Balancing prevention and pragmatism in invasive species management

Biosecurity: A Systems Perspective. Hester, S.M., Bland, L. M., Arndt, E., Bau, S., Camac J. S., Mannix, E., Trouvé, R. and A. P. Robinson. 2024. CRC Press, Boca Raton, FL. xiv+272 pp. £155.00 (hardcover). ISBN 978-1-032-18168-4. The Ecology and Management of Invasive Prosopis Trees in Eastern Africa. Schaffner, U., Van Wilgen, B., Ehrensperger, A., and K. Bekele. 2025. CABI, Wallingford, UK. xxviii+273 pp. £115.00 (hardcover). ISBN 978-1-8006-2362-0. Love Them to Death: Turning Invasive Plants Into Local Economic Opportunities. Applequist, W. L., editor. 2025. Missouri Botanical Garden Press, St. Louis, MS. vii+293 pp. US$30.00 (paperback). ISBN 978-1-935641-31-5. Together with climate change, land-use intensification, overexploitation of natural resources, and pollution, biological invasions represent one of the principal drivers of biodiversity decline worldwide (Jaureguiberry et al., 2022). Despite the widespread awareness of the problem, numbers of invasive non-native species continue to increase in terrestrial, freshwater, and marine ecosystems (Roy et al., 2024). Target 6 of the Kunming–Montreal Global Biodiversity Framework sets out the goal for nations to “eliminate, minimize, reduce and or mitigate the impacts of invasive alien species on biodiversity and ecosystem services.” Meeting that ambition demands not just resolve but operationally effective systems, durable financing, and social license (Hulme et al., 2025). Three recent volumes approach that challenge from contrasting vantage points that include systems-focused prevention, context-rich control under constrained capacity, and use as a management accelerant. Together they illuminate both the promise and the pitfalls of contemporary management of biological invasions. It makes economic sense to prevent biological invasions at or before they arrive at a national border and to have tools to eradicate an incursion prior to its establishment (Welsh et al., 2021). A range of approaches to achieve such goals are presented in Biosecurity: A Systems Perspective, which is an edited collection that distils over a decade's worth of research from the Australian Centre of Excellence for Biosecurity Risk Analysis. As might be expected, the case studies have a strong Antipodean focus, particularly on pathogens, pests, and weeds that affect primary industries, and they place strong emphasis on quantitative methods used to estimate and reduce the risk of biological invasions. It nevertheless makes a compelling case that biosecurity must be designed, governed, and evaluated as a whole system rather than a set of isolated projects. The editors structure the material logically across the preborder, border, and postborder continuum, explicitly integrating economic efficiency, institutional capacity, and behavioral factors. The volume is particularly useful for practitioners because the text offers valuable guidance in designing robust biosecurity systems that include mapping the system (e.g., actors, flows, leverage points), identifying bottlenecks (e.g., weak import screening, under resourced local surveillance), and prioritizing high-return interventions (e.g., pathway management) supported by sustained financing and clear accountability. A key message is that biosecurity operates amid uncertainty and rapid change, so programs need feedback loops that provide real-time evaluation of system performance. The editors warn that systems thinking can drift into abstraction unless anchored to operational tools. They offer some anchors, such as risk assessment frameworks, scenario planning, and multicriteria decision analysis that will help translate strategy into implementable designs and metrics. These are the necessary elements of scaffolding that will keep incentives aligned with prevention and rapid response rather than drifting into sporadic, project-based activities. Set against the backdrop of Australia and New Zealand's comparatively strong biosecurity legislation, governance, and coinvestment by government and industry, the book is exemplary, though readers in less‑resourced settings will need to adapt its framework to their institutional realities. Not all nations can sustain Australasia's model of systems‑led prevention. The Ecology and Management of Invasive Prosopis Trees in Eastern Africa illustrates the challenges of managing biological invasions in developing economies. Tanzania, Kenya, and Ethiopia all grapple with poverty, economic instability, governance challenges, and environmental pressures threatening food security (Adeyeye et al., 2023). Thus, the opportunities and challenges of managing biological invasions in Eastern Africa are thus much more likely to reflect the situation in much of the Global South (Nuñez & Pauchard, 2010). Based largely on the findings of a 7-year research program funded by the Swiss government, The Ecology and Management of Invasive Prosopis Trees in Eastern Africa introduces the history of Prosopis cultivation in Eastern Africa, describes the ecological, social, and economic consequences of the subsequent invasion, identifies the most appropriate techniques for management, and, finally, addresses the need for broad involvement in tackling this issue. Prosopis species are leguminous trees that have been widely promoted by international aid agencies as multipurpose trees that provide firewood, honey, and fodder in semiarid regions in Africa and South America. In Eastern Africa, the species often escaped plantations, proliferated via livestock-mediated seed dispersal, and aggressively colonized rangelands, riverine corridors, and farmlands. The authors compile a sobering ledger of negative impacts that include the conversion of open rangeland to thorn thicket that has resulted in reduced grazing access and altered hydrology