Forestry Commission Bulletin: Alternative Silvicultural Systems to Clear Cutting in Britain: a Review
Total Page:16
File Type:pdf, Size:1020Kb
Forestry Commission Bulletin 115 in Britain: A Review Cyril Hart Forestry Commission ARCHIVE FORESTRY COMMISSION BULLETIN 115 Alternative Silvicultural Systems to Clear Cutting in Britain: A Review Cyril Hart LONDON : HMSO © Crown copyright 1995 Applications for reproduction should be made to HMSO Copyright Unit, Duke Street, Norwich NR3 1PD ISBN 0 11 710334 9 Hart, C.; 1995. Alternative Silvicultural Systems to Clear Cutting in Britain: A Review. Bulletin 115, HMSO, London, xiv + 101pp. FDC 22: 221.1: (410): (4) KEYWORDS: Amenity, Broadleaves, Conifers, Conservation, Establishment, Forestry, Management Cyril Hart Dr Cyril Hart OBE is a Chartered Surveyor and Chartered Forester and is the Queen’s Senior Verderer for the Forest of Dean. He is author of several books on Britain’s forests and trees of which the best known is his authoritative Practical forestry for the agent and surveyor. Professor Julian Evans and Mr Gary Kerr of the Forestry Commission’s Research Division contributed to this important review through editorial involvement and text revision. Front cover: Weasenham New Wood, Please address enquiries Norfolk: mixed conifer selection system; about this publication to: in the picture, Major Richard Coke Research Publications Officer DSO MC, the present owner. The Forestry Commission (P e t e r G o o d w i n ) Research Division Alice Holt Lodge, Wrecclesham Back cover: Dr Cyril Hart OBE Farnham, Surrey GU10 4LH (D a v id G r e e n ) Acknowledgements This Bulletin was written with the benefit of Professor J.D. Matthews’s updat ing (1989) of Professor R.S. Troup’s two editions of Silvicultural systems (1928, 1952), the latter edition by Dr E.W. Jones. Eminently rewarding too has been co-operation received from David Paterson, recently retired from the Forestry Commission, whose publications and erudite comments, based on a wide expe rience of practice and research in silviculture, have been invaluable. Likewise acknowledged are texts of Professor M.L. Anderson, and of Forestry Commission staff, in particular: Julian Evans, John Everard OBE, Gary Kerr, Mark Yorke and Adrian Whiteman. Additional assistance relating to silvicul tural systems was received directly or indirectly from Simon Bell, John Blyth, Paul Bond, Graham Booth, Richard Broadhurst, Robert Budden, Vernon Daykin, Christine Cahalan, Murray Carter, Lord Cawdor, Major Richard Coke, Wilfred Fox, Bob Furness, Michael Gane, Ted Garfitt, Peter Garthwaite OBE, David Goss, Sandy Greig, Michael Harley OBE, Esmond Harris, Anthony Hart, Rodney Helliwell, Paul Hill-Tout, Peter Hughes, Phillip Hutt MBE, Robert Jordan, Talis Kalnars, Felix Karthaus, Steve Lee, Arthur Lloyd, Roy Lorrain-Smith, David Lowe, John MacKenzie, Douglas Malcolm OBE, John McHardy, Robert McIntosh, Philippe Morgan, Andrew Neustein, John Newcomb, Trefor Owen, Colin Price, Chris Quine, Michael Reade DSC, John Robinson, Martin Rogers, Irvine Ross, Roddy Ross, Robin Satow, Derek Stickler, Ken Stott, Charles Taylor, David Taylor, Keith Wallis, Guy Watt, Michael Wemyss, Helen Whitney Mclver, John Workman OBE, and Richard Worrell. References to many of them are made in the text. For useful com ments and editorial assistance throughout I thank Jenny Claridge. Literature of earlier years, particularly for the purpose of describing the few British examples of alternative silvicultural systems, indicated some con fusion in their classification. Professor Matthews’s admirable text (1989) effected clarification, and with his permission and that of Clarendon Press, Oxford his classification and descriptions of systems have been followed. The courtesy and assistance thus extended has enabled this Bulletin to benefit from a sound base on which to record past and present and suggest potential relevant practices in Britain. Nonetheless, readers will benefit by study of Professor Matthews’s text as well as those of Evans (1988) and Kerr and Evans (1993). Information gained by membership of the Continuous Cover Forestry Group, inaugurated in 1991, and from the Edinburgh University database on examples of irregular silvicultural systems in Britain is warmly acknowl edged. Profound thanks are recorded to the owners and/or their foresters of many private sector woodland stands visited; also to managers of Forest iii Enterprise’s relevant forest stands, where my visits have been welcomed and proved rewarding to me. I not only ended up with many friends but with a very large number of obligations. This Bulletin is written for landowners and foresters who wish to convert all or part of a wood or forest from pure, regular, uniform, even-aged stands to mixed, irregular, uneven-aged stands - in particular for those who desire to use