PROJECT DESCRIPTION
BACKGROUND
The Zouweboezem is a valuable wetland located in the Netherland’s province of South Holland. It has been designated as a Special Protection Area (SPA) and as a proposed Site of Community Interest (pSCI). The LIFE project area at the Zouweboezem, covering 126 ha, is largely owned by the South Holland Landscape Foundation. This marsh site consists mainly of reed beds, part of which is cut annually in the winter, and sections with perennial reeds. There are multiple waterways and groves distributed through the area, which has a particular high nature value for marsh birds, including purple heron, bittern, marsh harrier, spotted crake, black term, blue-throat and gadwall.
The high nature value of the Zouweboezem had been threatened by changes to the wetland habitat and formation of dry land in the marsh area. Reed and floating reed beds had been partly replaced by solid ground and newly created woods. In addition, sludge had clogged the waterways, which adversely affects drainage and water quality. This decreases breeding opportunities for various species for which the habitat is protected, including the purple heron, and also damages habitat conditions for fish species.
OBJECTIVES
The project’s main objective aimed to maintain and to improve the breeding and feeding possibilities for all marsh birds, especially the purple heron. By creating new options for breeding locations, the project set out to encourage the purple heron colony to divide itself into two or more locations. In order to reach these objectives, measures were taken to establish semi-natural hydrological conditions. Parts of the project site containing old and dry marshland were to be restored to wet areas hosting common reed beds. Forest land was also to be transformed into open marsh and the amount of mowed common reed fields would be decreased.
RESULTS
A programme of successful measures was implemented by the project to maintain and strengthen the rich natural values of the Zouweboezem. These included restoring succession processes in 4 ha of overgrown perennial reed by excavating soil just below the average water level. The area of perennial reed was increased by excavating soil (so encouraging reed growth) and also by reducing the area of reed that is cut annually. Project actions set in place work to reduce the amount of mown marsh area from 18 ha to approximately 9 ha. It was noted that stopping annual cutting completely is not desirable because this traditional land use method forms part of the area’s cultural heritage.
Banks of waterways were flattened to both create spaces for fish and increase water edge areas for reeds. Further project actions dredged almost 40 000 m3 of sludge from various waterways to increase water quality. Smaller scale measures resulted in the clearing of ditches, smoothing of ditch banks, and creation of three new pools for amphibians. Outcomes are expected to benefit protected species (like the great crested newt) and also to have a positive effect on the food supply of marsh birds.
Ongoing monitoring is helping to direct the site’s long-term management and favourable trends have already been observed indicating progress in the development of healthy reed beds, plus restored forage areas for marsh fauna.
Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).A programme of successful measures was implemented by the project to maintain and strengthen the rich natural values of the Zouweboezem. These included restoring succession processes in 4 ha of overgrown perennial reed by excavating soil just below the average water level. The area of perennial reed was increased by excavating soil (so encouraging reed growth) and also by reducing the area of reed that is cut annually. Project actions set in place work to reduce the amount of mown marsh area from 18 ha to approximately 9 ha. It was noted that stopping annual cutting completely is not desirable because this traditional land use method forms part of the area’s cultural heritage.
Banks of waterways were flattened to both create spaces for fish and increase water edge areas for reeds. Further project actions dredged almost 40 000 m3 of sludge from various waterways to increase water quality. Smaller scale measures resulted in the clearing of ditches, smoothing of ditch banks, and creation of three new pools for amphibians. Outcomes are expected to benefit protected species (like the great crested newt) and also to have a positive effect on the food supply of marsh birds.
Ongoing monitoring is helping to direct the site’s long-term management and favourable trends have already been observed indicating progress in the development of healthy reed beds, plus restored forage areas for marsh fauna.
Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).
