Forestry Statistics 2007 - Sources

Timber

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Background

The Sawmill Survey is an annual survey conducted by the Forestry Commission (in association with the Forest Service) of sawmills in the UK that are believed to use UK logs.

The survey, which previously covered sawmills in Great Britain only, was extended in 2004 to include sawmills in Northern Ireland. Figures for Northern Ireland in earlier years have therefore been estimated, based on responses to the 2004 survey.

The detailed survey has changed over recent years, both in terms of coverage and periodicity. For 1996 and earlier, detailed questionnaires were issued triennially to mills producing at least 1,000 m3 of sawnwood. From 1998 to 2004, the questionnaires were issued on a biennial basis to mills producing at least 5,000 m3 of sawnwood. From 2005, the detailed questionnaires have been issued annually, to mills producing at least 10,000 m3 of sawnwood.

Data collected

2 questionnaires are used for the Sawmill Survey:

  • a detailed questionnaire goes to around 50 mills that have annual production of at least 10,000 m3 of sawnwood, and
  • a short questionnaire to all other mills that are believed to take UK sawlogs (around 200 mills).

Both questionnaires collect information on:

  • the consumption of UK and imported logs,
  • the production of sawnwood and
  • (from 2006) sales to bioenergy.

In addition, the detailed questionnaire also collects information on:

  • the source of UK logs (England, Scotland, Wales or Northern Ireland),
  • sawnwood product markets,
  • other products and
  • sawmill employment.

Response rates

In 2006, detailed questionnaires were issued to 48 mills, of which 40 responded, giving a response rate of 83%. For the short questionnaire, 124 responses were received from the 216 forms issued, corresponding to a 57% response rate.

Sawmill Survey Response Rates (all questionnaires), 1997-2006

Year

Forms issued

Responses received

Response rate

1997

510

290

57%

1998

407

22555%

1999

40624460%

2000

374

193

52%

2001

260

172

66%

2002

28815052%

2003

26014355%

2004

26214756%

2005

25714356%

2006

26416462%

Methodology

Each year, figures for non respondents are estimated by rolling forward data from previous years for these mills.

Revisions

Results from the Sawmill Survey may be revised between the provisional figures published in the First Release UK Wood Production and Trade and the final data published in Forestry Facts and Figures and Forestry Statistics to take account of late returns and the results of additional data quality checking procedures.

All the main results (number of mills, consumption, production) are subject to revision annually, as information becomes available about mills opening or closing, or new information becomes available for previous non-respondents. The most common revisions are relatively small downward changes, but this can vary from year to year as special exercises are run to validate the survey population. Information about new mills opening can on occasion cause much larger upward revisions to softwood volumes, as in British Timber Statistics 2003. Results from the survey of larger mills, which provides more detailed information, are not normally revised.

Reporting

Statistics reported for each year are limited to mills that are known to use UK roundwood, but also include any imported logs used by these mills.

Tables for softwood are broken down by country (England, Scotland, Wales, Northern Ireland) and by size of mill. Given the low number of sawmills using UK hardwood, tables for hardwood are presented at a total UK level only.

The number of active mills is presented in tables 2.9 to 2.11.


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