Immediate effect on the occurrence of the functional groups
The two intensities of disturbance had different effects on the occurrence of the functional groups (Fig. 2). The probability of occurrence reduced for all groups after the strongest disturbance (Intensity 2), except for organisms with depressed body (group 1). The group of organisms with appendixes to fix in the substrate showed the highest reduction in the probability of occurrence at the highest intensity of the disturbance (group 8). For the weakest disturbance (Intensity 1), only Chironomidae, Baetidae and Trichoptera shelter builders (groups 3, 7 and 9) had a reduced probability of occurrence.