Forestry Commission W S The ARCHIVE Forestry I p ' Authority Forestry Commission

Bulletin 112

Native Woodlands John Rodwell Gordon Pattecson

FORESTRY COMMISSION BULLETIN 112

Creating New Native Woodlands

John Rodwella and Gordon Pattersonh aUnit of Vegetation Science, Lancaster University and bForestry Authority, Northern Research Station, Roslin, Midlothian, EH25 9SY Present address: Forestry Practice Division, Forestry Authority, 231 Corstorphine Road, Edinburgh, EH12 7AT

LONDON: HMSO © Crown copyright 1994 Second impression 1995 Applications for reproduction should he made to HMSO Copyright Unit. ISBN 0 11 710320 9

Acknowledgements

The authors would like to express their thanks to all those who scrutinised and commented helpfully on the draft text or parts of it, including Graham Gill, Bill Mason, John McNeill, Andy Moffat, Paul Tabbush and Julian Evans of the Forestry Authority, David Williamson of Forest Enterprise, and Peter Buckley of Wye College, University of London. Jenny Claridge, George Gate and John Williams of the Publications Section of the Forestry Authority at Alice Holt Lodge shaped up text and produced the figures, and the typing staff at the University of Lancaster and Northern Research Station coped admirably with several drafts without complaint. Last, but not least, the authors are grateful to Liz Cooper of the Unit of Vegetation Science who undertook much of the research project for the Forestry Authority which generated the idea of producing the advice in this Bulletin.

Rodwell, John S; Patterson, Gordon S. 1994. Creating New Native Woodlands Bulletin 112. HMSO, London, xiii + 82pp.

FDC 187: 182.8: 91: (410)

KEYWORDS: Forests, Lowlands, Native woodlands, NVC, Uplands, Woodland design

Front cover: A new native pinewood Enquiries relating to this publication formed by Scots pine and birch colonising should be addressed to: heather moorland on The Crannach, near The Technical Publications Officer Ballater, Deeside. (Peter Quelch, by per­ The Forestry Authority mission of Crannach Management Forest Research Station Group) Alice Holt Lodge, Wrecclesham Insets Chickweed wintergreen, a flower Farnham, Surrey GU10 4LH typical of woods like this. (E11023) A native mixed broadleaved wood planted about thirty years ago in lowland West Yorkshire. (38628) Contents

Page Acknowledgements ii List of figures v List of plates vi List of tables vii Foreword viii Summary ix Resume x Zusammenfassung xi Resumen xiii 1 Introduction 1 2 Types of semi-natural woodland in Britain 4 Classifying semi-natural woodlands 4 The National Vegetation Classification 4 Semi-natural woodland descriptions 4 Mixed broadleaved and oak-birch woodlands of the lowland zone 5 Mixed broadleaved and oak-birch woodlands of the upland zone 9 Beech woodlands 10 Scots pine and juniper woodlands 12 Wet woodlands with alder, downy birch and willows 13 3 Methods of creating native woodlands 16 Woodland design 16 Location 16 Design at the landscape scale 16 Using natural colonisation 18 Species choice for planting 18 Planting patterns 20 Planting sensitive species 22 Management practices 22 Ground preparation 22 Fertilisers 25 Herbicides 26 Grazing 26 Encouraging natural colonisation 27 Altering early canopy structure and composition 27 Disturbed sites 28 Farmland 28 Reclamation sites 30 Felled plantations 32 Introducing field layer plants 33 4 How to use the design prescriptions 35 Native woodland zones 35 Soil types 35 Geology, terrain and site types 35 Recommended trees and shrubs 35 Optimal precursor vegetation 38 Desired invaders 38 Woodland structure and pattern 38 5 Design prescriptions 43 Lowland mixed broadleaved woodland with dog’s mercury (W8) 43 Lowland mixed broadleaved woodland with bluebell/wild hyacinth (W10) 45 Lowland oak-birch woodland with bilberry/blaeberry (W16) 47 Upland mixed broadleaved woodland with dog’s mercury (W9) 49 Upland oak-birch woodland with bluebell/wild hyacinth (W ll) 51 Upland oak-birch woodland with bilberry/blaeberry (W17) 53 Beech-ash woodland with dog’s mercury (W12) 55 Beech-oak woodland with bramble (W14) 57 Beech-oak woodland with wavy hair-grass (W15) 59 Scots pine woodland with heather (W18) 61 Juniper woodland with wood sorrel (W19) 63 Alder woodland with common reed (W2) 65 Alder woodland with stinging nettle (W6) 67 Birch woodland with purple moor-grass (W4) 69 Alder-ash woodland with yellow pimpernel (W7) 71 References 73 iv List of figures

Page 2.1 The lowland zone of Britain 8 2.2 Mixed broadleaved and oak-birch woodlands of the lowland zone 8 2.3 The upland zone of Britain 9 2.4 Mixed broadleaved and oak-birch woodlands of the upland zone 10 2.5 The zone of semi-natural beech woodlands 11 2.6 Soil variation and types of semi-natural beech woodland 11 2.7 The zone of semi-natural pine woodland (native pinewoods) 12 2.8 The zone of juniper woodland in the uplands 13 2.9 The main zones of wet woodlands on fen peat 14 2.10 The main zones of wet woodlands on alluvium 14 3.1 Using geological and soil differences to develop mosaics in new native woodlands Facing Plate 11 3.2 Leaving open ground around crags and mires to increase diversity in new native woodlands Facing Plate 12 3.3 Using variable spacings and unplanted ground at margins for a natural appearance and habitat diversity Facing Plate 13 3.4 Using pure clumps or clumps with two or three well-matched species to develop mixed woodlands 21 3.5 Using varied clump size to increase diversity in new native woodlands 21 3.6 Allowing enough room around shrubs to prevent excessive shading by adjacent trees 21 3.7 Using varied spacing between clumps to increase diversity in new native woodlands 21 3.8 Using varied spacing within clumps to increase diversity in new native woodlands 22 4.1 Zones for new native woodlands 36 4.2 Frequency and abundance of major and minor trees and shrubs among a set of eight plantings 39 4.3 Major and minor tree species for new native woodland types 40 4.4 Major and minor shrub species for new native woodland types 41

v List of plates

1 Lowland mixed broadleaved woodland with dog’s mercury (W8) 2 Ground flora of a W8 woodland in the western upland fringes 3 Lowland oak-birch woodland with bluebell/wild hyacinth (W10) 4 Ground flora of W10 woodland 5 Lowland oak-birch woodland with bilberry/blaeberry (W16) 6 Upland mixed broadleaved woodland with dog’s mercury (W9) 7 Details of the flora of a W9 woodland 8 Upland oak-birch woodland with bluebell/wild hyacinth (W ll): silver birch with no shrub layer and a ground flora influenced by grazing 9 A more mixed W ll woodland: mature oaks with hazel and birch over wood sorrel, creeping soft grass and bracken 10 Upland oak-birch woodland with bilberry/blaeberry (W17), showing downy birch with rich moss and liverwort 11 An old pollarded oak with holly sapling and wavy hair-grass and bilberry in the field layer in an example of W17 woodland 12 Oak seedlings in profusion in a typical W17 woodland floor 13 Beech-ash woodland with dog’s mercury (W12) 14 Mature beech stand determined as W14 type by the bracken and soft grass at the edges 15 Scots pine woodland with heather (W18) 16 Juniper woodland with wood sorrel (W19) 17 Birch woodland with purple moor-grass (W4) 18 Alder woodland with tussock sedge (W5) 19 Sallow woodland with bottle sedge (W3) 20 Sallow-birch woodland with reed (W2) 21 Alder-ash woodland with yellow pimpernel (W7) 22 W7 flora among newly coppiced alder in an ancient semi-natural woodland area 23 A woodland flora developing under 34-year-old sessile oak planted on grazed heathland List of tables

Page 2.1 Woodland types: classification and nomenclature 6 3.1 Examples of successful mixtures of native timber trees 21 3.2 The influence of design and early management upon the development of field layer plant communities in new native woodlands 23 3.3 Field layer plants favoured by disturbance 24 3.4 Target new native woodland types for former arable and improved pastureland 29 3.5 Native trees and shrubs found suitable for reclamation sites 31 4.1 Soil types appropriate for new native woodlands 37 Creating New Native Woodlands

Foreword

The proportion of native trees and shrubs planted within woodlands of all kinds has increased dramatically over the last few years and there has also been a growing interest in establishing new woodlands, composed entirely of native trees and shrubs suited to the site. There are probably two principal motivations: firstly the desire to expand the remnants of our semi-natural woods and secondly the more general aim of reversing past losses of native species in the wider countryside. Very encouraging progress has already been made in the Scottish Highlands with New Native Pinewoods created under the Woodland Grant Scheme and this book will help to extend the new native woodland concept to other species associations by providing comprehensive advice on design and management for the main categories of semi-natural woodland in Britain. This Bulletin combines expertise in woodland ecology and up-to-date silvicul­ tural knowledge. It encourages the selection of the appropriate type of new native woodland for any particular site and gives guidance on the species com­ position, design and silvicultural methods which should be used in order to secure the development of the woodland ecosystem as a whole. The wide range of possible benefits from these new woods, including wood production, is recog­ nised and the practical advice is tailored accordingly. I therefore believe that this book will play a very useful role in encouraging the creation of new native woods which will suit particular local environments throughout Britain. This could eventually lead to a reversal of the present situ­ ation where the area of semi-natural woodlands is declining.

R. T. Bradley Head of the Forestry Authority January 1994 Creating New Native Woodlands

Summary

The use of native trees and shrubs in establishing new woodlands has increased greatly in Britain in recent years because of growing emphasis on obtaining environmental benefits from forests. In addition to planting native trees as part of mixed woods together with introduced species to combine tim­ ber production with environmental and social benefits, interest is growing in establishing new woods of a more natural character. These are both as exten­ sions to the surviving remnants of semi-natural woods to safeguard their future and in presently unwooded areas. Advice on design and management of these new native woodlands is provided in this Bulletin. The guidance is based upon knowledge of the composition of semi-natural woodlands and their relationship to site factors which has been derived from the recent National Vegetation Classification in Britain. The first part of the Bulletin describes the main characteristics of semi-natural woodland composi­ tion including trees, shrubs and field layer plants and how they depend upon soil and climate as well as management history. This is followed by guidance on methods of design and early management for new native woods which are likely to encourage communities of trees and shrubs and associated flora and fauna to develop similar to those of semi-natural woods on equivalent sites. The prospects for the development of the full flora and fauna will vary. For exam­ ple, it will be lower on more disturbed and isolated sites, but much of the char­ acter of semi-natural woods can still be encouraged. In some cases introduction of field layer plants might be considered and guidance is given on whether and how this should be done. Finally, the Bulletin provides a series of design prescriptions for individual woodland types. These are for selecting the appropriate type of new native woodland for a given site using information on the local climate, geology, soil and existing vegetation. Lists of recommended trees and shrubs, divided into major and minor species, are provided for each woodland type with notes on the characteristic structure of the woodland and its pattern in the landscape. There are also lists of the main vascular field layer plants which might be expected to colonise as the new native woodland develops. Creation de Nouveaux Bois Natifs

Resume

L’emploi d’arbres et d’arbustes natifs dans la creation de nouveaux bois a accru enormement en Grande Bretagne dans les annees recentes a cause du croissant interet marque d’obtenir des benefices du milieu forestier. En plus de planter des arbres natifs qui forment part des bois mixtes avec des especes introduites combinant la production de bois avec des benefices pour le milieu et sociaux, il y a un croissant interet d’etablir des nouveaux bois d’un carac- tere plus naturel. Ce sont, tous les deux, des extensions aux vestiges sur- vivants des bois seminaturels pour sauvegarder leur futur et dans des ter­ rains actuellement depourvus d’arbres. Des conseils sur le dessein et la gestion de ces nouveaux bois natifs sont fournis dans ce Bulletin. L’avis se base sur les connaissances de la composition des bois semi­ naturels et leur relation avec des facteurs du terrain qui ont ete derivees de la recente Classification Nationale de Vegetation de la Grande Bretagne. La premiere partie du Bulletin decrit les caracteristiques principales de la com­ position des bois semi-naturels, y inclus arbres, arbustes et plantes-couche de champs et comment ceux-ci dependent du sol, du climat et de l’histoire de leur gestion. Ceci est suivi par des indications sur des methodes de dessein et le tot manege des bois natifs nouveaux qui peuvent probablement encourager le developpement de communautes d’arbres et d’arbustes, de flore et de faune sauvage associee, similaires a celles des bois semi-naturels dans des terrains equivalents. Les perspectives de developpement integral de la flore et de la faune variera. Par exemple, il sera inferieur sur des terrains plus remues et isoles, mais une grande partie du caractere des bois semi-naturels peut etre tout de meme encourage. Dans certains cas, l’introduction de plantes-couche de champs sera convenable et orientation est donne vis a vis si et comment cela doit etre fait. Finalement, le Bulletin pourvoit une serie de formules de dessein pour des genres de bois individuels. Celles-ci aident a choisir le type qui convient au nouveau bois natif pour un terrain donne , utilisant l’information sur le cli­ mat local, la geologie, le sol et l’existante vegetation. Listes d’arbres et d’arbustes recommandes, divisees en especes majeur et mineur, sont pourvues pour chaque type de bois, avec notes sur la structure caracteristique du bois et son modele dans le paysage. II y a aussi des listes des principales plantes-couche vasculaires champetres qui pourraient coloniser au fur et a mesure que le bois natif se developpe. Die Schaffung neuer, einheimischer Walder

Zusammenfassung

Der Gebrauch von einheimischen Baiimen und Straiichem hat in Britannien in den letzten Jahren betrachtlich zugenommen, da man zunehmenden Wert darauf legt, von Waldern umweltliche Nutzen zu erlangen. Neben der Pflanzung von einheimischen Baiimen als Bestandteil eines Mischwaldes zusammen mit eingefiihrten Arten, um Holzproduktion mit umweltlichen und sozialen Vorteilen zu kombinieren, besteht ein zunehmendes Interesse an der Schaffung neuer Walder mit einem natiirlicherem Charakter. Dies gilt sowohl fur die Erweiterung der iiberlebenden Reste von Semi- Ursprungswaldem um deren Zukunft zu sichern, als auch fur momentan unbewaldete Gebiete. Ratschlage zur Planung und Pflege dieser neuen, ein­ heimischen Walder werden in diesem Bulletin gegeben. Die Anleitung basiert sich auf Kenntnisse, iiber die Zusammensetzung semi-urspriinglicher Walder und ihre Beziehung zu Gelandefaktoren, die man durch die kiirzlich in Britannien vollzogene, nationale Vegetations- Klassifizierung erlangt hat. Der erste Teil des Bulletins beschreibt die Hauptcharakteristiken der Zusammensetzung von Semi-Ursprungswaldern inclusive Baiime, Straucher und Feldpflanzen, und wie sie nicht nur von Boden und Klima, sondern auch vom Pflegewerdegang abhangen. Diesem folgt eine Anleitung zu Methoden der Planung und Anfangspflege neuer ein­ heimischer Walder, welche wahrscheinlich die Bildung von Gemeinschaften von Baiimen, Strauchern und der entsprechenden Flora und Fauna, ahnlich derer von Semi-Ursprungswaldem auf ahnlichem Gelande, fordern. Die Aussichten zur Entwicklung der vollen Flora und Fauna werden unter- schiedlich sein. Zum Beispiel werden sie auf gestorterem und isoliertem Gelande geringer sein, aber viel des Charakters eines Semi-Ursprungswaldes kann trotzdem unterstiitzt werden. In manchen Fallen Konnte man die Einfuhrung von Feldpflanzen erwagen und es wird somit eine Beschreibung gegeben, ob und wie dies getan werden sollte. Zuletzt liefert das Bulletin eine Reihe von Planungsbeschreibungen fur individuelle Waldtypen. Diese dienen zur Wahl des passenden Types fur den neuen, einheimischen Wald fur das gegebene Gelande, unter Benutzung von Information tiber lokales Klima, Geologie, Boden und vorhandene Vegetation. Fiir jeden Waldtyp werden Listen von vorgeschlagenen Baiimen und Straiichem, unterteilt in Haupt- und Unterarten, angegeben, mit Erlauterungen zur charakteristischen Struktur des Waldes und seiner Lage in der Landschaft. Es enthalt auch eine Liste hauptsachlicher Feldpflanzen, welche voraussichtlich den neuen, einheimischen Wald kolonisieren, wahrend er sich entwickelt. Creando Nuevos Bosques Nativos

Resumen

El uso de arboles y arbustos nativos en el establecimiento de nuevos bosques ha crecido muchfsimo en Gran Bretana en los ultimos anos a causa del cre- ciente enfasis en la obtencion de beneficios medio ambientales forestales. Ademas de sembrarse arboles nativos como parte de bosques mixtos junto con especies introducidas para combinar una production maderera con beneficios medio ambientales y sociales, esta creciendo el interes en establecer nuevos bosques de un caracter mas natural. Estos son ambos como extenciones de los vestigios de bosques seminaturales que sobreviven para resguardar su futuro y en actuales zonas desprovistas de arboles. Este Boletfn ofrece asesoramien- to sobre el diseno y manejo de estos nuevos bosques naturales nativos. El asesoramiento esta basado en lo que se sabe de la composicion de bosques seminaturales y de su relation con factores de localidad que se ha derivado de la reciente Clasificacion Nacional de Vegetacion en Gran Breta na. La primera parte del Boletfn describe las caracteristicas principales de la composicion de bosques seminaturales, incluyendo arboles, arbustos y plantas cubre campos y como estos dependen del suelo, del clima y de la historia de su manejo. Luego se indican metodos de diseno y de temprana gestion de nuevos bosques nativos que sean probables de fomentar comunidades de arboles y arbustos, de flora y fauna asociada, similares a los bosques seminaturales en terrenos equivalentes. Las perspectivas de desarrollo total de flora y fauna variara. Por ejemplo, sera inferior en areas mas removidas y aisladas, pero mucho del caracter de bosques semi-naturales puede aun ser fomentado. En ciertos casos, se considera la introduction de plantas cubre campos y se infor­ ma si esto se debe hacer y como. Finalmente, el Boletfn provee una serie de preceptos de diseno para tipos de bosques individuales. Estos son para seleccionar el tipo de nuevo bosque nativo apropiado a tal lugar, utilizando informacion sobre el clima local, la geologfa, el suelo y la actual vegetacion. Se suministran listas, divididas en mayores y menores especies, de arboles y arbustos recomendados para cada tipo de bosque, con notas sobre la estructura caracteristica del bosque y su aspecto en el paisaje. Tambien hay listas de las principales plantas vascu- lares cubre-campos que se podria esperar colonizarian a medida que el nuevo bosque nativo se desarrolla.

Chapter 1 Introduction

This Bulletin provides advice to land man­ produced (Forestry Commission, in press). agers and owners who are interested in estab­ These policies have resulted in a great in­ lishing new areas of woodland made up of crease in the planting and natural regenera­ communities of native tree and shrub species tion of native trees in recent years. which are appropriate to the site. Broadleaved planting of all types has In recent years the importance of conserv­ increased sixfold from 1844 ha in 1985 to 11 145 ing the remnants of Britain’s semi-natural ha in 1992 (Forestry Commission, 1985b; 1992) woodlands has been widely accepted and and the great majority of this has been with translated into policy. Semi-natural wood­ species native to Britain. Of all the proposals lands are largely composed of trees and for grant-aid for new areas of woodland sub­ shrubs that are native to the site. They have mitted to the Forestry Authority between developed from seedlings or stump regrowth June 1991 and November 1992, almost 95% of through successive generations from the origi­ broadleaved trees proposed for planting were nal trees in the wood which were self-sown native to Britain. (Kirby et al., 1989). They include: Native broadleaved trees and shrubs are increasingly being planted and regenerated • prim ary w oods on sites that have always within extensive coniferous forests for wildlife been wooded; conservation, amenity, recreation and other • secondary w oods which have colonised environmental benefits. Much of the charac­ bare ground within historical times. teristically smaller woodland recently estab­ Semi-natural woods, especially the oldest or lished on farms and in and around urban ‘ancient’ ones, are the nearest we have to truly areas also consists of native species. Native natural woodland. They are very valuable species are predominant, too, in larger wildlife habitats and an important part of our broadleaved plantations in the lowlands cultural heritage. The current area of ancient where timber production is important. By con­ semi-natural woodland is thought to be trast, thousands of hectares of new native approximately 300 000 hectares (ha) (Kirby et pinewoods are being planted or regenerated in al., 1989). the Scottish Highlands for which wood produc­ As a result of concern over the large losses tion is often considered less important than of ancient semi-natural woodland that have environmental objectives. occurred since 1945, the Forestry Commission All these uses of native species are likely to introduced new policies in 1985 and 1989 continue in future as major contributions to aimed at conserving the remaining areas of forestry for multiple objectives (Forestry Com­ semi-natural woodland, and of broadleaved mission, 1991). Indeed, there is considerable woodland more generally, and extending them interest in the expansion of native woodlands where appropriate (Forestry Commission, in sensitive areas where more intensively 1985a; 1989). Further guidance on the man­ managed forests of exotic species may be con­ agement of semi-natural woods has since been sidered inappropriate.

