Continuous cover silviculture

 

Summary

Continuous cover silviculture is based upon a presumption against clearfelling, the use of natural regeneration and the creation of a varied forest structure containing a range of species (Mason, et al., 1999; Mason and Kerr, 2004). Transformation is the process of increasing within-stand structural diversity in even-aged forests and in many cases will lead to conditions favouring continuous cover.

Continuous cover silviculture has recently become important due to a number of factors, such as the Rio-Helsinki process, the requirements of certification and an international movement favouring more natural forest management. All these factors began to change thinking about appropriate silvicultural systems for forests in Britain. Although many of the drivers for the transformation of even-aged forests to continuous cover are social and environmental, the production of timber will still be an objective.

This is resulting in a move away from the predominant silvicultural practice where even-aged stands of a few species are managed using the clearcutting system (Matthews, 1989) and the clearfelled areas are often 5-20 hectares or more in size.

The challenge is to provide a scientific basis and the associated technology transfer to help silviculture meet the demands of the rapid policy developments that have occurred over the past decade.

The aims of this research programme are thus to:

• Carry out research to increase understanding and improve practice of transformation and continuous cover silviculture in British forests
• Communicate with forest managers and scientists
• Examine the biological, environmental and economic implications of the increased use of continuous cover silviculture in British forests
• Ensure a balance of research and technology transfer that supports the requirements of the country strategies in England, Scotland and Wales
• Work with partners in the UK and abroad.

Research objectives

The medium term objectives are:

• Formulate and complete projects on:
  • Factors constraining the establishment (seed-seedling) and recruitment (seedling-sapling-tree) of natural regeneration
  • Operational aspects of transformation and continuous cover silviculture
• Develop decision support software for transformation and continuous cover silviculture
• Develop web pages that are an important source of information on transformation and continuous cover silviculture
• Hold a series of seminars to transfer key results to end-users
• Engage with other disciplines within Forest Research by organising one field-based workshop and a range of other contacts
• Establish a network of transformation experiments and demonstration plots of continuous cover silviculture.

Further information can be found on the respective projects pages.

Funders and partners

This research is funded by the Forestry Commission Alternative silvicultural systems for conifers programme and

EFORWOOD - Sustainability Impact Assessment of the Forestry-Wood Chain programme, under the EU “Global change and ecosystems “research activity of the Sixth Framework Programme..

Forestry Commission policy

Continuous cover silviculture is now being widely practised in British forests and it has been estimated that 5% of all Forestry Commission woodlands use it (Forestry Commission, 2003). There is no doubt that this percentage will increase because of policy developments. For example in Wales there is an objective to convert at least 50% of National Assembly woodlands to continuous cover over the next 20 years (National Assembly for Wales, 2003). In addition, the United Kingdom Woodland Assurance Scheme 2006 (UKWAS) requires forest managers to ‘increasingly favour’ CCF in windfirm conifer plantations and semi-natural woodland.

The Forestry Commission’s Science and Innovation strategy for British forestry (Forestry Commission, 2005) has recognised the changes outlined above and made ‘changing silviculture’ one of eight strategic research priorities.

Projects

Work in the programme is divided into a number of projects:

• Stand manipulation
  How to mange stands to achieve continuous cover
• Regeneration: establishment and recruitment
  Understanding the factors involved in regeneration
• Operational aspects
  Practical implementation of silvicultural prescriptions
• Risks of windthrow
  Improving existing models for application to continuous cover - a joint project with the Tree stability and climate change programme
• Decision support systems
  Guidance for forest managers
• Knowledge transfer
  Useful information and links.

See also Continuous cover forestry: social dimensions

A note on terminology

What is a silvicultural system?

The use of alternative silvicultural systems, such as shelterwood and selection, generally involve retaining some mature trees on the site during the regeneration phase. This approach is also known in Britain as Continuous Cover Forestry (CCF) which is defined in the UK Forestry Standard as the use of ‘silvicultural systems whereby the canopy is maintained at one or more level without clear-felling’.

The UK Woodland Assurance Standard audit protocol refers to ‘lower impact silvicultural systems’. These are synonymous, to all intents and purposes, with CCF.

Status

This programme is the result of a merger of the Alternative Silvicultural Systems (Uplands) and Alternative Silvicultural Systems (Lowlands) programmes.

This programme commenced in April 2006. Work will be reviewed after a three year period.

Contacts

Gary Kerr
Forest Research
Alice Holt Lodge
Farnham
Surrey GU10 4LH

Tel: 01420 22255
Fax: 01420 23653
Email: gary.kerr@forestry.gsi.gov.uk

The following people also work on the programme:

• Bill Mason, Head of Forest Management Division
• Colin Edwards, Project Leader
• Sophie Hale, Project Leader
• Duncan Ireland, Technical Development
• Victoria Stokes, Scientific support.

Team members work closely with colleagues in the Technical Services and other parts of Forest Research.

References

Forestry Commission (2003). Managing Continuous Cover Forests. Operational Guidance Booklet 7. Forestry Commission, Edinburgh.

Forestry Commission (2005). Science and innovation strategy for British forestry ^(PDF-2860K). Forestry Commission, Edinburgh.

Mason, B. and Kerr, G. (2004). Transforming even-aged conifer stands to continuous cover management ^(PDF-88K). Forestry Commission Information Note 40 (Revised). Forestry Commission, Edinburgh.

Mason, W.L., Kerr, G., Pommerening, A., Edwards, C., Hale, S.E., Ireland, D. and Moore, R. (2005). Continuous cover forestry in British conifer forests ^(PDF-616K). In Forest Research Annual Report and Accounts 2003-2004. The Stationery Office, Edinburgh, pp. 38-53.

Mason, B., Kerr, G. and Simpson, J. (1999). What is continuous cover forestry? ^(PDF-81K). Forestry Commission Information Note 29. Forestry Commission, Edinburgh.

Matthews, J.D. (1989). Silvicultural systems. Clarendon Press, Oxford.

National Assembly for Wales (2001). Woodlands for Wales: the National Assembly for Wales strategy for Trees and Woodlands. Forestry Commission, Aberystwyth.