Contribution of Pheidole fallax and Ectatomma ruidum (Hymenoptera: Formicidae) to the dispersion and germination of seeds in rehabilitated areas of the Cerrejón coal mine, Colombia
Seed dispersal is a key process in the re-establishment of vegetation on reclaimed lands. The aim of this study was to determine the contributions of the ant species Ectatomma ruidum and Pheidole fallax to seed dispersal and germination on reclaimed lands in the Cerrejón coal mine, Colombia. Four 6 x 40 m plots were installed in each area, in which the number of nests by species was counted and distances between closest nests of each species were measured. Five of the nests counted were chosen for seed extraction, and a nearby control sample was taken from each nest. In total, 295 nests were counted: 59 nests during the dry season and 236 nests during the rainy season, of which 84 belonged to P. fallax and 211 belonged to E. ruidum. A total of 21 304 seeds were found in nests and control samples, of which 19 349 were obtained from P. fallax nest refuse, and 318 were obtained from E. ruidum nests; 597 seeds were found in control samples. The number of seeds extracted from nests was significantly higher than the number of seeds removed from control samples. There was a significant difference between the number of seeds removed by P. fallax and the number of seeds removed by E. ruidum. The seed germination percentage from nests was higher than the percentage from seeds in control samples. In the case of P. fallax, the germination percentage was lower in control samples and higher in nests and refuse. The results suggest that the ant species E. ruidum and P. fallax may contribute to seed dispersal and re-establishment of vegetation in areas where they were found. These ants may thus significantly contribute to restoration processes in areas degraded by mining.