soil algae and nematodes versus bacteria????

I was part of the group 4 of discussion #2 with the questions... Why are the soil algae usually restricted to the uppermost soil layers? Soil algae are usually smaller than their aquatic counterparts? Explain why this is the case. Explain why this is not true for soil bacteria?

Our answer was:

Soil algae are restricted to the uppermost soil layers because:

• Soil algae require photosynthesis therefore require sunlight (hence being at uppermost layers)

Soil algae smaller than aquatic algae because:

Space:

• -there is more open space in water
• -free floating: can be widespread

Resource availability:

• -maximum sunlight in water
• -water availability in aquatic environment

Why this is not the case for soil bacteria: [Pls note that Maja edited this part of the answer]

Soil bacteria are unicellular organisms, therefore...

• -restrictive space in soils is not an issue for them

Thank you Tanya!