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Summary: Protecting native biodiversity is a difficult prospect in extremely modified landscapes, especially where high‐impact exotic species are widespread. Using new data and a review of the literature, this paper comments on the use of livestock grazing to manage the invasive and highly combustible pasture grass species, Buffel Grass (Cenchrus ciliaris) and thereby help conserve fire‐sensitive Brigalow (Acacia harpophylla) vegetation in reserves in Queensland, Australia. We cite evidence that shows that grazing is a potentially useful management tool in such cases and its use can be compatible with the protection of both fire‐sensitive vegetation and other native plant species within the understorey. However, there are limitations in implementing grazing within conservation reserves including the lack of a clear understanding of the influence of grazing on biodiversity and resource condition. Importantly, we highlight secondary invasion by the exotic grass Indian Couch (Bothriochloa pertusa) as a key emerging threat that may undermine the biodiversity benefits gained by grazing in reserves. Grazing can be a useful tool for conservation management in particular scenarios, but the associated risks demand accompanying monitoring and reporting of positive and negative impacts to ensure the fundamental aim of biodiversity protection is being achieved. [ABSTRACT FROM AUTHOR]

Invasive species cause severe threats to biodiversity and the economy, but often across multi‐actor landscapes. Therefore, collaboration among multiple actors across landscapes is often essential for managing invasive species. Deciding whether to collaborate depends on available resources and potential benefits. As such, it is vital to identify how different factors can influence the outcomes of collaborations.We developed and tested a conceptual model that integrates potential process factors and performance measures for outcomes of collaborative invasive species management. We surveyed professionals engaged in invasive species management in Queensland, Australia. We first assessed their perception of the presence of process factors and perception of the performance measures of collaborative invasive species management projects using descriptive methods. Then we tested the associations between process factors and performance measures using structural equation modelling.While confirming that a good collaboration of stakeholders (e.g. communication and trust) is essential to enhance performances, our results suggest that the way collaborative projects are structured (e.g. ability to participate in decision‐making, having shared goals) also significantly influences the performance of the projects, especially in achieving goals. Furthermore, results suggest that achieving long‐term collaborations and outcomes is directly influenced by the extent to which stakeholders support or oppose the collaboration. As such, our study contributes to a significant research gap by establishing a connection between the collaboration process and its outcomes.We conclude that decision‐makers should give equal importance to both designing favourable collaborative project structures and fostering collaborations with stakeholders through different means to enhance the benefits of collaboration in invasive species management. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

This paper examines invasion of grasslands on Cape York Peninsula, Australia, by Melaleuca viridiflora and other woody species, and the role of storm-burning (lighting fires after the first wet season rains) in their maintenance. Trends in disturbance features, fuel characteristics, ground layer composition, and woody plants dynamics under combinations of withholding fire and storm-burning over a 3-year period were measured on 19 plots in three landscape settings. Population dynamics of M. viridiflora are described in detail and 20-year population projections based on transition matrices under different fire regimes generated. Numerous M. viridiflora suckers occurred within the grass layer, increasing each year regardless of fire regime, and were rapidly recruited to the canopy in the absence of fire. Storm-burning had little impact on fuel, ground layer or woody plant composition, but maintained open vegetation structure by substantially reducing recruitment of M. viridiflora suckers to the sapling layer, and by reducing the above-grass-layer abundance of several other invasive woody species. Population projections indicated that withholding fire for 20 years could cause a sevenfold increase of M. viridiflora density on Ti-tree flats, and that annual to triennial storm-burning should be effective at maintaining a stable open vegetation structure. These findings argue against vegetation thickening being an inevitable consequence of climate change. We conclude that a fire regime that includes regular storm-burning can be effective for maintaining grasslands and grassy woodlands being invaded by M. viridiflora. [ABSTRACT FROM AUTHOR]

Trade‐offs exist between the point of early detection and the future cost of controlling any invasive species. Finding optimal levels of early detection, with post‐border active surveillance, where time, space and randomness are explicitly considered, is computationally challenging. We use a stochastic programming model to find the optimal level of surveillance and predict damages, easing the computational challenge by combining a sample average approximation (SAA) approach and parallel processing techniques. The model is applied to the case of Asian Papaya Fruit Fly (PFF), a highly destructive pest, in Queensland, Australia. To capture the non‐linearity in PFF spread, we use an agent‐based model (ABM), which is calibrated to a highly detailed land‐use raster map (50 m × 50 m) and weather‐related data, validated against a historical outbreak. The combination of SAA and ABM sets our work apart from the existing literature. Indeed, despite its increasing popularity as a powerful analytical tool, given its granularity and capability to model the system of interest adequately, the complexity of ABM limits its application in optimizing frameworks due to considerable uncertainty about solution quality. In this light, the use of SAA ensures quality in the optimal solution (with a measured optimality gap) while still being able to handle large‐scale decision‐making problems. With this combination, our application suggests that the optimal (economic) trap grid size for PFF in Queensland is ˜0.7 km, much smaller than the currently implemented level of 5 km. Although the current policy implies a much lower surveillance cost per year, compared with the $2.08 million under our optimal policy, the expected total cost of an outbreak is $23.92 million, much higher than the optimal policy of roughly $7.74 million. [ABSTRACT FROM AUTHOR]

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Aim To develop and test a general framework for estimating weed invasion potential (suitability and susceptibility) that utilized expert knowledge of dispersal, establishment and persistence and considered the influence of land management. Location The semi-arid Desert Channels Region of Queensland, Australia (476,000 km2). Methods We developed a general framework that integrated knowledge and empirical data of the environmental and land management variables influencing the dispersal, establishment and persistence of the invasive shrub parkinsonia ( Parkinsonia aculeata) using a Bayesian network linked to a Geographic Information System (GIS). We evaluated the influence of different land management scenarios on landscape suitability for parkinsonia. Model performance was assessed by comparing predicted landscape suitability with mapped parkinsonia locations and estimated parkinsonia density. Results Our predictions of moderate to high suitability corresponded reasonably well with mapped parkinsonia locations (71% match) and areas of common to abundant estimated density (92% match). They also suggested that parkinsonia has not reached its potential distribution within the study region. Under current land management conditions, 77,000 km2 of land was found to be highly or moderately suitable for parkinsonia. Scenario analysis indicated that maintaining moderate herbaceous ground cover levels, and using sheep to browse juvenile parkinsonia, reduced the predicted moderate to high suitability area to 27,000 km2, offering a potential management strategy for limiting parkinsonia invasion. Main conclusions Weed invasion potential can be reasonably estimated using expert knowledge of dispersal, establishment and persistence, integrated using a Bayesian network linked to a GIS. This modelling approach can be an alternative to process-based and phenomenological modelling, which can be problematic for modelling new and emerging weed invasions, particularly where data are patchy. The modelling approach also allows the influence of land management change on invasion potential to be investigated through scenario analysis. [ABSTRACT FROM AUTHOR]