Many species are adapted to live in open environments.
In even-aged forests, the last operation in forest rotation is regeneration felling. Most trees are harvested then, resulting in an open regeneration area. But not all trees are taken away. Retention trees are left to add structural variation and deadwood in the future forest. In addition, trees growing on the buffer zones to waters are not harvested and key habitats are kept outside of logging operations. Existing deadwood is left for biodiversity. By planning the placement of retention trees, the post-harvest landscape can also be enhanced.
A mature forest stand allows less sunlight to pass through and consumes most of the growth resources in forest soil. When final harvesting takes place, conditions change drastically. The space occupied by dominant big trees is reallocated to species that can’t thrive under a closed canopy. In fertile soils, different grass and weed species take their place in ground vegetation. Bracken (Pteridium aquilinum) appears and raspberry (Rubus idaeus), one of the major Finnish forest berries, finds a suitable habitat as a light-requiring plant. Due to big changes in vegetation, the insect fauna changes accordingly. Regeneration areas, with their blooming vegetation, attract pollinators.
The regeneration area remains open only for a short time. A new generation of trees is established soon after the final felling, often in the same year or the year after. Planted tree seedlings are accompanied by naturally regenerated seedlings. The new forest stand soon succeeds and trees take back their dominant position within a couple of years.
When looking at the forest landscape from a wider perspective, regeneration areas, young forest stands and mature forests change their place over time. It is important that on the landscape level, forest stands of different ages and development stages exist. Wood harvested from regeneration area is balanced by the growth of other forest areas at the same time. Sustainably managed forests continually offer resources to answer the needs of both nature and people.