Stora Enso increases mixed forests by decreasing spruce density in Finland
Stora Enso has launched a new operating model at its logging sites in Finland to improve the vitality and biodiversity of forests. In practice, this is done by reducing the density of planted spruce from 1,800 seedlings per hectare to 1,600 seedlings per hectare. This will increase mixed-species forests, which is one of the overarching objectives of Stora Enso’s biodiversity programme and part of the actions both in Finland and Sweden. A mixed forest is defined as a forest in which the main tree species does not exceed 75% of the growing stock. It may consist of coniferous trees (such as spruce or pine), broadleaved trees (such as birch), or a mixture of both. These kinds of forests are the environments where biodiversity prospers: especially broadleaved trees create vital habitats for many endangered species. Currently, broadleaves are a minority in boreal forests, which is why concrete actions are needed. As a new endeavor, forestry operations in Finland have expanded their biodiversity programme with the plan to decrease the density of spruce seedlings. Unlike many other tree species, spruce thrives also in the shadow. This means that when planting density is reduced, the spruce seedlings will let in more sunlight and thus create better conditions for other natural tree species, such as pine and birch. Forests that consist of diverse tree species are also more adaptive to the changes and risks posed by climate change..