Download HABITAT FACT SHEETS.indd - Kent Biodiversity Action Plan

P. Williams
Improved grasslands
I
mproved grasslands account for the majority of all
grassland found in rural and urban parts of the UK.
They are dominated by grass species, with few flowers,
and are often sown for agricultural or recreational use.
Alternatively, modifying or ‘improving’ unimproved
grasslands, by applying large quantities of fertilisers
and selective herbicides, can create improved
grasslands. They are particularly characterised by the
abundance of rye-grass species (Lolium spp) and white
clover (Trifolium repens). Sometimes these grasslands
are temporary and sown as part of a rotation of
arable crops, in which case they are known as leys.
On farmland, when these grasslands are not used
to graze livestock, they are often mown regularly, to
produce silage. This is where the cut grass is allowed
to ferment slightly, which preserves it during storage.
Improved grasslands in non-agricultural settings are
often used for recreational or amenity purposes, such
as parkland and football pitches, and are usually cut
even more often.
The biodiversity of improved grasslands is usually low.
Using fertilisers allows a small number of fast growing
grasses and flowering plants to grow at the expense of
other species. Typical improved grasslands are dominated
by rye grass, with varying amounts of other common
grasses such as red fescue (Festuca rubra), large-leaved
timothy-grass (Phleum pratense), rough meadow-grass
(Poa trivialis), meadow fox-tail (Alopecurus pratensis),
crested dog’s tail (Cynosurus cristatus) and cock’s-foot
(Dactylis glomerata). The few flowers found are common
species and, as well as white clover, can include small
amounts of creeping buttercup (Ranunculus repens),
greater plantain (Plantago major), ribwort plantain (P.
lanceolata), daisy (Bellis perennis), common mouse-ear
(Cerastium fontanum) and yarrow (Achillea millefolium).
Fields with a high stocking density, which leads to the
creation of areas of bare ground, have large numbers of
docks (Rumex spp), thistles (Cirsium spp) and/or ragwort
(Senecio jacobaea).
Most improved grassland does not have much
conservation importance in itself. Rather, it is the mosaic
of grassland, arable land, hedgerows and woodlands,
which form our rural landscape, that is important for
wildlife. However, very locally, improved grassland can
provide a habitat for wildfowl feeding in winter. In some
areas where open water occurs near improved grassland,
internationally important numbers of birds such as
Greenland white-fronted goose (Anser albifrons flavirostris),
barnacle goose (Branta leucopsis) and widgeon (Anas
penelope) gather to feed. Where the grass is not cut too
often, and stocking densities are low, ground-nesting birds
such as lapwing (Vanellus vanellus) and skylark (Alauda
arvensis) can use improved grassland. Skylarks are a UK
Biodiversity Action Plan species because, although they
are still common, the UK population declined by 54%
between 1969 and 1991. Other birds that use improved
grassland include starling (Sternus vulgaris), a Birds
of Conservation Concern Red List species (breeding
population decreased and/or breeding range contracted
by 50% or more in the last 25 years) and, in winter, golden
plover (Pluvialis apricaria).
grass
Results of the Countryside Survey 2000 estimate that there
are approximately 5,500,000 ha of improved grassland in the
UK, or about 24% of Great Britain, slightly more than the area
covered by crops. In Kent, improved grassland covers around
100,000 ha (representing about 26% of the total land cover) and
is found throughout the county. Along the north Kent coast,
areas of improved grassland are important for wintering birds.
Grazing marsh in Kent, much of which is improved grassland,
is concentrated along the Greater Thames estuary, in the Swale
estuary, Dartford marshes, and on the Walland and Romney
Marshes, with small areas at Sandwich Bay, Stodmarsh and
north of Dymchurch on the south east coast.
The UK Biodiversity Action Plan (UKBAP) defines Improved
Grassland as a Broad Habitat Type within which coastal &
floodplain grazing marsh is classified as a Priority Habitat
Type. Improved grassland is one of the few habitat types in
the UK that is not currently under threat. However, there has
been a trend in recent years towards further intensification, by
using non-native, aggressive strains of grasses, which outcompete native strains, combined with heavy use of fertilisers.
This in turn has decreased the biodiversity value of improved
grassland. The general trend towards cutting grass earlier in
the season has also affected ground-nesting birds that breed in
improved grassland.
Areas of improved grassland that are nationally important for
wintering birds are designated as Sites of Special Scientific
Interest (SSSI), meaning that the sites are of national
conservation importance, and areas of county importance
are designated as County Wildlife Sites/Sites of Nature
Conservation Interest. The Medway Estuary and Marshes
SSSI and The Swale SSSI are internationally important for
their wintering wildfowl, and are therefore classified as Special
Protection Areas (SPA) under the EU Birds Directive and
designated as Ramsar sites under the Wetland Convention.
Both contain improved grassland as part of a network of
FURTHER INFORMATION:
UK Biodiversity Action Plan: www.ukbap.org.uk
Kent Biodiversity Action Plan 2004: www.kentbap.org.uk
English Nature: www.english-nature.org.uk
Kent Wildlife Trust: www.kentwildlife.org.uk
Royal Society for the Protection of Birds: www.rspb.org.uk
Environment Agency: www.environment-agency.gov.uk
The Kent Red Data Book, available from Kent County Council:
www.kent.gov.uk/sp/biodiversity/data.html
The Kent & Sussex Farming and Wildlife Advisory Group has
helpful information on techniques for farming in a wildlife-friendly way, and some of the suggestions do not cost
anything to implement. Their website is: www.fwag.org.uk/
grazing marshes along the north Kent coast. In addition,
the voluntary Environmentally Sensitive Area scheme
for land managers in the North Kent Marshes promotes
the sensitive management of areas of conservation
importance.
Landowners can act to improve the biodiversity value
of improved grassland by sowing native strains of
grasses that are less aggressive and likely to support
more invertebrates, and by reducing the fertiliser and
herbicide inputs, allowing increased variety of plant
species and habitat structure to appear. A wildlife-friendly
mowing regime will increase the value of the grassland
for biodiversity, e.g. leaving central areas of long grass
in the breeding season for ground nesting birds suck
as skylarks, and retaining a headland of unmown grass
around the edges of sites to provide
shelter for invertebrates and small
mammals. Cutting grasslands from
the centre outwards helps to prevent
the unnecessary death of wildlife.
Very high intensity grazing should be
avoided as it can be detrimental to the
biodiversity value of the grassland,
and will encourage docks and ragwort
to invade. If these suggestions are
implemented by all landowners in
Kent, over a quarter of the county’s
land area will be of increased value to
biodiversity.
Published: 2004
grass
Kent Biodiversity Action Plan:
For more information on the targets set
by the Kent Biodiversity Partnership
for Improved Grassland and to view a
copy of the Kent Habitat Action Plan
for coastal & floodplain grazing marsh,
go to www.kentbap.org.uk.