Lowland Mixed Deciduous Woodland - Habitat Action Plan

Ref 2/H3 Habitat Action Plan 3
Plan Author: Norfolk County Council (Gerry Barnes)
Plan Co-ordinator: Woodland BAP Topic Group
Final November 2003
Reviewed October 2004
Final (revised) February 2006

Action Plan Summary

Current Status

National Status

  • It is generally agreed that the most important woodlands for wildlife are those on what are termed Ancient Woodland Sites, or primary woodland. These woods are believed to have been in existence since at least AD1600. There are many biodiversity-rich woodlands which are not ancient.
  • No precise data are available for the total extent of lowland mixed deciduous woodland in the United Kingdom. In the 1980s, the Nature Conservancy Council estimated the total extent of this type to be 250,000 ha. It is believed to have declined in extent by 30-40% over the last 50 years. These losses are attributed to clearance, overgrazing and replanting with non-native species.

Norfolk Status

  • In Norfolk, there are also no precise measurements of the extent of this habitat. However, the 2001 census by the Forestry Commission gives the following figures:

 

Forest Ownership in Norfolk

Forest Type

Forestry Commission

Other

All Woods

 

ha

%

ha

%

ha

%

Conifer

10,071

72.8

3,739

12.3

13,810

31.2

Broadleaved

1,580

11.4

18,157

59.8

19,738

44.6

Mixed

1,117

8.1

5,193

17.1

6,310

14.3

Coppice

0

0.0

0

0.0

0

0.0

Coppice-with-Stds

0

0.0

343

1.1

343

0.8

Windblow

0

0.0

0

0.0

0

0.0

Felled

548

4.0

75

0.2

624

1.4

Open Space

515

3.7

2,869

9.4

3,384

7.7

Total

13,831

100.0

30,377

100.0

44,209

100.0

  • These general classifications, useful for modern forestry and countryside planning purposes, do not necessarily have much historical significance. In particular, many of these broadleaved woodlands would have originally been coppice-with-standards or wood pasture, but neglect has led to the emergence of high canopy and suppression of the understorey.
  • Not all Ancient Woodland Sites support mixed deciduous woodland and mixed deciduous woodland may be found on recent sites and in secondary woodlands. Recent woodland sites may also be of conservation importance.
  • This HAP category spans woodland growing on the full range of soil conditions, from acidic to base-rich, and includes most of the semi-natural Ancient Woodland Sites in Norfolk. Despite great variety in the species composition of the canopy layer and the ground flora, some features are common to many stands. Most were traditionally coppiced, particularly those on moderately acid to base-rich soils; Quercus robur is by far the commoner oak (although Quercus petraea may be abundant locally in a few sites) and may occur with virtually all combinations of other locally native tree species; most sites are relatively small and have well-defined boundaries compared with some of the recent planted woodlands.
  • Primary, semi-natural woodland is the nearest there is to natural woodland. Norfolk's semi-natural woodlands are very varied, their composition largely dictated by climate, soil and biotic influences, including the influence of man over many centuries.

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Current factors causing loss or decline in Norfolk

