Ants are effective at moving seeds toward their nests, something that may benefit the seeds. We evaluated whether seed movements that may be useful for the rehabilitation of degraded pastures in Colombia can be enhanced by local ants. An artificial aril was prepared and then evaluated in six open cattle pasture farms. Twenty paper disks (each holding seeds with an artificial aril, honey, tuna oil, and control) were set up along linear transects at each farm, and monitored five times in 48 hours. A total of 340 out of 480 seeds were moved from the experimental units by ants. Seeds with tuna oil and an artificial aril were removed twice as frequently as the control and honey smeared seeds. Ectatomma ruidum, Solenopsis geminata, and Pheidole sp. removed the majority of seeds. Advantages of the artificial aril over tuna oil are discussed. This inexpensive technique can enhance seed movement by generalist ants in degraded pastures, likely contributing to regeneration and ecological rehabilitation.

Landslides and gullies are two common manifestations of land degradation in the densely populated Colombian Andes. In these unstable areas, further mass movements pose a serious threat to local populations and cause off-site environmental damage through sedimentation, pollution, and increased flooding. A novel approach for restoring severely eroded slopes combines the use of stabilization structures made with stalks of Guadua angustifolia Kunth, Poaceae (bamboo), with high-density planting of species that exhibit quick growth and sprouting. This study compared the vegetation and ground-dwelling ant assemblages of 10 pairs of gullies, each pair formed by one enhanced and one untreated or control gully, 6-8 years after restoration or abandonment. The restoration treatment had significant effects on the complexity of vegetation. Average values for plant species richness, basal area, stem density, foliage density index, and total vegetation volume were 11.6, 140, 30, 11.5, and 15.6 times larger, respectively, in enhanced than in control gullies. Mirroring the differences in vegetation, average ant species richness was significantly larger (13 vs. 7.6 species per gully), and a higher proportion of ant species nested within enhanced than control gullies (52.5 vs. 30%). While control gullies were dominated by generalist ants such as Ectatomma ruidum and Linepithema angulatum, enhanced gullies had more specialized grounddwelling species, normally associated with high plant cover and abundant leaf litter such as Octostruma balzani and Heteroponera inca. We conclude that this restoration strategy promotes a fast recovery of vegetation and the grounddwelling ant fauna in these tropical mountains.