British vegetation as a series of plant communities (Rodwell ... characters. It was the main ..... stands, or peaty hollows covered by bog mosses. Sphagnum spp.
JNCC Report No. 288 The relationship between Biodiversity Action Plan Priority and Broad Habitat Types, and other woodland classifications. J. E. Hall and K. J. Kirby
Joint Nature Conservation Committee Monkstone House City Road Peterborough PE1 1JY ©JNCC 1998
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Contents 1 2
Introduction.................................................................................................................. ...............................................5 The classifications........................................................................................................... ............................................6 2.1 Correspondence between classifications ...................................................................................... .......................6 2.2 Difficulties in classifying stands..........................................................................................................................6 2.3 The Main Classifications.................................................................................................... .................................6 2.4 Other classifications ....................................................................................................... .....................................7 2.5 BAP Broad Habitat Types..................................................................................................... ..............................7 3 The Priority Habitat accounts................................................................................................. ...................................12 3.1 Introduction ................................................................................................................ .......................................12 3.2 Lowland Beech and Yew Woodland .............................................................................................. ...................13 3.3 Lowland Wood-pasture and Parkland ........................................................................................... ....................17 3.4 Upland Mixed Ash Woodland................................................................................................... ........................19 3.5 Upland Oak Woodland......................................................................................................... .............................23 3.6 Native Pine Woodlands....................................................................................................... ..............................26 3.7 Wet Woodland ................................................................................................................ ..................................29 4 Other Important Semi-natural Woodland Types ................................................................................... ....................31 4.1 Introduction ................................................................................................................ .......................................31 4.2 Lowland Oak and Mixed Deciduous Woodland .................................................................................... ...........31 4.3 Northern Birchwoods ......................................................................................................... ...............................35 5 References.................................................................................................................... .............................................36 Appendix 1. NVC communities ..................................................................................................... ................................38 Appendix 2. Forest types on Annex I of the Habitats Directive, that occur in Britain...................................................39 Appendix 3. CORINE types mentioned in this report....................................................................................................39 Appendix 4. Peterken Stand Types ................................................................................................................................40 Appendix 5. Forest Practice Guide Types......................................................................................................................41 Appendix 6. Phase I types mentioned in this report.......................................................................................................41
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4
1
Introduction woodlands throughout Britain refers to Stand Types (Appendix 4).
Habitat classification is essential to nature conservation. A consistent means of labelling vegetation communities is vital if people are to understand each other without resorting to longwinded descriptions. For woodland several systems are used by the forestry and nature conservation organisations. They have been produced for different purposes, and at different times, but it is often necessary for individuals to be familiar with several of them.
The relationship between these different classifications is, therefore, important if the targets proposed in the HAPs are to be achieved.
Here we discuss the relationships between the Biodiversity Action Plan Priority Habitats; the National Vegetation Classification (NVC); the Peterken Stand Type system; the Forestry Authority Forestry Practice Guides; CORINE; and Annex I of the Habitats Directive. Our specific aim is to clarify the relationship between the Priority Habitats identified by the UK Biodiversity Action Plan process and the other classification systems. The UK Biodiversity Action Plan (HMSO 1995) identified six woodland Priority Habitats (then called Key Habitats) for which Habitat Action Plans (HAPs) should be produced. Two additional types are also included here, as they are important semi-natural woodland types, and may be identified as Priority Habitats in the future. Action proposed in these HAPs includes, as well as restoration and expansion targets for each type, completion of the notification of proposed Special Areas of Conservation (pSACs) and Sites of Special Scientific Interest (SSSIs), and the development of links with continental Europe. The SSSI notification process uses NVC (see Appendix 1), and the Habitats Directive requires designation of SACs for a given set of habitats including certain woodland types (see Appendix 2 for those that occur in Britain). The main habitat classification used to relate the different European systems has been CORINE (Appendix 3), although work to develop a new European classification - EUNIS - is in progress. In addition, a great deal of historical data for 5
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The classifications
2.1
Correspondence classifications
Woodland, like all natural and semi-natural habitats, is continuously variable; only rarely can a single characteristic be used to define a type of wood. Grazing or high rainfall may produce lowland woods with characteristics normally associated with upland conditions. Past management or natural catastrophes may leave a particular woodland lacking a major tree species or with an abundance of what is usually a minor species. The names used must, therefore, be treated as convenient labels, rather than as definitions.
between
Various criteria are used to describe woodland types; some classifications are based on ground flora, others on the range of canopy species and soil conditions, or on the dominant canopy species. Although there is a broad correspondence between the types defined by these different systems, very rarely is there a precise one-to-one coincidence. Attempts to force hard linkages are, consequently, bound to fail.
2.3 2.2
The Main Classifications
Difficulties in classifying stands Table 1 summarises the relationships between the different classifications, which are further discussed in the main part of the report.
Apart from the difficulties of correlating classifications, trying to force any given piece of woodland into a pre-defined category may be problematic. This is particularly true at the margins of the range (i.e. the geographical, altitudinal range etc) of woodland types.
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‘Western oak woods’ can occur in the east. Some communities found in the northeast of Scotland, or in the North York Moors, are categorised as this type on floristic grounds.
2.3.1 National Vegetation Classification The NVC aims to describe the whole range of British vegetation as a series of plant communities (Rodwell 1991a, 1991b, 1992, 1995, in press). The woodland section comprises 25 communities (Rodwell 1991a); seven types of wet woodland, eleven dry-land high forest communities and seven scrubs and underscrubs (Appendix 1). Summary descriptions of the communities (excluding scrubs), and an assessment of their relationship to each other are provided in Whitbread & Kirby (1992). Maps of the distribution of these types, based on survey information collected over the last ten years, are published in Hall (1997). These are used as the basis for the distribution maps of the habitat types discussed here. The NVC is currently the main classification system used by the statutory and voluntary conservation organisations to describe British woodland. A guide to its use for conservation is provided by Kirby, Saunders & Whitbread (1991).
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‘Oakwoods’ may, in places, contain very little oak. Many woods, or parts of them, are dominated by birch and rowan during the regeneration phase, but have similar ground and epiphyte floras to the typical oakwoods.
2.3.2 The Stand Type Classification The Stand Type system (Peterken 1981) divides woodland into twelve Stand Groups and 39 Stand Types (Appendix 4), largely on the basis of the trees and shrubs, but also using some soil characters. It was the main woodland classification system used by the conservation
Problems may also arise as a result of the way types are named and an assumption that the stand must exactly fit the characteristics included in the name. For example, ‘upland’ or ‘western oakwoods’ have long been recognised as a distinct category, but: • ‘Upland woods’ can exist at low altitudes. The woods around Loch Sunart run down to the sea but are considered some of the best examples of this type.