1 Native trees are clearly being planted for a It is important to emphasise, however, that wide range of objectives and situations. Some­ new native woods must not be regarded as a times only a few native species are suitable substitute for existing semi-natural wood­ for the purpose in mind, for example, oak, land. They will perhaps never attain the full beech, ash or gean for high quality timber in ecological value of ancient semi-natural lowland England (Kerr and Evans, 1993); but woods and, of course, new woods cannot often a wide range of native species can be replace the cultural and scientific interest of used to provide environmental and amenity the originals. Advice on the management of benefits. There are frequently opportunities semi-natural woodlands can be found in a to think in terms of encouraging whole com­ series of guides from the Forestry Authority munities of native trees and shrubs appropri­ (Forestry Commission, in press). ate to the site with the aim of approaching the The scope of this Bulletin includes all areas appearance and ecological integrity of semi­ of new native woodland being established, natural woodland. These new native woods whether by natural colonisation or by plant­ could range from small pockets along stream- ing, on currently unwooded ground outside sides in a forest of exotic conifers to extensive existing semi-natural woods. However, it is areas of several hundred hectares comprising more difficult to use semi-natural woods as a mosaic of woodland, heath and mire in the models on highly disturbed sites such as uplands. Lowland areas which are being con­ arable fields or industrial spoils where the verted from agricultural use also have poten­ soil or vegetation has been drastically altered tial. from the natural state, and the course of suc­ Advice is given on the site selection, design cession is more unpredictable. The advice is and early management of these new native therefore targeted principally at sites where woodland areas where one of the objectives is semi-natural vegetation persists, although to encourage the development of the native attempts are made to suggest adaptations for trees, shrubs and associated flora and fauna disturbed sites. suited to the site. Semi-natural woodland This Bulletin is based upon the National composition and structure is used as a model Vegetation Classification (Rodwell, 1991) upon which to base the advice. Semi-natural which provides a systematic description and woodlands vary greatly in their composition classification of woodland and other vegeta­ due to their long and varied management his­ tion types in Britain. It also draws upon a tory. The prescriptions given for new native research study carried out for the Forestry woodland are therefore deliberately broad Commission of plant communities in planted and flexible, and can accommodate other upland broadleaved woods ranging from 10 to objectives, including wood production and 70 years of age (Rodwell and Cooper, 1990). utilisation wherever appropriate. The information and advice is arranged in The advice in this Bulletin is based on the four sections: premise that achieving a good match to the appropriate semi-natural woodland type for • An outline description of the major types of the site in question will not only result in sim­ semi-natural woodland in Britain, their ilar tree and shrub communities, but also characteristic trees, shrubs and associated encourage the associated plants and animals floras and how they are influenced by cli­ to colonise if they are not already present. The mate, soil conditions and management focus is on plant communities and notably (Chapter 2). vascular plants. Plants are more readily sur­ • General guidance on the methods of design veyed and monitored than most animals. If and early management of new woods of the characteristic plant community of the native trees and shrubs which are likely to model woodland type develops, the animals encourage a composition similar to semi­ are more likely to colonise successfully too. natural woodland (Chapter 3).

2 • The use of the design prescriptions for main functions: to assist the reader to individual woodland types, with definitions choose the appropriate woodland type for a of the terms used (Chapter 4). given site and to provide advice on the trees • Design prescriptions for new native woods and shrubs to select, their relative abun­ modelled upon the major kinds of semi-nat­ dance and pattern in relation to the site ural woodland in Britain. These have two and vegetation (Chapter 5).

3 Chapter 2 Types of Semi-natural Woodland in Britain

Classifying semi-natural Using the NVC for designing new woodlands native woodlands The semi-natural woodlands of Britain are very diverse in their trees, shrubs and associ­ The NVC can provide a valuable working tool ated floras. The composition of these wood­ for the forester in the design and management lands and their structure are determined by of new woodland. It can: climate, soil conditions and biotic influences: • Predict the kind of woodland vegetation chiefly the impact of man through generations which we might expect to develop on a site if of woodland use and, more recently, tree succession were to proceed unhindered. planting. Understanding the patterns of varia­ • Provide lists of the most ecologically tion, and how they develop in relation to nat­ appropriate trees and shrubs to plant in such ural environmental factors and silvicultural situations, and give a rough indication of the proportions and patterns that could be used. practice, is essential for the sensitive design of native woodlands. • Identify optimal precursors among the variety of plant communities that could already occupy the site, so as to give a head start in The National Vegetation Classification the development of an appropriate ground cover. From the diverse wooded landscape of Britain, ■ Indicate other desirable plants characteristic the National Vegetation Classification (NVC) of the woodland type, whose appearance has described 19 major types of woodland could be expected and monitored, and (Rodwell, 1991). Each can be recognised by perhaps actively encouraged. distinctive mixtures of trees and shrubs, and • Suggest forms of management of the site, in establishment and subsequent phases, which has a characteristic associated flora of flower­ could aid development of the distinctive ing plants and often, too, some ferns, mosses, complement of woody and herbaceous liverworts and lichens. Each is limited to a plants. particular climatic zone and certain types of soil and represents the kind of climax vegeta­ tion that could develop wherever such condi­ tions occurred, if succession everywhere was allowed to take its full course. Although the Semi-natural woodland progress of such succession has often been descriptions modified by man, these woodlands still pre­ serve much natural diversity and provide This chapter describes all the different kinds important clues as to the kinds of vegetation of semi-natural woodland in Britain that it is we should aim for when creating new wood­ practicable to mimic in new native woods. The lands where wildlife conservation and visual main features of these woodland types, as we amenity are high priorities. see them at present in our landscape, are

4 described below under the following group­ developed from clay and shale rocks and ings: heavy, lime-poor drift. • Mixed broadleaved and oak-birch woodland At the base-rich extreme, oak (usually of the lowland zone (three types). Quercus robur with Q. petraea much more locally) is an important tree in the canopy • Mixed broadleaved and oak-birch woodland with small-leaved lime (Tilia cordata) and of the upland zone (three types). hornbeam ( Carpinus betulus), although many • Beech woodland (three types). woodlands have been treated as hazel (Cory- • Scots pine and juniper woodlands (two lus avellana) coppice. The most distinctive types). trees, however, are ash (Fraxinus excelsior), • Wet woodlands with alder, downy birch and various elms (Ulmus glabra and the suckering willows (four types). U. procera and U. carpinifolia) and a range of Yew woodland and those types of swampy associates dependent upon the warmer and woodland of lake and river margins which are drier climate of the south-east, i.e. field maple more difficult to develop are only briefly (Acer campestre), dogwood (Cornus san- described because they are not included in the guinea), wayfaring tree (Viburnum lantana) design prescriptions. and purging buckthorn (Rhamnus catharti- In the following account, the woodland cus). types are given their NVC code number and a On the more base-poor brown soils, lime, simplified vernacular name. Table 2.1 gives hornbeam and the introduced sweet chestnut their full scientific names and relates the (Castanea sativa) can be important dominants woodland types to the categories used in the among the trees, but overall it is oak and the Forestry Commission’s Management guides birches (usually Betula pendula but with some for semi-natural woodlands (Forestry Com­ B. pubescens) that are the most frequent mem­ mission, in press). bers of the canopy. Hazel is again a common dominant in coppiced stands and hawthorn ('Crataegus monogyna and the rarer C. laevi­ Mixed, broadleaved and oak- gata) remains frequent, but many of the trees and shrubs of more lime-rich soils now fade in birch woodlands o f the lowland importance. This often leaves just holly (Ilex zone aquifolium) and rowan (Sorbus aucuparia) as In the warmer and drier lowlands of south the most common companions in the under­ and east Britain (Figure 2.1), it is possible to storey, with elder (Sambucus nigra) on more recognise three distinct types of mixed nutrient-rich soils. broadleaved and oak-birch woodland, each On the most acidic soils, there is a continu­ associated with particular soil conditions (Fig­ ing reduction in the contribution from many of ure 2.2). One type of woodland is characteris­ these species, leaving just the oaks and tic of lime-rich soils that have developed from birches dominant in the canopy, with sessile calcareous bedrocks and drift: shallow, imma­ oak and downy birch now increasing their ture rendzinas on steeper slopes and deeper role. Holly and rowan are often the only com­ calcareous brown earths with mull humus ponents of the understorey. over gentler terrain. At the opposite extreme, Associated with these shifts in the composi­ another kind of woodland occurs on the highly tion of the tree and shrub elements, there are acidic soils: rankers, podzolic brown earths, distinct differences in the field and ground podzols and ironpan soils with mor humus layers of the woodlands on the various soil formed from sandstones and sandy superfi- types. On the most base-rich soils, for exam­ cials. Between these two extremes, a third ple, it is herbs such as dog’s mercury ( Mercuri- sort of woodland is found on base-poor brown alis perennis), wood avens (Geum urbanum), earths, often with moder humus, that have enchanter’s nightshade (Circaea lutetiana),

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.c (3 .o 3 co § < I 3 ^ I < 2 8 ^ *0 *0 in 5 ^ o 3 3 3 c TOt_ ~ S5 g ? 3 TOP> o CO TO E a TO c a CO CO > > CJO i 15 -c ZJ O) TO 0 .3 $ 5 ^ ? 3 .c § .0 •6 co § < I 2 ^ < P £ CD tz CO o CO TO TO o Q) PiTO 3 c TO S C TO c ■o o o ‘a < E 2 Q) -C 3T ^ TO co TO Q. TOm lL »- TO o 5 £ c §■£ Pi TO TOP P O p 3 5? C 3 X 8 1 'm *D 3 *D ^3 ■Q T3 O) TO TO Q. TO Q_ o CO CD > O TO TO$ 5 O O TO 7 sanicle (Sanicula europaea), early dog violet (Viola reichenbachiana), lords and ladies (Arum maculatum) and wood false brome (Brachy- podium sylvaticum) that give a distinctive char­ acter to the field layer. Or, on more clayey cal­ careous soils, derived from lime-rich shales or heavy drift, there can be an abundance of blue­ bell or wild hyacinth (Hyacinthoides non- scripta), wood anemone (Anemone nemorosa), primrose (Primula vulgaris) and, in parts of East Anglia, oxlip (P. elatior), ground ivy (Gle- choma hederacea) and yellow archangel (Lami- astrum galeobdolon) (Plates 1 and 2). It is vari­ ous mixtures of these plants, together with lime-loving mosses and liverworts of bare soil and exposed rock surfaces, that help give the lowland mixed broadleaved woodland with dog’s mercury (numbered W8 in the NVC scheme) its distinctive character. On more base-poor brown soils, most of the strongly lime-demanding species among these field and ground layer plants disappear leaving bluebell as the most common spring dominant among the herbs (Plates 3 and 4). By mid-sum­ mer, however, the woodlands here often have a dense cover of bracken (Pteridium aquilinum) or thick tangles of bramble ( Rubus fruticosus) and Figure 2.1 The lowland zone of Britain. honeysuckle (Lonicera periclymenum) where the soils are a little more moist. Other characteristic associates of this lowland mixed broadleaved woodland with bluebell/wild hyacinth (W10) are red campion (Silene dioica), greater Lowland stitchwort (Stellaria holostea), wood sage (Teu- Lowland Lowland mixed crium scorodonia) and foxglove (Digitalis pur­ mixed oak-birch broadleaved purea). broadleaved woodland woodland With the move on to the most acidic soils, woodland with with only bracken from among these plants remains with bilberry/ bluebell/wild at all common in the lowland oak-birch dog’s mercury blaeberry hyacinth woodland with bilberry/blaeberry (W16). The most common herbs are usually wavy hair- Rendzinas —> Base-poor —> Rankers, grass (Deschampsia flexuosa), tormentil (Poten- and calcareous brown earths podzolic tilla erecta), heath bedstraw (Galium saxatile) brown earths and ironpan and common cow-wheat (Melampyrum soils pratense). Where grazing is absent though, bil­ Figure 2.2 Mixed broadleaved and oak-birch berry or blaeberry ( Vaccinium myrtillus) can woodlands of the lowland zone. become very abundant with heather ( Calluna vulgaris) in less shady places (Plate 5). Although soil differences control much of the variation among these mixed broadleaved

8 and oak-birch woodlands, silvicultural treat­ and west of the country and distinctive tradi­ ments have also had a great impact on their tions of woodland use (Figures 2.3 and 2.4). composition and structure. Such treatments have not always reinforced the patterns of tree and shrub occurrence which are related to natural environmental factors: sometimes treatments have worked against that grain, obscuring such variation. Thus, the removal or planting of trees for timber, or the selective coppicing of different underwood crops can produce a great diversity of tree and shrub cover in what is still essen­ tially the same kind of woodland. The low ­ land mixed broadleaved woodland with dog’s m ercury (W8), for example, which has been a major source of wood and timber for centuries on the base-rich soils of lowland Britain, can be found as coppice of hazel, field maple or ash, or various combinations of these, with or without varying numbers of standards, usually common oak, sometimes ash, occasion­ ally field maple; with large-coppice underwood of small-leaved lime or hornbeam or mixtures of the two, again with or without standards; with invasive suckering elms; as semi-natural high forest; and in older plantations, particu­ larly of pedunculate oak or ash. Conversely, identical silvicultural treat­ ments applied to different kinds of woodland can result in stands which look very much alike in their tree and shrub cover and where, with dense shading, there may be little obvi­ Among the woodlands on base-rich soils in ous difference in the sparse field and ground the north-west, for example, the effect of the layers. The lowland m ixed broadleaved cooler, cloudier and shorter summers of the woodland with bluebell (W10), for example, region is well seen in the disappearance of var­ is also often found with the same woody cover ious woody and herbaceous plants characteris­ of hazel, lime or hornbeam coppice as is seen tic of the south-east. In the upland mixed in the dog’s m ercury w oodland (W8) where broadleaved woodland with dog’s mer­ these crops have been favoured on more base- cury (W9), then, small-leaved lime, horn­ poor brown earths. beam, field maple, dogwood, wayfaring tree, purging buckthorn, lords and ladies, early dog violet and yellow archangel are all characteris­ Mixed broadleaved and oak-birch tically absent (Plate 6). Other species, by con­ trast, favouring the more montane climate, woodlands of the upland zone increase in frequency: bird cherry ( Prunus A similar range of mixed broadleaved and oak- padus), stone bramble ( Rubus saxatilis), marsh birch woodlands occurs in the uplands of hawk’s-beard ( Crepis paludosa), wood crane’s- Britain, but with some important differences bill ( Geranium sylvaticum), globeflower ( Trol- which reflect the climatic contrasts of the north lius europaeus) and melancholy thistle (Cir-

9 sium helenioides). And, with the more moist A further distinctive feature of the upland soils and higher humidity, there is often an bluebell woodland is that stands are often abundance of ferns, notably hart’s tongue grazed, being open to stock from the unen­ (Phyllitis scolopendrium) and shield ferns closed hill land. Grasses such as creeping soft- (.Polystichum spp.), and a much greater cover grass (Holcus mollis), sweet vernal grass and diversity among the mosses and liver­ (.Anthoxanthum odoratum) and common bent worts (Plate 7). (Agrostis capillaris) are thus very common, while palatable plants (including the distinc­ tive bluebell) can be much reduced in abun­ Upland Upland Upland dance (Plates 8 and 9). mixed oak-birch oak-birch Combinations of climatic and management broadleaved woodland woodland effects have also left their mark on the upland woodland with with oak-birch woodlands with bilberry/blae­ with bluebell/wild bilberry/ berry (W17) which characterise the very acidic dog’s mercury hyacinth blaeberry soils of the north and west. Sessile oak and downy birch, together with holly and rowan, Rendzinas —> Base-poor —> Rankers, are the distinctive species of the canopy here and calcareous brown earths podzolic while among the heathy field layer there can be brouin earths and ironpan an extraordinary richness of mosses and liver­ soils worts, especially where woods develop over Figure 2.4 Mixed broadleaved and oak-birch very rocky terrain in humid and sunless woodlands of the upland zone. ravines (Plates 10, 11 and 12).

Losses and gains in temperature-sensitive plants can also be seen on more base-poor Beech woodlands soils in the north and west, where an upland Within the south-east lowlands of Britain, it is mixed broadleaved woodland with blue­ possible to distinguish a more restricted cli­ bell/wild hyacinth (W ll) is characteristic. matic zone within which beech ( Fagus sylvat- Compared with its south-eastern counterpart, ica) is a natural dominant in a variety of lime and hornbeam, together with yellow woodland types (Figure 2.5). Beech became archangel and wood spurge (Euphorbia amyg- abundant as a forest tree after the Post- daloides), are typically absent here while Glacial period in the warmest and driest parts chickweed wintergreen (Trientalis europuea) of the country, south of a line from the Wash, is a distinctive addition among the herbs. across to south Wales and down to Dorset. Increased humidity again encourages a rich What stopped its advance there is something fern flora, with broad buckler fern ( Dryopteris of a puzzle: planted beech grows well and dilatata) and its relatives becoming promi­ regenerates even in the north of Scotland, but nent, and abundant bryophytes. Higher pre­ its natural spread may have been dependent cipitation towards the north and west also upon some combination of congenial climate increases the tendency for the soils to become and human activity like the clearance of exist­ leached. Interactions between humidity and ing forest and agricultural neglect. soil conditions play an important part in the Within this zone, beech can become a wood­ increasing switch in these woodlands from land dominant on virtually the complete range pedunculate oak and silver birch to sessile oak of free-draining mineral soils and we can and downy birch, but leaching also encourages recognise three kinds of beech woodland in the spread of lime-avoiding herbs like tormen- Britain analogous to our lowland mixed til, heath bedstraw and wavy hair-grass into broadleaved and oak-birch types. A beech-ash the bluebell woodland of the north-west, some­ woodland with dog’s mercury (W12) is thing not seen in the lowlands. characteristic of shallow rendzinas (Plate 13 ),

10 Each of these woodlands shows some dis­ tinctive floristic features in its field layer com­ pared with its mixed broadleaf and oak-birch counterpart. In the calcicolous beech wood­ land, for example, sanicle, wall lettuce (Mycelis muralis), woodruff (Galium odoratum ) and a number of orchids can be represented and, in the brambly beech wood­ land, wood millet (Milium effusum) is particu­ larly characteristic. Often, however, the dense shade which beech casts and the fierce compe­ tition for water and minerals which its exten­ sive root mat exerts greatly impoverish the associated herbaceous floras. In fact, in mature stands, it can be hard to tell the differ­ ent kinds of beech woodland apart, so sparse are the characteristic field layer plants which survive. This convergence is accentuated by the tendency for shade-tolerant woody associ­ ates like holly and yew (Taxus baccata) to become abundant in all three types of beech woodland as a second tier to the canopy. Each of the lowland mixed broadleaved and oak-birch woodlands can act as a forerunner Figure 2.5 The zone of semi-natural beech to the beech-dominated counterpart but woodlands. whether our beech woodlands themselves rep­ resent the inevitable climax forest over this part of southern Britain is unclear. Where soil a beech-oak woodland with bramble conditions are such as to be equally favourable (W14) occurs typically on base-poor brown to woodlands with and without beech, there earths (Plate 14) and a beech-oak w oodland may be some natural cyclical replacement with wavy hair-grass (W15) is found on acid through time, one type giving way to the rankers and podzols (Figure 2.6). other. Even within the natural range of beech, the woodlands that it dominates have often origi­ nated by planting or been greatly affected by Beech-oak silviculture, as beech is widely grown and har­ Beech-ash Beech-oak woodland vested for its valuable timber. In the woodland woodland with Chilterns, in particular, many stands show with with wavy signs of former management under a selection dog’s mercury bramble hair-grass system, though more recently clearfell or shel- terwood regimes have predominated there and replanting often involved conifer nurses until Rendzinas —> Base-poor —> Rankers the mid 1970s. Beech has also been widely brown earths and podzols planted beyond its natural range, and can dominate there in impoverished versions of its semi-natural woodland types. Figure 2.6 Soil variation and types of semi-natural Yew is a distinctive associate in all three beech woodland. kinds of beech woodland but, especially on

11 very warm and sunny south-facing slopes with rendzina soils, it can pre-empt beech in the process of invasion and become dominant in yew woodland (W13). More open stands can have plants like dog’s mercury and stinging nettle, but the intense shade and very inhos­ pitable soil conditions often make this one of the most species-poor of our woodland types in Britain. Yew is certainly worth planting as an element in various other kinds of woodland, but the interest of pure stands is usually in their great age and the individual contorted character of the trees, factors which make the use of the tree on anything but a small scale an unattractive prospect. This woodland type is therefore not included in the Design Pre­ scriptions.

