sites. In clear cutting, old trees are removed from almost the entire regeneration area. Usually, only groups of retention trees are left to promote the emergence and diversity of rotten trees. In the clearing of the regeneration area, all underbush is left in the groups of retention trees, and in addition, dense bush growth can also be left for forest animals. 

Pine and birch-dominated forests can be regenerated by seed tree felling. In practice, 20 to 100 trees per hectare of healthy, good-quality and good-crowned seed trees are left on the regeneration area. Felling should be carried out in good seed years. Once seedlings have started to emerge on the regeneration area, the seed trees are removed to allow the seedlings to develop evenly. Seed trees are best removed when the seedlings are protected by snow. After seedling emergence, some of the seed trees are left as retention trees and groups of retention trees. 

In strip felling, coniferous forest is naturally regenerated with the help of an edge zone forest. The width of the strip to be felled can be 25 meters from such an edge zone forest. The felling method is mainly used in the moorlands of Northern Finland and in the eutrophic peatlands of Southern Finland, for example in mire coves. In strip felling, it is also a good idea to leave retention trees to secure the rotted tree continuum. 

Shelterwood felling can regenerate spruces naturally. The method is multi-step and risky. It is successful mainly in peatlands. The regeneration begins ten years before the regeneration felling of the forest by thinning the stands to the lower limit of the thinning model. If vital and viable spruce seedlings emerge in the area, an actual shelter felling can be done. In the felling, good quality pines and birches are left to protect spruce seedlings against ground frost and grassing, and spruces are left to ensure seedling emergence. Shelter trees are left on 100-300 hectares. Spruce seedlings born at the shelter trees removal stage are always damaged in felling, so there should be plenty of seedlings. 

According to the Forest Act, forest owners have the right to manage and use their forests in the ways required by diversity, landscape and multi-use. Special fellings are usually carried out in areas of scenic importance, sites important for diversity, such as open and sun exposed southern slopes, and in outdoor and recreational areas and routes. 

Special fellings can also be carried out on the sites comprising habitats of rare plants and other species. On the sites reserved for teaching, research or other special use, felling may be carried out as required by the intended use. Deviating felling methods and their reasons must be indicated in the forest use notification, which is submitted to the Finnish Forest Centre 10 days before the commencement of the measures. 

 From the Metsään.fi-service,  you can check if there are sites in your own forests suitable for regeneration felling. The measures proposed by the service are based on Tapio’s Best Practice Guidelines for Forestry. Prior to the commencement of the measures, a forest use notification concerning regeneration felling should be submitted to the Finnish Forest Centre.