Macro-invasion-ecology - toward understanding the global flows and distribution of alien species

• Applicant: Dr. Hanno Seebens
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Ecology and Biodiversity of Plants and Ecosystems
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 281619538

The number of alien species transported by human assistance has increased at unprecedented rate during the last centuries, and so are the impacts they cause. These biological invasions are one of the greatest threats to biodiversity, may affect ecosystem functioning and produce large economic impacts. The effective mitigation of further introductions requires detailed knowledge about global spreading dynamics, which is one aspect in the field of macroecology. However, global spreading dynamics are poorly understood mainly due to the lack of harmonisation of available data and the restriction of studies to certain taxonomic groups, geographic regions or single invasion pathways. A further synthesis of invasion ecology and macroecology would deepen our understanding of the global flows of alien species and improve the predictive power of models of biological invasions to prevent further introductions. This project aims at a comprehensive mechanistic understanding of the global distribution and flows of alien species. In a first step, the currently most comprehensive databases of native and alien species distributions of various taxonomic groups ranging from algae to mammals will be combined and analysed. This unique data set allows the establishment of networks of reported alien species flows (i.e. the flow of species from a native to an alien range) between countries for each taxonomic group. In a second step, these reported invasion networks will be combined with existing comprehensive databases of invasion pathways and environmental conditions to simulate the global spread of alien species and to identify the relevant mechanisms to reliably predict alien species flows. The reported and predicted invasion networks will be inspected for inter-taxonomic variations in network topologies, important source regions, major introduction routes and hot spots of invasions, and for spatio-temporal variations. Different scenarios considering global changes in socio-economic drivers or environmental conditions will be simulated and analysed. Finally, the "footprint concept" and innovative techniques from network theory will be applied to determine the flow of threats of biological invasions to local biodiversity (i.e. the "invasion footprint" of a country) and to identify vulnerabilities of the networks to mitigate these threats. The proposed project represents the first approach to take advantage of the enormous potential of existing large databases to analyse the global spread of alien species for various taxonomic groups on a global scale. The results will distinctly enhance our knowledge of global invasion processes and will improve the predictability of invasion dynamics. The results will help to disentangle the complex relationships between globalisation, biological invasions and biodiversity losses and to improve the efficacy of mitigation strategies.

• DFG Programme: Research Grants