Scots pine and juniper woodlands Scots pine (Pinus sylvestris) has been very widely planted as an ornament or substitute on mixed broadleaved and oak-birch woodland Figure 2.7 The zone of semi-natural pine sites throughout Britain, and within the nat­ woodland (native pinewoods). ural range of beech. In the Highlands of Scot­ land, however, it is possible to distinguish a zone where the tree has a natural role as the a luxuriant carpet over the ground, is also dominant in a Scots pine w oodland with enriched by some distinctive species, notably heather (W18) (Figure 2.7). the attractive moss Ptilium crista-castrensis, This woodland type occurs predominantly particularly in those scattered stands of this on impoverished, highly acidic podzolised kind of woodland which occur in the more soils, sometimes with an ironpan and peaty humid western Highlands. top, and it has a similar complement of field There is little doubt that the more natural layer plants to the upland oak-birch w ood­ stands of Scots pine woodland represent frag­ land with bilberry/blaeberry (W17), with ments of a once much more extensive forest, some additional associates reflecting the often providing an unbroken link with the landscape harsh montane climate. Heather, blaeberry of the Post-Glacial period in the cooler parts of and wavy hair-grass remain very common northern Scotland. Evidence also suggests (Plate 15), but they are frequently joined here that, in the past, the canopies of our native by cowberry ( Vaccinium vitis-idea) and crow- pine woodland were more varied than at the berry (Empetrum nigrum) and there can be present time, with birch and juniper occurring striking rarities like lesser twayblade (Listera often as integral elements of the wood cover. cordata), creeping lady’s-tresses (Goodyera These days, even among the more extensive repens), twinflower (Linnaea borealis) and tracts of woodland in the eastern Highlands, various wintergreens (Pyrola spp., Orthilia we see a greater separation in the roles these secunda and Moneses uniflora). The mixture species play, each tending to dominate differ­ of lime-avoiding bryophytes, which often form ent woodland types. It is also important to

12 remember that even the more varied stands of pine woodland, and it still occurs in close asso­ Scots pine woodland are just one element, ciation with this vegetation on very acidic and albeit the most important, in the landscape of impoverished soils, sharing much of the same the ‘Caledonian pine forest’ defined in its field layer flora and ground carpet of mosses. broad sense. In that majestic scene, quite Often, though, juniper woodland is found on apart from stretches of oak-birch and juniper better soils than this: circumneutral mull woodlands, there can also be birch-sallow brown earths, sometimes quite nutrient rich. woodland with purple moor-grass, sallow Then the associated flora is very similar to woodland with bottle sedge and alder-ash that in the upland m ixed broadleaved flushes with yellow pimpernel (see below). woodland with bluebell/wild hyacinth, Only in a very few places in the Scottish typical of mesotrophic brown soils throughout Highlands can juniper woodland with wood north-western Britain, with plants like com­ sorrel (W19) be seen as a convincing altitudi- mon dog violet, wood sorrel, tormentil and nal replacement for sub-montane forest, as in heath bedstraw, occurring among a grassy the low-alpine zone of Scandinavian moun­ ground of red and sheep’s fescue, creeping tains. For the most part, this vegetation per­ soft-grass and sweet vernal grass. Outlying sists in northern Britain (Figure 2.8) as a stands of this kind of woodland occur in the scrubby forerunner to woodland in the upland Lake District, the north Pennines, Northum­ fringes, which does not, for one reason or berland and the southern uplands of Scotland, another, progress to the climax of the succes­ but the centre of the range is in the east-cen­ sion. More often, in the past, juniper scrub was tral Highlands of Scotland where wood an integral part of the development of Scots anemone is a striking replacement for the more oceanic bluebell in this woodland, and other plants like chickweed wintergreen (Tri- entalis europaea) and hairy wood-rush (Luzula pilosa) reflect the boreal character of the cli­ mate (Plate 16). Where dense clumps of old juniper bushes give protection from grazing, tall herbaceous dicotyledons and ferns can also become luxurious.

Wet woodlands with alder, downy birch and willows We can recognise a number of wetter wood­ land types in Britain characterised by the dominance in the canopy of alder (Alnus gluti- nosa), downy birch (only rarely silver birch in these more moist situations) and various wil­ lows, sallows and osiers (Salix spp.). In the early stages of colonisation around open waters and on wet ground there is often a strong element of chance in the mixtures of woody species invading, but, with time, the canopy composition stabilises. Then, with increasing terrestrialisation and deepening Figure 2.8 The zone of juniper woodland in the shade, the distinctive field and ground layers uplands. develop. In maturing woodlands of these

13 kinds, differences in species composition are usually related to variations in the wetness of the ground, the base-richness of the soils and waters, and the amount of nutrients in the system. Often the combination of conditions favoured by a particular woodland type is found in a distinctive kind of mire or flush, and the distribution of the woodlands is fre­ quently related to the pattern of occurrence of such sites within regions of broadly suitable climate (Figures 2.9 and 2.10).

Figure 2.10 The main zones of wet woodlands on alluvium.

invaders of sedge swamp with the great tussock sedge (Carex paniculata), lesser pond sedge (C. acutiformis) and tufted sedge (C. elata) and a rich flora of tall fen herbs and ferns (Plate 18). More local, and largely confined to northern Britain, where suitable swamps are open to invasion around basin mires with more base-poor and nutrient-poor waters, is the sallow woodland with bottle sedge (W3). Alder has often not peat. reached these isolated sites and the most frequent colonising trees are grey sallow and the northern bay willow (Salix pentandra), with bottle sedge (Carex rostrata) accompanied, in what are often Two types of wet woodland can develop early floating rafts of field layer vegetation, by associ­ in the primary colonisation of swampy vegeta­ ates characteristic of poor fens (Plate 19). tion around standing or sluggish open waters. In Where the influence of base-rich and quite more base-rich and eutrophic systems, where eutrophic waters remains strong in lowland fen peats accumulate in floodplains, basins and fens (Plate 20), but where the peat surface is valley fens, alder woodland with tussock raised above the limit of winter flooding, alder sedge (W5) is characteristic. Here, alder and woodland with common reed (W2) devel­ grey sallow (Salix cinerea) are the most common ops. The commonest colonisers in such situa­

14 tions, in the primary successions developing in and raised mires and on the fringes of blanket floodplains, basins and valley fens, or where mires, are invaded by trees as the ground mowing-marsh has been abandoned, are grey dries and is freed from grazing. In the birch sallow, downy birch and alder. The field layer woodland with purple moor-grass (W4), inherited from the tall-herb fen usually has downy birch, often with a little grey sallow, much common reed (Phragmites australis) forms a generally open and rather decrepit with plants like meadowsweet (Filipendula canopy, with a field layer of purple moor-grass ulmaria), hemp agrimony (Eupatorium (.Molinia caerulea) and a variety of Sphagna. cannabinum), wild angelica (Angelica Fragments of the original bog or wet heath syluestris), marsh thistle (Cirsium palustre) flora often persist in this sort of woodland, and, more locally, yellow loosestrife (Lysi- and there can be a patchy prominence of machia vulgaris) and purple loosestrife grasses, sedges and rushes (Plate 17). (.Lythrum salicaria) (Plate 15). Then, as these Such woodland can extend into lowland val­ become sparse with the drying of the ground, ley bogs and into the water tracks and hill- bramble and broad buckler fern can appear slope flushes of the upland fringes, where peaty with a patchy carpet of rough meadow grass, gleys are kept very wet by seepage of base- and while ash, guelder rose and hawthorn grow up nutrient-poor waters. However, in more base- among the canopy. rich flushes on valley sides in the wetter parts In still more nutrient-rich systems, where of southern Britain, and more widely in the fen peats have been drained and disturbed, or north and west, where surface-water gleys the waters enriched with nutrients, or where show some local nutrient-enrichment, the rich alluvium accumulates in mature river alder-ash woodland with yellow pimper­ valleys or around silting water bodies, alder nel (W7) is characteristic. Downy birch and woodland with stinging nettle (W6) is grey sallow can remain frequent here, but alder characteristic. Along with alder, grey sallow is is generally the leading tree along with some a common invader here, but various other ash. Yellow pimpernel (Lysimachia nemorum), Salix spp. can also attain prominence, like the creeping buttercup ( Ranunculus repens), mead­ osier (S. viminalis), purple willow (S. pur­ owsweet (Filipendula ulmaria), opposite-leaved purea) or almond willow (S. triandra) or, on golden saxifrage (Chrysosplenium oppositi- wet river terraces, the crack willow (S. folium) and lady fern (Athyrium filix-femina) fragilis). More species-rich stands can have are typical herbs, together with bulky domi­ remnants of a fen flora, but characteristically nants like soft rush (Juncus effusus), tufted it is plants like stinging nettle (Urtica dioica), hair-grass (Deschampsia cespitosa), pendulous great willowherb (Epilobium hirsutum), bit­ sedge (Carex pendula), remote sedge (C. ter-sweet (Solarium dulcamara) and goose- remota) and smooth-stalked sedge (C. grass (Galium aparine) that form an often laevigata) (Plates 21 and 22). patchy and tangled field layer in this kind of Finally, among these wetter woods, we can woodland. distinguish a sallow w oodland with marsh Even in floodplain fens it is possible to find bedstraw (W l), where grey sallow is often more acidophilous areas of woodland which the only woody plant over mixtures of soft have developed where the peat surface is out rush, common marsh bedstraw ( Galium palus­ of reach of the influence of the base-rich tre), water mint (Mentha aquatica) and a vari­ ground waters. In such situations, downy ety of other water margin herbs. This can be birch tends to be the leading woody invader found on waterlogged mineral soils of moder­ and bog mosses ( Sphagnum spp.) form patchy ate base-status throughout the country, as in carpets among the reed, with calcifuge herbs wet neglected pasture, for example, but it is also making an appearance. However, damp especially well developed in more sheltered acidophilous birch woods are much more com­ situations around the west coast, in cliff-top monly found where true bog peats, in basin flushes and around dune slacks.

15 Chapter 3 Methods of Creating Native Woodlands

For those wishing to establish new woodlands land established on adjacent land. Sometimes, of native species where the composition and however, the value of open semi-natural habi­ structure of tree, shrub and field layers even­ tats might be conserved or enhanced by the tually approach those of semi-natural woods, sensitive establishment of new native wood­ this section sets out general advice on loca­ land over part of the area. On moorland, for tion, design and early management. The guid­ example, the conversion of some rank bracken ance given is broad and qualitative so that it (.Pteridium aquilinum) or purple moor-grass applies to most of the woodland types. More­ (Molinia caerulea) areas to native woodland over experience of creating and monitoring might often be regarded as beneficial to woodlands in these ways is very limited in nature conservation as well as to the scenic Britain, so precise quantitative advice is not value of the landscape. yet possible on many aspects. Where new native woods are established on more disturbed sites, such as improved pas­ tures or arable fields, i.e. semi-natural habi­ Woodland, design tats have already been lost, a net gain for When a new native woodland is planned, nature conservation will often result even thought must be given to a number of aspects though the prospects of developing an ecosys­ of design, including: tem like that of old semi-natural woodland • location may be poor, except in the very long term. • design at the landscape scale However, each case must be treated on its • use of natural colonisation merits and, where there is doubt, advice should be sought on the current status and • species choice for planting value of the proposed site from the appropri­ • planting patterns ate national conservation agency. • the planting of sensitive species. Design at the landscape scale Location In cases where establishing some area of new As with all new woodlands, careful considera­ native woodland is judged to be desirable, its tion must be given to where new native woods size and situation should be influenced by the are located. Although the new woodlands character of the landscape of the whole locality should eventually develop into valuable and the distribution of existing tracts of wood­ wildlife habitats, placing them on open ground land and other semi-natural vegetation, as well which currently has a high nature conserva­ as by the pattern of topography and soils. tion value could result in a net loss of value to Proximity to potential colonising sources of society. Avoiding the rare lowland heaths of plants and animals is important, especially in southern England is one example. the dry arable lowlands, where woodland Wetland habitats such as fens or raised species are often slow colonisers confined to mires may also be adversely affected by wood­ existing woods and hedgerows.

16 In the more moist west and north, notably trees and shrubs over similar slopes (Figure in semi-natural landscapes in the uplands, 3.1). Characteristic patterns in relation to colonisation is likely to be less restricted as landform and geology are described in more many woodland species are also found in detail for individual woodland types in the patches of moorland, grassland or wetland design prescriptions. Ecologically informed habitats, and even on roadside verges. design of this type can be used to create a Even in the uplands, however, siting new mosaic of woodland types suited to the varying native woods adjacent to semi-natural wood­ landform and soils. land on similar soils will normally be the most The design of new native woodlands should favourable location to encourage colonisation. also include open areas. These should be sited Riparian areas by streams should also be con­ first in habitats naturally less suited to wood­ sidered because they are frequently refuges land such as wetland, crags, screes, shallow for the native flora and fauna which have been soils and exposed ridges. These habitats are depleted in the wider catchment by more usually of intrinsic value for nature conserva­ intensive land uses. Dispersal and colonisa­ tion and will contribute to the structural tion are also assisted by running water and diversity and amenity value of a woodland some species such as alder are adapted to (Figure 3.2). Some further open ground in water-borne dispersal. places which are capable of becoming wooded The size and shape of a new native wood can be of great value for a variety of purposes may also affect the development of the field such as nature conservation, amenity, recre­ layer and consequently the woodland fauna. ation, deer management and field sports. This Small stands, especially narrow belts with a more artificial open ground can be designed to high proportion of well-lit woodland edge, are include the range of soil or vegetation types unlikely to develop a complete woodland flora. present or any notable habitats which are to In the eastern lowlands of England, new wood­ be conserved. Interconnected open areas flow­ lands may need to be at least 2 ha and perhaps ing irregularly through the woodland can pro­ over 5 ha to enable them to support the more vide important dispersal and colonisation net­ slowly colonising and exacting woodland plants works for animals, and perhaps plants (Hooper, 1977; Usher et al., 1992). However, (Forestry Commission, 1990), although the the size required is likely to depend also on the degree to which these are used by different proximity of colonising sources and on shape species is not yet known. and no precise threshold can be defined. Open areas may also be used around the The design of size, shape and location can edge of new native woodland along with vari­ be assisted by landscape design guidelines able tree spacing to integrate a woodland (Forestry Commission, 1991). It is important more naturally into the landscape in terms of to realise, however, that there are often good vegetation pattern and scenic appearance ecological reasons for choosing distinctive pat­ (Figure 3.3). The edge zone or ecotone which is terns of woodland types for a particular local­ thereby created is a distinctive habitat in ity. Very commonly, for example, mixed itself, intermediate in character between broadleaved woodland with bluebell woodland and open ground and often attrac­ (W10) is found on gentler slopes below rocky tive to birds and insects. ground with oak-birch w oodland with bil­ The amount of open ground within any new berry/blaeberry (W16) where base-poor native woodland should not follow any fixed brown earths pass to podzolised rankers. At formula but depend upon the character of the the junction of the two, where groundwater ground and the particular mixture of objec­ emerges in a flush as it meets impermeable tives which have been agreed. An indication of shales, there is often a stand of alder-ash any characteristic pattern of tree spacing and w oodland with yellow pim pernel (W7). open areas is given in the Design Prescrip­ Such patterns can be mimicked when planting tions for individual woodland types.

17 Open areas can also be used within types present to allow for the possibility of schemes which are partially planted to allow natural regeneration and colonisation in for future natural colonisation, as described future. These open areas should be substan­ below. This can be used to reduce the possible tial: sometimes as much as half the site in drawbacks of the large-scale establishment of total, and normally at least 20%. Some of this a new native woodland, over a short time- ground will not become wooded and will con­ scale, that is, a limited structural diversity tribute to the long-term open habitats of the and a tendency to use more intensive methods woodland. of cultivation and planting instead of natural colonisation. Thus, the more sensitive or frag­ Species choice for planting ile parts of the site might be left for natural Where natural regeneration is thought likely colonisation to occur gradually, thereby to be inadequate and on sites isolated from spreading the age structure of the wood. seed-parents, planting will be necessary to establish new woods with the full complement Using natural colonisation of appropriate trees and shrubs. Natural colonisation of unwooded sites is theo­ The planting recommendations in this Bul­ retically preferable to planting for the creation letin are based on the natural distribution of new native woodlands because it should patterns of native trees and shrubs on differ­ result in a more natural matching of trees and ent soils throughout Britain. Past planting shrubs to the local conditions and conse­ has often obscured these patterns but, in new quently a more irregular structure and nat­ native woodland, such patterns can be re­ ural appearance. Natural colonisation is also established. This is of much greater ecological more likely to conserve local genetic distinc­ value than trying to maximise diversity as tiveness and diversity than planting. such in any site or locality, which would lead In many cases, however, seed sources for to greater similarity between woods and lower some or all of the characteristic trees and diversity at a regional and national scale. shrubs desired for a site may not be present Therefore, when creating new native woods, nearby and planting may be necessary, for the trees and shrubs listed should not be some species at least. The birch species, rowan planted outside their natural ranges and, even and many willows can readily colonise more within their ranges, care should be taken to distant sites where conditions are suitable and respect local patterns of distribution. This is may dominate a new woodland in the early important even with such common trees as stage. To some extent, this is a natural pioneer the two oak species which show different nat­ phase and these trees may help to create con­ ural distribution patterns across the country ditions more suitable for slower colonisers such as a whole and in particular regions. Where as oaks or beech to establish themselves later. the species can be distinguished, care should However, a high density of early colonisers always be taken to maintain the relative pro­ may restrict opportunities for others, espe­ portions of pedunculate oak (Quercus robur) cially where their seed sources are scarce. A and sessile oak (Q. petraea). In particular, the balance must be struck, according to local cir­ former, which has been much favoured in the cumstances and management objectives, past, should not be planted in areas where between planting and encouraging natural apparently pure populations of sessile oak are colonisation (with or without management) to to be seen in nearby semi-natural woodlands. allow for future infiltration by missing species. Among the lists of recommended trees and Much will depend on the establishment shrubs, an indication is given where a species timescale which is envisaged and the propor­ is especially characteristic of part of its overall tions of particular species, e.g. timber-yielding range, or likely to show patchy abundance. trees, which are desired. Where planting is While species composition and structure used, some space should be left on all the soil are the most important aspects of design, con­

