Location of the 15 quadrants established for species survey, sampling and monitoring. Sampling sites DI1 to DI12 correspond to the Desembarcadouro islet and CI1 to CI3 are indicated for the Chão islets. Soil types in the Desembarcadouro islet are described. No information exists on the soil types for Chão islet. On both islets, the colours attributed to the circles for each sampling site correspond to a mean density of B. patula plants (plants X square metre).