Smart(phone)-Monitoring (SPM): An Efficient and Accessible Method for Tracking Alien Plant Species

The invasion of alien plant species outside of their home range constitutes an emerging problem threatening native plant diversity. The expansion of alien species is often favored in anthropogenic habitats, such as roads and urbanized areas, which allow the rapid colonization of new sites by these species. The development of suitable monitoring methods is fundamental both to keep pace with the fast expansion dynamics of these species and to enable appropriate and prompt control strategies. In this work, an efficient, accessible, and cost-effective method for monitoring alien plants using a smartphone is proposed (smartphone-monitoring-SPM). Using smartphones with a geolocation system, geographic coordinates of images matched to single plant records can be easily acquired and structured into exportable databases in a few steps. We tested the SPM method on three black-listed alien plants, Ailanthus altissima (Mill.) Swingle, Arundo donax L., and Robinia pseudoacacia L., along the road network and in major urban centers of the Tuscany region (central Italy).