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Countryside Survey 1990 (DoE 1993) - are summarised in Table 2.
agencies from 1977 to 1986, after which it was largely replaced by the NVC. Although there is a broad correlation between these two classifications, there is not a one-to-one relationship (Cooke & Kirby 1994). 2.3.3 Forestry Authority Practice Guides For the purposes of these management guides (Forestry Authority 1994a-h), Britain’s seminatural woodlands were divided into eight types (Appendix 5), based entirely on the dominant canopy species. It was felt that, for woodland management purposes, this gave the best balance between straightforward, practical guidance and the specific needs of the various types of ancient woodland. It is recognised that there are many more types, but, for this purpose, fine distinctions would over-complicate the advice. 2.3.4 CORINE The CORINE biotope classification (Commission of the European Communities 1991) was developed as a tool for describing sites of nature conservation importance in Europe. It divides woodland into many types, on several hierarchical levels. Those of most relevance to this report are listed in Appendix 3. 2.3.5 Annex I of the Habitats Directive The reference work for this annex was an earlier version of the CORINE classification, of which it is a sub-set. It comprises habitat types of European Community interest, whose conservation requires the designation of Special Areas of Conservation (SACs). Woodland types occurring in Britain are listed in Appendix 2. 2.4
Other classifications
Classifications by Rackham (1980) and by Bunce (1989) have been used in some woodland surveys, but are not included in this analysis. 2.5
BAP Broad Habitat Types
The links between the broader habitat classifications - Phase I (Nature Conservancy Council 1990, Appendix 6), Biodiversity Action Plan Broad Habitats (HMSO 1995), classes used in the FC National Inventory of Woodland and Trees (Forestry Authority unpublished) and in 7
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Table 1. Relationships between the various different types of woodland (Where a type is thought to be only a minor component of the BAP Priority Habitat it has been placed in brackets) See appendices for explanation of codes BAP Priority Habitat
Forestry Commission Guide Type 1. Lowland acid beech and oak woods 2. Lowland beech-ash woods
CORINE
Habitats Directive Annex 1 Type
NVC Type
Stand Types
Taxus baccata woods Asperulo-Fagetum beech forests Beech forest with Ilex and Taxus, rich in epiphytes
W13 W12 W14, W15
No direct equivalent 8C 8A, 8B, 8D, 8E
W8a-d (e-g) W10a-d (e), W16
1(A), B, 2, 3A, B, 4, 7C, 9, 10 5, 6C, D, 9, 12
41.52
(Tilio-Acerion ravine forests) (Stellario-Carpinetum oakhornbeam forests) (Old acidophilous oak woods with Quercus robur on sandy plains)
4. Upland mixed ashwoods
41.31, 41.32, 41.41
Tilio-Acerion ravine forests
1A, C, D, 3C, D, 4C, 7D
Upland Oak Woodland
5. Upland oakwoods
42.A71 (62.3) 41.53, 41.52
Taxus baccata woods limestone pavement Old oak woods with Ilex and Blechnum in the British Isles
(W7c) W8(a-c) d-g , W9 W13 W10e, W11, W16b, W17
6A, 6B (8A, 8B)
Northern Birchwoods1
6. Upland birchwoods
41.53, 41.52
Old oak woods with Ilex and Blechnum in the British Isles
W10e, W11, W17
Mainly stand group 12
Native Pine Woodlands
7. Native pinewoods
Wet Woodland
8. Wet woodland
Caledonian forest Bog woodland Bog woodland Residual alluvial forests
Scrub2
No equivalent
42.51 44.A2 44.A1 44.31 44.13 44.92 31.883 31.81
Lowland Beech and Yew Woodland
Lowland Oak and Mixed Deciduous Woodland 1
Upland Mixed Ash Woodland
1. Lowland acid beech and oak woods 3. Lowland mixed broadleaved woods
42.A71 41.13 41.12 (41.16) 41.23, 41.32 (41.24) (41.51)
Juniper formations on grasslands
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W4a, b W18, (W19) W4(a), b, c W4(a, b), c W5 - W7 (W8) W1, W2, W3 W19 (acid soils), W21d W21, W22
No direct equivalent
11 (12) 7A, B, D, E No equivalent No equivalent
Lowland Wood-pasture and Parkland3
Referred to particularly in Lowland acid beech and oak woods guide (1), but no real equivalent
84.5 (but not a good equivalent)
Includes examples of Beech forest with Ilex and Taxus, rich in epiphytes. Old acidophilous oak woods with Quercus robur on sandy plains
W14, W15
Group 8
W10, W16
Group 6
Notes 1 2 3
Not Priority Habitats, but included because of their importance as semi-natural woodland types. Not a Priority Habitat, but included for the sake of completeness, since most other classifications have some equivalent type. Lowland Wood-pasture and Parkland includes some non-woodland habitats as well as overlapping with various other Priority Habitats.
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Table 2. Relationships between various broad habitat classifications1 BAP Broad habitat
Phase 12
Broadleaved, mixed and yew woodland 3, 4, 5
Coniferous
Parkland and scattered trees9
A1.1.1 A1.1.2 A1.2.1 (if yew) A1.3.1 (most) A1.3.2 (most) A4.1 A4.3 (most)
A2 A1.2.1 (if pine) A1.2.2 A1.3.1 (some) A1.3.2 (some) A4.2 A4.3 (some) A3
Fore stry Commission Broadleaved Mixed
Coniferous Mixed (some)
CS1 990 Broadleaved Mixed
Shrub Coniferous Mixed (some)
Associated Priority habitats Lowland Beech and Yew Woodland Lowland Wood-pasture and Parkland (part) Upland Mixed Ash Woodland Upland Oak Woodland Wet Woodland (Lowland Oak and Mixed Deciduous Woodland)6 (Northern Birchwoods)6 Juniper7, 8 Native Pine Woodlands
Lowland Wood-pasture and Parkland (part)
Notes 1
2 3
4
5
6
7
8
Felled woodland and other minor habitats in woods (e.g. rides, glades) are classed with the surrounding woodland type. See Appendix 6 for explanation of codes. Yew is considered an honorary broadleaf. Yew stands usually form a mosaic with broadleaf woods, and are unlikely to be confused with other coniferous stands. Scrub vegetation, where the woody component tends to be mainly shrubs less than 5m high, and carr are included in this broad habitat type if the woody species form a canopy cover of greater than 30%. Most mixed woodland is classed with broadleaved and yew since that is generally the habitat from which it has been derived, or is the equivalent native woodland type for the site. In the native pine zone it may be more appropriate if mixed woodland is linked to the coniferous (Native Pine Woodlands) category. Not Priority Habitats, but included because of their importance as seminatural woodland types. Juniper is covered by a Species Action Plan.
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Other types of scrub are not covered by Habitat or Species Action Plans. Parkland/scattered trees is a Phase I land cover category, and does not equate to lowland wood-pasture as a land use. The latter also includes woodland in the Broadleaved and yew category. See Section 3.3.
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The Priority Habitat accounts
3.1
Introduction
The following descriptions and maps present our current understanding of each habitat type and its distribution. We welcome constructive comments and criticism.
For each Priority Habitat type we discuss the typical structural and floristic characteristics and its nearest equivalents in five other widely used habitat classification systems (NVC, Stand Types, Forestry Commission Guide Types, Habitat Directive Annex I types and CORINE). For most of the Priority Habitat types we also present maps showing our assessment of the GB range of the type, based the distribution of the component NVC communities. We use NVC data for two reasons: • most of the Priority types can be easily described in terms of one or more NVC communities (which is not always possible using the other classifications). • much more information has been accumulated for this than for the other classifications, so it is possible to demonstrate a reasonable illustration of the distribution of the communities. There is considerable geographical overlap between the maps. In many parts of Britain two or more Priority Habitats may be found, often within the same wood, according to local variations in soil, topography, site and management history. More work may be needed to refine the maps in order to distinguish the core and periphery of the range for each type. No map is presented for Lowland Wood-pasture and Parkland or for Wet Woodlands. Wet Woodlands occur throughout the country and it was felt that little useful information would be conveyed by producing a map demonstrating this. As a land-use type, rather than a vegetation type, Lowland Wood-pasture and Parkland is not easily reducible to NVC communities. It would not be possible to produce a meaningful map of the distribution of this Priority Habitat using the same type of information as that used to illustrate the others.
