| Introduction |
| Wet woodlands |
| Spotted Flycatcher |
| Lesser Horseshoe Bat |
Wet woodlands
are the bits of Alder Carr that we avoid if we are not wearing our wellingtons
- or is there more to it than that? Well, yes there is, but you will have to
read on if you want the official definition, as National Vegetation
Classification W1, W2, W4c, W5 and W6 sound too much like London postal codes
to lodge in the naturalist’s cranium. Because small areas of wet woodland are
spread along river valleys, flood plains, fens, mires and hollows, they do not
spring to mind as major habitats, yet they possess a very different character
to the open, drier land just a few metres away. Along the Lark, the poorly
drained Alder and Willow margins have been flooded for most of this winter, and
are one of the most fruitful birdwatching
zones. 
Otters too, are at home here (See White Admiral 50 for the SAP). The
invertebrates of wet woodlands include a number of BAP weevils and one
liverwort, but these are species which have not yet had their action plans
written, an indicator perhaps of inadequate knowledge and low priority. The
more visible birds that enjoy this habitat do have plans; the Song Thrush was
featured in White Admiral 51, and the Spotted Flycatcher SAP is reproduced in
this edition.
The rare Lesser Horseshoe bat has also been known to use wet woodland in the Brecks, and is thought to be declining with the loss of wetlands, amongst other factors.
The wet woodlands themselves have had a few good waterlogged seasons lately, but are subject to neglect, changing of water levels, silting and sometimes to poor water quality. The Habitat Action Plan sets some objectives, but it is difficult to see these being pursued as high priority targets, so the wet woodlands of Suffolk may have to settle for more neglect (which is not all bad!) On a more positive note, the wetland sites along the rivers Waveney and Little Ouse have been singled out by Norfolk and Suffolk county Councils to join the Transnational Ecological Network
(TEN), a wetland conservation project that spans similar habitat in the Netherlands and Germany. The Otter has been chosen as an indicator of habitat quality, and the project seeks to rectify habitat fragmentation and to enhance wetland biodiversity.
Wet woodlands occur on land that is ‘waterlogged or seasonally ‘waterlogged soils. They are frequently associated with river valleys, flood plains, flushes and plateau woodlands.
1 Definition
Wet woodlands can be found in a variety of situations where a high water table results from poorly drained or seasonally wet soils. Wet woodland habitats may be identified as containing a range of National Vegetation Classification (NVC) stand types. In Suffolk the following are likely to occur.
Grey willow
common marshbedstraw woodland
Salix cinerea
- Galium palustre woodland (Wl )
Grey willow -
downy birch – common reed woodland
Salix cinerea
– Betula pubescens – Phagmites australis woodland (W2)
Downy birch -
purple moor-grass woodland Sphagnum sub-community
betula
pubescens - Molinia caerulea woodland: Sphagnum sub-community (W4c)
Alder -
greater tussock sedge woodland (W5)
Alnus
glutinosa – Carex paniculata woodland (W5)
Alder - common nettle woodland (W6)
Alnus glutinosa - Urtica dioica woodland (W6)
These stands are found on flood plains as successional habitats on fens and mires, along rivers and streams, by flushes and in peaty hollows. The wet woodlands on the Boulder Clay in Suffolk tend to be considered as part of the ash - field maple - dog’s mercury woodland Fraxinus excelsior – Acer campestre Mercurialis perennis woodlands (W8 in the NVC) and are excluded from this habitat plan. These will form part of the wood pasture/parkland and mixed woodland plans.
The habitat supports a number of important BAP species in Suffolk. It is believed to be of primary importance for the weevil Melanapion minimum and a jumping weevil Rhynchaenus testaceus. It is of subsidiary importance for two birds (spotted flycatcher Muscicapa striatus and the song thrush Turdus philomelos) and the lesser horseshoe bat Rhinolophus hipposideros. Wet woodlands are believed to be used by a number of other BAP species that include a leaf-rolling weevil Byctiscus populi, the liverwort veilwort Pallavidnia lyelli, barbastelle and pipistrelle bats (Barbastella barbastellu. And Pipistrellus pipstrellus) and the otter Lutra lutra.
2 Current status
2.1 National
This habitat type has been poorly recorded both in Suffolk and nationally. An estimate for the total area of wet woodland is 50,000- 70,000 ha in the national Habitat Action Plan.
The Nature Conservancy Council estimated in the late 1980s that nationally there was between 25,000 and 30,000 ha of wet woodland.
