Forest structures and their importance for biodiversity : studied along a gradient of human impact

This study was conducted to find out if there are forest structural differences along a gradient of human impact: tree plantation, semi-natural forest, and natural forest. Two, forest areas in the north of Sweden were selected; Kulbäcksliden, which is dominated by mesic to moist spruce forest with gap dynamics, and a forest in the Eco park Skatan, which due to dry soils historically have been dominated by pine forest and fire dynamics. An assessment was made from the sampled areas to test if they, according to the Swedish Forest Agency checklist, could be counted as woodland key habitats. The study areas are located in the Vindeln municipality, Sweden. Boreal forests in the region historically had structures controlled by either forest fires or gap dynamics. However, due to today’s forestry oriented for maximize productivity, the former large variation in forest structures have largely decreased, and with them a large part of the diversity of flora and fauna. Policy wise, Sweden have both a production goal and an environmental goal concerning the forests. However, today, one can argue that in practice the production goal weighs heavier, and with that follows an intense conversion of forests to plantations. This leads to diminishing populations of species of various forest organisms, mostly due to habitat loss. This study showed that in Kulbäcksliden there was a significant difference in structure among plantations, semi-natural forests, and natural forests, concerning occurrence of high biodiversity value trees of spruce, and fallen dead wood. In Eco park Skatan, this study showed a significant difference in the number of high biodiversity value trees of spruce and standing dead wood between a natural forest and a semi-natural forest. Furthermore, of the five areas that were investigated, only the two natural forests in each area could be counted as a woodland key habitat. This indicates that our modern-day forestry destroys structures that are essential for many species, which can lead to declining populations. If we want to conserve our flora and fauna, we need to change our policies regarding our forestry and make the environmental goal equally important to the production goal, not only in theory, but also in practice. To do this we need to spread awareness to the public about the situation in our forests