18 sideration should also be given to the genetic Small-leaved lime (Tilia cordata) in wood­ origin of the planting stock (Kinloch et al., land types W8 and W10 1986; Worrell, 1992). This is especially impor­ Large-leaved lime (Tilia platyphyllos) in tant in the vicinity of long-established semi­ W8 natural woodlands, where local sources should Wild service tree (Sorbus torminalis) in W8 be used. Elsewhere, planting stock should at Midland hawthorn (Crataegus laevigata) in least be of British origin and ideally from sim­ W8 and W10 ilar site types within the native range of the Rare whitebeams of the Sorbus aria group, species. including Sorbus rupicola, S. lancastrien- Even with a widespread tree such as com­ sis, S. devoniensis, in W9 mon hawthorn (Crataegus monogyna), the use Box (Buxus sempervirens) in W12 of imported material from elsewhere in Europe can result in eccentric flowering times Wild pear (Pyrus communis) in W8. quite out of keeping with the British land­ Because of their complex genetics and scape and ill-coordinated with the emergence uncertain vulnerability to Dutch elm disease, of many dependent insects. And, with a all elms other than wych elm (Ulmus glabra) species such as juniper, which shows a great have also been omitted from the lists for diversity of growth form from place to place, planting. Sea buckthorn (Hippophae rham- some of it probably genetically controlled noides), a native shrub which is valued for (McVean, 1992), care should be taken not to planting on sandy soils in areas subject to introduce specimens that will develop a locally salt-laden winds, has also been omitted atypical appearance, or an unsuitable growth because of its very aggressive character. form for the particular environment. All these species should be welcomed as Under EEC regulations, the seed or cut­ natural colonisers of new native woodlands tings of some species must be collected from a where they do occur with the possible excep­ registered source if seed or young plants are to tion of the sea buckthorn in situations where be sold. Of our native species, the oaks, beech, it is liable to spread rapidly. Scots pine, black poplar, and aspen are cov­ All exotic trees and shrubs have been ered by these regulations. The EEC criteria excluded from the design prescriptions, for registration are based on timber quality, including long naturalised species like which can restrict the potential for collecting sycamore (Acer pseudoplatanus), sweet chest­ from local sources in some areas. However nut (Castanea sativa) and European larch relaxations of the EEC criteria are possible in (.Larix decidua). These species and other some circumstances, e.g. for Scots pine in exotics will frequently colonise new native native pinewoods. Advice should be sought woodlands to some extent and decisions will from the Forestry Authority where there is need to be made about whether to rigorously doubt. remove, control or ignore them. Sycamore, for Certain rarer trees and shrubs are not gen­ example, is a ready and prolific invader of erally recommended in this Bulletin for plant­ moist, but free-draining, and nutrient-rich ing in new native woodlands, even though soils throughout Britain and can establish they occur in distinctive kinds of semi-natural itself with some abundance in mixed broadleaf woodland. This is because their distribution and wet woodlands of a variety of types (par­ patterns are of intrinsic importance and they ticularly W6, W7, W8, W9, W10 and W ll). could be altered by planting. If any planting of Sweet chestnut has become abundant in a these species is undertaken, it should be much more restricted zone in the warmer recorded and monitored and special care parts of south-east Britain, but is especially taken to use local stock (Soutar and Peterken, tolerant of strongly waterlogged soils and has 1989). These species and their characteristic often been selected for use as a coppice crop in woodland types are: mixed broadleaf woodlands on heavy clays

19 (mostly types of W10). Larch can invade ate to the woodland types which it is intended mixed broadleaf woodlands, too, but together to encourage. The best guarantee of success is with various species of spruce and pine, to match sensitively the species choice and including Pinus sylvestris planted outside its planting pattern to the natural character of native zone, it will also colonise more acidic the site: notably the landform, soil and exist­ and nutrient poor soils, naturalising in oak- ing vegetation. birch woodlands (W ll, W16, W17). There is no point in precisely designing the Decisions about whether to remove or con­ detail of future canopy structure, because trol these species will be influenced by the nature will inevitably alter the details. A likelihood of rapid invasion and dominance by robust but varied pattern which gives each the trees in question, their value for conserva­ species a good chance of contributing to the tion and other purposes and the mix of objec­ mature woodland structure in the right places tives in the establishment of particular new and without relying heavily upon future stand native woodlands. management will generally be best. Repetitive Two other species, which should be rigorously formula-driven patterns should be avoided as removed as soon as they appear, are rhododen­ they will prevent a natural appearance and dron (Rhododendron ponticum), which has reduce the variety of potential niches for become very prominent among some mixed wildlife. broadleaf (W10 and W ll) and particularly oak- A combination of planted clumps and open birch woodlands (W16 and W17), and Japanese areas should be used. Subject always to the knotweed (Reynoutria japonica), which invades overriding dictates of the site characteristics, damp riverine and mixed broadleaf woodlands there are six main variables which can be (W6, W7, W8, W10). These plants are very used to develop a planting pattern. aggressive invaders, quickly overwhelming the • Species composition of clumps native field layers and hindering regeneration of native trees and shrubs. • Clump size and location • Spacing of trees and shrubs in adjacent Planting patterns clumps Semi-natural woodlands show a great variety • Spacing of trees and shrubs within clumps of structure and species-composition even • Size of gaps between clumps within a single woodland type, resulting from • Size and location of larger open areas a combination of natural site factors and man­ agement history. This allows considerable Experience with intimate mixtures has scope for imaginative variation in the design shown that it is often difficult to maintain all of new native woodlands in terms of the pro­ the species used. Growth rates are frequently portions of trees and shrubs and the structure, badly matched and slower growing species are both horizontally over the ground (woodland eliminated. Thus, particularly where future structure) and vertically in the layering of tending operations such as respacing and thin­ canopy and understorey (stand structure). nings are not envisaged, the use of intimate Some woodland types show great variations species mixtures, i.e. within clumps, should be in the structure of existing stands, for exam­ carefully restricted. It is best to use two or three ple, the lowland m ixed broadleaved w ood­ well-matched species at most (Figure 3.4). Table land with dog’s m ercury (W8) while others 3.1 lists some combinations of broadleaved trees are more simple and consistent such as the which have been found to be suitable. birch woodland with purple moor-grass The chances of maintaining an intimate (W4). Especially distinctive patterns are indi­ mixture after canopy closure can be improved cated in the design prescriptions and planting by using small clumps with gaps between in new native woods should be designed to adjacent clumps to allow sidelight. However, develop a composition and structure appropri­ the eventual canopy structure may then be

20 Table 3.1 Examples of successful mixtures of native timber trees (adapted from Evans 1984).

Intimate even aged mixtures Ash with alder Beech with gean Oak with alder Oak with ash Oak with gean

Nursing mixtures for shelter Birch nursing oak3 and frost protection Birch nursing beech3 Figure 3.4 Using pure clumps or clumps with two or three well-matched species to develop mixed wood­ 3 Oak or beech can be planted at the same time or after lands. birch, depending on birch density and degree of protection required. only slightly different from that produced by using small clumps of a single species. Inti­ mate mixtures within clumps could therefore be avoided except where they serve a specific purpose, such as softening species or wood­ land type boundaries. Great variety can be obtained by altering the other variables, and using single species clumps ranging in size from single isolated trees to larger stands of 50 m or more in width (Figure 3.5). Clumps of slow-growing trees or shrubs should be large enough to prevent excessive shading by adja­ cent groups of taller trees (Figure 3.6). Gaps between adjacent clumps can be varied from about 7 m (which will eventually close over in most cases) to 20 m or more (Figure 3.7). Gap- widths equivalent to the height of the mature canopy will stay well lit, favouring plant and animal species of woodland margins and open Figure 3.6 Allowing enough room around shrubs to ground but perhaps hindering colonisation by prevent excessive shading by adjacent trees. shade-tolerant woodland herbs. These would be more quickly favoured by smaller gaps of 10 m or so.

Figure 3.5 Using varied clump size to increase Figure 3.7 Using varied spacing between clumps to diversity in new native woodlands. increase diversity in new native woodlands.

21 Larger open areas greater than about 25 m Delaying the planting of these species until across can be used to provide glades and other trees are established to provide suitable accommodate valuable habitats as well as to conditions, or to await natural colonisation, allow for future colonisation and regeneration are possible tactics. However, delayed plant­ of trees. Spacing within clumps or in adjacent ing has not had a happy history, as the clumps can also be varied to avoid the appear­ younger trees tend to be overlooked in subse­ ance of rows and grids and to provide a range quent management and become browsed by of light and other conditions which should rabbits and deer which colonise the adjacent favour wildlife diversity (Figure 3.8). Close thickets. spacings of 2 m or less should be used where The most practical solution for sensitive timber quality is important and also to accel­ species where prospects of adequate natural erate canopy closure to provide earlier oppor­ colonisation are poor is generally therefore to tunities for specialist woodland plants and plant them at the start, but to take special animals to colonise. Spacings of 3-5 m will care to restrict them to the most suitable parts result in slower canopy closure and a bushier of the site and to favour them in subsequent form of tree or shrub. The simpler tactic is to tending operations. vary spacing in adjacent clumps rather than within a single clump, but the latter method will be valuable on irregular sites. Management practices A number of management practices can have a marked influence on the development of the communities of plants in any new woodland and uniform standards of silvicultural treat­ ments work against the emergence of diversity in composition and structure. Among lowland broadleaved plantations in Britain, for exam­ ple, disturbance and uniformly dense shade have tended to favour a convergence of many potentially varied woodland types to a gloomy, species-poor and rank variant of lowland mixed broadleaf woodland with bluebell Figure 3.8 Using varied spacing within clumps to (W10), often without bluebells! (Anderson, increase diversity in new native woodlands. 1979; Rodwell, 1991). Some sensitive variation of practice is therefore necessary, together All of these guidelines should be used flexi­ with an awareness of the impact of different bly and the pattern should be dictated primar­ operations upon the developing woodland ily by the character of the site. types. Knowledge of the precise effects of vari­ ous management practices and their persis­ Planting sensitive species tence is insufficient for detailed recommenda­ Some trees and shrubs which are found in old tions to be given, but enough is known about semi-natural woods are rather sensitive to their broad influences (Tables 3.2 and 3.3) to conditions which may be found in newly say that the scale, frequency and intensity of established woodlands such as exposure, frost disturbance in general should be low, espe­ and strong weed competition. These species cially on wet or fertile soils. tend to colonise later in natural successions and are adapted to moderate shade and shel­ Ground preparation ter and to well-developed woodland soils. Cultivation and drainage may be desirable to Beech, hornbeam, holly and yew are assist establishment for a variety of reasons examples. (Hibberd, 1991). These include providing a

22 Table 3.2 The influence of design and early management upon the development of field layer plant communities in new native woodlands. 0 3= LU 3= JO -O TJ _0 ■O □c ■o "55 *D O CD CT)O 0 0 0 o 0 0 o 0 o o E a. O Q_ C 0 5 O O co E CL o 5 CO C O O Q_ 0 t 3 5 O ^ O = 5 *9 -O c . .m- -Q T3 ■=*: 5.5. g -o O S P- *C3 T3 ' > o is IS € o S 9 •S =S n- ■s 5 *0 T3 . ® ■£ o U J •O *0 0 0 o 1 0 0 C vL ^ Qj S C cp C 6 0 <£ -C 9- R" qj nj r t/) 5: o 0 C T3 "O O .0 3 Oj -C 0 CJ) 0 ^ ^ £ y> I s § l E 0 a 3 b _

r COcfl ® tr J" _l "C -J L -Q CL ■F O) ■Q 'c *2 C ■ o E o Q a-I I .0 ® c •b= t2 I ■=. £ ”-=§ £ 1 ~ c O) 0 m 0 - 9 c S CO ^ I 0 0 -C c CD co O ^ o ra E CD -o ^ E CL i S cE E" « 3 0 O) 0° 0 g .3 c 8. o “ ff cl 0 t CD CO CD 0 Qo ■Q o c O 0 0 C O) 0 c o g C? 0 0 3

Q0 ■Q *0 *° Q 5 0 c 0 0 5 o 3 '* CL VJ ID Q 0 0 ^ ^ o w .0 nt 0 - • cu 0 0 CD + + cj

£ j ^ (jj c £ h "D T3 0 0 o E c 0 0 0 o 0 2 £ g ? ! I §■ M ® 0 r\ "O O 0 O w 2 0 Q. ^ 0 <0 o c =§ ^ S .0 b E 0 0 > 0 >> H 3 o o 0 f — m *0 m • y CD ! = -r^ "D ;g P o c CD 0 0 £ i £«s S€ • £ * * 9* ® § •=£ « . a I E Q .£ ■D 'ra > c .E ° r- ® 8 o 0 b 0 C 3 o § 0 0 * *b >* 2 &■-§ o> 2 J2S o c C 3 0 3 C (5

i 2 3 .2 D) o CO -Q JS co 0 0 O)0) ° 0 O 0 CD 0 ? u 2 w 0

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g 0 O C s g * =s -g W 0 ? *0 '5•2 1 I i H § f 0 0 0 ffl ^ .Q -S £ i 0 -i= tr i i E ^ o "O0 0 0 o O) E c h m 03 0 0 0 p 0 0 ^ 0 C CL3 S5 c 0 0 > c 0 c 0 o c o 0 « s «® 2 2 c ^

.b 0 = ip o '5 — ■D -Q 0 C > _ 0 0 0 0 O 0 3-o £ 0 C O O 0 CD 0 0 0 OC 3= u ® O T3 C C 0 > O 3 0 5 0 D E 0 >x o O O 3

. _0 1c _c "O CD £ 0 ^ 2 E t2 0 0 0 0 c c 0 0 i- 0 o c O) 0 0 O 0 - .0

“O) £ ~0 "o 0 0 0 5 0 0 0 0 0 E 0 >» 3= 1c 0 0 O— JD 0 -S E E * " “ O 0 0 0 "5 C 0 0 W Q. u O -S 00 S E c c E 0 0 E - « O LJ I _l ® Q. CL O — > <- 0 t ±= °> 0 « ra ® CI— o 5 £ § C > QC o ~a .■&S. 0 ^ 0 . ^ 00 >* o E CO 0)0 ? « E Q. « '5. 5 § Q ^ ° ® = S a 5 E 0 0 D)0 % k £3 0 cl "co O 0 5 0 O 0 _o JO - o o k- 0 O) C O c > o c 0 0 0 o 0 0 T3 CL 0 o 0 5

E o " LT "T o .E T3 *c JO cl o - c 0 <3 « 2 0 *9 ° > w*-£ 0 0 0 o 0 C C 0 0jo £

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sadA) /I.M ‘9tM ‘9tM /I.M sadA) EueuJin 23 24 Table 3.3 Field layer plants favoured by disturbance. Examples of species which commonly showed greater than expected abundance, com­ pared to semi-natural woods in a survey of upland broadleaved plantations (adapted from Rodwell and Cooper, 1990). co o o 0 E _ Q 0 O) o CL 3 ^ J U ,CT O § 2 *o -i -o S' T3iS 5 C T) 3 "o 3 * .? 1 £ I -i T3 -Q C - £ i ^ p t5 ^ § -S 5 T3 *5P 2 *0 s X) O •5 O S 3 c5 T3 CD g 0 *o C co CD E C CD a c O CD O 3 ^ 5 9 O iS O c CD C o co P ^8- -^ 8 ^ - 8 § = § c ■£2 11 C ^ *6 ^ £ is? e *0 2 JS

5 .w 6

**“ c E co !E co 3 3 co i92 CD O o)3 p CO C . O DC c C - ■O O O) l - E "SCD .co 2 3 o 5 o> CO P CD cd CO Q _ 0 _ 3 F 2 "§2 a: .8 CO CO (D 05 3 D) - a. I- iD = o o 05E f= ^ S c CD 2 o CD Q ~0 _o T b 2 O CD C 3 .co

• CO £ C . !c .Q O " C . O " o 0 0 . Q C 0 O 0 CO CD CO E 0 E . Q 0 5 0 o 3 _ Q CO c 5 5 O 0 CD 3 c CD c 0 X . Q ) 0 O 0 CD c < — c ! ’> ■O O " fo o t 0 E . Q 0 0 c CO 5 0 o 3 . Q 5 0 0 o . Q 0 O 3 0 , > 5 o o 0 CO 0 to well-aerated, weed-free planting position, The production of regular ridges and fur­ leading away excess surface water or lowering rows in ploughing also lends a highly artificial the water table and disrupting subsurface bar­ relief to the ground which can be reflected in riers to tree root penetration such as iron and long-persistent patterning among the develop­ clay pans and indurated layers. However, ing woodland flora. In upland bluebell/wild because deep and extensive forms of cultiva­ hyacinth woods, for example, ridges are tion, notably ploughing, disrupt the natural often picked out by the dominance of wavy profile of the soil, increase nutrient levels at hair-grass, and furrows by creeping soft-grass; the surface and reduce the variation in physi­ the former shedding, the latter accumulating cal conditions, they tend to restrict the range litter. On more base-poor soils, blaeberry often of microsites available and may hamper the joins wavy hair-grass on the ridges, the development of the full range of desired plants troughs tending to be so choked with decaying and animals in the new native woods. organic matter as to exclude any herbaceous Drainage can be an especially drastic plants or bryophytes. Wet birch woods on change leading to the destruction of existing ploughed peat may have wavy hair-grass or flushes and bogs and wasting the opportunity purple moor-grass on the ridges with bog- of using these to encourage wetter woodlands. mosses restricted to the hollows. Where these types are desired, all mechanical The degree and persistence of these cultiva­ cultivation and drainage is best avoided, the tion and drainage effects in relation to site sites being left unplanted for natural colonisa­ type and cultivation method is not well known tion or provided with aerated planting posi­ at present and so it is better to err on the side tions by hand-turfing. Even on somewhat less of caution. Generally the effects upon composi­ wet but still heavy soils, as around flush mar­ tion of the field layer are likely to be greater gins or over plateaux and hollows with clays, and more persistent with ploughing and ditch­ manual turfing is ideally preferable to using ing than scarifying or mounding and effects tractor-mounted equipment, at least until may be more persistent on wet sites and on knowledge of their impacts is improved. If fertile soils, especially those in low rainfall tractors are used, mounding with a continu­ areas. ous-acting mounder is generally preferable to On freely-draining podzolic soils in the excavator mounding or ploughing, as it has uplands the rate of leaching of nutrients may less disturbance and drainage effect. make the enrichment effect of cultivation rela­ The disturbance, nutrient enrichment, and tively short-lived, but the patterning of compaction produced by using tractor equip­ ploughing could still persist for many decades. ment on heavy mineral gleys can also favour Superficial patch scarification on these soils the spread of some troublesome aggressive may have relatively little effect on the long­ plants, such as tufted hair-grass which in term development of the flora and fauna and young m ercury woods or around alder-ash should be the preferred method. flush woods can be a vigorous competitor to young trees and shrubs. Rushes, too, especially Fertilisers soft rush, can become abundant in such situa­ Cultivation often has the effect of enriching tions. On drier soils, brambles may spread with the nutrient status of the soil by enhancing cultivation and overwhelm the developing field aeration and the rate of oxidation of organic layer in young bluebell woods, and wood matter. Application of fertiliser further false-brome becomes unusually abundant in enhances the growth of more nutrient- cultivated m ercury woods on free-draining demanding plants, such as purple moor-grass base-rich soils. Bracken is a common dominant on peat, rosebay willowherb on more base- on cultivated and newly planted ground with poor soils, bramble on somewhat better qual­ free-draining acid soils where upland bil­ ity brown earths and stinging nettle and berry/blaeberry woods are being sought. goosegrass on moist clayey soils and loams.

