Immediate responses in soil chemistry, vegetation and ground beetles to soil perturbation when implemented as a restoration measure in decalcified sandy grassland

Abstract

The species-rich calcareous grassland communities in Europe are gradually disappearing due to lack of management such as grazing or cultivation, resulting in decalcification and reduction of gaps in the vegetation. In this study, experimental soil perturbation (deep and shallow) was performed in degenerated sandy grassland in plots with a size of 8 9 8 m, using a randomised block design. The hypothesis that soil perturbation that inverts the soil layers decreases nutrient availability, creates vegetation gaps and thereby selects for desirable species was tested through comparisons with untreated controls as well as with nearby target habitats. The deep perturbation was designed to bring CaCO 3 up to the surface, whereas the shallow perturbation tested the effect of disturbance alone. The effects of soil perturbation on soil chemistry, vegetation and beetle communities were analysed for the 2 years following the treatments. Increased pH and calcium concentration, and decreased nitrogen and phosphorus availability, showed that deep perturbation was successful in restoring the soil chemistry to levels similar to those of the target habitat. Perturbated plots were rapidly colonised by the acid tolerant grass Corynephorus canescens, but the slow colonisation of the threatened calcicole species Koeleria glauca was an indication that the vegetation could be evolving towards the target vegetation. Six red-listed beetle species associated with open, dry grasslands were found, out of which four were found only in perturbated plots, although this could not be statistically tested. In conclusion, it may take many years or even decades for the establishment of desirable flora, and seeding could therefore be a suitable method of increasing the rate of succession.

Soil disturbance as a restoration measure in dry sandy grasslands

“…In addition, Sutherland (1992, 1994), Jones et al (2010) andÖ dman et al (2011) found that soil disturbance could increase the pH in the top-soil by bringing up CaCO 3 from the lower soil layers. However, top-soil removal seems to be the most successful method for increasing the CaCO 3 concentration of the top-soil by simply removing the decalcified soil (Olsson and Ö dman unpublished results).…”

“…Several studies have been published on their diversity and possible restoration, in particular in Germany and Sweden (e.g. Röder and Kiehl 2006;Kiehl and Pfadenhauer 2007;Eichberg et al 2010;Schnoor and Olsson 2010;Ö dman et al 2011). In Sweden for example, less than 50 ha of xeric sand calcareous grasslands remain (Olsson 1994;Tyler 2005).…”

“…It is recognised that soil disturbance and removal can be a successful restoration measure for sandy types of dry grasslands (Eichberg et al 2010;Faust et al 2011;Jentsch et al 2009;Ö dman et al 2011). This review focuses on anthropogenic soil disturbances such as rotovation (breaking up the soil), ploughing, sod-cutting, deep soil perturbation and top-soil removal, and their usefulness as restoration measures with respect to their effects on the soil nutrient content, the CaCO 3 content of the top soil and the vegetation of sandy grasslands.…”

Natural Establishment of Specialist Plant Species after Topsoil Removal and Soil Perturbation in Degraded Calcareous Sandy Grassland

“…A number of restoration methods, such as topsoil removal, sod cutting, and soil inversion have been implemented to restore abiotic conditions suitable for high diversity and threatened species in semi‐natural calcareous grasslands (Dolman & Sutherland ; Kiehl & Pfadenhauer ; Schnoor & Olsson ; Ödman et al ). The responses of specialist species to different kinds of disturbance must be better understood in order to preserve disturbance‐driven biodiversity and to improve our understanding of the dynamics in vegetation processes (Chapin III et al ).…”

“…We manipulated soil in two degraded sand steppe grassland areas in Sweden: the Lyngsjö site, where acidification has been identified as the driving factor behind sand steppe degradation (Mårtensson & Olsson ; Ödman et al ) and the Everöd site where eutrophication was suspected to be the driving factor behind sand steppe degradation (Olsson et al ). Topsoil removal was performed at three sites in the Everöd area in order to restore nutrient poor conditions, and soil perturbation was performed at the acidified Lyngsjö site in an attempt to restore a lime‐rich habitat by bringing up lime‐containing sand from deeper soil layers.…”