Abstract

Often, A. & Mjelde, M. 1999. Nyoppdaget masseforekomst av høstvasshår Callitriche hermaphroditica i Rendalen. Blyttia 57: 30-35.
A mass occurence of Callitriche hermaphroditica in Rendalen, Hedmark

A large population of Callitriche hermaphroditica is reported from Lomnessjøen, Rendalen municipality, Hedmark county, south Norway. The species is common along approximately 3 km of lake-shore down to at least 0.7 m depth. Co-dominating species are Myriophyllum alternifolium, Potamogeton perfoliatus, Ranunculus aquatilis and Nitella opaca. C. hermaphroditica is rare in south Norway, with a total of 16 recorded sites. In 1998 the population in Lomnessjøen is possibly the single extant population in south Norway. On three well investigated sites (Jarenvatn, Steinsfjorden, Juveren) C. hermaphroditica is possibly extinct as a result of water quality changes combined with invading stands of Elodea canadensis.

Anders Often, Norges Landbrukshøgskole, Institutt for biologi og naturforvaltning, boks 5014, N-1432 Ås
Marit Mjelde, Norsk institutt for vannforskning, boks 173 Kjelsås, N-0411 Oslo

Blyttia 57(1)
Blyttias hjemmeside
Lagt ut 14.7.1999 Jan Wesenberg