  • Overgrazing through expansion of deer populations, leading to change in woodland structure, impoverishment of ground flora and low rates of regeneration, especially in coppice. In some sites formerly managed as wood-pastures there may be the contrasting issue of too little grazing by domestic stock.
  • Invasion of ancient woodlands by non-native species leading to changes in the composition of the woods.
  • Dutch elm disease has changed the structure and composition of many woods since the early 1970s, and recurrences are still affecting them. Canopies opened by disease may be subject to higher rates of windthrow, and invasion of gaps by unrepresentative species, eg climax elder scrub, becomes more likely.
  • Recently there has been increasing concern about loss of oak through Sudden Oak Death.
  • Development, including urban growth, quarrying, recreational development, and trunk road improvements has caused deterioration or destroyed parts of many woods in recent years, and continues to threaten others.
  • Replacement of native trees with planted conifers occurred extensively in the 1960s and 1970s. Whilst this threat has receded large scale felling and modification of the composition of woodland, by intensive replanting, even of native broadleaved species, may contribute to the impoverishment of diversity in woods.
  • Modern agricultural practices have led to simplification of landscapes and greater ecological isolation of woods through removal of hedgerows, isolated trees and small patches of scrub in fields, deep drainage of adjacent arable fields, and through cultivation hard up to woodland boundaries. Local nutrient enrichment from fertilisers may be leading to changes in woodland soils and ground flora, and woodland edges can suffer from spray drift or run-off from adjacent agricultural land.
  • Cessation of traditional management practices such as coppicing has led to a reduction in structural diversity within many woods, and particularly to loss of temporary open space. This is required by many coppice-associated species, which are now rare and threatened.
  • Climate change could potentially result in changes in vegetation communities, although woodland would be more robust in this respect than many other habitats.
  • Poor restocking and management grant rates.
  • Oak dieback.

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Current Action in Norfolk

  • National forestry policy includes a presumption against clearance of broadleaved woodland for conversion to other land uses, and in particular, seeks to maintain the special interest of ancient semi-natural woodland. The Forestry Commission will continue to exercise this presumption unless there are overriding public benefits, for example, to restore important semi-natural habitats such as heathland or fen. Permission from the Forestry Commission is normally needed to fell growing trees; this is usually given in a Felling Licence. Some woods may receive additional protection through policies and strategies within development plans, by being subject to Tree Preservation Orders lying within Conservation Areas or being included as County Wildlife Sites (CWS).
  • Designation as Sites of Special Scientific Interest (SSSI) ensures compulsory consultation with the statutory nature conservation agencies over management operations and development proposals.
  • Several demonstration woodlands have been established and many events are held each year.
  • Guided walks are held throughout the year.
  • A fuelwood supply company, Anglian Woodfuels, has been set up, which should help stimulate management.
  • Cluster mapping for ecological networks has been undertaken.
  • The Anglian Woodland Project provides advice on woodlands.
  • In Leaf, a woodland magazine, is published twice a year.
  • Support is given to the Deer Initiative, including hosting training seminars.

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Action Plan Objectives and Targets

National

  • There is no national plan for this habitat, and therefore, no national targets.

Regional

  • Maintain 100% of existing.

  • Restore 1250ha by 2010.

  • Create 1250ha by 2010.

Norfolk

  • Maintain the current extent of ancient semi-natural woodland and the total extent and distribution of the woodland types.
  • Achieve favourable condition in 95% (by area) of lowland mixed deciduous woodland within the SSSIs by 2010.
  • Initiate restoration to lowland mixed deciduous woodland over at least 10% of replanted woodlands by 2010, where appropriate.
  • Where appropriate, initiate colonisation or planting equivalent to 5% of the current lowland mixed deciduous woodland. Complete establishment of half of this by 2010 and all of it by 2015.
  • The Norfolk targets established in this plan are based on the aim of maintaining the current extent of lowland mixed deciduous woodland, expanding it where appropriate and encouraging a balance of appropriate management regimes (for example minimum intervention, coppice, managed high forest and wood pasture) within regions and across the distribution of the type. The restoration targets are based on the desirability of restoring some of the former areas of ancient lowland mixed deciduous woodland that have been substantially planted with conifers in the last 50 years or that are currently dominated by other non-native species. Creation targets aim to encourage the expansion of lowland mixed deciduous woodland using natural colonisation or by planting species mixtures of site-native and local generic provenance.
  • The targets will require review and adjustment during the course of the plan. As an early step in plan implementation, more precise estimates of extent, and distribution of lowland mixed deciduous woodland will need to be determined. Criteria for determining the appropriate balance of different management regimes and suitable areas for woodland expansion and restoration will also need to be developed in accordance with the national guidance.

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