Wet Woodland

Habitat Description

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 hillside flushes. 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.

 

 Wet Woodland There are 7 NVC wet woodland communities:

W1 Grey sallow marsh bedstraw woodland

W2 Grey sallow Downy birch reed woodland

W3 Bay willow bottle sedge woodland

W4 Downy birch purple moor grass woodland

W5 Alder tussock sedge woodland

W6 Alder nettle woodland

W7 Alder ash yellow pimpernel woodland

Wet woodland has a canopy usually dominated by willow (Salix sp.), alder(Alnus glutinosa) or birch (Betula sp.) but stands vary considerably in their overall appearance. Riverside trees are also included, and are individuals that line the riverbanks throughout the county. These are important landscape features as well as supporting a wide range of invertebrates and other species.

Current UK Status and Trends

Total UK extent is approximated at 52,850 ha.

Wet woodlands are a scarce and easily damaged habitat.

Estimated Current Northants Resource

A number of wet flushes are present in ancient semi-natural woodland, but total extent is unknown.

Progress Towards BAP Targets 2002-2007

Unknown

Lead Partner

The Wildlife Trust

Main Issues and Threats

  • Very little remaining in Northamptonshire. Much is isolated in small fragments, dangerously reducing species' population sizes and making it impossible for individuals to move between them.
  • Alteration of hydrology: Flood prevention measures and lowering of water tables through drainage or abstraction lead to succession away from wet woodland; dredging of ponds and streams; groundwater abstraction.
  • Damage from mechanical operations, which have a detrimental effect on ground flora.
  • Over-tidiness resulting in the removal of dead trees and fallen dead wood.
  • Diseases such as Phytophthora, a root disease of alder.

General Strategy

  • Detailed survey to identify wet woodland sites and those that could support wet woodland.
  • Sympathetic management and restoration of existing sites, funded primarily through the Countryside Stewardship Scheme (Advice can be provided by The Wildlife Trust, RNRP or FWAG).
  • Maintain as a successional stage between open wetland areas and drier woodland. Particularly important within wet woodlands is a mosaic of habitats including lichen and moss covered trees, areas of higher ground, bare mud, stands of mature trees, clearings and rides, transitional edge habitat, fallen, submerged and standing dead wood and water bodies.
  • This habitat may occur across the entire county but specific target areas are the Nene Valley and Pitsford Reservoir.

Associated National Priority Species

  • Lesser redpoll
  • Lesser-spotted woodpecker
  • Marsh tit
  • Minor shoulder-knot (moth)
  • Oblique carpet (moth)
  • Otter see species action plan
  • Powdered quaker (moth)
  • Small square-spot (moth)
  • Song thrush
  • The crescent (moth)
  • Willow tit
Specific Management Required for Associated Species

Species

Northamptonshire Status

Management Prescriptions

Key Sites

Willow tit

Breeding

Maintain standing deadwood, particularly rotting stumps of willow, birch, and alder. Scrub required nearby.

Kings Wood Local Nature Reserve.

Targets

Target Code

Target Type

Target Description

Target Units

Northants Baseline Resource

Target

By

Unit Cost £

Total Cost £

NOR_WWO_T1

Maintain Extent

Maintain the current extent of at least LWS-standard wet woodland.

Hectares

33

33

2015

75/ha/yr

2,475/yr

NOR_WWO_T2

Achieving Condition

Achieve LWS standard of 5 ha of currently non-LWS wet woodland by 2015.

Hectares

33

38

2015

75/ha/yr

375/yr

NOR_WWO_T3

Expansion

Establish 10 ha of LWS-standard wet woodland on non-wooded or plantation sites by 2015.

Hectares

0

6

2015

1,500/ha + 200/ha/yr for 10 yrs

9,000 initial + 1,200/yr

Actions

Action Code

Action Description

Lead Partner

Support Partner(s)

Related Target

NOR_WWO_HS_A1

Ensure that existing wet woodland within designated sites is maintained in good condition through the control of water levels.

The Wildlife Trust , Natural England, Northamptonshire Biodiversity Partnership

Anglian Water, Severn Trent Water, Environment Agency

NOR_WWO_T1

NOR_WWO_SU_A2

Identify the location of all wet woodland outside of designated sites by 2012.

The Wildlife Trust

NBRC

NOR_WWO_T2

NOR_WWO_HS_A3

Provide management advice and incentives (through agri-environment schemes) to owners of wet woodland outside of designated sites in order that 5 ha achieves LWS condition by 2015.

Natural England

Northamptonshire Biodiversity Partnership

NOR_WWO_T2

NOR_WWO_HC_A4

Create 2 ha of wet woodland at Pitsford Reservoir and other nature reserves by 2012.

The Wildlife Trust

Anglian Water

NOR_WWO_T3

NOR_WWO_HC_A5

Create 2 ha of wet woodland through succession from open water bodies in the Nene Valley by 2015.

Natural England

The Wildlife Trust

NOR_WWO_T3

NOR_WWO_HC_A6

Create 2 ha of wet woodland through conditions on planning applications by 2015.

Developers, Local Authorities, WNDC, NNDC

The Wildlife Trust

NOR_WWO_T3