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3.2.1 General comments Lowland Beech and Yew Woodland includes a variety of distinctive types which reflect differences in soil and topographical conditions. Beech grows on acidic and calcareous soils, although its association with yew is most abundant on the calcareous sites.
treated according to the principles of the Lowland Beech and Yew Woodland HAP, except where there is a clear preference for restoration to another type e.g. Upland Mixed Ash Woodland or Upland Oak Woodland. Where beech appears naturally to be invading other types beyond its past natural range, decisions as to how to treat it must be made on a site-by-site basis.
3.2.2 The range of beech In the United Kingdom beech is considered native only in southern England and south-east Wales, the generally accepted range is indicated in Map 1 (based on Rackham 1997). A number of stands outside this line, e.g. in the Wyre Forest, Dendles Wood in Devon and Felbrigg Park in Norfolk, are taken to be native outliers. The northernmost site of native beech known to Rackham (1997) is Mallygill Wood near Durham and the westernmost is Coed DeriNewydd above Caerphilly; both have ancient coppice stools.
3.2.3 Structure and management The full range of forest structure and management types have been associated with beech and yew forest in the past. Although beech produces weak coppice shoots, such woods can be found, for example, in the Cotswolds and further west (Peterken 1981). Beech responds better to treatment as woodpasture, and fine examples can be found at Epping Forest and Burnham Beeches. The commonest management type is high forest, which can be found throughout the native and planted range.
The situation is complicated by the fact that the current climatic limits for beech are well beyond its accepted past-natural range. It would certainly have spread naturally to other areas of the British Isles had forest fragmentation not impeded its progress. Hence difficulties arise with regard to areas where beech occurs only at a low density; where it may be naturally invading stands; and where it exists as plantations outside its presumed native geographical/ecological range. Conversely, regeneration phases within beech woods often lack beech, and are dominated by either oak or ash.
3.2.4 The position of yew Yew stands in southern England, within the native zone of beech, are included in this Priority Habitat.
3.2
Lowland Beech and Yew Woodland
Stands of yew on Carboniferous and Magnesian limestones in northern Britain, growing in association with Upland Mixed Ash Woodland, should be considered under that plan. 3.2.5 National Vegetation Classification Beech woodland comprises W12, W14 and W15 according to soil conditions. These all occur in the native and the planted range of beech. Within these communities regeneration patches where beech is currently scarce usually fall into W8, W10 and W16 respectively. Yew woodland is W13.
These considerations make it difficult to set hard criteria for inclusion of stands within this Priority Habitat, but important factors include the maturity of the beech, and its abundance/cover. Regeneration patches should normally be included within this type unless they are very extensive and there appears little likelihood of their eventual return to beech woodland.
Main NVC types: W12 Fagus sylvatica - Mercurialis perennis woodland W14 Fagus sylvatica - Rubus fruticosus woodland W15 Fagus sylvatica - Deschampsia flexuosa woodland W13 Taxus baccata woodland
Restoration and expansion of beech woodland should be concentrated on sites within the native range. Beech stands outside this zone may be 13
Main Habitats Directive types: 41.12 ‘Beech forest with Ilex and Taxus, rich in epiphytes’ 41.13 ‘Asperulo-Fagetum beech forests’ 42.A71 to 42.A73 ‘Taxus baccata woods’
3.2.6 Stand Types There is good correspondence between Stand Group 8 (which includes beech on both calcareous and acid soils) and this Priority Habitat. Regeneration patches (where large enough) are classed as one of the corresponding ash (3) or oak groups (6C, D). There is no stand type equivalent for yew woodland. Strictly speaking, the Stand Type classification only applies to ancient semi-natural woodlands and should not be used in plantations. It is, therefore, restricted to stands of beech growing in the accepted native range.
3.2.9 CORINE 41.13 Neutrophilous beech forests 41.12 Atlantic Acidophilous beech forests 42.A71British yew forests
Main stand types: 8A Acid sessile oak-beech woods 8B Acid pedunculate oak-beech woods 8C Calcareous pedunculate oak-ash-beech woods 8D Acid pedunculate oak-ash-beech woods 8E Sessile oak-ash-beech woods 3.2.7 Forestry Commission Guide Type Guide type 2, Lowland Beech-Ash Woods, falls entirely within this type (Forestry Authority 1994b). Beech-dominated stands whose management is considered under Guide 1, Lowland Acid Beech and Oak Woods (Forestry Authority 1994a) are also included here. Lowland woods on acid soils which lack beech and are dominated by oak, hornbeam, lime etc. are considered as part of the Lowland Oak and Mixed Deciduous Woodland habitat type. Main Guide types: 1 Lowland acid beech and oak woods 2 Lowland beech-ash woods 3.2.8 Habitat Directive Annex I Old beech stands on acid soils include examples of ‘Beech forest with Ilex and Taxus, rich in epiphytes’. Many woods on neutral to base-rich types can be classified as ‘Asperulo-Fagetum beech forests’. A few stands on thin calcareous soils may be closer to ‘Calcareous beech forest (Cephalanthero-Fagion)’, but are currently included in ‘Asperulo-Fagetum beech forests’ because the latter tends to be dominant in such woods. Yew stands (wherever in Britain they occur) are described in the Directive as ‘Taxus baccata woods’. 14
15
16
3.3
•
Lowland Wood-pasture and Parkland
3.3.1 General comments Lowland Wood-pasture and Parkland is a vegetation structure rather than a vegetation community. It typically consists of large opengrown or high forest trees, of various species and at variable densities, in a matrix of grazed grassland, heathland and/or woodland floras. Tree management, usually pollarding, has often helped to produce the characteristic veteran trees, whilst grazing by domestic livestock or deer maintains the vegetation matrix.
•
Parklands originating in the 19th century or later with none of the above characteristics. Upland sheep-grazed high-canopy oak woodland (see Upland Oak Woodland Priority Habitat).
3.3.2
Overlap between this and other Priority Habitats The other woodland Priority Habitats are, broadly speaking, mutually exclusive; stands classified as Upland Mixed Ash Woodland cannot also be included in the Lowland Oak and Mixed Deciduous Woodland category. There are difficulties with defining boundaries, and dealing with intermediate stands, but conceptually they are separate land cover types.
Included in this category are: • Lowland Wood-pasture and Parkland derived from medieval Forests and emparkments, wooded commons, parks and pastures with trees in them. In some cases, a designed landscape was superimposed in the 16th to 19th centuries. Beech and oak usually predominate amongst the old trees but a range of other species, including nonnatives (e.g. beech and sweet chestnuts outside of their native range, horse chestnuts), may have been planted or regenerated naturally. • Parklands designed in the 19th century or later, containing veteran trees derived from an earlier landscape, or close to other areas with very old trees. There should be a realistic prospect that appropriate wood-pasture management would create conditions allowing specialist species (mostly invertebrates and fungi) to colonise within the long term (50-250 years). • Unmanaged and under-managed woodpasture with veteran trees, in a matrix of secondary woodland or scrub which has developed by regeneration and/or planting. • Parkland or wood-pasture which has been converted to other land uses (e.g. arable fields, forestry and amenity land) but where surviving veteran trees are of nature conservation interest. Some of the specialist species of worked woodpasture and parkland may have survived this change in land-use. Not included in this category are:
Lowland Wood-pasture and Parkland is an exception to this pattern. Parkland can be regarded as a separate land cover type, as in the Phase I classification (although not all parkland is covered by this Priority Habitat), but lowland wood-pasture is a land use category. It is woodland (or heathland and grassland with big old trees) which may be classified as one of the other Priority Habitats, and which is also being treated as wood-pasture. For example, Ebernoe Common is classified as Lowland Beech and Yew Woodland, but it may also be managed as wood-pasture (and would be included in a listing of wood-pastures) to improve its value to nature conservation. The total area covered by woodland Priority Habitats cannot, therefore, be calculated simply by summing the areas of the six types. Lowland Wood-pasture and Parkland must be treated separately, since some of its area will already have been included in other Priority Habitats. 3.3.3 National Vegetation Classification The woodland types most commonly associated with Lowland Wood-pasture and Parkland are W10, W14, W15 and W16. However, other types may occur. In addition, parkland and open wood-pastures may include various scrub, heathland, improved and unimproved grassland NVC types. Main NVC types for the wooded areas:
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W10 W14 W15 W16
Quercus robur - Pteridium aquilinum Rubus fruticosus woodland. Fagus sylvatica - Rubus fruticosus woodland. Fagus sylvatica - Deschampsia cespitosa woodland. Quercus spp. - Betula spp. Deschampsia flexuosa woodland.
