The ‘lawnification’ of Australia’s eastern grassy woodlands: The past, current and likely future spread of a damaging pasture and lawn grass, Bothriochloa pertusa

Abstract Many of today’s damaging invasive plants were intentionally introduced for pasture development. By examining the introduction history and consequent spread of these species, we can identify factors associated with their successful establishment and dominance. Using collated presence/absence and cover data, alongside a review of the literature and discussions with land managers, we present a comprehensive analysis of the introduction history and spread of the invasive perennial grass species, Bothriochloa pertusa throughout Queensland, Australia. Using this data, we also perform habitat suitability models to predict its potential distribution and local-scale cover across Queensland in relation to key environmental variables. We found that B. pertusa was introduced on multiple occasions and across a large area of Queensland, despite re-occurring doubts and poor evidence for its benefit to livestock production. Livestock grazing, associated disturbances (i.e. land clearing, soil erosion) and climatic extremes were commonly associated with its spread throughout the landscape. In 2020 the main area of B. pertusa invasion as indicated by occurrence records spanned 28,537,600 ha. Results from the habitat suitability models suggest the occurrence and local-scale cover of B. pertusa is largely determined by climate variables and the foliage projective cover of trees. Based on these results B. pertusa still has considerable capacity to spread and increase in dominance across many areas of Queensland, particularly further west and south of its current range. The introduction and spread history of B. pertusa suggests propagule pressure, traits, climate, land management and cultural perceptions are all key factors implicated in the spread of B. pertusa. We recommend more conservative grazing strategies and strategically selected protected areas to slow the spread of this species.