2.2 Local
East Anglia is noted in the national context for the concentration of wet woodlands, particularly those on fens. It is estimated that in Suffolk there is less than 100 ha of W5 woodland and 170 ha of flood plain woodlands.
The commonest type of wet woodland in Suffolk is probably the alderwoods, the bulk of which are to be found in the river valleys. These frequently have a history of being coppiced, but are now largely neglected. The strongholds for these woodlands are the Suffolk Broads, the Waveney and Little Ouse Valleys and the Suffolk River Valleys ESA.
Many of the wet birch woods and willow woodlands have developed on open wetland habitats, sometimes after the end of active management.
2.3 Natural Areas
Breckland, Suffolk Coast & Heaths, The Broads, East Anglian Plain, The
Fens
3 Current factors affecting the habitat in Suffolk
Wet woodland in the county is affected by numerous direct or indirect factors.
Recession in low intensity grazing of wetland is increasing the area of wet woodland.
Fen habitats
as they deteriorate frequently develop wet woodland habitats when unknown or
undergrazed.
Direct loss of the habitat through restoration to other land uses (for example fen restoration
work).
Succession
causing changes to other drier woodland types brought on by the dumping of
silt, cessation of management or changes in water levels.
Inappropriate
or no management causing changes in the structure and flora, leading to poor
regeneration and changes in the floristic diversity
Loss of
disturbance –succession systems due to the loss of natural surface water
processes, flooding etc.
Poor water
quality leading to changes in the flora and invertebrate communities.
Changes in the
flow patterns in the land drainage systems causing changes to woodland
hydrology .
Colonisation
of the woodland by nonnative species for example Himalayan balsam.
Climate change
may have a significant impact on the hydrology and biology of these woods.
4 Current action
In Suffolk
some areas of wet woodland have been given statutory conservation status. Some
have been designated within the boundaries of Sites of Special Scientific Interest
(SSSIs).
Others have the additional protection of being within internationally
important sites. These include Ramsar sites, Special Protection Areas (SP As)
and in candidate Special Area of Conservation (cSAC).
The Suffolk
Wildlife Trust have identified County Wildlife sites (CWSs) which have some
protection through the local planning authorities development plans. A number
of conservation bodies in the county have reserves that include wet woodland
habitats. Tree preservation orders and other policy decisions may also be
responsible for the protection of some woods.
There is
within national forestry a presumption against the loss of broad- leaved
woodland to other land uses. Felling licences from the Forestry Authority are
usually required if the woods are not covered by plans approved by them. The
relevant hydrological policy issues include water level manager plans, Local
Environment action Plans (LEAPs), impoundment licences and consents for
abstraction and land drainage issued by the Environment Agency .
5 Action plan objectives and targets
1 Improve knowledge of extent, distribution and quality of wet woodlands in Suffolk.
2 Identify wet woodlands that may need clearance to restore higher priority habitats.
3 Improve the targeting of the Woodland Grant Scheme to assist in wet woodland habitats.
4 Maintain the existing extent of high quality wet woodland.
5 Initiate measures to achieve favourable condition in 100% of wet woodlands within 555Is and Special Areas of Conservation, and in 80% of the total resource by 2004. Achieve favourable conservation condition over 70% of the designated sites and 50% of the total resource h1} 2020 where appropriate.
6 Fully restore to site native species 50% of the sub-optimal wet woodlands by 2010 and complete this by 2015 where appropriate.
7 Maintain and strengthen populations of key BAP species associated with wet woodlands including, a weevil Melanapion minimum, a jumping weevil Rhynchaenus testaceus.
8 Achieve the favourable management of 25 % of wet woodlands by 2005 and of 50% by 2010.
9 Develop new wet woodlands.
10 Develop favourable conservation status guidance.
The Spotted
flycatcher is an insectivorous 
summer migrant which utilises open wooded
habitats, large gardens and parks as nesting habitat. It has suffered a large
decline in numbers, especially being seen less and less on farmland, in recent
decades.
1 Current status
1.1 National
A widespread summer visitor across the UK although is scarcer in the far
north and west. Preferred habitats are mature broad-leaved woodland (although it will also use mature conifers), hedgerows with mature trees, parkland and large gardens. The species has been in decline since the early 1960s. Common Bird Census data show a 62% decline in spotted flycatcher populations in woodland habitats and a 70% decline on farmland between 1968 and 1991, although the range had reduced by only 6.6% between the two breeding atlases (1968-72 and 1988-91). The UK population estimate derived from the New Breeding Bird Atlas is 120,000 territories which represents only a quarter of the estimate in the first Atlas.
