Charophytes from the warm springs of Svalbard

Abstract

Two of Svalbard' Trollkjeldane (Troll Springs) have a luxuriant vegetation of charophytes. This article is based on material collected in the Trollkjeldane by Sissel Aarvik, of the Office of the Sysselmann (Governor) of Svalbard, on 28 August 1992 and 16 August 1993. Chara canescens is described, based on living material. The Svalbard specimens have been named Chara canescens f. spitsbergensis comb. nov., which is synonymous with Chara aspera f. spitsbergensis Nordstedt. An imperfect charophyte is described here as a new subspecies of C. canescens: Chara canescens subsp. hoelii, named after Adolf Hoel, who first collected specimens of this subspecies. It is believed that this subspecies originates from Chara canescens, presumably by a genetic reorganization or a mutation of the species. A new subspecies is justified because of the ecorticate internodes, the incomplete or lacking cortex of the branchlets, the occurrence of accessory branchlets and the special bulbils found in this taxon. These are interpreted as characteristics with positive selective value in the special environment of the spring, where asexual reproduction by bulbils presumably has the same selective value as the parthenogenic reproduction by oospores in Chara canescens f. spitsber- gensis.In a growth experiment, the best growth of C. canescens f. spits- bergensis from the springs was obtained in water with relatively low salt content.Growing tourism in Svalbard threatens to the springs; more active protection must be evaluated. There is also an urgent need to survey the springs in more detail.