3.3.4 Stand Types Most woodland managed as wood-pasture is likely to fall into stand groups 6 and 8, but ash or elm stands are possible. Non-woodland areas cannot be classified using stand types. Main Stand Types within wooded areas: 6C Lowland birch-oakwoods 8A Sessile oak-beech woods 8B Acid pedunculate oak-beech woods 8D Acid pedunculate oak-ash-beech woods 3.3.5 Forestry Commission Guide Type Wood-pasture treatment is a management option within several of the Guides; but is likely to be most appropriate to stands managed under Guide 1, Lowland acid beech and oak woods (Forestry Authority 1994a) and Guide 3, Lowland mixed deciduous woods (Forestry Authority 1994c). Main Guide types: 1 Lowland acid beech and oak woods 3 Lowland mixed deciduous woods 3.3.6 Habitats Directive Annex I Former and present wood-pasture areas occur within the Directive categories ‘Beech forests with Ilex and Taxus rich in epiphytes’, and ‘Old acidophilous oak woods with Quercus robur on sandy plains’. Main Habitats Directive types: 41.12 ‘Beech forests with Ilex and Taxus rich in epiphytes’ 41.51 ‘Old acidophilous oak woods with Quercus robur on sandy plains’ 3.3.7 CORINE 84.4 Bocage 84.5 Parkland
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3.4
•
Upland Mixed Ash Woodland
3.4.1 General comments Upland Mixed Ash Woodland comprises a broad range of woodland types on free-draining base-rich soils, frequently on limestone (Map 2). Ash is usually a major species, but oak, birch, elm and small-leaved lime may be locally abundant. The shrub layer usually contains abundant hazel, hawthorn and some calcicolous shrubs, although fewer than in ash woods in the south-east. High forest is the main management type in these woods, though many have a history of coppicing, and some have been wood-pasture.
•
•
Ashwoods in northern England and parts of Wales growing on or near limestone pavements, in a mosaic with open bare rock, light scrub and limestone grassland. Yew stands on the Carboniferous and Magnesian limestones of central and northern Britain, where yew is locally an important competitor with the major tree species of Upland Mixed Ash Woodland. Scrubby stands of hazel in the north-west of Scotland. Many of these stands are very rich in lichens and higher plants.
Despite the name, there is no lower altitudinal limit to the occurrence of this type. It includes, for example, stands at sea level in Roudsea Wood, Cumbria.
Many of these woods are ancient, but ash is a vigorous colonist of open ground, and secondary Upland Mixed Ash Woodland can form rapidly. In the uplands, and upland margin areas, ancient and recent woods are not so clearly differentiated as in the lowlands. Recent upland woods may be readily colonised by species which are regarded in the lowlands as indicators of ancient woodland. Indeed, some internationally important areas, such as the Peak District Dales Woodlands (a pSAC for ‘TilioAcerion ravine forests’), are mosaics of ancient and recent ash woodland.
3.4.2 National Vegetation Classification The most commonly occurring NVC types are W9 and the more westerly sub-communities of W8 (d-g). Less frequently the more southern and eastern sub-communities of W8 may occur. Yew stands on the Magnesian limestone of north-east England are included because they occur in mosaic with upland mixed ash stands. Stands of yew on the southern chalk are not included here, but should be treated with the Lowland Beech and Yew Woodland category.
Related (usually less extensive) communities included in this category are: • Mixed deciduous woods with field maple, small-leaved lime, gean and sessile and pedunculate oaks, which are frequent on south-western limestones. These grade into beechwoods in some districts. • Ash - pedunculate oak - hazel woods on poorly drained soils, which are frequent along the upland margins. Most of these have a history of coppicing. • Ash - hazel - hawthorn groves on soils of medium base status within Upland Oak Woodland. These are often restricted to the edges of streams, flush zones and the bases of slopes, and often grade into alder - ash woods on the wetter ground. The soils are deeper, moister and more fertile than in other Upland Mixed Ash Woodland. Such woods are usually as heavily grazed as the adjacent oakwoods.
Stands of W8d and W8e that occur in south-east England (Map 2), are not included within this HAP type, but as a component of Lowland Oak and Mixed Deciduous Woodland. The bulk of the range of Upland Mixed Ash Woodland is beyond the accepted native range of beech (although both occur in the Wye Valley). Beech has, however, often been planted and subsequently regenerated on sites where Upland Mixed Ash Woodland might be expected at least as far north as the Appin area of Argyll. Some such long-established beech stands may key out as W12 (less often W14) beech woodland. On deeper, more acid soils, patches of Upland Oak Woodland (usually W10e or W11) may occur along with the ash stands, while along stream sides there may be Wet Woodland patches, particularly the alder community W7. 19
There is broad correspondence with guide type 4, Upland Mixed Ashwoods (Forestry Authority 1994d), although the map accompanying this guide fails to pick out important outlying concentrations in the southern Peak District, the Magnesian and Carboniferous limestones on the upland fringes and on the south-western limestones such as the Mendips.
Main NVC types: W8 Fraxinus excelsior - Acer campestre Mercurialis perennis woodland (d) Hedera helix (e) Geranium robertianum (f) Allium ursinum (g) Teucrium scorodonia W9 Fraxinus excelsior - Sorbus aucuparia Mercurialis perennis woodland W13 Taxus baccata woodland
Main Guide types: 4 Upland Mixed Ashwoods
3.4.3 Stand Types The most commonly associated Stand Types are elm-ash (1A, 1C, 1D) lime-ash (4C) and ashhazel types (3C, 3D), although field maple may occur locally (particularly in the south-western woods), giving rise to examples of Stand Group 2. In most woods, particularly in the more extensive stands, the ash stand types (group 3) predominate. Slope Alderwood (7D) often has a strong ash component and is relatively dry, so may be better considered here rather than with Wet Woodland; particularly well-developed examples of this occur at Carnach Wood and N. Ballachulish in Lochaber. In the extreme northwest, ash and elm may be very scarce, leaving only birch-hazel stands on base rich soils (12B). Planted trees are ignored in the Stand Type system, so areas where beech has been introduced would generally be referred to the appropriate parent type; in the Wye Valley, however, semi-natural base-rich stands with scattered beech may be classed as 8C and 8E. The most likely associates on acid soil are the upland oakwoods (6A, B), and associated wet alder stands which fall into stand group 7.
