At Hjerkinn in the Norwegian mountains, nature is gradually reclaiming the restored landscape. Following Norway’s largest-ever restoration project, systematic long-term monitoring is providing valuable insights into what has worked well — and why.
The monitoring at Hjerkinn ranges from detailed vegetation surveys in small permanent plots to large-scale landscape monitoring and drone-based remote sensing. Photo credit: Dagmar Hagen/NINA
Norway’s largest-ever restoration project, carried out in the Dovre mountains, was completed in 2021. The Norwegian Institute for Nature Research (NINA) has since continued monitoring vegetation and landscapes in the former Hjerkinn military firing range on behalf of the Norwegian Environment Agency.
This long-term and systematic monitoring provides important knowledge about the long-term effects of nature restoration, which measures have worked well, and why.
– The knowledge we gain from monitoring allows for better planning and outcomes of future restoration projects, says Marianne Evju, Senior Researcher at NINA.
Restoring mountain vegetation in Arctic Norway takes time. Monitoring shows that there are still significant differences between vegetation on former road sections and in the surrounding terrain.
However, the results also show positive development: nature is gradually reclaiming the restored areas.
Different Monitoring Methods Provide a Comprehensive Overview
To restore the Hjerkinn firing range, roads and other installations were removed, and various measures were implemented to facilitate vegetation recovery.
Researchers have used three main monitoring methods.
The first is detailed vegetation monitoring in fixed, small plots. All species and their abundance are recorded, allowing researchers to track indicators such as vegetation cover, species richness, and species composition over time.
Because the restored areas are extensive, broader-scale monitoring is also necessary. Through large-scale field assessments, researchers evaluate the effects of restoration measures on landscape structure, terrain, regrowth, and wetland systems. Among other things, they have examined whether short-term results can predict long-term outcomes.
The third method involves drone-based remote sensing. Researchers have assessed how useful drones are for evaluating vegetation recovery and terrain development following restoration.
Nature is gradually erasing the former roads that were removed in the Hjerkinn firing range. Drone photo credit: Andrew Gray/NINA
Insights from Hjerkinn
Results from all three monitoring approaches point in the same direction and together provide several important insights.
– For example, we see that removing imported gravel and reshaping the terrain to match the surrounding landscape is key to restoring vegetation when former roads are removed, says Evju.
Another important lesson is that both the technical solutions chosen during restoration and the natural conditions at the site influence how vegetation develops over time.
– Decisions made during the process – concerning costs, time use, choice of machinery, and so on – are important for the final result. That is why knowledge and expertise among the involved actors are crucial, Evju explains.
Monitoring also shows that the effects of restoration measures can change over time. Short-term results do not necessarily predict long-term outcomes.
– This demonstrates why long-term monitoring is essential. In Norway and internationally, we know that the lack of long-term data following restoration limits our ability to plan and implement effective restoration measures, says Evju.
The different monitoring methods offer complementary perspectives on ecological condition and development.
Drone monitoring is well suited to assessing vegetation regrowth. It covers larger areas than traditional vegetation plots and is more objective and repeatable than large-scale field evaluations.
– At the same time, drone monitoring does not capture species composition, information about the restoration measures themselves, or the trade-offs made during implementation. It is a valuable supplement to other methods, but it does not replace them, says Evju.
Essential for Expanding Nature Restoration Efforts
Systematic and long-term monitoring of completed restoration efforts is essential for increasing the knowledge on the effects of various restoration methods under varying environmental conditions. This provides a foundation for more effective and efficient restoration in future projects.
– Without proper documentation and monitoring, there is a risk that good solutions are overlooked – or that ineffective solutions are continued. Thorough follow-up is also important for building legitimacy for technical solutions and for the fact that restoration takes time. Such legitimacy is crucial for scaling up restoration efforts and achieving the global biodiversity target of restoring 30 percent of degraded nature by 2030, says Dagmar Hagen, Research Director at NINA.
Read more: Hjerkinn Firing Range – Monitoring of Restored Areas. Results from 2023–2025 (Summary in English).
Learn more about nature restoration at Hjerkinn here
Contact: Marianne Evju