Effects of the intensity of controlled burning on soil and field vegetation diversity in Irati, Paraná, Brazil

Abstract

This study aimed to evaluate the effect of a controlled burning on the soil and field vegetation, in the Campus of Unicentro, Irati, Paraná, Brazil. The controlled burning remained at low intensity levels (176.12 ± 24.49 kcal m^-1 s^-1), the average fire spread rate was 0.0219 ± 0.01 m s^-1, with the fire effectively under control, and with an average blight height of 1.31 ± 0.42 meters. The phosphorus content in the burnt soil increased almost three times more (22.06 mg dm^-3) than the control soil (8.32 mg dm^-3). Apparently, the action of the fire did not harm the plants development, though there are indications that Cyperus luzulae (L.) Rottb. ex Retz had little tolerance to fire. It was concluded in this work that: i) the controlled burning in the intensity used reduced the organic matter content and increased the amount of phosphorus, potassium and sodium in the soil; ii) the controlled burning in the intensity used did not prevent the germination of the seeds of the studied vegetation; iii) the controlled burning in the intensity used caused no loss of diversity in the vegetation studied.