Exotic woody plants in Pelotas, Rio Grande do Sul, southernmost Brazil

Exotic species are spreading in various parts of the planet and sometimes becoming biological invaders. A floristic survey was carried out to find exotic trees, shrubs, and climbers in different communities in Pelotas, Rio Grande do Sul, southern Brazil. The traversal method was used at 26 sites. The richness totaled 26 species in 22 genera and 17 families. There are 19 trees, 5 arborescents, 1 shrub, and 1 climber. Most of the exotic species are already naturalized in the study area. Between 1 and 10 individuals sporadically occur at each site. For species of characteristically invasive exotic plants were observed, including 3 trees (Pinus elliottii Engel, Pinus taeda L. Engelm., and Pittosporum undulatum Vent.) and 1 shrub (Ulex europaeus L.). A continuous monitoring of exotic flora is needed to eliminate or control invasive plant species and to avoid economic and ecological damage to ecosystems.