Dear Zahraa,

that geogenic variables (e.g., pH, Electric Conductivity) of the soil solution deeply influence the taxonomic composition (major groups etc.) of the soil algae is well known since a long time (see e.g. Round 1981, 'The Ecology of Algae').

This is mirrored by observations in freshwater environments. With regards to spring habitats, I could, for instance, observe (Cantonati et al. 2012 attached) that acidic seepages and pools springs are mainly colonized by green algae, whilst cyanobacteria are more prominent in flowing springs with alkaline waters.

Also diatoms are well represented in soils, and able to colonize the whole soil-solution pH gradient with different species.

Best regards.

Marco Cantonati