and nutrient cycling. A particularly striking impact is the encroachment by Prosopis along the margins of Lake Bogoria in Kenya that has led to the estimated death of at least 20,000 lesser flamingos due to their becoming physically trapped in the trees on takeoff or landing. The widespread and ongoing cultivation of Prosopis in Eastern Africa means the opportunities for prevention are limited and a series of phase-specific strategies are recommended. Where Prosopis is in the early stages of invasions, containment involving seed pod management and movement controls can work, but where it is established, integrated management must combine mechanical removal and follow up resprout control. Even with such interventions, Prosopis populations can continue to grow, and there is a need to explore the options of using biological control agents to reduce plant performance and thus increase the effectiveness of mechanical removal. The volume will prove invaluable for practitioners, but the insights are context dependent because Prosopis dynamics, governance conditions, tenure complexities, and institutional capacity differ across regions, so transfer requires careful adaptation. Nevertheless, there are important messages regarding the management of conflict species that involve socioeconomic trade-offs in which the perceived benefits of increased fuelwood availability must be balanced against the severe costs of agricultural encroachment and biodiversity loss. One issue that practitioners must tackle when managing Prosopis is the use of community-based harvest for charcoal production and timber to offset management costs because this can risk entrenching the invader in the local economy and thus creating further conflict. The idea that we can turn invasive plants into local economic opportunities and thus encourage their removal is the focus of Love Them to Death, which is written largely from a North American perspective. Through a series of essays, the volume investigates the proposition as to whether can we “love” invasive plants to death by mobilizing local enterprise to turn biomass into products that yield removal pressure. People tend to be motivated to pursue control-through-consumption activities by the challenge of using invasive-based ingredients, level of commitment, and environmental benefits and as an outlet for leisure (Seaman et al., 2025). The book details multiple uses beyond eating, for example, using root starch as a culinary thickener, producing medicinal extracts, generating fibre, creating natural dyes, making paper, and weaving baskets from stems. It is not just humans who are being encouraged to eat non-native plants; opportunities to encourage livestock to be weed managers are also considered. An overarching philosophy is that many communities face limited budgets for conventional control and thus if harvesting can provide financial support for ongoing management, it can align ecological goals with livelihoods. Although this perspective is refreshing and the compilation of case studies is certainly original, it is not without its concerns. For example, the language in the chapters that discuss the value of common reed (Phragmites australis), Japanese wisteria (Wisteria floribunda), and oriental bittersweet (Celastrus orbiculatus) shifts to one of acceptance and to the need to respect the cultural histories of non-native plants. The volume points out that use is not a panacea; most invasive plants do not provide a ready source of income and those that do are often low value products that require a sizeable market demand to reduce populations significantly. Markets can be fickle, and the novelty of kudzu jelly, knotweed pickle, or mugwort tea might be short-lived. Moreover, commercialization risks perverse incentives because if the non-native plant becomes profitable (e.g., as feedstock for livestock or for biofuel generation), local communities may oppose eradication or even facilitate spread. One way to address this risk is to use the market simply as a temporary control accelerant and to have a clear exit strategy tied to management milestones. This might work in theory, but such a scenario will be unattractive to investors who may wish to set up infrastructure, such as processing plants, or establish a national supply chain. The difference in emphasis across the three volumes reflects the perennial tension in the management of biological invasions between the need for preventive, systemwide approaches versus pragmatic, on-the-ground control that works within economic and social realities. A major reason for this tension is the tendency for managers and policy makers to plan extensively without executing the necessary resources to ensure translation to field operations. Indeed, each volume targets a different aspect of this continuum, but taken together, these books are complementary and timely. They make a clear case for a management approach that not only understands the ecology of the target species, such as its spread dynamics and resilience to control treatments, but also recognizes the complexity of management that is strongly shaped by interactions among national policy, local institutions, economic incentives, and human behavior. Fiscally challenged managers need to be able to think entrepreneurially without losing sight of ecological imperatives and to remember that management sits within a wider context, rather than a series of isolated actions, and they must be in for the long term, especially where an invader has already transformed landscapes. The most effective management is a stack of complementary methods, each suited to the phase of invasion and the institutional and social context in which action must happen. Such a shift in thinking will be crucial if nations are to deliver Target 6 of the Kunming–Montreal Global Biodiversity Framework.