The short-term biomass dynamics of periphyton communities in running water is
characterized by deep variations. This temporal variability is mainly produced by changes in
running water velocity. The shear force caused by the friction of water over the surface of the
periphyton produces a removal of biomass and creates open sites for colonization. Running
water also brings new suspended algae that can establish on open sites. An increase in the
velocity of the water can also improve the renewal of nutrients in depleted areas and the …