Drought survival test of eight fen moss species

Eight fen moss species (Aulacomnium palustre, Bryum pseudotriquetrum, Calliergonella cuspidata, Campylium stellatum, Climacium dendroides, Hamatocaulis vernicosus, Plagiomnium elatum and Tomentypnum nitens) were studied in order to assess their ability to survive long-term drought. The mosses differed significantly in their desiccation resistance. The highest survival rate was shown in the hummock moss species Climacium dendroides, Aulacomnium palustre and Tomentypnum nitens, with more than 10 of stems surviving after 20 weeks of desiccation. On the other hand, in Campylium stellatum and Plagiomnium elatum, almost no stem survived after 6 weeks without water supply. The remaining mosses (Hamatocaulis vernicosus, Calliergonella cuspidata and Bryum pseudotriquetrum) showed medium desiccation resistance, which differed little among species. After 12 weeks of desiccation, less than 10 of their stems were able to restore their growth. In general, most species displayed remarkable desiccation resistance, unexpected for species from permanently wet fen habitats.