Opening up for more continuous cover forestry

Clear-cutting has been the dominant logging method in Norway since World War II. An alternative to clear-cutting is what's known as continuous cover forestry (CCF).

CCF entails a suite of silvicultural systems including the selection-, shelterwood- and group systems. They have in common that at each harvest intervention, only some of the trees are felled, ensuring a continuous cover of trees. There is currently a growing interest in CCF in Norway, which suggests that the proportion of CCF will increase in the coming years.

Local conditions, such as the risk of windthrow, influence how suitable the forest is for CCF. A challenge is that a significant proportion of today's forests are dense even-aged stands which are vulnerable to windthrow after partial harvesting. Nevertheless, new studies conducted by NIBIO, NINA and NIVA show that the potential could be considerably greater than what is currently utilised. As much as 38 percent of the forest area in mature coniferous forest may be suitable for CCF.

Different proportions of CCF also affect carbon uptake. Model simulations showed that the scenario with the highest proportion of CCF resulted in an additional uptake of nearly 32 million tonnes of CO₂ by 2100. However, the simulations also showed that to be able to harvest the same timber volume as in a scenario reflecting current practice, an increased proportion of CCF would also require logging on a larger proportion of the forest area.

The study also showed that more CCF could have positive implications for certain aspects of biodiversity, primarily mycorrhizal fungi and other species that require shaded conditions. However, harvesting across a larger total area could negatively impact other animals, plants and fungi.