§ Mr. Simon HughesTo ask the Secretary of State for the Environment what recent assessment he has made of the effect of acid deposition on trees; what percentage of trees he estimates are(a) dying from (b) otherwise affected by acid deposition; and if he will make a statement.
§ Mr. Heathcoat-Amory[holding answer 24 April 1990]: The Forestry Commission has carried out a national monitoring programme of annual tree health surveys since 1984. In 1989, tree health showed an overall improvement for the second year running.
A study of the effects of air pollution, including acid deposition, on trees was carried out for the Department by the United Kingdom terrestrial effects review group (TERG). The report was published in July 1988 and copies placed in the Library of the House. It concludes that there is as yet no direct proof that air pollution is damaging trees in the United Kingdom, but that some forests are subjected to pollution climates which may be expected to cause stress.
Further laboratory and field study data, including information from the Forestry Commission's programme, have become available since the publication of the TERG report which may enable more precise conclusions to be drawn. The Department has therefore set up a sub-group of TERG specifically to evaluate this new information. The group will report in January 1991.