Propagation and development of dry, moist and wet heath in the Dwingelderveld SPA and pSCI
The former agricultural enclave 'Noordenveld' (about 220 hectares) located in the heart of the Natura 2000 area Dwingelderveld is a serious threat to the existence of habitat types *H7110, H7150, H4010, H3160 and H7120. The Noordenveld has a draining effect on the Natura 2000 Area Dwingelderveld and causes dehydration, eutrophication and acidification of the heath system. Finally, after 40 years
Natuurmonumenten (Dutch Society for the Preservation of Nature) and Staatsbosbeheer (Dutch Forestry Service) have succeeded in procuring the last agricultural plots in the Noordenveld.
The core of this LIFE project proposal is the restoration of the natural water balance of Dwingelderveld and the transformation of the Noordenveld into dry heath (H4030), moist heath (H4010) and depression vegetation (H7150). This transformation is essential for the existence of the wet heath system and active raised bogs (*H7110) in the Dwingelderveld.
The proposed measures will create a robust, sustainable and continuous water system that has a positive influence on the quality and quantity of the acid fens, moist heaths and raised bogs over an area of more than 1100 hectares. In addition, around 360 hectares of new moist heath (H4010), acid fens (H3160), dry heath (H4030), depression vegetation (H7150) and species-rich grasslands (*H6230) will be developed.
The province of Drenthe, Staatsbosbeheer and Natuurmonumenten - the three partners in this project - support the same goals in the Dwingelderveld: combating dehydration, eutrophication and acidification of the Dwingelderveld, enlarging the area of moist heath (H4010) in the Natura 2000 area, improving the quality of the habitat types H3160, *H7110, H7150, H7120 and H4010 and reducing disruption to animals and birds characteristic to the area.
The province is the competent authority and has the ultimate responsibility for setting up the Natura 2000 Dwingelderveld management plan (in the context of the Nature Conservation Act). Together with the Ministry of LNV the province of Drenthe is ensuring that the objectives for the area are achieved.
Staatsbosbeheer and Natuurmonumenten own and manage the majority of the Dwingelderveld.
Natura 2000 Area Dwingelderveld
The Natura 2000 Area Dwingelderveld is a nature reserve in the south-west of the province of Drenthe (see attached map 1). As most of the heathland has disappeared in Europe, the Dwingelderveld is now the largest continuous wet heathland of Western Europe. The nature values are unique, as is the
location of the area within a virtually intact farming-village landscape. In 1991 the Dwingelderveld was therefore proclaimed by the Ministry of Agriculture, Nature and Food Quality (LNV) as a National Park.
The area comprises about 3,800 hectares and is part of the national Ecological Main Structure and qualifies as both a bird directive area and a habitat directive area (Natura 2000 area). The area contains expansive areas of moist heath, fen-bogs, acid fens, active raised bogs, dry heath, drift sands and juniper shrubs. The area contains more than 15 % of the acid fens (H3160), moist heaths (H4010) and active raised bogs (*H7110) in the Netherlands. The Dwingelderveld contributes greatly to conserving these habitat types.
As well as the value of the area for various habitat types the area is also very important to birds. Over 90 species of nesting birds can be found in the Dwingelderveld, both in fens and marshes and in open and half open heaths. In the draft decision the area is designated for bird species such as Woodlark,
Bewick's swan and Black woodpecker (79/409/EC, appendix I) and Little grebe, Black necked grebe, Whinchat, Common stonechat, Shoveler, Wheatear and Teal (79/409/EC, section 4.2). The area has also been designated for the rare Northern-crested newt (92/43/ EC, appendix II).
Actions and means involved:
Turning the Noordenveld into heathland
Located within the Dwingelderveld is the former 'Noordenveld' agricultural enclave. The groundwater levels are being kept artificially low for the benefit of agriculture by a system of drainage channels and ditches. This has resulted in dehydration and acidification of the heathland in the Dwingelderveld. It has a negative impact on the quality of the habitat types present, H3160, H4010, *H7110 (priority), H7120 and H7150. Now that Staatsbosbeheer and Natuurmonumenten have acquired the agricultural land, it can be developed into dry heath (H4030), moist heath (H4010), depressions (H7150), acid fens (H3160) and species-rich grasslands (*H6230). The groundwater levels can be raised. However, as the topsoil of the Noordenveld is very rich in phosphates as a result of fertilisation for agricultural purposes, it must first be removed before the groundwater levels can be raised. If this is not done, internal eutrophication will occur in the Noordenveld and nutrients, particularly phosphates, will drain away to the very sensitive heath system to the south-west of the Noordenveld. Hence, the main goal of the project, before raising the groundwater level, is the removal of the topsoil.
