From deforestation to blossom: Large-scale restoration of montane heathland vegetation

Land-use change and atmospheric nitrogen deposition have negatively affected heathlands with severe consequences for biodiversity. One possible way to counteract these negative impacts can be habitat restoration. The aim of this study was to evaluate the success of montane heathland restoration on former spruce forests using vascular plants as indicators. We compared the three following land-use types (i) grazed montane heathlands, (ii) grazed restoration sites on former spruce forests where seed transfer has been applied, and (iii) ungrazed clear-cuts of spruce forests. Four to five years after restoration each land-use type was according to an indicator species analysis characterised by different indicator species. Despite the short time period since the implementation of the restoration measures and many similarities in plant species assemblages between restoration and clear-cut sites, Calluna vulgaris had vigorously established on restoration sites with a mean cover of nearly 20%, whereas it was largely absent at clear-cut sites. In addition, there was a clear trend that plant assemblages of restoration and clear-cut sites become more clearly separated. The cover of non-target species significantly increased at clear-cut sites and the cover of C. vulgaris remained extremely low. The conducted restoration measures are able to initiate the establishment of typical montane heathland vegetation on former spruce forests. However, restoration of the complete plant assemblage would require additional sod transplantation as both Vaccinium myrtillus and V. vitis-idaea mainly depend on vegetative regeneration. Furthermore, topsoil removal of the most nutrient-rich parts would be necessary to counteract the encroachment of Cytisus scoparius.