The travertine flora of Juizhaigou and Munigou, China, and its relationship with calcium carbonate deposition

The flora of two large travertine deposits in Sichuan Province is described. Travertine compositions were similar to those of Europe, averaging 95% CaCO3 (low Mg-calcite). Travertines were covered in algae (mainly cyanobacteria and diatoms) and bryophytes. The most frequent cyanobacteria (N=15 species) were Calothrix and Dichothrix, and Achnanthes and Cymbella were most common among the diatoms (N=21). 68% of the algae have been reported from European travertines. Among the bryophytes (13 mosses, 3 liverworts), Cratoneuron, Fissidens and Gymnostomum were the most abundant, but only 50% of the species are known from European sites. Among the algae, close spatial relationship with the deposited calcite could be established only for Oocardium. In the mosses Bryum, Fissidens and Gymnostomum, parallels were established between the distribution of carbonate and leaf morphology, reminiscent of the intercellular calcification model for marine algae. The implications are discussed with reference to travertine formation on dams and cascades,