3.4.5 Habitats Directive Annex I Most ‘Tilio-Acerion ravine forests’ are Upland Mixed Ash Woodland, except for a few outlying stands on the southern chalk in Hampshire and Sussex (which are placed with the Lowland Oak and Mixed Deciduous Woodland habitat type). ‘Taxus baccata woodland’ occurs locally as small groves (e.g. Avon Gorge and Castle Eden Dene), a counterpoint to its occurrence with beech in the lowlands on the chalk. In some areas, particularly around Morecambe Bay and across through the Yorkshire Dales (but also, for example, on Skye), Upland Mixed Ash Woodland has developed naturally on limestone pavement. Long-established stands of such woodland should be maintained even where there is a need elsewhere to remove trees to keep the pavement open. Main Habitats Directive types: 41.4 ‘Tilio-Acerion ravine forests’ 42.A71 to 42.A73 ‘Taxus baccata woodland’ 62.4 Limestone pavements examples)
Main Stand Types 1A Calcareous ash-wych elm woods 1C Calcareous ash-wych elm woods on dry soils. 1D Western valley ash-wych elm woods. 3C Northern calcareous hazel-ash woods 3D Acid sessile oak-ash-hazel woods 4C Western maple-ash-lime woods Examples of these types in the south and east of England are not included in this Priority Habitat, but are grouped with Lowland Oak and Mixed Deciduous Woodland. 3.4.4
(wooded
3.4.6 CORINE 41.31 Ash-rowan-dog’s mercury forests 41.32 British ash-field maple-dog’s mercury forests 41.41 Ravine ash-sycamore forests 42.A71British yew woods
Forestry Commission Guide Types
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3.5
Upland Oak Woodland •
3.5.1 General comments Upland Oak Woodland is characterised by a predominance of oak (most frequently sessile, but pedunculate can be locally common) and birch in the canopy, with varying amounts of holly, rowan and hazel as the main understorey species. The amount of birch tends to increase in north-west Scotland, where Upland Oak Woodland may be replaced by the Northern Birchwoods habitat type.
on more fertile soils or in lower rainfall areas; north and westerly distribution in UK.
3.5.2 National Vegetation Classification The main types are W11 and W17 in their entirety, W10e and W16b (Map 3). Locally, other sub-communities of W10 and W16 may occur in a mosaic with the above main types. Small base-rich patches (W8, W9) and wet areas (mainly W4, W7) are common, and if extensive should be referred to the appropriate Priority Habitat. Invasion by beech outside its native range may produce patches of W14 or W15.
The diversity and composition of the ground layer varies, according to the underlying soil type and degree of grazing, from bluebell bramble - fern communities through grass and bracken dominated stands, to heathy mossdominated areas.
Main NVC types: W11 Quercus petraea - Betula pubescens Oxalis acetosella woodland W17 Quercus petraea - Betula pubescens Dicranum majus woodland W10e Quercus robur - Pteridium aquilinum Rubus fruticosus woodland: Acer pseudoplatanus - Oxalis acetosella subcommunity. W16b Quercus spp. - Betula spp. Deschampsia flexuosa woodland. Vaccinium myrtillus - Dryopteris dilatata sub-community.
Most woods contain areas of more base-rich soils as well, often along streams or towards the base of slopes, where much richer communities occur. Ash and elm are found in the canopy here, hazel is more prominent in the understorey, and ground flora species such as dog’s mercury Mercurialis perennis, false brome Brachypodium sylvaticum, ramsons Allium ursinum, enchanter’s nightshade Circaea lutetiana, and tufted hair-grass Deschampsia cespitosa occur. There may also be small alder stands, or peaty hollows covered by bog mosses Sphagnum spp. These elements are an important part of the Upland Oak Woodland system.
3.5.3 Stand Types The main corresponding Stand Types are 6A and 6B, with base-rich and wet stands mainly falling into 1D, 3D and 7A, BD. Where beech has invaded, stands may be classified as 8A or 8B.
The dominant species of oak, prevailing climate and altitude are not sufficient individually to characterise the type. However the key characteristics of Upland Oak Woodland are probably best summarised as: • dominance of oak (locally birch) of either species, or hybrids; • usually grazed, in an unenclosed landscape; • usually upland (including North York Moors and Yorkshire Dales), but may also occur at sea level, particularly along the coast (Devon, Cornwall, Wales, Scotland); • NVC types W11, W17 predominate, but W10e or W16b may be locally abundant
Main Stand Types: 6A Upland sessile oak woodland 6B Upland pedunculate oak woodland 3.5.4 Forestry Commission Guide Type The corresponding Guide is 5, Upland Oakwoods (Forestry Authority 1994e). The Priority Habitat also includes many stands in the south-west (particularly along the coast, on the fringes of Exmoor and Bodmin Moor, on the Welsh Borders, around the coast of Wales and around the North York Moors) that are not within the Upland Zone as indicated by the Guide Map. Main Guide types: 5 Upland Oakwoods 23
3.5.5 Habitats Directive Annex I This Priority Habitat is broadly equivalent to ‘Old oak woods with Ilex and Blechnum in the British Isles’. Main Habitats Directive types: 41.53 ‘Old oak woods with Ilex and Blechnum in the British Isles’ 3.5.6 CORINE 41.524 Pennine sessile oak-wavy hair-grass woods 41.53 British and Irish sessile oak woods
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3.6
regeneration areas, may fall into W11 or W17; and areas of juniper are W19. Main NVC type W18 Pinus sylvestris - Hylocomium splendens woodland
Native Pine Woodlands
3.6.1 General comments Relict Native Pine Woodlands, dominated by self-sown Scots pine Pinus sylvestris, occur throughout the central and north-eastern Grampians, and in the northern and western Highlands of Scotland (Map 4). It is an important western representative of the European boreal forests, in which natural structure and succession was probably determined by storms and natural fires caused by lightning.
3.6.3 Stand Types Stand Types 11A, 11B cover the native pine stands. Birch stands within the pinewood area which lack pine are placed in group 12. Stand Type 11C, calcareous pine woods, has been identified at one or two sites but is usually likely to be part of a mosaic with Upland Mixed Ash Woodland, and may, therefore, be better treated with the surrounding woods.
Native Pine Woodlands occur on infertile, strongly leached, podsolic soils. Compared with some more fertile habitats, they do not support a great diversity of plants and animals. However, many of the community’s characteristic species are rare and uncommon. Although the main tree species is Scots pine, birches Betula spp., rowan Sorbus aucuparia, alder Alnus glutinosa, willows Salix spp. and bird cherry Prunus padus are also found. Sessile oak Quercus petraea occurs infrequently, and mainly in the north-east of Scotland. Where browsing levels are low enough to allow the development of a shrubby understorey, this may include common juniper Juniperus communis, aspen Populus tremula, holly Ilex aquifolium and hazel Corylus avellana.
Main Stand Types 11A Acid birch-pine woods 11B Acid oak-pine woods 3.6.4 Forestry Guide Types For the most part the corresponding Guide Type is 7, Native Pinewoods (Forestry Authority 1994g). Areas of extensive birch could be covered by type 6, Northern Birchwoods (Forestry Authority 1994f). Main Guide types: 6 Northern Birchwoods 7 Native Pinewoods 3.6.5 Habitats Directive Annex I The native pine areas fall within the ‘Caledonian forest’ types. Some stands of pine on peat which have been classed as ‘Bog woodland’ may be better considered as part of this Priority Habitat, along with the adjacent dry ground pinewoods, rather than in the Wet Woodland Priority Habitat.
There is some debate regarding the inclusion of pine stands of uncertain origin, with similar physiognomy and composition to woods considered genuinely native, and birchdominated stands within the native range of pine, on sites where pine might be expected to grow. The former, probable non-native stands of Scots pine, are included within the Priority Habitat (but considered of lower quality). Whether birch stands (or birch with only a very small proportion of pine) are included is likely to depend on their extent and their proximity to other stands of native pine. The larger, more remote, birch stands are better considered under the Northern Birchwoods habitat type.
