Algae, Fungi, and Lichens on Inselbergs

Büdel B., Becker U., Follmann G. & Sterflinger K.
In: Porembski S. & Barthlott W. (eds), Inselbergs. Ecological Studies, vol. 146
p. 69–90, Springer, Berlin, Heidelberg
Chapter in book. [Conclusion: ] It is not clear whether the biofilms of the bare rock of inselbergs are old communities, but there are many reasons to believe so. First of all, cyanobacteria are the oldest organisms on earth, possessing oxygenic photosynthesis, which, in many species, is combined with the ability to fix atmospheric nitrogen. The second is the ability of cyanobacteria, as well as of cyanolichens, to withstand long periods of drought in a dehydrated state, showing no measurable signs of activity or energy consumption. Since the discovery of Taylor et al. (1995), we know that cyanolichens are at least 400 Ma old. It might therefore have well been that cyanolichens, together with cyanobacteria, dominated rock surfaces for a long period of time before they became out-competed by more efficient eukaryotic photosynthesizers. As a result, we find them today in habitats which are not convenient for modern algae, mosses, and higher plants. Ancient cyanobacteria and cyanolichens, with their ability to weather rock, might have contributed to soil formation, a necessary step in accommodating larger terrestrial plants. Many rock faces which are thought to be completely bare of life are thought to be extreme in conditions for life; but they are not naked; instead, they are inhabited by a community of historically "old" primary producers, of which we do not know how much they contribute to the Earth's CO2 sink. The discovery of new species shows us that even the species number of the biofilms and the vegetation patterns are only poorly understood. Further investigations will focus on this topics. In the present work, we have tried to give a first overview on species composition and ecology of biofilms of rocks on inselbergs, and with this we hope to bring the vividly living community to the awareness of the readers.
Thursday, 20 June 2024 09:45