Woodland regeneration in a coastal heathland area in central Norway

Abstract

The open coastal heathlands in Norway have changed character in recent decades, mainly because traditional practices such as burning, cutting and grazing have been abandoned or reduced. In a project aimed at increasing our knowledge of woodland regeneration in oceanic boreal heathlands, an area on the island of Kalvøya in the archipelago of Vikna on the extreme outer coast of central Norway has been studied. Kalvøya has calcareous bedrock; rich heath, rich fens and low-herb woodland cover 20% of the island. Large parts are paludified, and wet heath and mire vegetation cover 60%. The island has not been inhabited, but it was used for summer farming in the latter part of the 19th century and later for stock grazing. The woodland and scrub were mapped using aerial photographs from 1961 and 1981 and by fieldwork in 2001. Vegetation changes were analyzed using GIS techniques. Woodland and scrub increased from 3. 0% in 1961, to 4.3% in 1981, to 11.6% in 2001. Betula pubescens is the commonest woody species. The oldest trees are 150 to 175 years old, growing in the most heavily wooded area, far away from the summer farm. In addition to human impact (summer farm, grazing pressure), the geology, terrain (degree of exposure), and climatic factors are important for woodland colonisation and distribution.

Landscapes Lost? Tourist Understandings of Changing Norwegian Rural Landscapes

“…This development put an end to outfield resource utilization, and led to the abandonment of many farms along the coast and in the mountains that were not suitable for large-scale farming (Barlindhaug, Holm-Olsen, & Tømmervik, 2007; Daugstad, Rønningen, & Skar, 2006;Norderhaug, 2008). This led to large-scale spontaneous reforestation of these previously cultivated areas, with scrubs, bushes and trees popping up in areas where they were previously kept down by humans or animals (Bryn & Debella-Gilo, 2011;Fjellstad & Dramstad, 1999;Moen, Nilsen, Aasmundsen, & Oterholm, 2006;). The process of reforestation is generally assessed negatively in Norwegian public debate; with the destruction of visually appealing landscapes as well as the loss of biodiversity as the most frequently mentioned arguments.…”

Rule-based GIS-modelling for management purposes: A case study from the islands of Froan, Sør-Trøndelag, mid-western Norway

“…Moreover, increased nitrogen downfall from polluted acid rain has been reported to change the species composition within the coastal Calluna heaths of northern Europe (Power et al 1995;Terry et al 2004), and specifically registered as increasing the distribution and density of Molinia caerulea. This does not seem to be the case in Froan, and Molinia caerulea has not yet been registered in Froan (Moen et al 2006b;Bryn 2008a). Moreover, the last decades of industrial legislations to hinder acid rain have actually reduced the nitrogen pollution over Norway during recent years (Strand et al 2005), although the long-term response of reversed pollution is still unclear (Terry et al 2004;Holden et al 2007).…”

“…For most factors the modelling builds on a large number of baseline ecological studies from coastal heath ecosystems (e.g. Moen et al 2006b;Critchley et al 2008;Måren 2009). The effects on vegetation regeneration of soil humidity, sheep grazing behaviour and exposition, however, were more uncertain.…”

“…During recent decades human use of the heaths has declined in Norway (Christensen 2002;Almås et al 2004). The coastal heath habitat has diminished and forests have expanded, both as a result of forest plantations and natural forest regeneration (Moen et al 2006b;Øyen 2008;Bryn 2009). These processes will continue and the GIS-models introduced in this article illustrate the potential for vegetation change and the relative management needs in different localities given three different near-future development options in a landscape dominated by coastal heaths.…”

“…Many efforts have been made to map, analyse, model, and monitor shrub encroachment and reforestation, as well as the effects of different restoration regimes in European heath ecosystems (Degn 2001;Manning et al 2005;Moen et al 2006b). There have also been studies of the ecological responses of Calluna heaths under different regimes of sheep grazing (Read et al 2002;Mitchell et al 2008) and periodic burning (Nilsen et al 2005;Mohamed et al 2007;Måren 2009).…”