1.2 Local
The Provisional Suffolk Breeding Bird Atlas (1993) shows that the Spotted flycatcher is found in around 50% of 2 km tetrads within the county. There is evidence of a local decline in numbers, particularly in the west of the county (Suffolk Birds, 1997).
1.3 Natural Areas
All.
1.4 Protection
The Spotted flycatcher is protected under the Wildlife and Countryside Act 1981 and the EC Birds Directive.
2 Current factors causing loss or decline
These are not well known, but may include one or more of the following:
Weather
effects. These appear to be important and could have population impacts if
long-term climate change occurs. The key factor appears to be summer weather
conditions as more birds breed early if temperatures are warmer, and one study
found that clutch sizes are larger when there is more sunshine.
Drought in the Sahel region. This has been implicated in the declines of a number of
trans-Saharan migrants. The Spotted flycatcher passes through the Sahel region
en route to wintering grounds in southern Africa. Changes in conditions in the
Sahel or the wintering areas could be a factor in the species’ decline but no
clear link has been established.
Changes in
agriculture. Firm data on the importance of this for Spotted flycatcher is
lacking, but there is growing evidence that a range of birds found on lowland
farmland are affected by low invertebrate availability during the summer .
Loss of nest
sites. Many Spotted flycatchers nest in large trees and there has been a
large-scale loss of these in woodland, parks and hedgerows (especially
following Dutch elm disease), which are favoured habitats. However, there are
no quantitative data on the effect of these losses.
3 Current action
Until recently the Spotted flycatcher was not regarded as a species of conservation concern,
so little action has been carried out. However, some aspects of broad-leaved
woodland management, particularly the creation and maintenance of clearings and
wide rides, will have benefited the species.
Provision of
nest-boxes (usually for other species) may also have helped Spotted
flycatchers, particularly in areas with few natural nest sites.
4 Action plan objectives and targets
1 Establish the size of the Spotted flycatcher population within the county by 2003, to allow monitoring of any changes in population sizes.
This is one of Britain’s smallest and rarest bats. It hunts amongst deciduous woodland and permanent pasture feeding on crane flies and moths. Breeding sites are more often found in the roof spaces of large country houses or outbuildings that are warmed by the sun, although small loft spaces are occupied on occasions.
The bats hibernate in cellars, caves, tunnels and ice-houses.
1 Current status
1.1 National
An endangered species in UK. The population is less than 14,000 with only 23 colonies comprising more than 100 animals.
1.2 Local
There has only been five animals recorded in the county during the last
100 years. An individual hibernated in an ice house during the winters of
1996 and 1998.
1.3 Natural Areas
Breckland.
1.4 Protection
Protected by the Wildlife and Countryside Act 1981, the EC Habitats and Species Directive (Annex 2), under the Conservation Regulations 1994, the Convention of the Conservation of Migratory Species of Wild Animals (Bonn 1980) and the Agreement on the Conservation of Bats in Europe (London 1991). Local impact can be limited by activities in accordance with PPG9 (Planning Policy Guidance in Nature Conservation 1994).
2 Current factors causing loss or decline
Reduction in
insect prey abundance due to intensive farming practices and loss of wetlands,
hedges and other suitable prey habitats.
Loss and
disturbance of hibernation sites in buildings, underground tunnels and
structures.
Disturbance
and destruction of maternity roosts owing to toxic chemicals used in timber
treatment and building works.
3 Current action
All known roosts
are listed in the County Wildlife Sites Register which is updated annually and
supplied to all local authorities.
English Nature
have engaged the Suffolk Bat Group to undertake all practical work associated
with bat conservation to enable EN to provide statutory advice to householders,
developers, timber treatment companies etc.
The Suffolk
Bat Group advises and deals with over 100 English Nature enquiries a year,
additional public enquiries and 12-15 talks and walks per year-
The species is a target for the National Bat Monitoring programme being
developed by the Bat Conservation Trust with funding from DETR.
4 Action plan objectives and targets
1 Monitor existing hibernation site.
2 Carry out bat detector Surveys in suitable habitat near to the hibernation site in summer to determine the existence of a local population.
3 Obtain permission to survey suitable buildings for potential breeding/roost sites.
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