HÅRNERVMOSSA I SANDSJÖBACKA NATURRESERVAT: Analys av hårnervmossans invasivitet på ljunghedens vegetationstyper

Abstract

Heath star moss (Campylopus introflexus) is an alien species in Sweden and is currently classified as composing a "very high risk” of becoming invasive in the country according to SLU, and has in several parts of the world taken over large areas in a short time. The moss is characterized by its preference for disturbed and burned land, something that occurs on the heathland in the Sandsjöbacka nature reserve, when burning for nature conservation purposes is carried out annually. Sandsjöbacka's heathland is a valuable ecosystem and is one of the few heathlands in a favorable condition that remains in Sweden after strong reforms in modern agriculture in the last century, which led to forest succession of these cultural environments. Heathlands are one of the most threatened environmental types in Europe, of which 95 % are estimated to have disappeared from Sweden since the 1800’s and around 200 red-listed species have been linked to the environment that heathlands offer, which means that heathlands need to be prioritized within nature conservation. C. introflexus is today established in the reserve and the question is the following: does the moss pose a threat to the heathland at the present time - and if so, is there any preferred type of vegetation that is particularly vulnerable to the invasion? By sampling random replicates from three commonly occurring vegetation types (heather type on shallow peat soils, heather type on moraine soil, Agrostis capillaris type) in Sandsjöbacka nature reserve, the frequency of heath star moss was calculated and in statistical analysis it could be deduced that there was a strong statistically significant difference for the Agrostis capillaris type compared to the two other vegetation types where the frequency of heath star moss on Agrostis capillaris type was significantly much lower. The null hypothesis could therefore be rejected, and the conclusion was drawn that C. introflexus poses no threat to grasslands (of Agrostis capillaris type), but for heather and heather peat no further conclusions can be drawn.