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

Abstract

The coastal heath region along the western coast of Norway, dominated by Calluna vulgaris, is undergoing rapid change. Vegetation changes are caused by changes in management, including reduced frequency or abandonment of periodic heath burning and reduced cutting and grazing. The islands of Froan, in the outermost part of Sør-Trøndelag County in mid-western Norway, are dominated by coastal heath in a state of recession due to reduced traditional land use. The coastal heath is acknowledged as vulnerable and valuable by national environmental authorities, and local landscape management is supported by different national subsidies. The authors mapped the vegetation on Froan and used rule-based GIS-modelling to predict the relative potential for future vegetation changes. The model was based on a range of map layers, including management themes such as history of heath burning and peat removal, current practices of sheep grazing, and also themes derived from the vegetation map, such as soil nutrients, soil moisture and present management status. The resulting model output provides relative probabilities of future changes under different land-use scenarios, and highlights where management efforts should be focused in order to maintain the traditional landscape character.

Keywords:

• coastal heath
• cultural landscape
• rule-based GIS-modelling
• management
• vegetation mapping

Acknowledgements

We thank Svein Frisvoll, Katrina Rønningen, Michael Angeloff, Geir-Harald Strand, and the reviewers for valuable comments and technical assistance. The article was supported by the Research Council of Norway (project no. 177998/I10) and is a part of the scientific project ‘Froan-scenarier – Bruk av scenarier som verktøy for dialog, næringsutvikling og forvaltning i verna kystområder’ (Building scenarios as a tool for dialogue, business development and management in protected coastal areas (COAST-SCENES))’, administered by Bygdeforskning (Centre for Rural Research).

Notes

1. See also ‘GIS-based prognosis of potential forest regeneration affecting tourism destinations and cultural landscapes in south Norway’ by A. Bryn & M. Debella-Gilo, manuscript submitted to Scandinavian Journal of Tourism and Hospitality.

2. The three maps are available for download from the Internet (www.skogoglandskap.no).

3. See also Norwegian Research Council project 178209 by Ann Norderhaug ‘Feral sheep in coastal heaths – developing a sustainable local industry in vulnerable cultural landscapes’ (2007–2011). http://www.forskningsradet.no/servlet/Satellite?c=Prosjekt&cid=1193731621978&pagename=ForskningsradetNorsk/Hovedsidemal&p=1181730334233 (accessed August 2009).