Effects of topsoil removal as a nature management technique on soil functions

We studied the effect of topsoil removal, a nature management technique used in The Netherlands and other countries in North Europe to restore heathland vegetation. Sandy soils under original heathland vegetation were compared with sites that were transformed to farmland in 1950 and sites where after the transformation topsoil removal took place in the 1990s. All soils were sandy and acidic. Topsoil removal led to an 88–94% reduction in the C storage. Therefore, the C storage and the buffer function of the soils have drastically decreased. The N and P storages in the soils where topsoil was removed have also greatly reduced. In the topsoil removed soils no re-colonization of earthworms had occurred and microbial activity has significantly reduced. The soil biological properties were similar between the reference site and the topsoil removed soils. The high bulk density and the typical abiotic soil structure are most likely the results of a combination of management using heavy machinery and no recolonization by earthworms. These changes in soil properties negatively influenced several soil functions which are relevant in nature and environmental protection, e.g. C-storage, filtering and buffering. We therefore conclude that removal of topsoil cannot be recommended as a nature management technique due to its negative effects on soil quality.

► The long term effects of topsoil removal on soil functions were studied. ► It leads to a decline in Corg, CEC, and biological activity and an increase in soil density. ► Soil carbon storage, habitat, buffer and filter functions are strongly affected. ► We do not recommend this for nature management due to a strong decline in soil quality.