Tufa algae and biological karstification at Huanglong,Sichuan

To gain a clear idea of biogenic origin in the development of tufa at Huanglong, Sichuan Province, the tufa algae samples are identified and analyzed in the paper. Meanwhile, it probed into the role of tufa algae in the biological karstification at Huanglong. The results show that there are86 species, varieties and forms, belonging to 19 genera and4 phylum, the dominant genera are Tolypothrix, Gloeocapsa and Cymbella. In different environmental area at Huanglong, there are different dominant algae. The role of tufa algea in the precipitation of carbonate isn’t the same at different karst landscapes. The carbonate precipitation which cyanophyta (cyanobacteria) participate in is primarily contributing to the formation of tufa rimstone. The carbonate precipitation which diatom participates in is primarily contributing to the formation of tufa slope. Besides the carbonate precipitation, algae will also corrode the tufa landscapes. Under the situation of longtime lacking karst water, the destructive effect of tufa algae is especially serious, so tufa landscapes at Huanglong is urgently need defense and treatment.