Campo sujo consists of an herbaceous/sub-shrub layer dominated by grasses with some scattered shrubs of poorly developed cerrado sensu stricto species. We did a phytosociological survey of the herbaceous/sub-shrub layer of a campo sujo at the Água Limpa Farm, Brasília, DF (15º55'35,4''-15º56'4,1''S; 47º54'20,8''-47º54'21,9''W.) by sampling over time. We randomly set 40-meter transects inside a 400×400 m plot divided in four quadrats of 200×200 m. The line intercept method was adopted for sampling where each line was divided in 1 m sections. We found a total of 163 species belonging to 78 genera and 39 families. Poaceae was the most important family with 67.04% of cover. Sørensen's similarity indices were high (0.60 to 0.69) when comparing the transections, probably due to the uniform soil. The similarity between sampling periods was also high probably because there was little variation in cover rates for the main species over the year. However, sampling more than once a year seems to be necessary to register rarer, low-cover and ephemeral species.
Cerrado; line intercept method; similarity; herbaceous layer; fire
