Modelling Invasion by AustralianAcaciaSpecies: Progress, Challenges and Opportunities

Australian Acacia species (‘wattles’) have been widely introduced outside Australia and some now rank among the most widespread and damaging invasive trees globally. Early-warning systems that monitor the establish- ment and spread of alien species or track their distribution are required to aid scientists, policy makers, land managers and other stakeholders in the prevention of further wattle introductions and the control of invasive populations already established. This chapter provides an overview of commonly used models to study wattle invasions and, specifically, modelling approaches aimed at predicting invasiveness that are useful for the early warning, assessment and monitoring of wattles. A systematic review of published literature is first conducted to understand the spatial-temporal extent of modelling applications across different wattle species, and to provide an overview on the main modelling techniques and types of data adopted in wattle research. Applications of these models are then illustrated by a set of case studies, specifically focused on the use of (i) remote sensing data, (ii) citizen science data and (iii) the application of dynamic models to address wattle invasions. The chapter integrates ideas and examples that can be useful for guiding the prediction of future wattle introductions, establishment and invasions. Even though modelling tools have their limitations, they allow the study of real-world problems through testing hypotheses and analysing potential scenarios, which is useful to address topics like the adaptive management of ever-shifting social-ecological systems, such as invasive wattles.