25 Each of these is a natural element of various tems, although the type and the number of woodland types, but overwhelming dominance grazing animals are now very different from of each results in marked impoverishment of those in the truly natural woodland of prehis­ the respective field layers. Colonisation by less toric times. However, grazing should be care­ competitive woodland plants may be delayed fully considered in the management of both and the persistence of these effects may be existing semi-natural and new native woods. considerable. Mature semi-natural woods, notably in the In order to minimise such problems, fertilis­ uplands, are frequently subject to high graz­ ers should be confined to sites where they are ing and browsing intensities mainly from essential for establishment and even then only sheep and deer. This often prevents tree applied around the individual trees and regeneration and reduces the diversity of the shrubs, so as to avoid widespread enrichment. field layer. However, low grazing pressures Special care should also be taken near can be beneficial in maintaining diversity by streams and flushes to avoid exporting nutri­ preventing competitive exclusion of smaller ent enrichment into drainage systems. The plants, such as distinctive bryophytes in west­ careful selection of appropriate tree and shrub ern oak-birch woods, and by creating niches species, as recommended in the prescriptions for colonisation and regeneration. in Chapter 5 should minimise the need for fer­ Grazing needs to be considered from the tiliser. outset when planning new native woods. To Narrow woods in arable landscapes are vul­ allow establishment of the trees and shrubs, nerable to fertiliser enrichment from spray total exclusion by fencing is the simplest and drift or in drainage water from adjacent land safest option. Where trees and shrubs are and this should be taken into account at the being planted, grazing can be removed for the design stage. vulnerable period, anything from 5 to 20 years or more depending upon the site. Total Herbicides removal of grazing, however, can lead to the loss of smaller grasses and herbs which were Herbicides may often be preferable to cultiva­ maintained in the close-cropped turf, as they tion in suppressing weeds and hastening tree become smothered by dominants like bramble, growth especially on fertile brown earths. bracken or tussock grasses. This may lead to a They should be applied as selectively as possi­ loss of conservation value in open areas within ble, however, avoiding desired plants or the new native woodland and a loss of poten­ uncommon species. One-metre spot applica­ tial colonists for the wooded parts, since tions around the planted trees are normally heathland and rough grassland often harbour preferable to band or overall treatments, woodland herbs such as wood anemone, dog except where the aim is to eradicate bracken violet and primrose. In these mainly upland or pernicious exotics such as rhododendron. situations, maintaining low-intensity grazing Another use of herbicide is to eliminate rank or reintroducing it quickly should be consid­ weedy field layers in disturbed farm, urban or ered where it is practical. reclamation sites, both to hasten tree growth Where natural colonisation by trees and and to provide opportunities for woodland shrubs is expected to be the main method of plants to invade or to be introduced (see page establishing new native woods, permanent 30). Techniques for herbicide application exclusion of grazing animals may also not should follow those in Forestry Commission always be the best solution, as it may lead to Fieldbook 8 (Williamson and Lane, 1989). reduced opportunities for the germination of trees and shrubs. Grazing often produces con­ Grazing ditions suitable for germination of trees and Grazing and browsing by large herbivores are shrubs but the seedlings are then frequently natural features of many woodland ecosys­ browsed back to the level of the field layer

26 until grazing pressure is reduced. Grazing about 100 m from seed sources may be unsuit­ could be considered as a means of encouraging able especially for heavy-seeded trees. How­ gradual colonisation of a new native woodland ever, local examples of enclosures should be site by continuing with a light grazing regime examined to judge how successful colonisation over several years and then perhaps removing is likely to be. Species such as rowan, animals completely for a time to allow estab­ hawthorn, birch and sallows can sometimes lishment of the seedlings. colonise more distant areas quite abundantly, Other woodlands such as m ercury woods but high stocking densities should not be and alder-ash flush w oods would probably expected. develop better without any grazing because so The site conditions can be manipulated to many of their characteristic field layer plants encourage natural colonisation by means of are highly palatable. cultivation and perhaps by control of grazing Grazing could also be used as a form of as described earlier. Light patch-scarification ‘ground preparation’ for natural colonisation, or mounding are the preferred methods of cul­ e.g. by using a high intensity regime for a tivation to avoid excessive disturbance and short period before a good seed year. These still produce a seedbed. They should be timed approaches could be suited to areas near exist­ for late summer to precede seedfall. Herbi­ ing semi-natural woodland as an alternative cides may be needed to eliminate dense to cultivation. It must be stressed, however, bracken which normally prevents any coloni­ that manipulating grazing in these ways is sation by trees or shrubs. not well tested. Local advice should be taken It may often be best to observe the existing as each site will be different. colonisation pattern for a few years before Deer are a potential threat to the develop­ undertaking ground preparation, to be sure ment of new native woodland. They tend to whether it is necessary or not. browse selectively on woody species and palat­ able herbs and even at relatively low total den­ Altering early canopy structure and sities such as 5-10 km-2 they may restrict composition colonisation by trees, shrubs and field layer There may be a variety of reasons for remov­ plants (P.R. Ratcliffe, personal communication). ing trees or shrubs after they have estab­ Deer should therefore be excluded or con­ lished, such as: trolled at low densities for longer than the establishment period of the trees to encourage • Removing unwanted species, notably inva­ the full plant community to develop. sive exotics such as rhododendron or Sitka spruce. Encouraging natural colonisation • Reducing the cover of prolific colonisers in Reference has already been made to the theo­ favour of less common desired species or to retical desirability of using natural colonisa­ maintain designated open habitats. tion where seed sources and site conditions • Reducing canopy cover to create suitable are suitable, and especially for new native light conditions for the characteristic field stands near to existing semi-natural wood­ layer to develop. lands. A judgement will be needed about the distance from seed sources over which it is In general, it is desirable to avoid drastic acceptable to rely upon natural colonisation. interventions which cause abrupt changes in This will depend on many factors and should light regimes. The need to alter canopy cover be decided on a site-by-site basis. The time- for the benefit of the field layer can be avoided scale which is acceptable for establishment by designing the planting pattern as described will be important. In practice, this will often earlier to produce a range of light conditions be the lifetime of a fence, around 15-20 years. right through to maturity. However, there will If this is so, then new woods further than be some situations, notably on disturbed sites

27 with strong weed growth, where initial dense to the desired semi-natural woodland flora is planting with few gaps is preferred, to shade likely to be longer and the outcome more out weeds for example, and gaps and wider uncertain than for more natural sites. This is spacings will then need to be created after particularly true for reclamation sites and canopy closure. Ultimately, of course, thinning arable farmland, where the model woodland and felling of parts of the wood may be field layers may never fully develop by natural intended for wood production and these are colonisation, and plants more typical of field dealt with in detail in Forestry practice (Hib- margins and edges will remain for long peri­ berd, 1991) and Growing broadleaves for tim­ ods of time. ber (Kerr and Evans, 1993). Wherever trees or shrubs are removed, care should be taken to Farmland avoid compaction and other disturbances of the Grant assistance is available to encourage the soil which can have undesirable effects (see establishment of woodland on farms, espe­ page 25). For example, on heavy mineral gley cially on improved pastures and arable land. soils, the sudden creation of a large gap in a This reflects the current policy of diversifying closed canopy, if combined with soil distur­ land use and reducing surpluses of agricul­ bance, can favour the rapid spread of the tural products. Where wildlife conservation is tufted hair-grass (Deschampsia cespitosa), a major objective of such projects, the encour­ smothering other species with its dense tus­ agement of native woodland communities can socks, perhaps for decades (Davy, 1980). be considered as an option (Table 3.4). How­ Where timber production is not an objective ever, particularly with arable land, or fields of canopy restructuring, soil disturbance can that have been resown as leys, the soil and be avoided by felling to waste. Another alter­ vegetation will have been greatly altered from native to consider is thinning by using stem their natural state and native herbaceous injection of herbicides to kill standing trees in plants may have been almost completely elim­ situ. Although the effects on the flora have not inated. yet been tested experimentally, it may be bet­ Unfortunately, because such farmland has ter than felling for the gradual development of often been much improved by fertilisers, the the field layer as it avoids creating piles of high nutrient status of the soils can be a real brash which encourage brambles and coarse hindrance to the development of the appropri­ grasses. ate woodland flora, by encouraging vigorous growth of tall and rank plants like stinging nettle (JJrtica dioica), rosebay ( Epilobium Disturbed sites angustifolium), Yorkshire fog (Holcus lanatus) On some sites, vegetation, the soil or even the and docks (Rumex spp.) at the expense of shape of the whole landscape have been so desired species. Arable soils may be especially altered by human activity that it can be diffi­ rich in seed of potential weeds and unusually cult to predict the kinds of woodland that it high alkalinity of the soils may also inhibit might be appropriate to encourage, and some­ colonisation by appropriate plants. Fertiliser times difficult to establish the desired trees should rarely be required for tree and shrub and shrubs. Yet, with some thought, it is pos­ growth on such sites but, even where none is sible to apply the same basic approach to used, it may take decades for fertility to improved pasture and arable farmland, in decline sufficiently to allow woodland herbs to derelict sites and areas affected by mineral colonise. workings or landfill. Clearfelled areas for­ It may be necessary to space trees and merly occupied by densely shading plantations shrubs regularly in rows to allow for machine are also briefly considered below. access for weeding, although the rows can be In general, however, on all kinds of dis­ made irregular and given a less artificial turbed site, the time required to approximate appearance by gentle curves and gaps. Sup-

28 Table 3.4 Target new native woodland types for former arable and improved pastureland (adapted from Williamson, 1992). | 5 ° O CL *S *S CL O 0 £ CO i 2 i I C CO£n Q. r i •S' a o 76 T Q. H"T T . § 9 • •8-8 Q. h-2 0 03 o =3 CO o ca Al 3: O ca K a co o •o 05 -Q^ k ^ | u 1 qj 2 v S CO o co co co co ^ 0 CO o c 3 : : 3 c o 2 co Jto I s . N . K C a 03 co a c ^ c ^ I - M o C 03 ‘co CD *0 CD *o CL _Q _Q3 _ Q D J CD ■o cd c CO ) O 0) B ■O O O O o O O o o 5 0 TO 0) o o O O LL X 1c tr 1c X c . 0 >* 3 0 E ) O 3 0 3 0 CD "cO _Q O •o _C CD .c CO *0 »♦— : a ^ C -o £ ■ T3 o * Q. 0 o Q. o 0 E 0 o c 0 0 0 0 o c 03 c 0 c 5 0 0 0 0 > 0 0 o c 0 O o 0 0 0 o C O O C 03 o o c ^ O) ° 0 O CO 0 Q_ o C 0 Q. 0 c o Q. o c o N 0 *o !o .c _c _0 •C T3 ill r t § o ~ % 'o O 0 0 0 0 E 0 c 0 0 0 0 0 > 0 0 c o 0 C 5 0 0 o 0 L_ 0 _ - t o »_ "O 0 — i l C 0 O 3 0 2 CO ■o 5 § M COCM 5 5 5 § - t - i o a i- o § CD § 5 03 i- O 0 0 Tf CO f T - 5 in § § CM z O " 5 5 5 5 5 1 5 5 tr CO T- ^ CM — 3 0 5 5 5 3 0 - h § 5 r-- i s o 5 0 ° 3 0 - t 03 > -

•C "O 3 T o _ _C *o -C _>% tr tr 0 c 0 0 E 0 s > 0 > 0 . Q c o 0 c 5 0 3 0 c 0 flowers can reduce weed prob­ deficiencies are typical, especially of nitrogen. lems on arable sites and provide some of the Heavy metals or other substances can also species desired in the target woodland type. occur at toxic levels. Close spacing and fewer gaps between groups A range of treatments are required to alle­ may be more appropriate than for more nat­ viate these problems sufficiently to grow trees ural sites because this will hasten weed sup­ successfully, including landscaping the pression. The canopy can then be gradually ground, cultivation, replacing subsoil and top- opened up to create suitable conditions for soil and fertilising with sewage sludge or min­ woodland flora, taking care not to stimulate eral fertilisers. These are described fully in fresh weed growth (see page 28). Detailed Forestry Commission Bulletin 110 (Moffat and advice on establishment methods for planted McNeill, 1994). However, reclaimed sites can farm woodland is available in Establishing remain very difficult locations for the estab­ farm woodlands (Williamson, 1992). lishment of native woodlands to mimic semi­ Natural colonisation by trees and shrubs natural communities because of their gross may be slow on rich ex-arable sites, but disturbance and artificial unbalanced ecosys­ seedlings of hawthorn and oak are quite often tems. They are generally suited to pioneer present in less improved pastures and these tree species which can cope with poor nutri­ can get away readily after the withdrawal of tion and other stresses. Only where good qual­ grazing. Other species can invade from nearby ity soil has been replaced will there be a hedges or existing woodland, and an imagina­ chance to plant more demanding species such tive and economic approach may be to leave as ash, oak or gean from the start. some areas adjacent to such established seed Alders are particularly good pioneer trees sources unplanted from the start. Proximity of for reclaimed sites because they increase the new plantings to older woodland can also facil­ nitrogen levels in the soil. Nitrogen is ‘fixed’ in itate colonisation by desired herbaceous root nodules by soil micro-organisms called plants. Isolated plantings, set in a lowland Frankia and taken up by the alder roots. landscape or arable or improved pasture, also Alder leaf litter is nitrogen rich. Alders can be need to be large enough to avoid a preponder­ used in mixtures with other trees such as ash ance of rank, weedy edge vegetation beneath: to improve their growth (Moffat et al., 1989). Usher et al. (1992) suggested at least 2 ha as a The native common alder (Alnus glutinosa) minimum for attracting the less mobile wood­ could be used as a pioneer on most reclaimed land flora. Long, narrow plantations, though sites where native woodland is desired except perhaps useful as shelter or as corridors the most freely drained or waterlogged soils. allowing migration of plants and movement of Other native pioneers which have been suc­ animals, are more likely to retain a high pro­ cessfully planted on reclaimed land, and portion of marginal herbs and underscrub. which often colonize naturally, are rowan, birches and willows, notably goat willow. On Reclamation sites infertile sites with little or no topsoil, the best Woodland is often chosen for revegetating method to develop some form of native wood­ land which has been reclaimed after mineral land is to plant pioneer trees and shrubs or extraction, landfill refuse disposal or urban wait for them to colonise gradually. Common dereliction. Sites of this kind typically have an alder should be a large component, probably artificial landscape with highly disturbed soils at least 20-30%, and preferably in small drifts that present a range of problems for trees, between other species. After about 20 years,

30 Plate 1 Lowland mixed broadleaved woodland with dog's mercury1 (V/8), in Hay ley Wood, Cambridgeshire. A rich display of dog’s mercury, wood anemone and nxlip associated with coppice with standards management.

iM O ' . P H C X T O U

Plate 2 Ground flora of a WiS woodland in the western upland fringes showing ram­ sons, wood anemone, pignut, dog's mercury and barren strawberry. Coed Gorsu en,

North Wales. i i h - » i i

Plate 3 Lowland mixed broadleaved woodland with bluebell / wild hyacinth (W10). Fifehead Magdalen, Dorset.

(M.C.F. PROCTOR)

Plate 4 Ground flora ofWlO wood­ land including bramble, bluebell I wild hyacinth, broad buckler fern and bracken. < j . r o d w e l l > Plate 5 Lowland oak-birch woodland with bilberry I blaeberry (W16). Ground vegetation domi­ nated by wavy hair-grass due to grazing pressure. Birches, oak and holly form the canopy. u. RODWEU,

Plate 6 Upland mixed broadleaved woodland with dog's mercury (W9).Old hazel coppice over a rich flora includ­ ing flowering ramsons and blue­ bell /wild hyacinth in Argyll.

(M.C.F. PROCTOR

Plate 7 Details of the flora in a W9 woodland, includ­ ing dog’s mercury, enchanter's nightshade, wood avens, wood false- brome, ramsons and wood speedwell. <««-<*] i Plate 8 Upland oak- birch woodland with blue­ bell /wild hyacinth (W ll), dominated here by silver birch with no shrub layer and a ground flora influenced by grazing, con ■ slating mainly of grasses and bracken. Rannoch. Tayside Region. iM.C' K I’ R IK T O U i

Plate 9 Upland oak-birch woodland with bil­ berry I blaeberry (W17) at Shieldaig, Wester Ross, showing twisted, moss covered downy birch, hum­ mocks of blaeberry, mosses and liverworts on a steep bouldery slope. l‘K0CT0R>

Plate 10 A more mixed patch of W ll woodland with mature oaks, hazel and birch in the shrub layer and wood sorrel, creeping soft-grass and bracken in the field layer. < e?m9i ivootfl.imf »inW totbcr< v o n pnei^o

Ktmoti oroadleovad woocfituid m iti bluebell on tinso-poor fc/own e.vlH over sfr.iJo

Figure 3.1 Using geological and iw/hAlder-#sl\ y*no*fiimpettiti wMMdtaJitf on soit . 1 ditj€rsnc6s r • /v* to . develop j | mosaics Hushed sod . ' r J in new native woodlands.

Figure 3.2 Leaving open ground around crags and mires to increase diversity in new native woodlands.

friiorrg/ a ! tw *

IVn/t'r frm .'nni*

N .lfioi»' ilfM'M .K »IM'N*1.I

Figure 3.3 Using variable spac­ ings and unplanted ground at margins for a natural appearance and habitat diversity. Plate 11 An old pol­ larded oak with holly sapling and wavy hair- grass and bilberry in the field layer in an example o f W17 woodland.

(J RODWELL)

Plate 12 Oak seedlings in profusion among bilberry, wavy hair-grass, hard fern and mosses in a typical W17 wood­ land floor in Maentwrog, North Wales. (06-91)

Plate 13 Beech-ash woodland with dog’s mercury (W12) in Wye and Avon. Bluebells and dog’s mercury dominate the vigorous field layer in a well-lit open stand o f beech.

(015/0/93/5* Plate 14 Mature beech woodland often has no ground vegetation and the woodland type can be hard to determine except by exam­ ining the marginal vegeta­ tion and the soil. This New Forest stand is probably of the beech-oak woodland with bramble CW14) type because of the presence of bracken and soft grasses at the edges of the stand. Any bramble would be rapidly removed by browsing deer and ponies. (EN'V.HQi

Plate 15 Scots pine woodland with heather (W18) at Abernethy Forest, Badenoch and Strathspey, with an open varied structure and wide age range of pine and scattered juniper bushes. The field layer is heather and blaeberry; broadleaves are absent partly due to deer browsing. i« 2 7 « i

Plate 16 ;Juniper woodland with wood sorrel (W19) at Creag Fiaclach, Cairngorms, one of the few examples left of a natural tree-line at altitude in Britain. Juniper replaces Scots pine as the latter dies out in the harsh condi­ tions upslnpe. iM.c.RPltooTOKi Plate 17 Birch woodland with purple moor-grass fW4) at Middle Fen, Malham, Yorkshire, showing the open canopy of downy birch carpets o/'Sphagnum and Poly trichum mosses between clumps of

purple moor-grass. >m .c . k . i m m x t o r i

Plate 18 Alder woodland with tussock sedge (W5) at Penn Hill, Sidbury. Large clumps o f the great tussock sedge domi­ nate the field layer on base-rich fen soil. i.M C.F I’ KCM TO R i

Plate 19 Sallow wood­ land with bottle sedge (W3J at Malham Tarn, York­ shire. Here marsh marigold and valerian are prominent in the flora. i M.C.f .p r o c t o r i

Plate 20 Alder woodland with common reed (W2) at Catfteld Great Fen, fM.C.F. I'KOCTOK) Plate 21 Alder-ash woodland with yellow pimpernel (W7), formerly coppiced with a rich flora on a wet flushed area by a small stream channel. 1.1. rodwelli

Plate 22 Vf7 flora among newly coppiced alder in an ancient semi-natural woodland area in the Forest of Ae, Nithsdale. Meadowsweet, marsh thistle, soft rush and marsh hawk’s-bcard are prominent. i 0 7 - » i i

(a) (b)

Plate 23 (a), (b) This 34-year-old stand of sessile istic of acidophilous oak-birch woodlands fW16 and oak near Lockerbie, Nithsdale was planted on W17). The pattern o f the ploughing can still be seen grazed heathland dominated by heather which has (a) in the concentration o f mosses and wavy hair- since disappeared. Now the field layer is largely grass on ridges and thick leaf litter in trenches. The composed o f bramble, broad buckler fern, bracken, abundance of fern and bramble may partly result wavy hair-grass, blaeberry and heath bedstraw, from ploughing and fertilising (see Tables 3.2 and several mosses and liverworts, a mixture character­ 3.3). more demanding trees and shrubs could be broad terms and eventually encourage trees introduced in matrix with alder, which might and shrubs to colonise. need to be coppiced to allow their establish­ Native trees and shrubs which have been ment. On sites with adequate topsoil, more found to be suitable for infertile reclamation demanding trees like ash may be planted as a sites are shown in Table 3.5 with an indica­ minor element from the start. tion of the relevant woodland communities Grasses and legumes have been sown suc­ which they might help establish. The cessfully on infertile sites to stabilise the prospects for a good approximation to the ground and develop biologically active topsoil semi-natural woodland types are, however, (Moffat and Roberts, 1990; Moffat et al., 1989). very uncertain and long-term. The field layer This should hasten successional change in plant community on such disturbed sites is

Table 3.5 Native trees and shrubs found suitable for reclamation sites3 (adapted from Wilson, 1985; Hibberd 1989; Moffat and McNeill, 1994).

