A common approach to the conservation of farmland biodiversity and the promotion of multifunctional landscapes, particularly in landscapes containing only small remnants of non-crop habitats, has been to maintain landscape heterogeneity and reduce land-use intensity. In contrast, it has recently been shown that devoting specific areas of non-crop habitats to conservation, segregated from high-yielding farmland ("land sparing"), can more effectively conserve biodiversity than promoting low-yielding, less intensively managed farmland occupying larger areas ("land sharing"). In the present paper we suggest that the debate over the relative merits of land sparing or land sharing is partly blurred by the differing spatial scales at which it is suggested that land sparing should be applied. We argue that there is no single correct spatial scale for segregating biodiversity protection and commodity production in multifunctional landscapes. Instead we propose an alternative conceptual construct, which we call "multiple-scale land sparing," targeting biodiversity and ecosystem services in transformed landscapes. We discuss how multiple-scale land sparing may overcome the apparent dichotomy between land sharing and land sparing and help to find acceptable compromises that conserve biodiversity and landscape multifunctionality.

The spatial distribution of organic soil nitrogen (N) in alpine tundra was studied along a natural environmental gradient, covering five plant communities, at the Latnjajaure Field Station, northern Swedish Lapland. The five communities (mesic meadow, meadow snowbed, dry heath, mesic heath, and heath snowbed) are the dominant types in this region and are differentiated by soil pH. Net N mineralization, net ammonification, and net nitrification were measured using 40-day laboratory incubations based on extractable NH 4 + and NO 3 À . Nitrification enzyme activity (NEA), denitrification enzyme activity (DEA), amino acid concentrations, and microbial respiration were measured for soils from each plant community. The results show that net N mineralization rates were more than three times higher in the meadow ecosystems (mesic meadow 0.7 mg N g À1 OM day À1 and meadow snowbed 0.6 mg N g À1 OM day À1 ) than the heath ecosystems (dry heath 0.2 mg N g À1 OM day À1 , mesic heath 0.1 mg N g À1 OM day À1 and heath snowbed 0.2 mg N g À1 OM day À1 ). The net N mineralization rates were negatively correlated to organic soil C/N ratio (r = À0.652, P < 0.001) and positively correlated to soil pH (r = 0.701, P < 0.001). Net nitrification, inorganic N concentrations, and NEA rates also differed between plant communities; the values for the mesic meadow were at least four times higher than the other plant communities, and the snowbeds formed an intermediate group. Moreover, the results show a different pattern of distribution for individual amino acids across the plant communities, with snowbeds tending to have the highest amino acid N concentrations. The differences between plant communities along this natural gradient also illustrate variations between the dominant mycorrhizal associations in facilitating N capture by the characteristic functional groups of plants.

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.

Severely disturbed habitats such as military training grounds, gravel pits and sand pits contribute to the species diversity of the agricultural landscape in Europe. They host a number of red-listed species not found elsewhere, illustrating that many plant species are threatened by extinction due to too little soil disturbance. Implementing a suitable disturbance regime is therefore crucial to ensure species-rich environments. We have reviewed the literature on soil disturbance as a restoration measure in dry sandy grasslands, with a special focus on xeric sand calcareous grasslands as these are severely threatened. Our objective was to elucidate the relations between diversity and disturbance regimes, and to determine how disturbance can be used to counteract acidification, to reduce nutrient availability and to create gaps in the vegetation. Our findings indicate that the current disturbance regime should be based on the historical disturbance regime, the productivity of the habitat and the propagule supply, in order to promote diversity at a landscape scale. Based on earlier studies and on the diversity/disturbance theory, we propose a conceptual model that can be used to determine the appropriate soil disturbance regime for restoration purposes. Our analysis highlights the importance of considering soil productivity, soil chemistry and dispersal limitations when choosing restoration measures and disturbance regimes for the conservation of biodiversity.

Specialist plant species in calcareous sandy grasslands are threatened by acidification and high nutrient levels in the topsoil. We investigated whether topsoil removal and soil perturbation in degraded sandy grasslands could lead to establishment of specialist species belonging to the threatened xeric sand calcareous grassland habitat. Restoration actions performed in 2006 resulted in increased soil pH and reduced nitrogen availability. We found early colonisztion of the perennial key species Koeleria glauca after both deep perturbation and topsoil removal, and high seedling establishment in topsoil removal plots 5 and 6 years following the restoration treatment (2011-2012). After topsoil removal, overall vegetation composition in 2012 had developed toward the undegraded community, with target species accounting for 20% of the community after topsoil removal, compared to 30% in the undegraded vegetation, and less than 1% in untreated controls. Deep perturbation led to 7% target species, while there were almost no effects of shallow perturbation 6 years following treatment. These results demonstrate that topsoil removal can promote colonization of target species of calcareous sandy grassland and highlights the importance of considering the regeneration niche for target species when implementing restoration measures.