The Oostvaarderplassen is a nature reserve in the Netherlands,
Despite its age, the polder it exists in only became dry in 1968, it has an international importance as a European wetland. The Oostvaardersplassen can be divided into two areas, wet and dry.
In the wet area along the Markermeer , there are large reedlands on clay, where moulting geese often feed. This area is also home to cormorants, spoonbills, barnacle geese, white herons and the Great Bittern, among many other animals.
The dry area was originally a habitat for willow trees. The first year hundreds of seedlings could be found on a square metre. The area is kept open by konik, deer and Heck cattle. These big grazers are kept out in the open all year round without supplemental feeding. The theory is that in time, the current open landscape will evolve into a natural forest. The only big grazers missing are the moose and the wisent (European bison). It is unlikely that the moose will be introduced but there is hope for the wisent as it fills a different niche from Heck cattle.
The Oostvaardersplassen today covers 5600 ha, of which 3600 ha are marshland and 2000 ha are grasslands and roughs.

 

source: oostvaardersplassen.biofaan.nl