Species Soil and site conditions

Mainly coarse/sandy texture Mainly fine/clay texture CalcareousExposure and spoils air pollution Dry Moist Acid pH < 6 Neutral/alkaline pH > 6

Silver birch • • • • E, P Downy birch • • • • • • E, P Rowan • • • • • • E, P Goat willow • • • • • P Common alder • • • • • • E, P Hawthorn •••• E, P Scots pine • • E Crack willow •••• P Black poplar (•) • • • (•) P Whitebeam (•) ••• E, P Gean (•) P Ash • • Sessile oak (•) (•) (•) E, P Pedunculate oak (•) ••• E, P Field maple •• E, P

Closest potential NVC woodland types

Upland W17 W 11 convex site W7 W7 W7 (W18) W7 concave site W4 W9 W9 (W11) (W4) concave site (W11) (W6)

Lowland W16 (W10) W10 W2 W6 WB W15(W14) W4 concave site W4 W8 W12 W5 concave site W6 (W13) (W10) (W14)

3 Assumes little or no topsoil is present. Key • • Highly suitable • Suitable ( ) Occasional; marginal E Suitable for exposed sites P Suitable for air pollution

31 likely to develop into a great variety of tempo­ although some allowances may need to be rary mixtures due to the chance colonisation made for the changes to soils caused by previ­ and disturbed nature of the sites. These could ous tree growth and silviculture, such as irre­ persist for many decades, thereby excluding versible drying on ploughed and drained deep woodland species. As for arable farmland peats. The current vegetation will not give so sites, planting at close spacing with few gaps reliable a guide as in semi-natural sites but is likely to speed up the onset of conditions for some of the precursors and some of desired woodland herbs to colonise by excluding invaders listed in the design prescriptions weeds. Thinning or respacing would then be may be present. necessary to maintain suitable light levels for The establishment of the new native wood woodland plants. on felled ground should follow the general guidance for less disturbed sites but there are Felled plantations some peculiar factors to consider. Plantations of densely shading trees such as • Regeneration and colonisation by trees and Sitka spruce (Picea sitchensis) or beech (Fagus shrubs will sometimes occur profusely on sylvatica) can completely eliminate the field felled ground shortly after felling. These and ground layers of vegetation, especially may include exotic species, such as Sitka where they have not been thinned. After spruce or larches, as well as native trees felling, the vegetation which develops natu­ which are part of the desired community. rally is influenced by local climatic and soil Birches are notable examples of native conditions, but early colonisers often come colonisers. from seed stored in the soil from before • Felling residues, notably tree branches and canopy-closure of the previous tree stand and needles (brash) play an important part in from neighbouring vegetation, especially the early vegetation succession. plants with wind-dispersed seed. Harvesting • Harvesting machinery used in the clear- practices, particularly the extent of distur­ felling can cause site disturbances which bance and treatment of felling debris, are also have effects like those of cultivation influential. Especially on base-poor, upland machinery (see page 25). soils, where conifer planting has been concen­ trated, clearfells are often dominated by mix­ Regeneration of unwanted species can be very expensive to remove. Care in planning the tures of rosebay, grasses and rushes, with felling operation (avoiding good seed years for heather and bracken, foxglove (Digitalis pur­ unwanted species or felling before seed ripens) purea) and, on somewhat better ground, bram­ should help to reduce the problem. ble. Regeneration of the planted tree species and colonisation by birches and willows often The way in which brash is managed can occurs also. influence the early development of vegetation Managers may sometimes wish to convert including tree seedlings. Piles of brash slow such clearfelled sites to native woodlands down revegetation of the site and species such which are modelled upon semi-natural wood­ as heather which germinate from dormant land types. This may be done to increase the buried seed when exposed to the light will not general wildlife and amenity value of planta­ develop in thicker brash and litter. Birch can tion forests or specifically to extend small colonise freshly felled ground where the litter semi-natural woodland remnants, for example is disturbed and brash is light but cannot along streamsides. readily invade the grassy field layer which The broad approach of this Bulletin can be then develops within 2-3 years. applied to these situations even though the From what is currently known of the influ­ site has been recently wooded. Climate, geol­ ence of brash upon the succession of vegeta­ ogy, landform and soils can be used as normal tion on felling sites, the best general policy is to select an appropriate model woodland type, probably to ensure that much of the site,

32 preferably over half, has little or no brash left of them to appear. Small woods have fewer on it in order to encourage a diversity of such species at a given age. colonisers. However, the prospects for colonisation of Where wet woodland types are desired it ancient woodand species vary regionally may be valuable to restore wetland conditions, according to soil, climate and their existing e.g. by blocking drains, except perhaps where abundance in the landscape as described ear­ irreversible drying of peat has occurred. How­ lier. Generally, colonisation is likely to be ever this suggestion requires testing by faster in the northern and western woodland research and monitoring. types and those woods established on and Conversion of single-species broadleaved close to semi-natural habitats. Woodland plantation stands towards native woodland plants can often survive in the open in these communities may occasionally be attempted, areas which they cannot do on arable or e.g. when dense beech or sycamore stands improved pasture land in the lowlands. are felled. Similar factors to those in conifer plantations are involved. However, the brash has less of a smothering effect (although it In any area the prospects for colonisation can provide a template for brambles to by specialist woodland plants can be spread) and often a field layer of native improved by the design and early manage­ woodland plants will already exist before ment measures described earlier, notably: felling. • Location on suitable precursor vegeta­ Coppice regrowth and mixed natural regen­ tion. eration of broadleaved trees and shrubs may • Location of new woods near to existing give more opportunities to convert the wood woodlands, especially old semi-natural towards the desired type without much plant­ woods or hedgerows. ing than for conifers. On stable sites, there • Avoiding very narrow and small woods will be opportunities for gradual conversion by (>2 ha in a compact shape is preferable). heavy thinning which may reduce the risk of • Avoiding highly disturbed or enriched existing woodland species being smothered by soils. a burst of ‘weedy’ growth as often happens after clearfelling. • Avoiding intensive management prac­ tices, e.g. ploughing and drainage, espe­ cially on wet or fertile site. Introducing field layer plants • Developing moderate to strong shading As indicated earlier, it may take a very long i over linked areas to enable spread of time for many woodland plants characteristic shade-bearing species. of semi-natural woodlands to colonise new native woods, especially isolated stands in dis­ turbed arable or urban landscapes. The work Even so, there may be situations where the of Hooper (1977), Peterken and Game (1984) prospect of colonisation is still thought to be and Usher et al. (1992) in lowland eastern too slow and uncertain and where introducing England, for example, indicated that some field layer plants may be thought desirable to ancient woodland plants such as dog’s mer­ speed up the development of the target wood­ cury (Mercurialis perennis), primrose (Prim­ land type. ula vulgaris), bluebell ( Hyacinthoides non- Introducing such species to new woodlands scripta), sanicle (Sanicula europaea) and the is still relatively untested. Although a number grass wood melick (Melica uniflora), were slow of projects have recently been monitored over to colonise secondary woods. Most woods a short period (e.g. Buckley and Knight, 1989; under 100 years old contained only a few such Francis et al., 1992), the long-term success species and it took around 250 years for most and cost-effectiveness of various methods,

33 namely sowing, planting and the transfer of nated or weakened. Light levels of 10-15% soil containing buried seeds, bulbs and roots, of open conditions are most suitable for is not yet known. shade-bearing woodland species (Buckley At present it seems that planting container- and Knight, 1989). Alternatively, introduc­ grown stock is probably a more reliable tions can be made after canopy opening. method than sowing for the more shade-toler­ After planting or sowing, subsequent tending ant woodland herbs, which tend to rely on veg­ may be needed to control canopy shading and etative reproduction, while sowing can be competition from other field layer plants effective for a number of common woodland- including invasive shade-tolerant species such edge plants like red campion (Silene dioica) as common nettle (Urtica dioica) and bramble and hedge bedstraw (Galium mollugo). The (Rubus fruticosus). Disturbance from harvest­ latter are adapted to take advantage of peri­ ing machinery or repeated trampling by the odic disturbance which stimulates the germi­ public should be avoided in the vicinity of nation of seed stored in the soil. introduced plants. However, the cost of quickly establishing As for trees and shrubs, rare species should enough woodland plants to make a rapid generally be avoided at present for introduc­ visual impact is high. For example, at approxi­ tion to new native woods; their requirements mately 30-50 p per plant, an area of 100 m2 and current distribution are often poorly planted densely at 0.5 m spacing with, say, known and they are likely to be harder to primroses would cost £120-£200 to plant at establish successfully than more common 1993 prices. This does not include any herbi­ species. cide treatments which might be needed to Genetic conservation and adaptation does eliminate competition by other plants. Plant­ not seem to have received much consideration ing or sowing at lower densities, merely seek­ so far when wild flowers are sold as seed or ing to establish a colonising source, would cer­ plants. Local adaptation may be at least as tainly be less expensive but the future success great as it is for trees and shrubs. Planting of the species would be less certain. stock is mostly produced from seed collected in Introductions should therefore be treated southern England and may not be well with considerable caution at present. Where adapted to conditions further north. they are contemplated, success is likely to be In summary, given the current state of greater for a given level of expenditure, if: knowledge, it is generally appropriate to con­ • Planting or sowing is concentrated in sider the possibility of using introductions in patches which provide more protection from the future to speed up colonisation of the competition by existing species and easier desired woodland flora, but not to rely upon relocation for monitoring and subsequent introduction as a simple substitute for natural tending if required. colonisation. The emphasis should be on • Introductions are timed for the onset of design and management which favours nat­ canopy closure when competitive light- ural colonisation, as described earlier in this demanding field layer plants will be elimi­ chapter and the previous one.

34 Chapter 4 How to Use the Design Prescriptions

Specific design advice is given for new native Soil types woodlands modelled upon all the major types Clearly, not all the semi-natural woodlands of semi-natural woodland that occur in characteristic of a planting zone will occur Britain, and which it is practicable to mimic. on all kinds of soil represented in the region. Yew woodland and the three wettest types of The particular sites available for planting the alder-downy birch-willow woods have been are also likely to have a limited range of omitted. The following sections will help the soils occurring in them. Table 4.1 sum­ reader to select those kinds of woodland marises the range of soil types which can appropriate for a particular site and define the support each of the different kinds of semi­ terms used in the Design Prescriptions. natural woodland, using standard terminol­ ogy (Pyatt, 1982). The soil types present at the site should be Native woodland zones identified and the kind or kinds of woodland The distribution patterns of our major types of which might suitably be encouraged upon semi-natural woodland effectively define a them in that region. Further details of soil small number of broad zones for establishing conditions given within the guidelines should new native woodlands (Figure 4.1). For the help confirm the selection. most part, these zones reflect gross climatic differences, such as the pattern of tempera­ Geology, terrain and site types ture and rainfall across the country. With some wetter woodlands, however, it is more The prescriptions also list the broad categories sensible to map the distribution of suitable of bedrock and superficial deposits with which the soil types and their woodlands are associ­ ground conditions within the optimal climatic ated in the different zones. The general kinds zone. The user should locate him/herself in a of terrain and site types within which the dif­ zone and note the range of semi-natural wood­ ferent semi-natural woodlands are character­ lands appropriate to that region. istically found are also briefly described. The boundaries of the zones as shown on the maps are not precise and rigid. They are meant as a guide only. It is possible to find Recommended trees and shrubs some semi-natural woods outside their normal Trees and shrubs are listed which are particu­ zones where the local climate or soil is partic­ larly characteristic of the semi-natural mix­ ularly suitable. For sites located near to the tures developed under the specified climatic edges of the zones on the maps local semi-nat­ and soil conditions. Some of these might ural woodlands can be used to help to decide already be present on a site as a result of nat­ what is appropriate as well as the evaluation ural colonisation and not all of the species of local climate, soil, geology, terrain and pre­ listed need be planted in every new woodland cursor vegetation. of each type. Nor should the species always be

35 Low land south and east

Lowland zone

Wet woods on fen peats

F igure 4.1 Zones tor new native woodlands.

36 Table 4.1 Soil types3 appropriate for new native woodlands

Calcareous/base-rich Acid/base-poor

(a) Freely or imperfectly drained mineral soils

Northern Juniper with wood Scots pine with and sorrel W19 heather W18 western upland areas Brown earths 1,1 u, 1 z and (1 b) Podzolised brown earth 1z (cooler and Podzol 3 Podzols 3, 3p, 3pg, 3m, 3s, 3ms wetter) Intergrades to ironpans 4b (Ironpans 4, 4z, 4p, 4pg, 4zp) Podzolic peaty gley 6z Podzolic surface water gley 7z Podzolic ranker 13p

Upland mixed broadleaves Upland oak-birch with Upland oak-birch with bilberry/ with dog’s mercury W9 bluebell/wild hyacinth W11 blaeberry W17

Calcareous brown earth 12b Brown earths 1, 1 u, 1z Podzols 3s, 3ms Argillic brown earth 12t Brown surface-water gley 7b Podzolic ranker 13z Basic brown earth 1 b Podzolic ironpan 4z Calcareous ground-water gley 5k Calcareous surface-water gley 7k

Southern Lowland mixed broadleaves Lowland oak-birch with Lowland oak-birch with and eastern with dog’s mercury W8 bluebell/wild hyacinth W10 bilberry/blaeberry W16 lowland areas (drier and Basic brown earth 1 b (1 bg) Brown earth 1 Podzolised brown earth 1z warmer) Calcareous and basic ground Ground-water gley 5 Podzol 3, 3m, 3s, 3ms water gleys 5k, 5b Brown surface-water gley 7b Podzolic ranker 13z Surface-water gleys 7b, 7i, 7k Calcareous soils 12a, 12b, 12tg

Beech-ash with dog's Beech-oak with Beech-oak with wavy mercury W12 bramble W14 hair-grass W15

Calcareous soils 12b, 12t, 12bg, Brown earth 1 Podzolic brown earth 1z 12ab (Brown ground-water gley 5) Podzol 3

(b) Wet and peaty soils

Northern Alder-ash with and yellow pimpernel W7 western uplands Ground-water gley 5, 5f Surface-water gley 7, 7i, 7f, 7h, 7b

Azonal Birch with purple moor-grass W4

Molinia bog 9a, b, c, d, e Sphagnum bog 10a, 10bb Peaty gleys 6, 6b Flushed bogs 8b, 8c

Southern Alder with common Alder with stinging and reed W2 nettle W6 eastern lowlands Ground-water gley 5f (5k) Ground-water gley 5f Surface-water gley 7f, 7h (7k) Surface-water gley 7f, 7h Flushed basin bog 8a, 8d Flushed basin bog 8a, 8d a Soil types follow the Forestry Commission classification (Pyatt, 1982). bThis site type will rarely be appropriate for planting because of its high conservation value.

37 planted in the same proportions. Major trees Some decision then has to be made about and shrubs are those which could make up a whether to sacrifice such existing character more consistent element of such mixtures (pre­ for the sake of the potential attraction of the sent in over half the sites) and which, on any eventual woodland cover. particular site, can be used in abundance, collec­ If these optimal plants are not present, a tively making up over half the eventual crown likely situation where woodland is being cover (Figure 4.2). Minor trees and shrubs are established on improved pasture, former those which could figure less frequently among arable land or reclaimed industrial land, the the mixtures (in fewer than half the sites being desired woodland flora may still be able to planted) and which should usually be used more develop but is likely to take longer. sparsely on particular sites (total eventual crown cover less than 50 %). Large and small circles distinguish these Desired invaders categories in Figures 4.3 and 4.4 which list all Many semi-natural woodlands contain plants the trees and shrubs in the different semi-nat­ which were often absent from the existing ural woodlands. Where it is appropriate to herbaceous vegetation invaded by the trees concentrate planting of a particular tree or and shrubs, but which colonised after the shrub within part of a planting zone, or to development of woody cover, sometimes very sometimes use a tree or shrub with local slowly. The design prescriptions list species of abundance, this is noted in the design pre­ this kind as desired invaders, the appearance scriptions and marked in Figures 4.3 and 4.4 of which will help build the full complement of by the use of open circles. the appropriate woodland flora. In some situa­ tions, it might be possible to seed or plant cer­ tain woodland herbs, but the success of devel­ Optimal precursor vegetation oping herbaceous communities from seed Even a single site available for planting could mixtures or transplants is uncertain, as clearly already support a variety of herba­ described earlier. Moreover, such introduc­ ceous vegetation types characteristic of the tions should always be undertaken thought­ particular climate and soil conditions. Some of fully, and should not encourage species which these might well contain plants which are also are absent locally from semi-natural woods. typical of the semi-natural woodland the site could carry. The design prescriptions list opti­ mal mixtures of herbaceous species which Woodland structure and pattern should be favoured for planting with the speci­ The guidelines give an outline of the range of fied trees and shrubs where there is some structure found within the different woodland choice of precursors. However, it should types, to provide an indication of the variety of always be remembered that such existing veg­ mixtures and patterns of trees and shrubs etation may have great conservation and that could be aimed for in planting. A note is amenity value in its own right: rich assem­ also given of the ways in which each of the blages of colourful herbs on flushed ground, woodland types can be found in close spatial for example, would give a head start in devel­ association with other woodlands and differ­ oping the flora of certain types of wet wood­ ent herbaceous vegetation, so as to inform the land, but are probably highly prized already. landscape design of whole sites.

38 Figure 4.2 Frequency and abundance of major (left) and minor (right) trees and shrubs among a set of eight plantings.

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PUp 0 05 C CO 0 <-> 0 5 tr /aO 5 co pi t i ? S'6oP(J CO Q . C /P< p ^ p ^ 3 — 2 © *IUjP ue/4\Oy Po°*< • 1 I 0 O • 1 • •OOI | | | • | | CD > c.o oCO 7= c CO CO 5 o 0 0 o o E Major and minor shrub species for new native woodland types. 2 in ^ 0 0 0 0 5 Q. Q. £2 2O O 5 s CO CO O w « 0 5 s 0 “ ^ | 05 5 O 0 1 O -O TJ 2 C o o o ° ) ° •= TJ I O 1 I ‘co ‘co 0 j o 0 C CO 0 Q. I TJ 2 I t ~ S O 0 2k 0 Q. 2k CO 'c E 0 3 0 CO 'co 3 Figure Figure 4.4

41

Chapter 5 Design Prescriptions

Lowland mixed broadleaved woodland with dog’s mercury NVC woodland W8

Zone Throughout the warmer and drier lowlands of southern and eastern Britain.

Soil types Rendzinas, brown calcareous earths, basic brown earths and base-rich ground-water gleys.

Geology Sedimentary limestones, calcareous shales and clays and heavy lime-rich superficial deposits like boulder clay.

Terrain and site types Gently undulating basins, vales and low plateaux across central and eastern England, and limestone scarps, particularly towards the north and'west, with more steeply sloping and often rocky ground.

Major recommended trees Ash Pedunculate oak Sessile oak (patchily throughout and to the north-west of the zone) Wych elm (to the north-west of the zone) Major recommended shrubs Field maple (England and Wales only) Hazel Hawthorn Minor recommended trees Downy birch Minor recommended shrubs Silver birch Blackthorn Holly Elder Crab apple Guelder rose Rowan Goat willow Aspen Wild privet Grey sallow Dogwood (England and Wales only) Gean (locally) Spindle (England and Wales only) Common whitebeam (locally) Wayfaring tree (England and Wales only) Hornbeam (to the south and east) Purging buckthorn (England and Wales only)

43 Optimal precursor vegetation Wood anemone (Anemone nemorosa) Damp rank grasslands with Primrose (Primula vulgaris) Tufted hair-grass (Deschampsia cespitosa) Early dog violet (Viola reichenbachiana) Yorkshire fog (Holcus lanatus) Common dog violet (Viola riviniana) False oat-grass (Arrhenatherum elatius) Ground ivy (Glechoma hederacea) Cock’s-foot (Dactylis glomerata) Lesser celandine (Ranunculus ficaria) Creeping bent ( Agrostis stolonifera) Yellow archangel (Lamiastrum galeobdolon) Rough meadow grass (Poa trivialis) Wood avens (Geum urbanum) Hogweed (Heracleum sphondylium) Enchanter’s nightshade (Circaea lutetiana) Stinging nettle (Urtica dioica) Wood sedge (Carex sylvatica) Creeping thistle (Cirsium arvense) Lords and ladies (Arum maculatum) Spear thistle (Cirsium vulgare) Ramsons (Allium ursinum)

Dry rank grasslands with False oat-grass (Arrhenatherum elatius) Woodland structure and pattern Wild parsnip (Pastinaca sativa) This is one of our most diverse woodland types Upright brome (Bromus erectus) with a great variety of composition and struc­ Tor grass (Brachypodium pinnatum) ture among the trees and shrubs of semi-nat­ False brome (Brachypodium sylvaticum) ural stands, especially to the south and east of Maijoram (Origanum vulgare) England and Wales. Design options are there­ Perforate St John’s-wort (Hypericum perfo­ fore numerous, and additional variety can be ratum) encouraged around open areas and along mar­ Agrimony (Agrimonia eupatoria) gins where light-demanding shrubs like dog­ Wood sage (Teucrium scorodonia) wood, purging buckthorn and privet can be Herb robert (Geranium robertianum) concentrated. The colourful herbaceous flora characteristic here, and especially well seen Underscrub with some of the above plants and after coppicing, establishes only slowly, but Bramble (Rubus fruticosus) damper rides and clearings can develop Ivy (Hedera helix) diverse tall-herb vegetation fairly quickly pro­ Ground ivy (Glechoma hederacea) vided taller grasses can be held in check. Where sites include more base-poor brown Desired invaders earths, planting across the soil boundary can Dog’s mercury (Mercurialis perennis) be designed to point up a shift to the lowland Bluebell (Hyacinthoides non-scripta) bluebell wood (W10).