silvicultural systems alternative to that of extensive clear cutting, with a view to achieving diverse structure leading to biological diversity and semi-perma- nent or continuous forest cover. The information provided can be adopted to suit individual owners’ or foresters’ own constraints and objectives. Other aims are to draw attention to what has been achieved in Britain, and the opportunities for further attempts, and to highlight the need for further research, trials and demonstration areas. A few of the plates were taken by myself; others were taken by my son, Anthony, and by friends in the forestry world; the remainder were selected from the Forestry Commission’s photographic library. Permission of John Matthews CBE (Emeritus Professor, University of Aberdeen), David Paterson and Chris Quine to include certain tables (amended) is gratefully acknowl edged: the sources are recorded in appropriate places in the text. Cyril Hart 1995 Foreword Compared with much of Europe, British forestry has largely been dominated by just one silvicultural system in recent decades, viz. clearfelling and replant ing. There are sound silvicultural reasons for this, in particular the windiness of our upland climate. Nevertheless, today, there is increasing interest in extending rotation lengths and in diversifying forest structure which, along with greater attention to lowland woods, create more opportunities for alter native silvicultural systems. This Bulletin draws together experience in Britain with many different types of silviculture which have been tried out or practised during the present century. I hope foresters, woodland owners, and all those interested in the management of Britain’s woodlands and forests will find the assemblage of experience of considerable use. The Forestry Commission is deeply indebted to Dr Cyril Hart OBE for bringing together, analysing and synthesising experience with these alterna tive silvicultural systems from all parts of the country. This task has not been easy and the Forestry Commission is most grateful that the job has been undertaken by one so eminent. I hope that readers will find the text itself informative and interesting and the plates instructive of the different kinds of silviculture discussed. Each detailed account of individual woods and the silvicultural system practised is headlined in colour. It is these descriptions, brought together for the first time, which are at the heart of this Bulletin and, I believe, will make it such an invaluable reference work in the future. T.R. Cutler CBE Director General Forestry Commission June 1995 Contents Page Acknowledgements iii Foreword v List of plates viii Summary x Resume xi Zusammenfassung xiii Resumen xiv 1 Diverse woods and forests: the role of silvicultural systems 1 Introduction 1 Alternative silvicultural systems to clear cutting 2 Preparatory work in conversion 5 2 Shelterwood systems 6 Introduction 6 Use in Britain: broadleaves 8 Uniform shelterwood 8 Group shelterwood 10 Use in Britain: conifers 12 Uniform and group shelterwood 12 Conclusions on shelterwood systems 14 3 The group selection system 17 Introduction 17 Use in Britain: broadleaves 17 Use in Britain: conifers and mixed stands 25 Conclusions on the group selection system 35 4 The single tree selection system 39 Introduction 39 Application on the Continent 39 Use in Britain 41 Conclusions on the single tree selection system 44 5 Other silvicultural systems 46 Two-storied high forest 46 High forest with reserves 48 Coppice and coppice with standards 49 Restructuring extensive conifer forest by patch clear cutting 50 VI Restructuring beechwoods by (mainly) group regeneration 52 Conclusions on other silvicultural systems 53 6 The economics of irregular forestry 54 Introduction 54 The single tree selection system 55 The shelterwood uniform and group systems 56 The economic justification of uneven-aged and continuous forest cover 56 Conclusions on the economics of irregular forestry 57 7 Influence of environmental factors on alternative silvicultural systems and conversion 58 Effect of wind 58 Effect of damaging mammals 60 Deer 60 Grey squirrels 61 Effects on landscape 61 Impact on nature conservation 62 Effect on recreational potential 63 Conclusions on the influence of environmental factors 63 8 Conclusions: resources and benefits, opportunities and recommendations 64 General 64 Experience in Britain 65 Opportunities in Britain 65 Conversion 68 Summary of benefits of alternative systems 69 Environmental benefits 69 Silvicultural benefits 69 Management economics of alternative systems 70 Postscript 71 References 72 Glossary 1 Definition of terms 78 Glossary 2 Scientific names and authorities of the main English names used in the text 80 Appendix 1 Classification of silvicultural systems 81 Appendix 2 Summary of factors to consider in choosing