Exciting first records of biological soil crusts in the Fynbos region

A recent paper published by C·I·B postdoctoral research associate, Dr Denise Mager and C·I·B researcher Dr Cang Hui investigated the presence of soil microbial communities in the Table Mountain National Park. Although biological soil crusts (BSCs) have colonised almost all habitats and soil types, these microbial communities were thought absent in the Fynbos biome due to soil acidity. However, a widespread formation of BSCs (covering up to 80 % of surface soil) was reported in the park, and also a significantly higher carbon content associated with the presence of BSCs.

Denise Mager sampling BSC formations in the Table Mountain National Park

Dr Denise Mager sampling BSC formations in the Table Mountain National Park (Photo: Dr Mager)

Biological soil crusts are formed by an association of soil mineral particles and microorganisms which live in the top few millimetres of the soil. Through photosynthesis, microorganisms, such as cyanobacteria, modify habitats by increasing the carbon content in the surrounding soil, decreasing soil erosion with the formation of stable aggregates, decreasing nutrient leaching and delaying evapotranspiration losses. Further studies have shown that the increased organic carbon in the soil from BSCs could serve as useful tools for limiting the spread of invasive species.

It is clear that in order to better understand the role of BSCs in soil carbon storage and the success of invasions by exotic annual plants we need to include further field studies of the spatial and temporal distribution of BSCs. The research team, together with C·I·B core team member Prof Karen Esler, is currently exploring the spatial distribution of soil microbial communities and taxonomic composition at different sites of the Cape Floristic Region and the Karoo biome. Ultimately, Dr Denise Mager and colleagues are aiming to produce a regional map of soil microbial communities using ecological niche modelling.

Read article: Mager DM, Hui C. 2012. A first record of biological soil crusts in the Cape Floristic Region. South African Journal of Science. 108(7/8), Art. #1013, 4 pages.

For further information, contact Dr Denise Mager at