|Resultaten van een gedempt getijdenregime in polder Breebaart|
Peletier, H.; Wanningen, H.; Speelman, B.; Esselink, P. (2004). Resultaten van een gedempt getijdenregime in polder Breebaart. Levende Nat. 105(5): 191-194
In: De Levende Natuur: tijdschrift voor Natuurbehoud en Natuurbeheer. Stichting De Levende Natuur: Oosterbeek; Amsterdam; 's-Graveland. ISSN 0024-1520, more
|Authors|| || Top |
- Peletier, H.
- Wanningen, H.
- Speelman, B.
- Esselink, P.
Polder Breebaart is located in the NE of The Netherlands, on the edge of the Eems-Dollard estuary, The polder was embanked in 1979, and became a nature reserve in 1991. A plan to restore tidal influence was developed by the Foundation 'Het Groninger Landschap' together with Water Board 'Hunze en Aa's', Since 2001, seawater flows in from the estuary through a culvert in the sea-wall. The effects of this drastic change in the ecological situation in the former polder are monitored by following the populations of the microflora, vegetation, macrofauna, fish and birds. After three years on the sediment-rich outer edges dense algal mats have developed with species charaderistic of brackish shallow tidal flats. The original vegetation has disappeared completely to make place for vegetation adapted to saltwater such as Glasswort, Annual seablite, Lesser sea spurrey and Sea aster. The bottom fauna did not come in yet, its density is still very low. Fish in the former polder are diadromous and estuarine species. Birds such as Avocet and Black-headed gull are dominant in the area. In the former Breebaart polder sediment accumulates at a rate of 30 cm per year. The area will consequently change rapidly in a morphological sense. A clear fresh-to-salt gradient has not been achieved yet. The monitoring programme has a high educative value; many volunteers participate. The developmentof a new natural situation in this former polder can be regarded as a model for other areas that could become brackish again, influenced by tides -the situation of past times. More-over, the development in Breebaart shows that natural conservancy, participation of the public and artificial nature development can go together quite well.