§ Dr. David Clarkasked the Secretary of State for the Environment what evidence he has about the effect of air pollution on the vitality of British conifers.
§ Mr. WaldegraveThe Forestry Commission has been conducting annual surveys of forest tree health and has recently published the findings of its 1986 survey. This 235W suggests a worsening of tree condition, but I understand that there is no firm evidence that points to a cause such as air pollution as distinct from other factors such as climate, or the depredations of insects or fungi. The Forestry Commission and my Department are continuing their research to further the understanding of the roles played by climate, soil factors and pollutants and their interaction in tree health. In consultation with the NCC and other interested bodies, further extension in terms of species and areas covered are being planned for 1987.