Conditional inference tree for total abundance and richness indexes with environmental variables of every sampling stations based on fourth root transformed responses. For each inner node, the Teststatistic P-values are given and the conditional independence tests as α = 0.05, the response variables are displayed for each terminal node (Mean ± SD). The units of each environmental variables are showed in Figure 3. Environmental variables code: SS, Sedimentary sulfide; SOC, Sedimentary organic carbon; STP, Sedimentary total phosphorus; DO, Dissolved oxygen; CO, Water colour; RP, Reactive phosphorus.