On the basis of phosphate research it has been established how much of the topsoil has to be removed in order to create the right conditions for the development of dry and moist heath on the Noordenveld. Along with the removal of the topsoil, the original depression structure of the area needs to be restored. Ditches, gullies and channels must be filled. After the ditches and gullies are filled and the phosphate retentive super stratum has been removed, the old depression landscape will appear again. This will create the right conditions for habitat types H4010, H4030, H3160, *H6230 and H7150 to develop. Digging up the nutritious super stratum will lead to a varied and moist heath landscape within ten years, with species-rich grasslands (*H6230, priority), among others, in the habitat gradient towards the dry heath landscape. This is a considerably shorter time than would be possible through natural phosphate degradation processes.
Using removed topsoil from the Noordenveld for acoustic fencing along A28
Approximately 552,000 m3 of topsoil must be removed in the Noordenveld. Most of this topsoil will be used as acoustic fencing along the A28 motorway. This will achieve two goals. The removed topsoil will be processed very close to the source, ensuring lower transportation costs and less CO2 emission. At the same time the road traffic noise from the A28 over an area of about 135 hectares will be reduced to a level acceptable to nesting birds, thus enlarging the nesting and resting area for birds native to the area.
Restoration of the natural water balance in the Dwingelderveld
To restore the natural drainage via the system of depressions all the gullies, ditches and channels that currently disrupt that system need to be filled. These are the gullies and watercourses in the Noordenveld as well as the drainage ditch (LV-20) between the two areas.
Where the natural borders of the strata in the heathland have been lowered or removed, for example where they are bisected by gullies, ditches and old, worn dirt tracks, these 'borders' must be restored to their original height. This way, the water can 'accumulate' in the strata and drain gradually and naturally.
The water will infiltrate the substratum and can flow through the boulder clay.
The measure will lead to an improvement in the natural water balance by restoring the system of depressions in the Dwingelderveld. The measure will have a very positive influence on the quality of the habitat types H3160, *H7110, H7120, H4010 and H7150 and is an essential condition for the conservation and qualitative development of these rare habitat types in the Dwingelderveld.
Monitoring conditions for managing the development of heath
As part of the project, the development of dry and moist heath will be monitored. After removing the topsoil from the Noordenveld the vegetation development and micro, meso, and macrofauna will be monitored in wet and dry parts of the area under differing management conditions. The results of the measurements in the first three years will be evaluated and presented at a seminar at the end of the
LIFE period (see action D.7). Following the LIFE project the monitoring will continue for three more years. The knowledge and experience gained from this demonstration project will be circulated within the Netherlands and Europe through various means (seminars, brochures, publications, see form C1d).
Expected results (outputs and quantified achievements):
The effect of the conversion of the former agricultural enclave Noordenveld into heathland will result in enlargement of the important habitat types - dry heath (H4030, about 103 ha.), moist heath (H4010, about 107 ha.), depression vegetation (H7150, about 6 ha.), acid fens (H3160, about 20 ha.) and species-rich grasslands (*H6230, about 5 ha).
Combating dehydration and acidification by restoring the natural water balance will also lead to an improvement in the quality of the habitat types active raised bogs (priority, *H7110), moist heath (H4010), acid fens (H3160), recovering raised bogs (H7120) and depression vegetation (H7150) within the existing heath system with an area greater than 1,100 hectares. Wetting the Dwingelderveld is expected to increase the area of moist heath (H4010) outside the Noordenveld by about 160 hectares, the area of acid fens by about 34 hectares and the area of depression vegetation (H7150) by around 8 hectares. This will be partially at the expense of the dry heath (H4030).
In the long term, and given sufficient hydrological restoration of the Dwingelderveld, an increase in the development of habitat type *H7110 active raised bogs (priority raised bog landscape) from habitat type H7120 recovering raised bogs will be possible.
The installation of the acoustic fencing along motorway A28 will result in an increase in suitable nesting and resting biotope of about 135 hectaresThe biotope of several important nesting birds present in the Dwingelderveld will be enlarged substantially by this measure. The main species that will benefit from this measure are the Black woodpecker, Woodlark (79/409/EC, appendix I), Little grebe, Black necked grebe, Common stonechat, Shoveler and Teal (79/409/EC, section 4.2).