WET WOODLAND ACTION PLAN
The Trees and Woodlands Sub Group of the
Northamptonshire Biodiversity Partnership Group has developed this Plan. The group comprises representatives from
Boughton Estate, English Nature, Forestry Commission, Northamptonshire County
Council, Rockingham Forest Trust, Royal Forestry Society and The Wildlife
Trust.
Lead Agencies: Public Sector Forestry Commission
Voluntary
Sector Royal Forestry Society
Wet Woodlands frequently occur in mosaic with
other woodland and open ground habitats. Many alder woodlands are ancient and
have a long history of coppice management that has determined their
structure. Other Wet Woodland has
developed through natural succession on open wetlands and structurally has
encountered little influence from direct forestry treatments. While few rare
plants depend on Wet Woodlands per se,
there may be relict species from the former open wetlands.
Wet Woodlands occur on poorly drained or
seasonally wet soils, usually with alder, birch and willows as the predominant
tree species. It is found on
floodplains as successional habitat on fens and bogs, around water bodies and
along stream and hillsides flushes. The
soils on which these woods occur range from nutrient-rich mineral to very acid,
nutrient-poor organic soils. Boundaries
with dry land woodland may be sharp or gradual and can change over time though
natural succession or as a result of human influence.
Habitats included in this plan:
Ancient
Woodland Sites
Willow / alder
carr
Riverside
trees for example willow pollards
Associated Habitats:
Lowland Mixed
Woodland
Ancient Woodland Sites are sites that have had
a continuous woodland cover since at least AD1600 and where the original tree
cover has been felled and replaced.
These differ from the majority of other Ancient Woodland Sites in the
ground flora they support.
Wet Woodland on these sites combines elements
of many other ecosystems and is important for many taxa. The number of
invertebrates associated with alder, birch and willows is very large.
Example One: High Wood, near Preston Capes, Northampton.
Grid Ref. SP590548
High Wood
(16ha) is one of a localised group of Ancient Semi-Natural Woodlands lying
mainly on acid soils derived from Northampton Sands and Upper Lias clay. The woodland exhibits a high degree of
naturalness and has a well-preserved coppice-with-standards structure. The varied topography and drainage gives
rise to a rich ground flora and it is these areas, dominated by willow and
alder, which constitute the Wet Woodland on the Ancient Woodland Site.
This woodland,
a Site of Special Scientific Interest, is owned and managed by the Wildlife
Trust and is open to the public.
5.1.2 Carr
Carr woodland has a canopy dominated by willow
(Salix cinera) or alder (Alnus glutinosa) but stands vary
considerably in their overall appearance.
Where invasion is more recent, there can be a mass of bushes of varying height
and density, but older stands have a more even structure with, usually, a
single tier of forming a canopy of 4-8m high.
Here there can be an abundance of standing dead wood beneath, where
thickly-set colonising bushes have been shaded out by the developing survivors,
but long-established stands of willow carr, especially with multi-stemmed trees
which form broadly-spreading crowns, usually cast a light shade.
Example Two: Pitsford Reservoir, near Northampton. Grid
Ref. SP785700
Pitsford
Reservoir was built to supply Northampton with water in 1955. Since the late sixties The Wildlife Trust
have managed a section, north of the causeway, as a Nature Reserve. In 1971 the whole reservoir was designated
as a Site of Special Scientific Interest, principally because of the large
numbers of wintering fowl.
Four streams
enter the reservoir and their valleys form large bays of shallow water. There is evidence that the area supported
wetland fauna prior to the flooding.
Willow carr is now developing around the periphery of the Nature
Reserve.
These are individual
trees, of any age, which line the river banks throughout the county. These are important landscape features as
well as supporting a wide range of invertebrates and other species (the roots
of some riverside trees have been used as otter holts). They can also provide a stabilising function
in certain locations. Willow pollards
are a distinctive feature of many of the rivers in southern England, the Midlands
and East Anglia.
Willow pollards are
willow trees which have had their crown removed to encourage growth of young
shoots which can then be used for firewood, thatching spars, basket making or
fencing. The cutting is usually done on
a 3–15 year rotation, depending on the size of material needed. There was a cessation of willow pollarding
after the Second World War as plastics and other more convenient materials
became available. Without regular
cutting of the crown, these limbs become too heavy for the trunk and can split
the tree apart.
Example Three: Foot Meadow, near St James Retail Park,
Northampton. Grid Ref: SP752599
These willow
trees, owned and managed by Northampton Borough Council, have been pollarded in
recent years. They are mature willow
trees with large trunks. They are a
good example of the willow pollards characteristic of the Nene Valley.
Some wet woods
include habitats identified under Annex 1 of the EC Habitats Directive, for
example Residual Alluvial Forests and Bog Woodland.
Wet Woodlands are a
national priority for Biodiversity Action Plans as they are a scarce habitat
and are easily prone to damage and destruction through external forces.
There is no precise
data on the total extent of Wet Woodland in the UK, but in the late 1980’s the
Nature Conservancy Council estimated the total extent of this type in the whole
of the country to be about 50,000 – 70,000ha.
The extent of this habitat
is not known at present, although there are a number of wet flushes within
existing Ancient Semi-Natural Woodlands throughout the county.
Otter (Lutra lutra), Weevils (Melanopion minimum), Craneflies (Lipsothrix ecucullata, L. nervosa, L. errans
& L. nigristigma)
See Appendix 2 Trees and
Woodlands Priority Species for full list
·
Historical clearance and conversion to other
land-uses, particularly in woods recently established on wetland sites.
