Short-term effects of Salix plantings and seeding of Festuca ovina on vegetation recovery in a disturbed alpine heathland in the Dovre Mountains, Norway

Abstract

Alpine ecosystems are particularly vulnerable to anthropogenic disturbances and have a slow natural recovery rate. Open questions remain as to which forms of active restoration measures could accelerate alpine ecosystem recovery from severe disturbances. This study evaluated the short-term effects of two restoration treatments – planting of propagated Salix shrubs in three different densities (1, 2.5 and 4 plants/m2) and seeding of the grass Festuca ovina – on vegetation recovery in a disturbed alpine heathland in the Dovre Mountains, Norway. In addition, the relationships between soil moisture and vegetation recovery, and between soil substrate and vegetation recovery were investigated. Measurements were obtained in permanent monitoring plots, five years after implementation of the measures. Results showed that the effectiveness of the restoration treatments depended on the metric used to assess vegetation recovery. Salix plantings with higher densities had a higher naturally recovered vascular plant diversity and a higher Salix recruitment but the plantings did not affect naturally established vegetation cover. Seeding of F. ovina resulted in a higher bottom and field layer cover but did not affect vascular plant diversity. Vegetation recovery was positively related to soil moisture and fine soil substrate. Exploratory aerial photography suggested that the large-scale revegetation pattern in the study site was linked to artificially created topography. If the outlined restoration goal is to increase both vascular plant diversity and vegetation cover, this study suggests that planting and seeding might be used complementary to each other and in conjunction with improving soil water retention capacity and creating artificial relief.