Light periphton algae response curves

Tom Barr

Staff member
Jan 23, 2005
A little dated, but still pretty good paper.

Discusses some aspects of phytoplankton vs Periphyton differences.
Also, shows some PAR ranges and rates of photosynthesis for different exposures of light.

At the lower end, you can see how little growth there, at 200-400 micromols of light, many specie shave a nice maximum then decline slowly. An interesting idea is how the lowest layer of the periphyton community is the basal attachment site, and if they dies, gets light limited, then the entire periphyton film sloughs off the leaf. Good current can help this sloughing process.

This is likely what occurs during a blackout/reduction of light for many species.
Plants also respond by requiring less CO2 and nutrients.

Tom Barr