Enumerate the role of Soil algae on soil flora

Soil algae are microscopic, chlorophyll containing organisms, being the simplest chlorophyllous plants. These are phototrophic aerobic organisms who obtain energy from sunlight through chlorophyll and fix atmospheric carbon dioxide and synthesise their own food.  Soil algae occur as unicellular organisms or as filaments or as colonies as seen on the surface soil, which have adequate moisture level and receive sunlight.  A few algae may be found as heterotrophs below surface soil, some of the algae are symbiotic while others are nonsymbiotic.  Moisture and adequate sunlight are the most significant environmental conditions influencing the algal population.  The optimumactivity pH range varies from strain to strain. Algae also help  in building up of soil structure, but do not contribute significantly to the biochemical transformation in soil.  They contribute a lot to the organic matter level of soil; the blue green algae, in particular, adding nitrogen to the soil.