Observations on 16 years of microfloral recolonization data from limestonesurfaces, Aldabra Atoll, Indian ocean: Implications for biological weathering

A richmicroflora community (or biofilm) dominated by cyanobacteria coats mo st exposed rock surfaces (in both marine and terrestrial environments) in t he tropics. Such biofilms are thought to play a role in weathering, crust f ormation and nutrient cycling. An initial, short-term study (1982-83) of mi crofloral colonization on 0.1 x 0.1 m cleared plots on Quaternary reef lime stones on Aldabra Atoll revealed considerable variability in colonization r ates, with wetter sites and soft er rocks prone to more luxuriant growths. This paper reports on further studies of colour, biomass and effects of the developing microfloral communities from almost 100 out of the c. 300 origi nal plots which were revisited in 1998. Many sites still show limited colon ization Where a microfloral community has re-established, weathering effect s are notable and consistent with those found on surrounding rock. Copyrigh t (C) 2000 John Wiley & Sons, Ltd.