Effect of storage and reinstatement procedures on earthworm populations in soils affected by opencast coal mining.
Abstract
Earthworm populations were estimated in topsoil stored during opencast mining for coal and in replaced soil. Soil from the surface of storage heaps was replaced separately from that within heaps. One year after soil replacement and seeding, worm populations were measured at 'surface' and 'subsurface' heap sites on land subjected to normal replacement cultivation and on uncultivated field margins. Sampling was also carried out on a remaining section of stored soil. Populations were markedly reduced by storage, but numbers were sufficient to provide an inoculum in replaced soils. Soil spreading and levelling caused a further decrease in populations. Later site cultivations effectively eliminated any surviving earthworms. Where this cultivation was avoided, earthworms were found with greater frequency and in larger numbers in soil originating from the surface of heaps.