Restoration from military training area to National Park

Restoring the Hjerkinn military training area to natural state has set the standard for ecosystem restoration. The project demonstrates the full cycle of a large-scale restoration and illustrates the diversity of measures, solutions and cooperation needed during such an extensive project.

Before-after: Standard method to remove roads included removing added gravel, reshaping original terrain surface and transplanting turfs from road verges to wipe out the artificial borders and promote vegetation recovery. Photo: Dagmar Hagen/NINA.

The Hjerkinn military training area at Dovrefjell used to be the largest military training facility in southern Norway, 165 km2, and used for military purposes since 1923. Soldiers from Norway and allied countries used the area for training and testing of equipment and ammunition until 2008.

Two decades of restoration

In 1999 The Norwegian Parliament closed down the existing military training area of Hjerkinn in the Dovrefjell area, as part of a larger decision on reorganising and updating military training facilities in southern Norway. The decision specified that the closure included restoration of the area for civilian use, future protection and “back to original” ecosystem and landscape quality.

A region of significant natural and cultural value

The Dovrefjell area is a region of significant natural and cultural value, and the military area is surrounded by protected areas. This area is a high-mountain ecosystem where the wild reindeer is a key species, and the area also hosts populations of wolverine, arctic foxes, golden eagles, gyrfalcons and other rare and threatened animal species, a high number of rare and red-listed plant species and a large diversity of vegetation types. Main vegetation types include lichen heaths and shrub heaths, mires as well as alpine meadows and snow beds. Dovrefjell holds the only European population of musk oxen, which was introduced from Greenland in the 1950′s and remains highly attractive for tourism and wildlife watching

A standard technique for removing roads and permanent constructions

The technical removal of roads and infrastructure was implemented by professional construction companies and organised as annual tenders, according to legal regulations. Standard method to remove roads included removing added gravel, reshaping original terrain surface and transplanting turfs from road verges to wipe out the artificial borders and promote vegetation recovery.

In drained or filled wetland areas, such as peatland and freshwater habitats, the drainage tubes were dug out, and the construction gravel removed down to the original water level, with the purpose of restoring original hydrological structures and drainage.

Production of native species for large scale restoration

The establishment of new vegetation in the restored sites in Hjerkinn PRO mainly relied on recovery through the natural dispersal of seeds and plant fragments in transplanted turfs, or from intact surroundings. Ib large and severely disturbed sites active planting and seeding were used to speed the development of a vegetation cover for ecological and aesthetical reasons. Due to legal restrictions, commercial seed from introduced plant material to support the restoration could not be used, and the project produced native seeds and plants for this purpose. Local seeds of Festuca ovina were collected locally and propagated. In addition propagated native willow species were planted in severely disturbed sites.

“Green training”

Hjerkinn PRO developed an innovative system for interactions between project owner contractors and restoration ecologists. “Green training” is a three-step model for cooperation and learning, improving the ecological understanding of restoration among the contractors, ensuring a common language between operators, project owner and restoration ecologists, and from this make the operators’ technical expertise available to the project.

Before-after: The restoration at Hjerkinn is unique throughout Europe due to its size and complexity. Part of the success is beeing able to both see the big picture and focus the smallest elements. Photo: Dagmar Hagen/NINA.

The outcome from the restoration is reported according to the overall goal, and four subgoals, set by the Norwegian Parliament:

1. Considerable nature benefit

In total 80.5 km of roads were removed, and the restored area amounted to 5.2 km2. More than 120 subterrain tubes were removed to restore natural hydrology systems. Additionally 80 buildings and 8 bridges were demolished and recycled. As roads and technical infrastructure were removed, the interference-free area, located greater than 1 km from heavy infrastructure, more than doubled, from 51 km2 to 114 km2. Road removal also increased available habitat for wild reindeer.

2. Nature Protection

The Natur Protection Plan for the area was developed in parallel with Hjerkinn PRO by the Coubty Governor. In 2018, major parts of the former military area was protected as National Park and Landscape Protected Area.

3. Civilian use

Almost 100 years of military use have left a considerable risk for undetonated explosives ordnances (UXO) in the area, in addition to substantial amounts of associated waste and shrapnel. Clearing the area has been a major task in Hjerkinn PRO, and a premise for secure future civilian use. More than 15,000 soldiers searched the entire area on foot, more than 19,000 UXOs were found and destroyed, and 550 tons of metal trash were removed.

4. Restore back to natural state

The early monitoring revealed that removal of added gravel from roads was a prerequisite for vegetation recovery, and that reshaping the terrain allowed for recovery of the local vegetation community.

The monitoring and parallel research in the area show that time is the most important factor for establishment of species and vegetation cover, which is important to communicate to project owners, the public and other stakeholders, to ensure realistic expectations on recovery time.

The restored area of 5.2 km2 consisted mainly of lichen heaths and shrub heath, with some wetlands and mires. The newly restored landscape is capable of storing an estimated 54,500 t carbon, with the additional sequestration of over 1,800 t carbon per year from net primary productivity. This is equivalent to taking 4000 vehicles off the road each year.

On-site restoration projects demonstrate the potential for restoration on a landscape scale, and systematic evaluation of these projects is needed to build knowledge for the future upscaling of restoration. The restoration of the Hjerkinn military training area demonstrates the full project cycle of a large-scale restoration and illustrates the diversity of measures and solutions needed during the implementation stage of such an extensive project.

Before-after: From combat education to ecosystem restoration. The project was approved by the Norwegian Parliament in 1999. The Norwegian Defence Estate Agency was commissioned to do the job. The goal was to restore the area to natural state. It is now protected as National Park and Landscape Protected Area. Photo: Dagmar Hagen/NINA.