Main Habitats Directive types: 42.51 ‘Caledonian forest’ 44.A1 to 44.A4 ‘Bog woodland’ 3.6.6 CORINE 42.51 Caledonian forest 44.A2 Scots pine bog woods
3.6.2 National Vegetation Classification Native Pine Woodlands is directly equivalent to W18. Associated birch stands, including
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3.7
Woodland type. In contrast, some alder stands (particularly NVC community W6 and Stand Type 7D) may be fairly dry, at least at the surface. A practical problem is the very limited extent of many Wet Woodland stands, which will often be managed as part of the ‘dry-land’ mosaic. Likewise the dryer, ash or oak dominated, fringes of a wet wood may be treated as part of the Wet Woodland habitat.
Wet Woodland
3.7.1 General comments Wet Woodland occurs on poorly drained or seasonally wet soils, and alder, birch and willows are usually the dominant species of tree. Such woods are distributed throughout the UK, typically on flood-plains, as successional habitats on fens, mires and bogs, and forming mosaics with other woodland types in peaty hollows and hill-side flushes.
3.7.2 National Vegetation Classification The whole of NVC communities W1-3 and W57 are normally included within this type. The situation as regards W4 is more complicated. Some stands are relatively dry and, for management purposes, better treated alongside other extensive birch stands. Sub-communities W4a and W4b in the north are provisionally regarded as contributing to the Northern Birchwoods habitat type, while W4c, and southern examples of W4, are considered as Wet Woodland.
Flood-plain forests have been virtually lost as a habitat in the UK, but highly fragmented stands of limited extent occur beside many rivers. The canopies are predominantly composed of alder, willows and ash, and the ground flora is diverse and often luxuriant, with a significant component of nitrophilous species. Succession from open herbaceous wetlands results in a wide range of structures and compositions, determined by the composition of the original vegetation, the climate and the nutrient status. There is frequently an admixture of ‘dry-land’ species. Such woodland varies from low willow scrub, on wet mineral soils at lake edges and in damp pastures, to stands of alder which have developed on rich fens and which possess a diverse ground flora, often dominated by large sedge Carex species or common reed Phragmites australis. In nutrientpoor situations, such as peat-filled hollows, birch and pine stands may develop over bogtype vegetation.
Wet flood-plain forests of ash, elm and oak, lacking alder, are most likely to fall into W8. Main NVC Types: W1 Salix cinerea - Galium palustre woodland W2 Salix cinerea - Betula pubescens Phragmites australis woodland W3 Salix pentandra - Carex rostrata woodland (W4a Betula pubescens - Molinia caerulea woodland: Dryopteris dilatata - Rubus fruticosus sub-community) (W4b Betula pubescens - Molinia caerulea woodland: Juncus effusus subcommunity) W4c Betula pubescens - Molinia caerulea woodland: Sphagnum sub-community W5 Alnus glutinosa - Carex paniculata woodland W6 Alnus glutinosa - Urtica dioica woodland W7 Alnus glutinosa - Fraxinus excelsior Lysimachia nemorum woodland.
In upland areas, alder stands occur in valley bottoms, on flushed hill-sides and water-logged plateaux, frequently forming a mosaic with Upland Oak Woodland. Ash is often important in these situations, and transitions to Upland Mixed Ash Woodland occur. Inevitably there are ambiguities concerning the boundaries between this type and other woodland. Some lowland ash stands may be seasonally very wet, but are generally placed in the Lowland Oak and Mixed Deciduous Woodland habitat type. However, some floodplain forests of ash, oak, elm, poplar and tall willows (occurring as only fragmentary stands) could be considered as belonging to the Wet
3.7.3 Stand Types Most alder stands in Group 7 fall into this category, but some examples of 7C (plateau alderwood) and 7D (slope alderwood) may be 29
better placed in Lowland Oak and Mixed Deciduous Woodland and Upland Mixed Ash Woodland respectively. Wet birch stands fall into Group 12. Recent wet stands of willow have no equivalent in this classification, as it was intended to describe ancient woodland only. Main Stand Types 7A Valley alderwoods on mineral soils 7B Wet valley alderwoods 7C Plateau alderwoods 7D Slope alderwoods 7E Bird cherry alderwoods 12 Birch woodland 3.7.4 Forestry Commission Guide Type The corresponding Guide Type is 8, Wet Woodlands (Forestry Authority 1994h), with the proviso that some W4 birchwoods will now be regarded as belonging to the Northern Birchwoods habitat type. Main Guide types: 8 Wet Woodlands 3.7.5 Habitats Directive Annex I ‘Bog woodland’ that is not part of a mosaic with Native Pine Woodlands falls into this category. Most ‘Residual alluvial forests’ are likely to be considered here, although if there are no alders or willows present, and depending on the size of the stands, such woodland could be considered under the Lowland Oak and Mixed Deciduous Woodland habitat type. Main Habitats Directive types: 44.A1 to 44.A4 ‘Bog woodland’ 44.3 ‘Residual alluvial forests’ 3.7.6 44.92 44.1 44.13 44.31
CORINE Mire willow scrubs Birch and conifer swamp woods White willow gallery forests Ash alder woods of rivulets and springs
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4
Other Important Semi-natural Woodland Types
4.1
Introduction
4.2
The six woodland BAP Priority Habitat types described in Section 3 do not include the whole range of variation found in semi-natural woodland in Britain.
Lowland Oak and Mixed Deciduous Woodland
4.2.1 General comments This is a large category which may need further sub-division, particularly from a management perspective. It spans woodland growing on the full range of soil conditions, from very acidic to base-rich, and includes most semi-natural woodland in southern and eastern England, and in parts of lowland Wales and Scotland (Map 5). 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 generally the commoner oak (although Quercus petraea may be abundant locally) 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, for example, Upland Oak Woodland or Native Pine Woodlands.
Two major woodland types are not currently covered by the BAP Priority Habitat classification and, as a result, are not covered by the Habitat Action Plan process. These are: • all lowland, dry-land woodland not dominated by beech, and which is not being managed as wood-pasture. This category encompasses most ancient woodland in the lowlands of England and Wales, as well as the majority of more recent stands. • birch dominated woodland in the north of Scotland, beyond the geographical or altitudinal ranges of oak and pine. To fill these gaps in coverage, two further woodland types, Lowland Oak and Mixed Deciduous Woodland, and Northern Birchwoods, have been proposed by the UK Native Woodland Habitat Action Plan Steering Group. Although these have not yet been accepted as Priority Habitat types, they are included here because of their importance as semi-natural woodland types.
4.2.2 National Vegetation Classification The bulk of this type falls into W8 (mainly subcommunities a to c in ancient or recent woods; in the lowlands W8d mostly occurs in secondary woodland) and W10 (sub-communities a to d) with lesser amounts of W16 (mainly W16a). Locally, it may form a mosaic with other types, including patches of beech woodland, small wet areas, and types more commonly found in western Britain (particularly in south-east England). Rides and edges may grade into grassland and scrub types.
The accompanying accounts for these two types follow the same structure as those for the Priority Habitat types already accepted. No distribution map is presented for Northern Birchwoods as it generally falls into the same NVC communities as Upland Oak Woodland, making it difficult to portray the distribution using this data.
