6th European Conference on

ECOLOGICALRESTORATION10 September 2008 | Ghent (Belgium)

Excursion MapBourgoyen-Ossemeersen

Excursion Bourgoyen-Ossemeersen

(Gent, Oost-Vlaanderen)

10 September, 2008

Bourgoyen - Ossemeersen (Gent, O. Vl.)

1. Short description of the area 1.1. name, municipality

Gent (prov. Oost-Vlaanderen)

1.2. biogeographical region

Pleistocene river valleys

1.3. management authority

City of Gent & Natuurpunt

1.4. protection status

Nature reserve, no Natura 2000 area

1.5. ecological characteristics

Species rich floodplain meadows and marshes, partly also groundwater fed, total area of 230 ha

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2. Map w

ith managem

ent units

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3. Management/restoration objectives and techniques 3.1. Period 1985-2008

Starting point and restoration measures

After the construction of a major canal around Gent the Bourgoyen-Ossemeersen became isolated from the southern floodplain meadows along the river Leie. The area was drained for more intensive agricultural land use. High winter water levels with vast parts of the area flooded during longer periods were history. In 1985 a weir was constructed to hold up water levels from rainfall during winter. This resulted in the yearly flooding of the lowest meadows (c. 100ha) in the central and western part from the end of October till March.

Objectives Species rich wet meadows with breeding meadow birds.

Management measures Mowing and grazing after breeding season. Banning of pasture.

Evaluation After many years of management species rich meadows dominate with abundance of target species as Rhinantus angustifolius, Myosurus minimus, Veronica scutellata, Eleocharis palustris, Odontites vernus, Scutellaria galericulata … The reserve has become one of the main wintering areas for ducks and waders in Flanders (proposed Ramsar site). Species as Wigeon (Anas penelope), Shoveler (Anas clypeata), Teal (Anas crecca), Ruff (Philomachus pugnax) and Lapwing (Vanellus vanellus) are abundant. Breeding numbers of Black-tailed Godwit (Limosa limosa), Lapwing, Shoveler and Tufted Duck (Aythya fuligula) all increased. Future points of attention for sustainable results: Cyclical dredging will be necessary to maintain open water communities in the ditches. Also the removing of invase willows in the ditches and lowest meadows after dry summers will be necessary because they are problematic for both plant communities, wintering and breeding birds. Eradication of breeding Canada Geese (Branta canadensis) still needs future attention.

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3.2. Period 2004-2007

Starting point and restoration measures (see map) (1) Over a total lenght of 2 km in the canal “Loopgracht”, 17.000 m³ of partly polluted sludge

is removed. (2) Restoration of the marshes “Schapenweide”: During the construction of a major canal

around Ghent in the 1960-ies, an area of 14 ha of the marshes were raised with sandy and partly polluted soil. A total volume of 210.000 m³ of soil is digged off to restore the original level of the marshes, including the reconstruction of the historical network of ditches.

(3) Construction of new weirs: The construction of the noise reducing dams along the

highway destroyed the existing weir which was used to hold up water levels from rainfall during winter.

Objectives (1) Removal of heavy-metal-polluted sludge. Restoration of a stable aquatic environment in

the canal for water related fauna and flora. (2) Restoration of the historical landscape with marshes. Restoration of historical species rich

(peaty) meadows with development of local marshy areas and open water. (3) The construction of 3 new weirs re-ensures an adequate water management in the

reserve.

Management measures Seasonal high water level (winter), possibility for grazing and mowing in summer if not to wet.

Evaluation Restoration of the marshes “Schapenweide”(2): In the pioneer stage the open water is dominated by Charophytes and Stellaris palustris. A thorough inventory is scheduled next year. The marshy parts are dominated by Salix spec., Lythrum salicaria , Mentha aquatica, Lycopus europaeus, Phragmites australis and Iris pseudacorus. From early spring on, when water levels are lowered in the surrounding meadows, the area is the main attraction for all species of waterbirds as open water with mudflats are available into the summer. This resulted in much higher breeding numbers of all species of ducks (mainly Shoveler and Gadwall (Anas strepera)), Little Grebe (Tachybaptus ruficollis). Great Cormorant (Phalacrocorax carbo) colonised the area with 0 tot 132 nests in 4 years. Garganey (Anas querquedula) returned to the area after a non-breeding period of 10 years and also Common Tern (Sterna hirundo) and Little Ringed Plover (Charadrius dubius) have been breeding. Migrating waders occur now in tenfolds of the former numbers.

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Future points of attention for sustainable results: Restoration of the marshes “Schapenweide” (2): Salix spec. invades the areas from seeds on exposed mudflats in June-July. During the summer of 2007 high water levels halted a further expansion but this will probably reoccur in the future. Mechanical removal of these young trees is hardly possible. Holding higher water levels in the summer with intensive mowing in surrounding meadows in drier periods might create a bigger water body with development of mudflats in the transition zone to the meadows. Controlled invasion of reed beds in high water zone might attract lost breeding species such as Little Bittern (Ixobrychus minutus) and Savi’s Warbler (Locustella luscinioides), while mowing might halt expansion of trees to transition zone.

3.3. Public support

Lying next to a major city the area has thousands of visitors each year (3000+ on best days). With a new footpath along the longest side of this new restoration area with large numbers of waterbirds, both breeding and wintering, the public greatly enjoys the walk along this side of the reserve. Supporting authorities are the Agency for Nature and Forests, Flemish Land Agency and the Research Institute for Nature and Forest.

4. Annexes 4.1. Annex 1: Project perimeter, nature restoration ‘Bourgoyen-Ossemeersen’ 4.2. Annex 2: Recreation facilities

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Annex 1: Project perimeter, nature restoration ‘Bourgoyen-Ossemeersen’

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Annex 2: Recreation facilities

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VLAAMSE LANDMAATSCHAPPIJUW PARTNER IN DE OPEN RUIMTE