Effects of disturbance on the probability of permanence and
colonization
After the parameters of permanence and basal colonization of the
functional groups were estimated, we used the results of the artificial
substrates under different disturbances to assess the effect of water
flow changes on genus occurrence. We added a new parameter to the model,
which modifies the probability of genera permanence of during the
experiment. The model used was:
\begin{equation}
{O_{i,k,t}\sim Bern\left(P_{i,k,t}\right)\backslash n}{P_{i,k,t}=\theta_{g}+O_{i,k,t-1}\bullet\psi_{g}\bullet\delta_{k,g}\backslash n}{\delta_{k,g}\sim N\left(0,0.001\right)}\nonumber \\
\end{equation}(model 3)
where Oi,k,t is the occurrence of genus iin treatment k at time t . In model 3 \(\delta_{k,g}\) was
the deviation of the probability of permanence of group g from
treatment k , when compared to the baseline permanence of the
group observed in the control (\(\psi_{g}\)). We assumed the six
factorial interactions by treatment
(I1.F1,
I1.F2,
I1.F3,
I2.F1,
I2.F2 and
I2.F3).
We highlight that the parameters of interest in the study were the
hyperparameters estimated in model for \(\psi\) and \(\theta\). These
hyperparameters are calculated using the values for \(\alpha\) and\(\beta\). Thus, each genus has its estimated probability value;
however, all are linked to the baseline values of the functional groups
in which they were categorized.