A New Tree Generation
Regeneration secures the emergence of a new tree generation. In multiple-use forests, silviculture is generally based on regeneration fellings followed by a regeneration phase, and then tending of seedling stands and thinnings. In forest regeneration it is important to select the correct regeneration and site preparation methods as well as tree species that are suited to the site. These decisions will secure the establishment and good early development of the seedlings in the regeneration area.
Forests are usually regenerated either naturally, using seed-tree felling, or by clear-felling followed by sowing or planting. Existing viable seedlings and seedling groups are utilised when establishing a new stand. In regeneration areas, forest cover is also maintained by groups of retention trees and single trees left in them.
The site preparation methods used are as light as possible but sufficient to facilitate regeneration. It is also important to identify poor sites that will allow seedling establishment without preparation. Buffer zones are left along water bodies to prevent any leaching of nutrients from regeneration areas.
Regeneration areas are designed to follow natural boundaries as much as possible. This way they will blend in with the landscape of the surrounding terrain and forest.
In gap felling, the site is regenerated in stages and preserving the landscape character, making small gaps that vary in size and shape. Generally, gap felling is applied to 20–25% of the total area of the site. In southern Finland the gaps are up to 0.5 hectares in size, while further north the maximum size of a gap is one hectare.
Retention felling is a regeneration felling that leaves clearly more retention trees than usual. It can be applied to landscape sites or sites aimed at increasing the amount of deadwood in the long term.