Hydrological and phytosociological studies were conducted in a 550 m topographic profile installed perpendicularly to the Cuiabá River, in the municipality of Rosário Oeste, MT, Brazil, in order to analyze the influence of flooding on riparian vegetation distribution. A backwater hydrological model under a subcritical regime was fitted allowing the establishment of a hydrological series in the study area. From this series, the recurrence intervals for the area were obtained. The results suggested that the banks of the main channel, the secondary channel and its lateral dike, the flood plain, and the terrace are flooded at every ~1 1.7 years, ~1.77 2.8 years, ~3 years, and from ~3.25 to ~39 years, respectively. The species Combretum leprosum Mart. (Combretaceae) presented the greatest VI in the bank of the main channel; Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) presented the greatest VI in the bank of the main channel and in the terrace; and Licania parvifolia Huber (Chrysobalanaceae), Cariniana estrellensis (Raddi) Kuntze. (Lecythidaceae), and Vochysia divergens Pohl. (Vochysiaceae) in the flood plain. The results indicated that flooding frequency and especially the flooding time are the main determinative ecological factors of plant species distribution along the topographic profile.
Hydroperiod; Limiting factors; Phytosociology