44 Lowland mixed broadleaved woodland with bluebell/ NVC woodland W10 wild hyacinth

Zone Throughout the warmer and drier lowlands of southern and eastern Britain.

Soil types Typical brown earths, moderately acidic brown earths and base-poor ground-water gleys.

Geology Non-calcareous sedimentary shales and clays, granites and lime-poor superficial deposits like clay-with-flints, more ill-draining sands and gravels and old alluvium.

Terrain and site types Gently undulating basins, vales and low plateaux across central and eastern England, and valley bottoms and gently sloping valley sides, particularly towards the north and west.

Major recommended trees Pedunculate oak Sessile oak (locally and to the north-west of the zone) Silver birch

Minor recommended trees Guelder rose Holly Wayfaring tree (England and Wales only) Rowan Common gorse/whin (in more open places) Crab apple Broom (in more open places) Downy birch Aspen (locally) Optimal precursor vegetation Gean (locally) Rank grassland with Hornbeam (to the south and east) False oat-grass (.Arrhenatherum elatius) Ash (to the north-west) Yorkshire fog (Holcus lanatus) Wych elm (to the north-west) Cock’s-foot (Dactylis glomerata) Major recommended shrubs Creeping soft-grass (Holcus mollis) Hazel Hogweed (Heracleum sphondylium) Hawthorn Stinging nettle (Urtica dioica) Rosebay willowherb ( Epilobium angusti- Minor recommended shrubs folium) Blackthorn Creeping thistle (Cirsium arvense) Elder Spear thistle (Cirsium vulgare)

45 Underscrub with some of the above plants and Woodland structure and pattern Bramble ( Rubus fruticosus) Semi-natural stands of this kind of woodland Common gorse (Ulex europaeus) tend to be less diverse in their trees and Broom (Cytisus scoparius) shrubs than those of the low land dog’s Bracken (Pteridium aquilinum) m ercury w oodland, but there is still ample Foxglove (Digitalis purpurea) opportunity for variety among the minor Red campion (Silene dioica) trees and shrubs. This should be used to help Wood sage (Teucrium scorodonia) differentiate more south-easterly planting Ivy (Hedera helix) sites from those towards the upland fringes. Open areas and margins can also be distin­ Desired invaders guished by encouraging gorse and broom. Bluebell (Hyacinthoides non-scripta) Associated herbaceous vegetation is often Wood anemone (Anemone nemorosa) rather species-poor and bramble or, on drier Honeysuckle (Lonicera periclymenum) soils, bracken, can be a problem, or where Hairy wood-rush (Luzula pilosa) there has been disturbance and soil enrich­ Male fern (Dryopteris filix-mas) ment, nettle or rosebay. Geological and soil Yellow archangel (Lamiastrum galeobdolon, transitions to more lime-rich substrates England and Wales) should be marked by a switch to the richer Broad buckler fern (Dryopteris dilatata, to mixtures of trees and shrubs typical of the north-west) low land m ercury w ood. Flushed areas Common dog violet (Viola riviniana, to north­ should be planted with alder-ash-yellow west) pimpernel woodland (W7). Lowland oak-birch woodland with bilberry/blaeberry NVC woodland w16

Zone Throughout the warmer and drier lowlands of southern and eastern Britain.

Soil types Acid sands, rankers, acidic brown earths and podzols.

Geology Sedimentary sandstones, grits and sands and gravels, and pervious lime-poor superficial deposits such as sandy drift, aeolian sands and fluvioglacial sands and gravels.

Terrain and site types Dip slopes and plateaux, and free-draining basins and terraces, localised over suitable deposits in eastern and southern England, and extending on to valley sides and scarps towards the north and west.

Major recommended trees Pedunculate oak Sessile oak (locally and towards the north and west of the zone) Silver birch Downy birch (locally) Western gorse (Ulex gallii) Minor recommended trees Bilberry/blaeberry ( Vaccinium myrtillus) Holly Wavy hair-grass (Deschampsia flexuosa) Rowan Common bent (Agrostis capillaris) Aspen (locally) Common whitebeam (locally) Bristle bent ( Agrostis curtisii) Red fescue (Festuca rubra) Recommended shrubs Sheep’s fescue (Festuca ovina) Elder (locally) Tormentil (Potentilla erecta) Alder buckthorn (locally) Heath bedstraw (Galium saxatile) Common gorse/whin (in more open places) Underscrub or fern stands with some of the Optimal precursor vegetation above and Grasslands and heaths with Common gorse/whin (Ulex europaeus) Heather (Calluna vulgaris) Broom (Cytisus scoparius) Bell-heather (Erica cinerea) Bracken (Pteridium aquilinum) Dwarf gorse (Ulex minor) Broad buckler fern (Dryopteris dilatata)

47 Desired invaders hold, the prospects for short-term interest are No herbs other than those listed but, particu­ poor. However, there is some opportunity for larly towards the north and west, semi-nat­ local variety among minor trees and shrubs and ural woodlands of this kind can develop a rich more open plantings will help establish some­ bryophyte flora. what richer heathy field layers. This is also one of the situations where modest disturbance of Woodland structure and pattern the ground can be beneficial in allowing the Even in the warmer south-east, the impover­ establishment of common gorse scrub. Any ished base-poor soils characteristic here offer patches of less acidic soils or of wetter ground little encouragement for diversification in plant­ should allow more diverse plantings of lowland ings and, if dense young birch gets an extensive bluebell or flush and mire woodlands.

48 Upland mixed broadleaved woodland with dog’s mercury NVC woodland W9

Zone Throughout the cooler and wetter uplands of northern and western Britain.

Soil types Calcareous brown earths, basic brown earths and base-rich surface-water gleys.

Geology Sedimentary limestones and calcareous shales, basic igneous and metamorphic rocks, lime-rich boulder clay, head and downwash.

Terrain and site types Ravine and valley sides and heads, often steep and rocky or choked with drift, and sometimes with modest flushing.

Major recommended trees Ash Downy birch Rowan

Minor recommended trees Sessile oak Pedunculate oak (locally) Wych elm Alder Holly and aspen (local) Yorkshire fog (Holcus lanatus) Bird cherry Rough meadow grass (Poa trivialis) Major recommended shrubs Sweet vernal grass (Anthoxanthum Hazel odoratum) Common bent ( Agrostis capillaris) Minor recommended shrubs Meadowsweet (Filipendula ulmaria) Hawthorn Water avens (Geum rivale) Elder Germander speedwell (Veronica chamaedrys) Grey sallow Common sorrel (Rumex acetosa) Bush vetch (Vicia sepium) Optimal precursor vegetation Primrose (Primula vulgaris) Damp grasslands and tall-herb vegetation with Pignut (Conopodium majus) False oat-grass (Arrhenatherum elatius) Common dog violet (Viola riviniana) Tufted hair-grass (Deschampsia cespitosa) Lady’s mantle (Alchemilla glabra) Cock’s-foot (Dactylis glomerata) Hogweed (Heracleum sphondylium)

49 Femy banks with some of the above plants and Male fern (Dryopteris filix-mas) Great wood-rush (Luzula sylvatica) Scaly male fern (D. borreri) Lady fern (Athyrium filix-femina) Herb robert ( Geranium robertianum) Male fern (Dryopteris filix-mas) Scaly male fern (D. borreri) Woodland structure and pattern Devil’s bit scabious ( Succisa pratensis) Wild angelica (Angelica sylvestris) Although potentially not so diverse in its com­ plement of trees and shrubs as its lowland counterpart, this kind of woodland often Desired invaders shows structural complexity because semi­ Dog’s mercury (Mercurialis perennis) natural stands are characteristic of irregular, Bluebell (Hyacinthoides non-scripta) flushed terrain. Difficult sites can therefore Wood sorrel (Oxalis acetosella) provide challenging opportunities for concen­ Sanicle (Sanicula europaea) trating birch around windswept upper mar­ Wood avens (Geum urbanum) gins and alder in transitions to alder-ash yel­ Enchanter’s nightshade (Circaea lutetiana) low pim pernel woodland. More open Marsh hawk’s-beard (Crepis paludosa) plantings and unplanted areas should be Wood crane’s-bill (Geranium sylvaticum) encouraged, especially on wetter ground as Yellow pimpernel (Lysimachia nemorum) they can develop colourful herbaceous or fern- Lady fern (Athyrium filix-femina) dominated vegetation.

50 Upland oak-birch woodland with bluebell/wild hyacinth NVC woodland W11

Zone Throughout the cooler and wetter uplands of northern and western Britain.

Soil types Acidic brown earths and podzolic brown earths.

Geology Non-calcareous shales and softer lime-poor igneous and metamorphic rocks, lime-poor superficial deposits like boulder clay, flu- vioglacial sands and gravels, head and collu- vium.

Terrain and site types Talley sides and hill slopes around the upland fringes and on well-drained terraces of larger rivers.

Major recommended trees Sessile oak Downy birch

Minor recommended trees Silver birch (major in east-central Scotland) Tormentil (Potentilla erecta) Pedunculate oak (locally) Common dog violet (Viola riviniana) Rowan Field wood-rush (Luzula campestris) Holly and aspen (local) Yarrow (Achillea millefolium) Recommended shrubs Fern vegetation with some of the above and Hazel Hawthorn Bracken (Pteridium aquilinum) Juniper (in more open places) Lemon-scented fern (Thelypteris limbosperma) Optimal precursor vegetation Hard fern (Blechnum spicant) Grasslands with Broad buckler fern (Dryopteris dilatata) Sheep’s fescue (Festuca ovina) Great wood-rush (Luzula sylvatica) Red fescue (Festuca rubra) Sweet vernal grass (Anthoxanthum odora- Desired invaders tum) Bluebell (Hyacinthoides non-scripta) Common bent ( Agrostis capillaris) Primrose (Primula vulgaris) Yorkshire fog (Holcus lanatus) Pignut (Conopodium majus) Heath bedstraw ( Galium saxatile) Wood sorrel (Oxalis acetosella)

51 Wood sage (Teucrium scorodonia) birch following the removal of all good-quality Creeping soft-grass (Holcus mollis) timber. However, more open areas can be given Wood anemone (Anemone nemorosa) mixtures of rowan, birch, juniper and holly. Chickweed wintergreen (Trientalis europaea, Open areas will show a strong tendency to in east-central Scotland) become bracken dominated, but where this has an understorey of bluebell there is greater Woodland structure and pattern interest. Rocky ground and wetter places Semi-natural stands have little diversity promise more diversity in associated herba­ among the trees and shrubs, a feature accentu­ ceous vegetation, and, in some of the latter, ated by the widespread use of the woodlands as plantings can encourage development of alder- oak-coppice with grazing or by the spread of ash-yellow pimpernel woodland.

52 Upland oak-birch woodland with bilberry/blaeberry NVC woodland W 17

Zone Throughout the cooler and wetter upland fringes of northern and western Britain.

Soil types Rankers, podzolic brown earths and podzols.

Geology Sedimentary sandstones and grits, igneous rocks like lime-poor granites and lavas, quartzites and gneisses, and pervious lime- poor superficial deposits like coarse flu- vioglacial sands and gravels.

Terrain and site types Scarps, valley sides and hill slopes, often with rugged terrain, around the upland fringes of the north and west.

Major recommended trees Sessile oak Downy birch

Minor recommended trees Pedunculate oak (with local abundance in east-central Scotland) Silver birch (with local abundance in east-cen­ Mat grass (Nardus stricta) tral Scotland) Common bent ( Agrostis capillaris) Holly Sweet vernal grass {Anth.oxanth.um odora- Rowan tum) Heath bedstraw {Galium saxatile) Recommended shrubs Tormentil {Potentilla erecta) Hazel (only on better soils) Hard fern {Blechnum spicant) Hawthorn (only on better soils) Juniper (in more open places) Tall-herb and fern vegetation with some of the Optimal precursor vegetation above and Grasslands and heaths with Bracken {Pteridium aquilinum) Heather (Calluna vulgaris) Broad buckler fern {Dryopteris dilatata) Bilberry/blaeberry ( Vaccinium myrtillus) Great wood-rush {Luzula sylvatica) Bell-heather (Erica cinerea) Wood sorrel {Oxalis acetosella) Crowberry ( Empetrum nigrum) Cowberry ( Vaccinium vitis-idaea) Desired invaders Wavy hair-grass (Deschampsia flexuosa) Few herbs other than those listed except in Sheep’s fescue (Festuca ovina) east-central Scotland where the following are

53 common in semi-natural woodlands of this coppice or of birch where this has spread after kind: clearance. Even in new woodlands there is Chickweed wintergreen (Trientalis europaea) limited scope with this type for species diver­ Hairy wood-rush (Luzula pilosa) sity among trees and shrubs. However, varia­ tions in the pattern of the few important trees Further west, there is an increasingly rich and shrubs, local concentration of minor com­ bryophyte flora in woods of this kind, particu­ ponents on patches of richer soils and inclu­ larly where boulders and crags provide shel­ sion of unplanted areas will give some variety tered and shaded niches. and opportunity for transitions to heath and fern-rich vegetation. Only on bouldery sites Woodland structure and pattern will the full richness of mosses and liverworts Many existing stretches of this kind of wood­ develop and, on deeper soils, the spread of land show a preponderance of oak in former bracken is always a threat.

54 Beech-ash woodland with dog’s mercury NVC woodland W 12

Zone Warmest and driest lowlands of south-east England and south Wales.

Soil type Rendzinas and brown calcareous earths.

Geology Chalk, Oolitic and Carboniferous limestones.

Terrain and site types Scarps and screes, and steeply sloping ground in gaps and on knolls on the limestone hills of south-east Britain.

Major recommended trees Beech Ash

Minor recommended trees Pedunculate oak Common whitebeam Yew Silver birch Field maple Holly Tor grass (Brachypodium pinnatum) Hornbeam Upright brome (Bromus erectus) False brome ( Brachypodium sylvaticum) Major recommended shrubs Marjoram (Origanum vulgare) Hazel Perforate St John’s-wort (Hypericum Hawthorn perforatum) Agrimony (Agrimonia eupatorium) Minor recommended shrubs Wood sage (Teucrium scorodonia) Elder Herb robert ( Geranium robertianum) Guelder rose Stinging nettle (Urtica dioica) Wayfaring tree Burdock (Arctium minus) Spindle Deadly nightshade (Atropa belladonna) Wild privet Great mullein (Verbascum thapsus) Dogwood (in more open places) Common figwort (Scrophularia nodosa) Juniper (in more open places) Ploughman’s spikenard (Inula conyza)

Optimal precursors Desired invaders Dry rank grasslands with Dog’s mercury (Mercurialis perennis) False oat-grass (Arrhenatherum elatius) Enchanter’s nightshade (Circaea lutetiana)

55 Bluebell ( Hyacinthoides non-scripta) opment of a richer associated flora. If such Lords and ladies (Arum maculatum) diversity is desired, more balanced mixtures Woodruff (Galium odoratum) of trees and shrubs should be used and more Yellow archangel (Lamiastrum galeobdolon) open areas integrated into the plantings. Sanicle (Sanicula europaea) Varied and colourful edges can also be Wall lettuce (Mycelis muralis) encouraged using ash, birch and the minor Wood melick (Melica uniflora) shrubs. However, these will quickly spread White helleborine ( Cephalanthera damasonium) into gaps and transitions to short, herb-rich Broadleaved helleborine (Epipactis helleborine) swards will only be maintained by grazing or mowing. Shifts, within a site, to less base- Woodland structure and pattern rich brown soils should be reflected by plant­ Beech is such a densely shading tree that ing beech-oak woodland with hramhle close planting will always inhibit the devel­ (W14).

56 Beech-oak woodland with bramble NVC woodland W14

Zone Warmest and driest lowlands of south-east England and south Wales.

Soil types Typical brown earths.

Geology Non-calcareous sedimentary shales and clays, and lime-poor superficial deposits like clay- with-flints and plateau drift.

Terrain and site types Dip slopes and plateaux, often drift-covered, on the low hills of southern Britain.

Major recommended trees Beech Pedunculate oak Holly

Minor recommended trees Silver birch Sessile oak (locally) Yew Ash Hogweed (Heracleum sphondylium) Rowan Creeping thistle (Cirsium arvense) Goat willow Spear thistle (C. vulgare) Gean Stinging nettle (Urtica dioica)

Recommended shrubs Underscrub with some of the above plants and Hazel Bramble ( Rubus fruticosus) Hawthorn Common gorse/whin (Ulex europaeus) Elder Broom (Cytisus scoparius) Wild privet Bracken (Pteridium aquilinum) Foxglove (Digitalis purpurea) Optimal precursor vegetation Red campion (Silene dioica) Rank grassland with Wood sage (Teucrium scorodonia) False oat-grass (Arrhenatherum elatius) Ivy (Hedera helix) Yorkshire fog (Holcus lanatus) Cock’s-foot (Dactylis glomerata) Desired invaders Creeping soft-grass (Holcus mollis) Wood sorrel (Oxalis acetosella) Rosebay willowherb ( Epilobium Wood millet (Milium effusum) angustifolium) Wood melick (Melica uniflora)

57 Woodruff (Galium odoratum) spacing, richness among the field layer is Wood spurge (Euphorbia amygdaloides) never going to be very great. The spread of Butcher’s broom (Ruscus aculeatus) bramble in such situations may be seen as a problem too, although this plays an important Woodland structure and pattern role in maintaining the quality of the soil. Beech can make its best growth of all on the Unplanted areas are likely to become rank soils characteristic here, so the creation of and weedy or to scrub up with birch and gorse lofty canopies can be a long-term aim, with if grazing or mowing are not maintained. the hope of a second tier of holly and yew. Transitions to more acidic soils can be planted Semi-natural stands of such woodland are with much the same tree mixtures, but will often bare below and, even with more open develop a more heathy associated flora.

58 Beech-oak woodland with wavy hair-grass NVC woodland W 15

Zone Warmest and driest lowlands of south-east England and south Wales.

Soil types Acidic brown earths and podzols.

Geology Sedimentary sandstones, grits and sands and gravels, and coarse textured, pervious and lime-free superficial deposits.

Terrain and site types Dip slopes and plateaux, often drift-covered, on the low hills of southern Britain, and free- draining basins and terraces between.

Major recommended trees Beech Pedunculate oak Holly

Minor recommended trees Silver birch Yew Rowan Sessile oak (locally) Underscrub or fern stands with some of the above and Recommended shrubs Common gorse/whin (Ulex europaeus) Alder buckthorn Broom (Cytisus scoparius) Optimal precursor vegetation Bracken (Pteridium aquilinum) Grasslands and heaths with Heather (Calluna vulgaris) Woodland structure and pattern Bell-heather (Erica cinerea) Wide spacing and the inclusion of unplanted Dwarf gorse (Ulex minor) areas will not encourage great diversity on Western gorse (Ulexgallii) these impoverished acidic soils but the associ­ Bilberry/blaeberry ( Vaccinium myrtillus) ated heathy flora can be visually very attrac­ Wavy hair-grass (Deschampsia caespitosa) tive where the heathers and gorse have suffi­ Common bent ( Agrostis capillaris) cient light to flower. Such a cover of Tormentil (Potentilla erecta) sub-shrubs in more open areas may also hin­ Heath bedstraw (Galium saxatile) der the spread of birch and bracken. Colonisa­ Sheep’s sorrel (Rumex acetosella) tion by pine and other conifers may also be a Sheep’s fescue (Festuca ovina) problem.

