Coalescing past and present to predict the future: historical attributes and current situation of a non-native palm on an island in the Atlantic Forest

Abstract

For a non-native plant to become invasive in a new area where it was introduced it has to establish and maintain self-sustaining populations with plants that survive and reproduce at significant distance from the original point of introduction. Here, we searched for locations with the occurrence of a non-native palm and use historical attributes to infer their introduction date on an island in Atlantic Forest. We checked all existing trails, inhabited and semi-deserts areas on the island and detected seven sites where the non-native palm was present. We found a large number of adult palms in three of these sites, including reproductive palms farther than 100 m from areas different from those they were planted. This indicates that the species is spreading farther from the source populations. We estimated the minimum residence time in 110 years by means of historical records. The results of our study indicate that the species is in the final stage of the invasion process. Therefore, threat abatement measures should be undertaken with urgency, involving local residents. Engaging residents in decision making may increase the success of management programs. Our results also showed the relevance of using historical attributes as a resource in studies on invasive alien species.