At 600–700 metres above sea level in Åmotsdal, Seljord, Kvistaul is a mature spruce-dominated forest with trees over 140 years old, a rich understory of herbs and ferns, and a mix of deciduous trees. Without protection, the forest could eventually be harvested.
Fossagrim and the landowner have secured the forest from harvesting for at least 30 years, allowing it to continue growing and storing carbon while preserving its existing habitat.
## Protecting a mature mountain forest
Kvistaul covers 95.1 ha and includes large, old spruce trees alongside Norway maple and other deciduous species. The forest's varied vegetation and age structure provide habitat while allowing the forest to continue developing naturally.
The preservation agreement secures continued, undisturbed forest growth and natural carbon sequestration for a minimum of 30 years.
## Key performance indicators
*Estimates, 30-year project period*
**1. Nature-positive climate benefit: 4,982 tonnes CO₂** (discounted, Parisa et al 2022, net discount rate 3.3%). Full estimate: 7,325 tonnes CO₂. Carbon that would be released through harvest stays stored in living biomass. The estimate is deliberately conservative, discounted and buffered, so the forest likely delivers more than promised.
**2. Average tree age: from 123.3 to 152.4 years**, an improvement of 29.1 years. The forest grows almost one year older for every year it stands, disproving the common assumption that forests must be felled to keep growing.
**3. Deadwood volume: from 5.2 to 15.6 m³/ha** (standing + downed), a project benefit of 12.7 m³/ha compared to harvest. Deadwood is where insects and microorganisms live and birds build their nests. It increases when the forest is left standing, and drops when it is felled.