59

Scots pine woodland with heather NVC woodland W 18

Zone Cold and wet uplands of the Grampians and western Highlands.

Soil types Podzols and peaty podzols, with some podzolic gleys and peaty podzolic gleys, and some pod­ zolic brown earths.

Geology Pervious, siliceous bedrocks such as sand­ stones, schists and quartzites and permeable superficial deposits, especially fluvioglacial sands and gravels.

Terrain and site types Upland plateaux and hill slopes, and particu­ larly the undulating terraces of major river valleys.

Major recommended trees Scots pine

Minor recommended trees Silver birch (mainly east-central) Downy birch (mainly western) Desired invaders Rowan Lesser twayblade (Listera cordata) Recommended shrubs Creeping lady’s-tresses (Goodyera repens) Juniper Wood sorrel (Oxalis acetosella) Hairy wood-rush (Luzula pilosa) Optimal precursor vegetation Heaths with Semi-natural stands of this woodland also Heather (Calluna vulgaris) have extensive carpets of bryophytes, includ­ Blaeberry (Vaccinium myrtillus) ing bog mosses (Sphagnum spp.) in boggy hol­ Cowberry (V. vitis-idaea) lows and towards the west. Crowberry ( Empetrum nigrum) Bell-heather (Erica cinerea) Woodland structure and pattern Bearberry (Arctostaphylos uva-ursi) Pine forest on the grand scale of the past was Wavy hair-grass (Deschampsia flexuosa) a varied tapestry of this kind of woodland with Tormentil (Potentilla erecta) associated stands of oak-birch and juniper and Heath bedstraw (Galium saxatile) wetter woodland with alder, willows and ash. Common cow-wheat (Melampyrum pratense) Where new sites for planting have a diversity Hard fern (Blechnum spicant) of soils, such mosaics should be aimed for with

61 ample areas left unplanted for the encourage­ are a natural feature of this woodland which ment of heath, tall-herb and grassland vegeta­ has tended to regenerate after disturbance by tion. Even-aged stands of pine of varying size wind or fire.

62 Juniper woodland with wood sorrel NVC woodland W19

Zone Locally through the cold and wet uplands of northern England, the southern uplands of Scotland and the eastern Highlands.

Soil types Typical and acidic brown earths and podzolic brown earths, sometimes moderately mesotrophic and with mull or moder humus, and podzols with mor.

Geology Sedimentary shales and sandstones, and vari­ ous igneous and metamorphic rocks like quartzites, gneisses and rhyolites, locally with some lime-enrichment, and also sandy or gravelly superficial deposits.

Terrain and site types Valley sides and hill slopes in the uplands.

Major recommended trees Juniper

Minor recommended trees Downy birch Common bird’s-foot trefoil (Lotus Scots pine corniculatus) Rowan White clover (Trifolium repens) Ribwort plantain (Plantago lanceolata) Optimal precursor vegetation Yarrow (Achillea millefolium) Grasslands with Sheep’s fescue (Festuca ovina) Grasslands and heaths with Red fescue (Festuca rubra) Heather (Calluna vulgaris) Sweet vernal grass (Anthoxanthum Bilberry/blaeberry (Vaccinium myrtillus) odoratum) Cowberry (V. vitis-idaea) Wavy hair-grass (Deschampsia flexuosa) Wavy hair-grass (Deschampsia flexuosa) Common bent ( Agrostis capillaris) Sheep’s fescue (Festuca ovina) Brown bent (Agrostis canina montana) Common bent (Agrostis capillaris) Heath grass (Danthonia decumbens) Sweet vernal grass (Anthoxanthum Heath speedwell (Veronica officinalis) odoratum) Common dog violet (Viola riviniaha) Alpine lady’s-mantle (Alchemilla alpina) Alpine lady’s mantle (Alchemilla alpina) Heath bedstraw (Galium saxatile) Harebell (Campanula rotundifolia) Tormentil (Potentilla erecta) Field wood-rush (Luzula campestris) Hard fern (Blechnum spicant)

63 Desired invaders juniper woodland of this type is strictly Wood anemone (Anemone nemorosa) speaking a stage in the succession to pine or Chickweed wintergreen (Trientalis europaea) oak-birch woodland. Since it has similar soil Wood sorrel (Oxalis acetosella) preferences to these other communities, it Hairy wood-rush (Luzula pilosa) offers an alternative option for planting and Broad buckler fern (Dryopteris dilatata) can be used to bring some patchy diversity to Lemon-scented fern (Thelypteris limbosperma) their cover or concentrated in irregular Beech fern (T. phegopteris) groups in and around open areas and wood­ Oak fern (Gymnocarpium dryopteris) land margins. It may attain a semi-perma­ nent status where grazing among the bushes Many semi-natural stands of this kind of prevents the spread of invading trees, but woodland also have patchy carpets of stock will also limit the development of richer bryophytes in more open places. associated floras of tall herbs. Juniper has very diverse growth forms in different areas Woodland structure and pattern and local stock should be used for planting to At all but the highest altitudes in Scotland, help develop this distinctiveness.

64 Alder woodland with common reed NVC woodland W2

Zone Locally through the warmer and drier low­ lands of southern and eastern Britain.

Soil types Topogenous fen peats and peaty alluvial soils.

Geology Topogenous fen peats or peaty alluvium over impervious bedrocks or superficial deposits.

Terrain and site types Floodplain and some basin mires, valley mire terraces and around artificial open waters through the flat or gently undulating low­ lands.

Major recommended trees Alder Downy birch

Minor recommended trees Ash Pedunculate oak Crack willow Marsh thistle (Cirsium palustre) Major recommended shrubs Stinging nettle (Urtica dioica) Grey sallow Lesser pond-sedge (Carex acutiformis) Bitter-sweet (Solarium dulcamara) Minor recommended shrubs Yellow iris (Iris pseudacorus) Alder buckthorn Water mint (Mentha aquatica) Purging buckthorn Guelder rose Desired invaders Hawthorn Bramble (Rubus fruticosus) Eared willow Broad buckler fern (Dryopteris dilatata) Rough meadow grass (Poa trivialis) Optimal precursor vegetation Tall-herb fen with Woodland structure and pattern Common reed (Phragmites australis) Younger semi-natural stands of this kind of Meadowsweet (Filipendula ulmaria) woodland are characteristically rather differ­ Wild angelica (Angelica sylvestris) ent one from another with chance colonisa­ Agrimony (Agrimonia eupatorium) tion producing local abundance of either Purple loosestrife (Lythrum salicaria) alder, birch or sallow. Irregular patches or Yellow loosestrife (Lysimachia vulgaris) mixtures of these species can therefore be

65 concentrated on wetter ground with more or beech woodland. Unplanted areas are balanced or richer plantings on drier areas. likely to become colonised by trees and Dense spacing will quickly extinguish richer shrubs quite quickly if flooding stops or the wetland floras and discourage colonisation. drier ground is not mown. Disturbance and Surrounding slopes can be planted up with enrichment of the ground is likely to encour­ the appropriate mixed broadleaved, oak-birch age the spread of nettle.

66 Alder woodland with stinging nettle NVC woodland W6

Zone Locally through the warmer and drier lowland of southern and eastern Britain.

Soil types Moist alluvia] soils and enriched fen peats.

Geology Voung alluvium and disturbed or enriched fen seats.

Terrain and site types Pluvial terraces in more mature river valleys nd silting margins of standing open waters, \tural and artificial, and in disturbed or itrophicated floodplain and basin mires.

7 Taj or recommended trees -der : rack willow

linor recommended trees idowny birch Ash Pedunculate oak Optimal precursor vegetation Holly Tall-herb or grassy fen with Goat willow Common reed (Phragmites australis) Stinging nettle (Urtica dioica) Major recommended shrubs Goosegrass (Galium aparine) Grey sallow Great willowherb ( Epilobium hirsutum ) Elder Bitter-sweet (Filipendula ulmaria) Hemp agrimony (Eupatorium cannabinum) Minor recommended shrubs False oat-grass (Arrhenatherum elatius) Hawthorn Hogweed (Heracleum sphondylium) Guelder rose Creeping thistle (Cirsium arvense) Blackthorn Butterbur ( Petasites hybridus) Alder buckthorn (locally) Hedge bindweed ( Calystegia sepium) Purging buckthorn (locally) Tufted vetch (Vicia cracca) Almond willow Osier willow Marginal vegetation with some of the above Purple willow and some of Reed sweet-grass (Glyceria maxima) Greater pond-sedge (Carex riparia)

67 Lesser pond-sedge (C. acutiformis) osier and purple willow often predominate Cyperus sedge (C. pseudocyperus) and these can be planted in patchy concentra­ Bulrush (Typha latifolia) tions between and around mixtures of the Branched bur-reed ( Sparganium erectum) major trees. Mature stands usually have a Fool’s watercress (Apium nodiflorum) tall closed canopy but can develop a decrepit Watercress (Nasturtium officinale) appearance on alluvial flats that are still Brooklime (Veronica beccabunga) periodically flooded. Wide spacing and open Reed canary-grass (Phalaris arundinacea) areas are essential to maintain any kind of Water mint (Mentha aquatica) richness in the associated flora but there is Water forget-me-not (Myosotis scorpioides) always a tendency on rich soils of this kind Tufted forget-me-not (M. laxa cespitosa) for nettle, goosegrass and great willowherb to Water plantain (Alisma plantago-aquatica) predominate. Transitions on drier riverside slopes would naturally be to mixed Woodland structure and pattern broadleaved woodland with bluebell or dog’s In younger semi-natural stands, almond, mercury.

68 Birch woodland with purple moor-grass NVC woodland W4

Zone Throughout the wetter regions of Britain and locally in the lowlands where site conditions are suitable.

Soil types Flushed and unflushed acid peats, and peaty surface-water gleys.

Geology l^eats or over impervious shales and clays, or heavy superficial deposits, where flushed with base-poor waters.

Terrain and site types Margins of blanket mires, valley bogs and hill- bope and valley-side flushes and the margins of cut-over or drained raised mires.

Major recommended trees Downy birch

Minor recommended trees Goat willow Alder

Recommended shrubs Wild angelica (Angelica sylvestris) Grey sallow Tormentil (Potentilla erecta) Eared willow Bay willow (in northern Britain) Wet heath, degraded mires and flushes with Optimal precursor vegetation Purple moor-grass (Molinia caerulea) Wet grasslands and rushy pastures with Cross-leaved heath (Erica tetralix) Purple moor-grass (Molinia caerulea) Heather (Calluna vulgaris) Soft rush (Juncus effusus) Sweet gale (Myrica gale) Sharp-flowered rush (J. acutiflorus) Heath rush (Juncus squarrosus) Yorkshire fog (Holcus lanatus) Mat grass (Nardus stricta) Brown bent ( Agrostis canina) Deer grass (Scirpus cespitosus) Common bent (A. capillaris) Star sedge (Carex echinata) Sweet vernal grass (Anthoxanthum odora­ Carnation sedge (Carex panicea) tum) Sharp-flowered rush (Juncus acutiflorus) Greater bird’s-foot trefoil (Lotus uliginosus) Marsh violet (Viola palustris) Marsh thistle (Cirsium palustre) Common cotton-grass (Eriophorum angusti- Devil’s-bit scabious ( Succisa pratensis) folium)

69 Desired invaders young birch or an open and decrepit canopy Tufted hair-grass (Deschampsia cespitosa) of older trees. Plantings can aim for a little Creeping soft-grass (Holcus mollis) more diversity by varying the abundance of Bramble ( Rubus fruticosus) associates and, especially on flushed ground, Honeysuckle (Lonicera periclymenum) wider spacing will encourage the develop­ Broad buckler fern ( Dryopteris dilatata) ment of a richer field layer. Drier sites offer Narrow buckler fern ( Drtopteris carthusiana) less promise of variety but open areas can Smooth-stalked sedge (Carex laevigata) have transitions to heath vegetation. A shift on to acid peaty mineral soils on surround­ Woodland structure and pattern ing terrain is common and here oak-birch Semi-natural stands of this sort of woodland woodland with bilberry/blaeberry would usually have a vigorous and dense cover of be usual.

70 Alder-ash woodland with yellow pimpernel NVC woodland W7

Zone Throughout the wetter regions of Britain, par­ ticularly around the upland fringes of the north and west.

Soil types Moderately base-rich and mesotrophic sur­ face-water gleys and flushed brown earths, and some ground-water gleys.

Geology impervious sedimentary shales and clays, and eavy superficial deposits like boulder clay nd clayey head or downwash.

Terrain and site types alley sides and hill slopes with flushes and eepage lines, streamsides and older alluvial i .Traces, and waterlogged brows and Gateaux.

Major recommended trees Alder Ash

Minor recommended trees 1 towny birch Optimal precursor vegetation Coat willow Tall-herb fens and rushy pastures with Pedunculate oak Meadowsweet (Filipendula ulmaria) Sessile oak Soft rush (Juncus effusus) Rowan Sharp-flowered rush (J. acutiflorus) Holly Tufted hair-grass (Deschampsia cespitosa) Bird cherry (in northern Britain) Rough meadow grass (Poa trivialis) Sweet vernal grass (Anthoxanthum odora­ Major recommended shrubs tum) Grey sallow Marsh thistle (Cirsium palustre) Hazel Wild angelica (Angelica sylvestris) Hawthorn Common valerian (Valeriana officinalis) Creeping buttercup (Ranunculus repens) Minor recommended shrubs Marsh marigold (Caltha palustris) Elder Cuckoo flower (Cardamine pratensis) Guelder rose Common dog violet (Viola riviniana) Blackthorn Water mint (Mentha aquatica) Bay willow (towards northern Britain) Stinging nettle (Urtica dioica)

71 Desired invaders kind of woodland have a rather open and Creeping soft-grass (Holcus mollis) irregular cover of trees and shrubs, some Wood sorrel (Oxalis acetosella) keeling over where the ground slumps. More Yellow pimpernel (Lysimachia nemorum) widely spaced plantings will also encourage Opposite-leaved golden saxifrage the retention or development of a richer asso­ (Chrysosplenium oppositifolium) ciated flora and, even where there is no graz­ Remote sedge (Carex remota) ing, the wetness and instability of the ground Smooth-stalked sedge (C. laevigata) will help discourage canopy closure. Stands Pendulous sedge (C. pendula) will often be small, marking out isolated slope Lady fern (Athyrium filix-femina) flushes, but plantings should not be too Broad buckler fern (Dryopteris dilatata) closely crowded by the surrounding wood­ Marsh hawk’s-beard (Crepis paludosa, in lands. Transitions on such drier slopes will northern Britain) usually be to mixed broadleaved or oak-birch woodlands and, on any alluvium or peat Woodland structure and pattern below, to alder-reed or alder-nettle wood­ Characteristically semi-natural stands of this lands.

72 REFERENCES HOOPER, M.D. (1977). Effects of area and iso­ lation on communities. Nature Conservancy ANDERSON, M. A. (1979). The development of Council Chief Scientists Team Report No. plant habitats under exotic tree crops. In 93. NCC, Peterborough. Ecology and design in amenity land manage­ KERR, G and EVANS, J. (1993). Growing ment. Wye College and Recreation Ecology broadleaves for timber. Forestry Commission Research Group Symposium, ed. S. E. Handbook 9. HMSO, London. Wright and G. P. Buckley. Wye College, KINLOCH, B. B„ WESTFALL, R. D. and FOR­ Kent, 78-109. REST, G. I. (1986). Caledonian Scots pine; BUCKLEY, G. P. and KNIGHT, D. G. (1989). origins and genetic structure. New Phytolo- The feasibility of woodland reconstruction. gist 104, 703-729. In Biological habitat reconstruction, ed. G. P. KIRBY, B. J., PETERKEN, G. G„ SPENCER, Buckley. Belhaven Press, London, 171-188. J. W. and WALKER, G. J. (1989). Invento­ DAVY, A. J. (1980). Biological flora of the ries of ancient semi-natural woodland. British Isles. Deschampsia caespitosa. Jour­ Focus on Nature Conservation No. 6 (2nd nal of Ecology 68, 1075-1096. edition). Nature Conservancy Council, EVANS, J. (1984). Silviculture of broadleaved Peterborough. woodland. Forestry Commission Bulletin 62. McVEAN, D. N. (1992). Notes on some forms of HMSO. London. the common juniper in Scotland. Scottish FORESTRY COMMISSION (1985a). Guidelines Forestry 46, 145-147. for the management of broadleaved woodland. MOFFAT, A. J., ROBERTS, C. J. AND Forestry Commission, Edinburgh. McNEILL, J. D. (1989). The use of nitrogen- FORESTRY COMMISSION (1985b). 65th fixing plants in forestry reclamation. annual report and accounts. HMSO, London. Forestry Commission RIN 158. The Forestry FORESTRY COMMISSION (1989). Guidelines Authority, Famham, Surrey. for the management of native pinewoods. MOFFAT, A. J. and ROBERTS, C. J. (1990). Forestry Commission, Edinburgh. Grass mixtures for afforested open cast FORESTRY COMMISSION (1990). Forest spoils in South Wales. Land Degradation nature conservation guidelines. HMSO, Lon­ and Rehabilitation 2, 127-134. don. MOFFAT, A. J. and McNEILL, J. D. (1994). FORESTRY COMMISSION (1991). Forestry Reclaming disturbed land for forestry. policy for Great Britain. Forestry Commis­ Forestry Commission Bulletin 110. HMSO, sion, Edinburgh. London. FORESTRY COMMISSION (1992). 72nd PETERKEN, G. F. and GAME, M. (1984). His­ annual report and accounts. HMSO, London. torical factors affecting the number and dis­ FORESTRY COMMISSION (in press). Man­ tribution of vascular plant species in the agement guides for semi-natural woodlands. woodlands of central Lincolnshire. Journal Forestry Commission, Edinburgh. of Ecology 72, 155-182. FRANCIS, J. L., MORTON, A. J. and BOOR­ PYATT, D. G. (1982). Soil classification. MAN, L. A. (1992). The establishment of Forestry Commission RIN 68/82/SSN. The ground flora species in recently planted Forestry Authority, Farnham, Surrey. woodland. Aspects of Applied Biology 29, RODWELL, J. S. (Ed.) (1991). British plant 171-178. communities, vol. 1: Woodlands and scrub. HIBBERD, B. G. (Ed). (1989). Urban forestry Cambridge University Press, Cambridge. practice. Forestry Commission Handbook 5. RODWELL, J. S. and COOPER, E. A. (1990). HMSO, London. The development of vegetation in recently HIBBERD, B. G. (Ed). (1991). Forestry practice. established broadleaved woodlands in Forestry Commission Handbook 6. HMSO, upland Britian. Unpublished report to the London. Forestry Commission.

73 SOUTAR, R. and PETERKEN, G. F. (1989). WILLIAMSON, D. R. and LANE, P. B. (1989). Native trees and shrubs for wildlife. Tree The use of herbicides in the forest. Forestry News September, 14-15. Commission Fieldbook 8, 3rd edition. USHER, M. B., BROWN, A. C. and BEDFORD, HMSO, London. S. E. (1992). Plant species richness in farm WILSON, K. (1985). A guide to the reclamation woodlands. Forestry 65, 1-13. of mineral workings for forestry. Forestry WALLACE, H. L. and PATTERSON, G. S. (in Commission Research and Development prep.). The status of birch (Betula pubesens Paper 141. The Forestry Authority, Fam- Ehrh) and Betula pendula Roth.) in Sitka ham, Surrey. spruce restocks: evidence from Scottish WORRELL, R. (1992). A comparison between Forests. European continental and British prove­ WILLIAMSON, D. R. (1992). Establishing farm nances of some British native trees: growth woodlands. Forestry Commission Handbook survival and stem form. Forestry 65, 8. HMSO, London. 253-280.

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