Preferring mixed forests increases the overall sustainability of forests

In Finland, even-aged trees of a single coniferous species have traditionally been preferred in silviculture. Forest management practices need to be updated to prepare for climate change and coordinate the goals set for the use of forests. Mixed forests offer a solution to increase the overall sustainability of forests.

Global warming increases forest damage especially in spruce forests. We can prepare for climate change by increasing the proportion of pine and silver birch as well as other less-used deciduous trees in silviculture.

Spruce forests continue to be the most profitable financially speaking. Mixed forests help not only prepare for any future damage but also coordinate various goals. The goal of mixed forests is to coordinate wood production, carbon sequestration, damage resistance and biodiversity in forests.

When establishing a forest consisting of a single tree species or a mixed forest, it is important to select the correct species for each growth location. In more recent and vital locations, the planting of spruce seedlings may also be the dominant regeneration method in the future, but silver birch should be preferred more broadly in forest regeneration. According to our studies, currently planted spruce seedlings grow so rapidly during early stages that natural silver birches in a planted spruce stand can generate a mixed forest growing at the same pace.

Information about the impact of different tree species on regeneration results in specific growth locations was produced in the Forest management regimes of mixed forest project (2020–2023). It was part of the Ministry of Agriculture and Forestry’s Catch the Carbon package of climate measures. Its measures aim to reduce greenhouse gas emissions in agriculture, forestry and other land use sectors, and strengthen carbon sinks and stocks.