ogging in combination with input of acidifying compounds especially in Scandinavian boreal forest ecosystems slowly depletes the soils of essential elements. Recycling of wood ashes counteracts depletion and withholds vital forests.

Forwarder spreading fly ash from Kristianstad heat plant

o be able to manage a forest ecosystem and to be successful in silviculture You need basic knowledge in what a sustainable forest ecosystem is. Different schools has their own definitions which can be summarized in a short sentence: To maintain the biodiversity and productivity of the ecosystem even though the need for economical and social aspects should be fulfilled.

o household with the elements in the forest soils, not accepting further soil acidification or soil depletion due to misplaced logging regimes seems fundamental. Let me give an example. The soil profile of a typical Northern Boreal forest ecosystem could contain 25 000 kg/ha of calcium, but the easily moveable and plant available store of the same element is only 70 kg/ha. In the light of this it is obvious that sustainability only goes together with careful treatment of the supply of elements in the soil. To find the right mix of tree species, logging regimes, turn over rates and recycling rates to maintain productivity as well as species diversity and social and economical aspects of the forests are challeging tasks for foresters and ecologists now and in the future.