Eco-friendly Remediation of Lampenflora on Speleothems in Tropical Karst Caves

[摘要] This paper presents an experiment on lampenflora removal in show caves located in a tropical monsoon climate insoutheast Asia. Lampenflora thrive in wet conditions on surfaces directly illuminated by white light. They colonizedifferent levels in show caves, from the cave ceiling, with a biota characterized of mainly cyanobacteria (Oscillatoria,Spirulina), algae (Chlorella, Oedoclarium), and mosses (Cyathodium, Thuidium), to near the cave floor, with a morecomplex biota including higher plants like ferns (Asplenium) and flowering plants (Centella). Mature lampenfloramats also harbor non-phototrophic fungi and bacteria. With the use of environmental scanning electron microscopy,speleothem surfaces were found severely damaged by lampenflora and their associates. In this study, we used H2O2as an environmentally friendly chemical to exterminate lampenflora. The applied solution should be at least 15%H2O2 to efficiently destroy microbiota such as green algae, diatoms, and bacteria. For a complex community includingmosses, fungi, and vascular plants, repeated spraying of chemical and, if possible, water jet washing at carefullyselected places are required to recover the aesthetic characteristics of speleothems. Only a combination of suchcleaning practices, and then some modification of the illumination regime, can minimize lampenflora development inshow caves.

[学科分类] 地质学