Predicting the invasiveness of plant species
European researchers have investigated invasive plants and their evolution, compiling large genetic and ecological datasets with results from 10 years of field studies in the Azores archipelago - located in the North Atlantic about half-way between Europe and the Americas. The EU-backed project 'Community phylogenetics and conservation on an oceanic archipelago: the flora of the Azores as a case study' (Azores) has also reconstructed the evolutionary relationships, known as phylogenetics, for all of the islands' 796 plant species. Observations reveal that introduced plant species are most likely to become invasive when they are not closely related to other species in the area. The findings also support Charles Darwin's 'naturalisation hypothesis', published in 1859. Darwin proposed that exotic plants with relatives that were native to the new environment would not be as successful as those without native relatives. He believed that this was because newly introduced plants with native relatives were susceptible to the herbivores and diseases that attacked their native relatives. Project partners found that evolutionary relatedness was a reliable predictor for the invasiveness of a species. Some ecological traits such as the species size and the size of its seeds also enabled invasiveness to be predicted for the Azores, but this was not the case in other ecosystems. Therefore researchers have suggested that plant invasions can best be forecast through measuring the closeness of evolutionary relationships. Thanks to the work of the Azores consortium plant invasions can now be predicted, helping to solve this problem around the world. With the help of state-of-the-art DNA sequencing technologies scientists can now determine the species-level phylogenetics for a growing number of ecosystems across the world, helping to predict groups of plants that are potential invaders. Research conducted by the Azores will help identify which plants pose the greatest threat of invasive activity to vulnerable ecosystems, thereby helping to preserve biodiversity.