·
Lack of ongoing management, in particular
willow pollarding, leading to over-mature crowns and eventual splitting of
boles.
·
Lowering of water tables through drainage or
water abstraction, resulting in change to drier, commonplace woodland types.
·
Past and ongoing flood prevention measures,
river control and canalisation, leading to a loss of dynamic
disturbance-succession systems and invertebrate communities, as well as
reductions in the extent of sites.
·
Poor water quality arising from eutrophication,
urban effluents or rubbish dumping leading to negative changes in the
composition of ground flora and invertebrate communities.
·
Habitat fragmentation leading to the creation
of small sites which are then vulnerable to the adverse effects of adjacent
intensive land use and to loss of species dependent upon large habitats.
·
Damage from mechanical operations, which have a
detrimental impact on ground flora.
·
Diseases such as Phytophthora, a root disease of alder.
·
Some protection may be afforded this habitat as
some wet woods include habitats identified under Annex 1 of the EC Habitats
Directive, for example Residual Alluvial Forests.
5.1.2 Local
·
Statutory site protection plays a small part
locally in the conservation of this habitat type with SSSI’s notified for their
wetland and other interests characteristic of Wet Woodland.
·
There are a number of Wildlife Sites
incorporating Wet Woodland, mainly associated with the reservoirs and lakes
throughout the county.
·
Felling licences from the Forestry Commission
are required for licensable timber in woods, but “scrub woodland” may be
vulnerable to clearance as it can be outside the felling regulations.
·
Some groups of trees can be afforded protection
with a Tree Preservation Order (TPO).
·
All woodlands are expected to be managed
according to the UK Forestry Standard 1997.
·
The Forestry Commission Guide to the Management
of Wet Woodland, published 1994, is the model that should be adopted, in
particular in order to qualify for grant aid of felling licences from the
Forestry Commission.
·
Forestry Commission’s National Inventory of
Woodlands and Trees – initiated 1995 is a good source of information on the
extent, distribution and composition of woodland in the whole of the country.
·
Research is undertaken by various bodies and
individuals, for example the Forestry Commission work on Phytophthora disease
and the conservation of the black poplar.
·
The Environment Agency gathers other
information through surveys and monitoring of rivers and water quality.
·
Wildlife and tree management advice is
available locally through the statutory conservation agencies, agricultural
advisors, Farming and Wildlife Advisory Group, the Wildlife Trust and the
County Council. Arboricultural advice
is available from local planning authorities when trees are protected by a Tree
Preservation Order or in a Conservation Area.
The experience of woodland managers is also developed and promoted by
organisations such as the Small Woods Association, Timber Growers Association,
Royal Forestry Society, Institute of Chartered Foresters and Association of
Professional Foresters.
6. WET WOODLAND OBJECTIVES AND ACTIONS
|
|
OBJECTIVE |
ACTION |
LEAD AGENCY |
PARTNERS |
TARGETS |
|
6.1 |
Policy and legislation |
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|
|
Objective One: Ensure that BAP species and their habitats
are given an appropriate level of protection in local plans |
Include habitat and species protection
policies in local plans and/or supplementary guidance |
Local Authorities |
Wildlife Trust |
By 2003 |
6.2
|
Site safeguard and
management
|
||||
|
|
Objective Two: Increase the area of Wet Woodland throughout county
through the management of existing woodlands |
Where appropriate, manage existing woodlands
to promote Wet Woodland habitat, for example by selectively felling existing
trees and replanting with site native species |
Forestry Commission |
English Nature, Wildlife Trust and land
managers |
Produce and commence implementation
management plans for all SSSI and CWS Wet Woodlands by 2003 |
|
|
Objective Three: Create new areas of Wet Woodland through restoration
of old mineral sites and other areas in river valleys, in appropriate sites |
Take advantage of opportunities for new Wet
Woodland planting through negotiation with planners and mineral companies
when deciding how to restore obsolete mineral workings |
Local Authorities |
Wildlife Trust and Quarry Products
Association |
Double the extent of Wet Woodland by 2010 |
|
|
Objective Four: Create new native Wet Woodlands with locally
native species. Avoid creating new
woodlands on other valuable semi-natural habitats |
Promotion of Wet Woodland planting through
Woodland Grant Scheme |
Forestry Commission |
County Council |
As above |
6.3
|
Advisory |
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|
|
Objective Five: Provide advice to landowners on the creation
and management of Wet Woodland |
Produce local guidance notes |
County Council |
|
Ensure Wet Woodland management guidance is
included in Landscape Guidelines Handbook by 2002 |
6.4
|
Monitoring and
research
|
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|
|
Objective Six: Determine the extent and location of Wet
Woodland in the county– as component of larger woodland blocks, as component
of other habitat and areas of Wet Woodland alone |
Undertake a desktop and field survey. Compile
database with associated maps showing location of all areas of Wet Woodland
in the county |
Wildlife Trust |
Forestry Commission, Local Authorities |
By 2002 |
|
6.5 |
Communication and Publicity |
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|
|
Objective Seven: Ensure that decision makers and land managers
are aware of the location of Wet Woodland |
Publish information on the extent and
location of Wet Woodland |
Wildlife Trust |
Local Authorities |
By 2003 |
|
|
Objective Eight: Publicise the progress made in delivering
this Action Plan in a BAP Annual Report |
|
|
BAP Partners |
Annual |