Active raised bogs are a priority habitat for conservation and are included in Annex I of the Habitats Directive. This habitat has suffered a steep decline in Europe in recent years. In Lille Vildmose (and in Denmark overall) active raised bogs have an unfavourable conservation status. This is mainly due to drainage, the invasion of trees, in particular birch, and deposition of airborne nitrogen from agricultural use and long-distance transport.
The objective of the Lille Vildmose project was to restore the largest remaining raised bog in lowland northwest Europe, Lille Vildmose in Denmark. The project aimed to improve the conservation status of this priority habitat by facilitating re-growth of sphagnum moss and raising the water table in areas of degraded raised bogs or in areas where peat has been excavated. These actions will result in a significant enlargement of the habitat area. Other wetland habitat types, such as natural dystrophic lakes and ponds, transition mires, and quaking bogs will also increase in size and number. Bog woodland coverage will decrease in areas selected for active raised bog restoration but will increase in other areas thanks to restoration – many areas have until recently been used for peat extraction.
The Lille Vildmose project achieved all its objectives to protect and improve the Lille Vildmose active raised bog in Denmark, by enhancing ecological coherence and connectivity. This resulted in the improvement of the conservation status of the entire Nature 2000 site. Most of the effects of the projects measures are expected to unfold over many years, as the raised bogs habitats gradually respond to the restored hydrological system. However, in many areas the response has been immediate and is already visible.
Significant improvements in hydrological conditions have occurred, particularly in the impacted edge areas where active raised bog borders farmland. The large-scale clearance of tree growth and the introduction of grazing by large herbivores is expected to significantly improve the conservation status of 2 100 ha, mapped as the habitat type Active raised bogs (7110*), which was in unfavourable conservation status mainly due to birch invasion and desiccation. The projects actions also restored and improved other habitat types in Annex I of the Habitats Directive: Degraded raised bogs still capable of natural regeneration (7120), as well as Natural dystrophic lakes and ponds (3160), Transition mires and quaking bogs (7140) and Bog woodland (91D0*) on more than 900 ha.
Due to the significantly enlarged wetland areas, combined with a predator-control programme for securing breeding sites for ground-nesting birds, living conditions for the Annex I species black stork, wood sandpiper, hen harrier, white-tailed eagle, crane, and short-eared owl have been improved. However, due to initial low national population sizes, it will take more time to see significant results. Furthermore, the predator-control actions have revealed that even with a large effort, especially for racoon dog, populations still seem to increase. This trend is also seen in the rest of the country and in neighbouring countries. Several rare moth and butterfly species occur in the central parts of the raised bog areas, including two with their only Danish occurrence here (Orgyia recens and Idaea pallidata).
Today, the overall Natura 2000 site is one of the largest and most coherent natural area in Denmark, with unique opportunities to experience large areas of a unique type of natural wetland. With the designation as a wetland of international importance through the Ramsar Convention in 2013, Lille Vildmose is today used as a case study in how to restore peatland areas. In August 2013, Lille Vildmose was the first wetland site in the history of the Ramsar Convention to be considered for a Ramsar criterion on climate regulation.
The many actions to raise the water table have initiated the succession towards bog. The intention of the 770-ha new established wet areas in Mellemomrdet was to establish a more coherent bog that over time will bind together the fragments of existing raised bog. The raised water level in Hstemark Fenner increased sphagnum moss populations spontaneously in former peat excavation sites, revealing the right conditions for a succession towards raised bog vegetation.
The project helps implement the EU Habitats Directive; Biodiversity Strategy to 2020 and 2030 Biodiversity Strategy (by protecting species/habitats and maintaining and restoring ecosystems); and climate change policy by reducing the emission of greenhouse gases from drained peatlands. The estimated carbon content in the organic soil (peat) of Lille Vildmose is approximately 7.4 million ton or approximately 10% of the Danish peat carbon volume.
The inoculation of sphagnum mosses on former grass fens has provided valuable knowledge on how to design, prepare and maintain a site for conversion to bog. The construction of large dams unique in Denmark also led to innovate new tools, such as a metal box for incorporating watertight PE membrane in peat soil.
The project raised interest in raised bogs ecology and conservation at local, regional and national levels. Lille Vildmose Naturfond (LVNF) funded the production of a film, shot using a drone, showing the many project activities. The film can be viewed on the project website. Project actions significantly increased visitors, especially attractive being the restored Lake Birkes, new public facilities, and grazing by deer and moose. More people passing through the visitor centre in Lille Vildmose generated additional funding for visitor facilities. The economic benefit of Lille Vildmose has been estimated at around 1.4 million per year, with increased economic flow in the area generating 16 to 18 new jobs.
Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).