Lowland Wetland
Lowland wetlands encompass those habitats known as bog and
fen. They do not include open waters such as lakes and rivers, and
they interface with the 'wet' end of several other habitats such as
heathland, grassland, and wet woodland. Several types of lowland
wetland are Priority Habitats under the
UK Biodiversity Action Plan.
Raised bog is an acidic, nutrient-poor environment, composed only
of peat and fed solely by atmospheric precipitation. Fen, on the
other hand, is also dependent on groundwater, and may also contain
inorganic matter as silt. The constituents of the groundwater and
land management practices determine what sort of fen it is –
perhaps base-rich in chalk and limestone areas and nutrient rich
where fed by lowland rivers.
Estimates of current extents are imprecise, but in the UK
there are probably about 5,000 ha of reedbed, less than 6,000 ha of
intact or slightly degraded raised bog, and an undetermined area of
fen, though individual areas, such as the Norfolk Broads may be
large (3,000 ha).
Lowland bogs may be affected by peat cutting, afforestation,
landfill and built development. Biodiversity Action Plan (BAP)
targets to shift UK horticulture onto peat alternatives, and
updated forestry policy, are expected to reduce some of the
pressure. Recently, the UK government has provided compensation to
stop peat extraction on England's three largest lowland bogs. Fens
are vulnerable to agricultural claim, drainage, water abstraction
and nutritional enrichment from diffuse and point source pollution.
Both bogs and fens can benefit from carefully targeted and designed
agri-environment incentives. Whole-catchment planning for water
resources and agriculture are especially important for bogs and
fens. Active raised bogs and several types of fen are priority
habitats under the EC Habitats Directive and support many species
of plant, animal and birds of international importance.
- the development of common standards for evaluating the
condition of individual wetland features;
- providing specialist advice to support site designations;
- site condition monitoring.
The work involves overviews of the national extent of fens and
bogs, and their more detailed classification. The use of remote
sensing methods is being explored to estimate the current extent
and condition categories of lowland raised bog in the UK and to set
a baseline against which change can be measured. Other inter-agency
research includes the hydrological requirements of fens and bogs,
especially at their boundaries.
Resources
Report 366 Remote Sensing of Bog Surfaces
(2005)
Report 365 Characterisation of Hydrological
Protection Zones at the Margins of Designated Lowland Raised Peat
Bog Sites (2005)
National Report submitted to the 8th Meeting of
the Conference of the Parties, Valencia, Spain, 2002 (2002)