Main NVC types: W8 Fraxinus excelsior - Acer campestre Mercurialis perennis woodland (a) Primula vulgaris - Glechoma hederacea sub-community (b) Anemone nemorosa subcommunity (c) Deschampsia cespitosa subcommunity. (d) Hedera helix sub-community. 31
W10
W16
Main Guide types: 1 Lowland acid beech and oak woods 3 Lowland mixed broadleaved woods
Quercus robur - Pteridium aquilinum Rubus fruticosus woodland (a) Typical sub-community (b) Anemone nemorosa subcommunity (c) Hedera helix sub-community (d) Holcus lanatus sub-community Quercus spp. - Betula spp. Deschampsia flexuosa woodland (a) Quercus robur sub-community
4.2.5 Habitat Directive Annex I Despite its importance in a British context, this woodland is poorly represented in Annex I of the Habitats Directive. Some hornbeam stands are sufficiently ‘continental’ in their composition to be considered as ‘StellarioCarpinetum oak-hornbeam forests’; some lowland ash-lime stands fall into the ‘TilioAcerion ravine forests’ but in each case the bulk probably do not. Some acid oak stands have similarities to the ‘Old acidophilous oak woods with Quercus robur on sandy plains’ category, but again, these are the minority.
4.2.3 Stand Types A major strength of the Stand Type system is its separation of canopy variations in Lowland Oak and Mixed Deciduous Woodland. Not surprisingly, a wide range of Stand Types are encompassed within this category. These include most of the field maple (2), lime (4, 5), suckering elm (10) and hornbeam (9) Stand Groups, and substantial proportions of the wych elm (1), ash (3) and oak (6) Stand Groups. More rarely, birch (12) and some alder stands (7C) may also occur. Some of these will require separate management treatments.
Main Habitats Directive types: 41.24 ‘Stellario-Carpinetum oakhornbeam forests’ 41.4 ‘Tilio-Acerion ravine forests’ 41.51 ‘Old acidophilous oak woods with Quercus robur on sandy plains’ 4.2.6 CORINE 41.23 Sub-Atlantic oxlip - ash - oak forests 41.32 British ash - field maple - dogs mercury forests 41.24 Sub-Atlantic oak - hornbeam forests 41.51 Pedunculate oak and birch woods 41.525 English pedunculate oak - birch - wavy hair-grass woods.
Main Stand Types: 1B Wet ash-wych elm woods 2A Wet ash-maple woods 2B Ash-maple woods on light soils 2C Dry ash-maple woods 3A Acid pedunculate oak-hazel-ash woods 3B Southern calcareous hazel-ash woods 4A Acid birch-ash-lime woods 4B Maple-ash-lime woods 5A Acid pedunculate oak-lime woods 5B Acid sessile oak-lime woods 6C Lowland sessile oak woods 6D Lowland pedunculate oak woods 7C Plateau alder woods 9A Pedunculate oak-hornbeam woods 9B Sessile oak-hornbeam woods 10 Suckering elm woodland 4.2.4 Forestry Commission Guide Types Most woods included here should be considered under Guide 3, Lowland mixed broadleaved woods (Forestry Authority 1994c). Some very acid oak, chestnut, hornbeam and lime stands may be better treated under Guide 1, Lowland acid beech and oak woods (Forestry Authority 1994a).
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4.3
although if extensive should be referred to the appropriate Priority Habitat.
Northern Birchwoods
4.3.1 General comments Most semi-natural woodland in northern Scotland is dominated by birch. Oak and pine reach their altitudinal limit at about 150 m in the north west Highlands, and at 300 m in the east (Forestry Authority 1994f). In the cool, boreal climate of these areas, stands of almost pure silver and downy birch develop, with only small amounts of rowan, juniper, ash, aspen and hazel.
Main NVC types W10e Quercus robur - Pteridium aquilinum Rubus fruticosus woodland: Acer pseudoplatanus - Oxalis acetosella subcommunity. W11 Quercus petraea - Betula pubescens Oxalis acetosella woodland W17 Quercus petraea - Betula pubescens Dicranum majus woodland
The ground flora varies, according to site history and soil type, from very herb-rich stands, to those dominated by grasses and dwarf shrubs.
4.3.3 Stand Types Most stands fall into Stand Group 12, with patches of 1D and 3C in more base-rich areas, and of 7A and D in wet stands with alder.
On more acid soils, rowan is the most common associate and aspen can dominate in places. Juniper is frequent, especially in the north-east, where it may form an underwood beneath the birch. The ground flora in such areas is generally dominated by grasses (Agrostis tenuis, Deschampsia flexuosa, Festuca ovina) or dwarf shrubs (especially Vaccinium myrtillus). Many stands have light, open canopies, and grassland and bog species are commonly present.
Main Stand Types: 12A Rowan - Birch woods 12B Hazel - Birch woods 4.3.4 Forestry Commission Guide Types The corresponding guide is 6, Upland Birchwoods (Forestry Authority 1994f). 4.3.5 Habitats Directive Annex I Many stands could be considered as examples of ‘Old oak woods with Ilex and Blechnum in the British Isles’. Despite the absence of oak, the epiphyte community (one of the main features of the Annex I habitat) is similar to that of Upland Oak Woodland, and is often extremely rich. The ‘Old oak woods with Ilex and Blechnum in the British Isles’ of the Loch Maree Complex cSAC are, to a great extent, Northern Birchwoods. That of Shieldaig Woods (one of the component SSSIs) is, according to the SSSI citation, one of the best oceanic birchwoods in the district.
In older woods and on more base-rich soils, hazel, hawthorn and bird cherry are more prominent in the shrub layer and the ground flora can be very rich, with species such as Conopodium majus, Mercurialis perennis and Potentilla sterilis. Northern Birchwoods occur in association with several other woodland communities. On the southern edges of the range, transitions to Upland Oak Woodland are found. There may be small areas of Wet Woodland, also dominated by birch, or by willow or alder, and, in the pine zone, transitions to Native Pine Woodlands. Upland Mixed Ash Woodland is also often found in association with Northern Birchwoods, although many extreme northern stands are dominated by hazel or aspen.
Main Habitats Directive types: 41.53 ‘Old oak woods with Ilex and Blechnum in the British Isles’ 4.3.6 CORINE 41.53 British and Irish sessile oak woods
4.3.2 National Vegetation Classification The main types are W10e, W11 and W17. Small base-rich patches (W8 - sub-communities b, e and f have been recorded this far north, W9) and wet areas (mainly W4, W7) are common,
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5
References
Bunce, R.G.H. 1989. A field key for classifying British woodland vegetation, Part 2. London, HMSO. Commission of the European Communities. 1991. CORINE biotopes manual. Luxembourg, Office for Official Publications of the European Communities. Cooke, R., & Kirby, K.J. 1994. The use of a new woodland classification in surveys for nature conservation purposes in England and Wales. Arboricultural Journal, 18: 167-186. Department of the Environment. 1993. Countryside survey 1990, summary report. Department of the Environment.
Eastcote,
Forestry Authority. 1994a. Forestry Practice Guide 1. The management of semi-natural woodlands: lowland acid beech and oak woods. Edinburgh, Forestry Authority. Forestry Authority. 1994b. Forestry Practice Guide 2. The management of semi-natural woodlands: lowland beech-ash woods. Edinburgh, Forestry Authority. Forestry Authority. 1994c. Forestry Practice Guide 3. The management of semi-natural woodlands: lowland mixed broadleaved woods. Edinburgh, Forestry Authority. Forestry Authority. 1994d. Forestry Practice Guide 4. The management of semi-natural woodlands: upland mixed ashwoods. Edinburgh, Forestry Authority. Forestry Authority. 1994e. Forestry Practice Guide 5. The management of semi-natural woodlands: upland oakwoods. Edinburgh, Forestry Authority. Forestry Authority. 1994f. Forestry Practice Guide 6. The management of semi-natural woodlands: upland birchwoods. Edinburgh, Forestry Authority. Forestry Authority. 1994g. Forestry Practice Guide 7. The management of semi-natural woodlands: native pinewoods. Edinburgh, Forestry Authority. Forestry Authority. 1994h. Forestry Practice Guide 8. The management of semi-natural woodlands: wet woodlands. Edinburgh, Forestry Authority. Hall, J. 1997. An analysis of National Vegetation Classification survey data. JNCC Report, No. 272. HMSO. 1995. Biodiversity: the UK Steering Group report. Volume 2: Action Plans. London, HMSO. Kirby, K.J., Saunders, G.R., & Whitbread, A.M. 1991. The National Vegetation Classification in nature conservation surveys - a guide to the use of the woodland section. British Wildlife, 3: 70-80.
