Marshes, bogs and swamps: area
Between 1950 and 1990 the area of marsh, bog and swamp in the Netherlands increased.
| Area of marsh, bog & swamp per geographical region | ||
| geographical region | 1950 | 1990 |
| hectares | ||
| Carr peat area | 24 800 | 20 540 |
| Marine clay area | 8 160 | 17 080 |
| River clay area | 4 160 | 4 040 |
| High-lying sandy soils | 6 070 | 5 540 |
| Total | 43 190 | 47 200 |
| Source: CBS | CBS/NC/Oct02 | |
Area
The total area of Marsh, bog and swamp in 1990 is estimated to be just under 50 000 ha. This area includes extensive wetlands such as the Naardermeer (960 ha), the Oostvaardersplassen (5000 ha), the Weerribben (3115 ha), the Wieden (4663 ha), the Nieuwkoopse plassen (1085 ha) and the Alde Feanen (1340 ha).
Trends
Marsh, bog and swamp is one of the few ecosystems that increased in area between 1950 and 1990 (by over 9%). A further increase is anticipated because of habitat creation projects, particularly those around the river region. It is expected that not only the birds of marsh, bog and swamps but also the Eurasian beaver will benefit from this.
In about 1990 the total area of marsh, bog and swamp was over 47 000 hectares, compared with over 43 000 hectares in about 1950. This represents an increase of 9%. The increase is largely because of the creation of the Oostvaardersplassen in the newly reclaimed polder province of Flevoland and the closing off of tidal inlets (for example, Lauwersmeer), which resulted in saltmarsh becoming marsh.
Most of the marsh, bog and swamp habitats are in the carr peat and marine clay areas.
Many Dutch marshes, bogs and swamps are too small for many species to be able to survive in them for a long period, particularly if these areas are very isolated. It is not only habitat fragmentation that puts the flora and fauna at risk: a further problem is that the vegetation is not rejuvenating and shrubs and trees are encroaching. Other negative factors are intensive mowing regimes and water recreation. Pleasure boats can be damaging because of the wash they create and because reed is damaged when they are moored.
