We congratulate Dr Maria Loreto Castillo with the successful defense of her PhD, which was carried out in the Woody Weeds project at the Centre for Invasion Biology in South Africa. The thesis, entitled “Processes and drivers of Prosopis invasions in Eastern Africa”, was supervised by Jaco Le Roux, Brian van Wilgen and Urs Schaffner.

Maria’s thesis investigated the ecological and evolutionary processes underlying Prosopis invasions in Eastern Africa. She first tackled age-old issues around the problematic taxonomy of the genus using molecular genetic approaches. This part of her work illustrated that many Prosopis species can hybridise freely and that existing taxonomic issues are unlikely to be resolved using genetic data. Maria also found invasive Prosopis juliflora in Kenya to, not only have flexible ecological strategies (i.e. high phenotypic plasticity), but also to have undergone rapid post-introduction evolution. Her comparative research between invasions in Ethiopia and Kenya also found demographic processes, like dispersal, to differ markedly between these two countries.