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Nature Conservancy Council. 1990. Handbook for Phase 1 habitat survey - a technique for environmental audit. Peterborough, JNCC. Peterken, G.P. 1981. Woodland conservation and management. London, Chapman and Hall. Rackham, O. 1980. Ancient woodland, its history, vegetation and uses in England. London, Edward Arnold. Rackham, O. 1997. Where is beech native? Tree News, Autumn 1997. Rodwell, J.S. 1991a. British Plant Communities. Vol. 1: Woodlands and scrub. Cambridge University Press.
Cambridge,
Rodwell, J.S. 1991b. British Plant Communities. Vol. 2: Mires and heaths. Cambridge, Cambridge University Press. Rodwell, J.S. 1992. British Plant Communities. Vol. 3: Grassland and montane communities. Cambridge, Cambridge University Press. Rodwell, J.S. 1995. British Plant Communities. Vol. 4: Aquatic communities, swamps and tall herb fens. Cambridge, Cambridge University Press. Rodwell, J.S. In press. British Plant Communities. Vol. 5: Maritime communities and the vegetation of open habitats. Cambridge, Cambridge University Press. Whitbread, A.M., & Kirby, K.J. 1992. Summary of National Vegetation Classification woodland descriptions. Peterborough, Joint Nature Conservation Committee. (UK Nature Conservation, No 2.)
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Appendix 1. NVC communities Wet Woodland communities W1 W2 W3 W4 W5 W6 W7
Salix cinerea - Galium palustre woodland Salix cinerea - Betula pubescens - Phragmites australis woodland Salix pentandra - Carex rostrata woodland Betula pubescens - Molinia caerulea woodland Alnus glutinosa - Carex paniculata woodland Alnus glutinosa - Urtica dioica woodland Alnus glutinosa - Fraxinus excelsior - Lysimachia nemorum woodland
Dry-land high forest communities W8 W9 W10 W11 W12 W13 W14 W15 W16 W17 W18
Fraxinus excelsior - Acer campestre - Mercurialis perennis woodland Fraxinus excelsior - Sorbus aucuparia - Mercurialis perennis woodland Quercus robur - Pteridium aquilinum - Rubus fruticosus woodland Quercus petraea - Betula pubescens - Oxalis acetosella woodland Fagus sylvatica - Mercurialis perennis woodland Taxus baccata woodland Fagus sylvatica - Rubus fruticosus woodland Fagus sylvatica - Deschampsia flexuosa woodland Quercus spp. - Betula spp. - Deschampsia flexuosa woodland Quercus petraea - Betula pubescens - Dicranum majus woodland Pinus sylvestris - Hylocomium splendens woodland
Scrub communities W19 W20 W21 W22 W23 W24 W25
Juniperus communis ssp. communis - Oxalis acetosella woodland Salix lapponum - Luzula sylvatica scrub Crataegus monogyna - Hedera helix scrub Prunus spinosa - Rubus fruticosus scrub Ulex europaeus - Rubus fruticosus scrub Rubus fruticosus - Holcus lanatus underscrub Pteridium aquilinum - Rubus fruticosus underscrub
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Appendix 2. Forest types on Annex I of the Habitats Directive, that occur in Britain 31.88 41.12 41.13 41.24 41.4 41.51 41.53 42.51 42.A71 to 42.A73 44.3 44.A1 to 44.A4 (62.4
Juniperus communis formations on calcareous heaths or grasslands Beech forest with Ilex and Taxus, rich in epiphytes (Ilici-Fagion) Asperulo-Fagetum beech forests Stellario-Carpinetum oak-hornbeam forests Tilio-Acerion ravine forests Old acidophilous oak woods with Quercus robur on sandy plains Old oak woods with Ilex and Blechnum in the British Isles Caledonian forest Taxus baccata woods Residual alluvial forests (Alnion glutinoso-incanae) Bog woodland Limestone pavement)
Appendix 3. CORINE types mentioned in this report 31.81 31.883 41.12 41.13 41.16 41.23 41.24 41.31 41.32 41.41 41.51 41.52 41.53 42.51 42.A71 44.13 44.31 44.92 44.A1 44.A2 62.3 84.5
Medio-European rich-soil thickets Juniper - wood sorrel woodland Atlantic acidophilous beech forests Neutrophilous beech forests Beech forests on limestone Sub-Atlantic oxlip ash - oak forests Sub-Atlantic stitchwort oak - hornbeam forests Ash - rowan - mercury forests British ash - field maple - mercury forests Ravine ash - sycamore forests Pedunculate oak and birch woods Atlantic acidophilous oak forests with beech British and Irish sessile oak woods Caledonian forest British yew woods White willow gallery forests Ash - alder woods of rivulets and springs Mire willow scrub Sphagnum birch woods Scots pine bog woods Pavements Parkland
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Appendix 4. Peterken Stand Types 1A 1B 1C 1D 2A 2B 2C 3A 3B 3C 3D 4A 4B 4C 5A 5B 6A 6B 6C 6D 7A 7B 7C 7D 7E 8A 8B 8C 8D 8E 9A 9B 10A 10B 11A 11B 11C 12A 12B
Calcareous ash - wych elm woods Wet ash - wych elm woods Calcareous ash - wych elm woods on dry and/or heavy soils Western valley ash - wych elm woods Wet ash - maple woods Ash - maple woods on light soils Dry ash - maple woods Acid pedunculate oak - hazel - ash woods Southern calcareous hazel - ash woods Northern calcareous hazel - ash woods Acid sessile oak - hazel - ash woods Acid birch - ash - lime woods Maple - ash - lime woods Sessile oak - ash - lime woods Acid pedunculate oak - lime woods Acid sessile oak - lime woods Upland sessile oak woods Upland pedunculate oak woods Lowland sessile oak woods Lowland pedunculate oak woods Valley alder woods on mineral soils Wet valley alder woods Plateau alder woods Slope alder woods Bird cherry - alder woods Acid sessile oak - beech woods Acid pedunculate oak - beech woods Calcareous pedunculate oak - ash - beech woods Acid pedunculate oak - ash - beech woods Sessile oak - ash - beech woods Pedunculate oak - hornbeam woods Sessile oak - hornbeam woods Invasive elm woods Valley elm woods Acid birch - pine woods Acid oak - pine woods Calcareous pine woods Rowan - birch woods Hazel - birch woods
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Appendix 5. Forest Practice Guide Types 1 2 3 4 5 6 7 8
Lowland acid beech and oak woods Lowland beech-ash woods Lowland mixed broadleaved woods Upland mixed ash woods Upland oak woods Upland birch woods Native pine woods Wet woodlands
Appendix 6. Phase I types mentioned in this report A1.1.1 A1.1.2 A1.2.1 A1.2.2 A1.3.1 A1.3.2 A2 A3
Broad-leaved, semi-natural woodland Broad-leaved, plantation woodland Coniferous, semi-natural woodland Coniferous, plantation woodland Mixed, semi-natural woodland Mixed, plantation woodland Scrub Parkland/scattered trees
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