Dead Wood Habitats

Dead wood habitat project

Since 2007, I have been working with my colleague David Hurst on a new method for the rapid assessment of dead wood habitat. Dead wood is well known as an important habitat for a diverse range of invertebrate species and as such is of great conservation value. Indeed, some 1800 British species are known to be dependant on wood decay processes (Alexander 2002). A large proportion of these are local or rare, and many are in decline in Britain and further afield (Kirby 2001) with few sites showing continuity of large volumes of dead wood, especially given woodland management’s tendency to ‘tidy up’ dead wood and ‘unsound’ trees (Fry & Lonsdale 1991). The three key factors in assessing dead wood habitat (DWH) are considered to be Diversity, Volume and Continuity.

Why was this methodology developed?

• Although known to be of considerable ecological importance, DWH is under-recorded.
• The amount and quality of DWH needed to support a diverse invertebrate fauna is widely and greatly underestimated.
• There was no standard method for assessing DWH. To survey the invertebrate fauna directly is time-consuming, requires considerable specialist expertise, and is often prohibitively expensive. It is limited to certain times of year and may be undesirably destructive to the habitat. The approach where fallen timber volume is calculated using line transects misses most dead wood and is felt to be of limited practical value.

Therefore, it was desirable to develop a method that was quick, cheap, inclusive of a wide range of dead wood types, usable by non-specialists and able to be undertaken at any time of year. No specialism is required, simply reasonable observational and recording skills and at least a basic level of woodland knowledge. The output is based on a description of the current status of dead wood in the survey area and management recommendations designed to maintain or improve this.

The standard recording form is shown below and includes the dead wood categories used as well as the assessment scoring scheme.

We are also seeking funding to produce a nationally usable handbook for this method - if you can help, please do get in touch.

References

• Alexander, K.N.A. (2002). The invertebrates of living and decaying timber in Britain. A provisional annotated checklist. English Nature Research Reports 467. English Nature, Peterborough.

• Fry, R & Lonsdale, D. (1991). Habitat Conservation for Insects – a neglected green issue. Amateur Entomologists’ Society, Middlesex.

• Kirby, P. (2001). Habitat Management for Invertebrates: a practical handbook (2^nd edition). RSPB, Sandy.

My publications on this subject

• Hubble, D.S. & Hurst, D.T. (2007). Rapid dead wood habitat assessment. In Practice 56: 4-6.
• Hubble, D. & Hurst, D. (2007). A new dead wood habitat survey method. British Wildlife 18 (5): 324.
• Hubble, D. & Hurst, D. (2008). Rapid dead wood habitat assessment. Quarterly Journal of Forestry 102 (1): 29-34. 
• Hubble, D. & Hurst, D. (2008). Leave them where they lie. Tree News Spring/Summer 2008: 25-26.