Vegetasjon og naturgrunnlag i Tveitaneset Naturreservat, Rogaland

Abstract

Tveitaneset, an exposed point in Nedstrandsfjorden, Rogaland county, was in 1977 protected by law due to the occurrence of oceanic evergreen forests typical of the district. The bedrock consists of mica schist, but without especially high calcium content; the flora is therefore dominated by mainly oligotrophic species. The climate is humid, with a yearly precipitation of about 1751 mm and a favourable combination of high summer temperatures (slightly above 16oC in July) and mild winters (January mean temp. above 0oC). Along a dry-wet gradient, plant communities either belonging to or closely related to the following pine forests are found. Cladonio-Pinetum (and a moss-dominated variety), Barbilophozio- Pinetum, Vaccinio-Pinetum, and Vaccinio uliginosi-Pinetum. The community names refer to Kielland-Lund (1973). Lack of differential species makes an exact phytosociological determination difficult. This is a problem often met with in Western Norway. The seashore mainly consists of exposed cliffs, with an interesting transition through boulder and stone shores to a small sand beach in the bay east of Tveitaneset. Amongst the total of 91 species of vascular plants found are Circaea intermedia, Goodyero repens, and several oceanic or suboceanic species llke Ilex aquifolium, Blechnum spicant, Erica tetralix, Carex binenis, Narthecium ossifragum.