Predicting impacts of alien plant invasions on community diversity

The Anthropocene, the current geological epoch, is characterised by human-induced ecological changes, which have prompted a global biodiversity crisis. Human-introduced alien plants could help to offset native species loss, augmenting diversity and maintaining the services and capital that humans derive from nature. However, alien species that become invasive are themselves a key threat to biodiversity. Alien species thus presents a huge challenge for biodiversity conservation in the Anthropocene: should their arrival and establishment be inhibited or disregarded as they can potentially both exacerbate and ameliorate biodiversity loss? Coupling empirical and theoretical approaches, ALIENIMPACTS will directly address this challenge by developing an approach for accurately predicting impacts of alien plant invasions on plant community diversity and identifying the circumstances under which negative impacts will occur. Using temperate grasslands as a model system, ALIENIMPACTS will use innovative field experiments and global observations to systematically quantify – for the first time – how often, for how long, to what extent, under what conditions and in what ways alien plants can impact plant community diversity. ALIENIMPACTS will develop mechanistic niche models, validated with empirical data from grasslands in North America, Europe and Australia, that will enable realistic scenarios of invasion biodiversity impacts to be forecast, now and in the future. Developing empirically accurate mechanistic models that predict invasions and their biodiversity impact is a highly ambitious goal. Its achievement will mark a step-change in ecological theory and understanding, will inform environmental policy and management, and address a critical research challenge of the Anthropocene: how to conserve the biodiversity of plants – the dominant life form on earth – under global environmental change.