Soils and earthworms as a final chapter in the narrative of a steelworks

Abstract

Hallside steelworks, South Lanarkshire, Scotland, employed thousands of people and constructed rails and ships for over a century, before this successful industry closed in the 1970s. The site, south-east of Glasgow, was then reclaimed from dereliction during the 1990s to produce biomass through Short Rotation Coppice (SRC) of willow trees (Salix spp.). On site, the contaminated soil was removed, and a rudimentary substrate created with a mixture of sewage sludge and colliery spoil, the latter moved from nearby tips to release land for housing. Trees were planted and earthworms (Annelida) added to potentially assist growth. Initially recognised as a flagship for reclamation, the site was then abandoned. In 2018, information was gathered on the development of soils and on earthworm communities. This was achieved by sampling across the 35 ha site below willow, other planted tree species and grassland. The results showed that reclaimed soils were very stony, compacted, resistant to water infiltration but relatively uncontaminated. Willow had grown, but coppicing had not occurred. Earthworm introduction was initially unsuccessful, but colonisation took place from adjacent unadulterated areas and 16 species from three ecological groups were recorded. Mean community density was 208 ± 18.1 earthworms m-2 with a mean mass of 71 ± 6.1 g m-2. Type of vegetation cover had a significant (P <0.05) effect on community density and biomass. The site is now used for recreation and is an effective greenspace close to Glasgow.