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Location Belgium, Vlaams Gewest
Central coordinates 5o 11.00' East  51o 1.00' North
IBA criteria C6
Area 7,010 ha
Altitude 15 - 50m
Year of IBA assessment 2000

BirdLife Belgium

Site description The area is situated in the Demer river valley, west and east of the town of Diest. It comprises a rich variety of former river arms, peat ponds, marshes, reedbeds, sedge-fields, humid grasslands and alluvial forests, including heathland relicts on the sandy hills bordering the valley.

Key Biodiversity A breeding and staging area for meadow birds, waders and waterfowl.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Bluethroat Luscinia svecica breeding  1995  65-80 breeding pairs  good  C6  Least Concern 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Demerbroeken Nature Reserve 57 protected area contained by site 57  
Langdonken Nature Reserve 62 protected area contained by site 62  


IUCN habitat Habitat detail Extent (% of site)
Forest Alluvial and very wet forest; Broadleaved deciduous woodland  10%
Grassland Humid grasslands  15%
Wetlands (inland) Standing freshwater; Water fringe vegetation  20%
Artificial - terrestrial Arable land; Forestry plantations; Perennial crops, orchards and groves; Urban parks and gardens  60%

Land use

Land-use Extent (% of site)
agriculture 40%
forestry 30%
nature conservation and research 20%
urban/industrial/transport 10%
tourism/recreation 5%

Protection status National Low International High57 ha of IBA covered by Nature Reserve (Demerbroeken, 57 ha). 62 ha of IBA covered by Nature Reserve (Langdonken, 62 ha). 7,010 ha of IBA covered by Special Protection Area (De Demervallei, 7,010 ha).

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Demervallei. Downloaded from on 27/10/2016

To provide new information to update this factsheet or to correct any errors, please email BirdLife