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Abstract Biological invasions have substantial and rising social‐ecological impacts threatening human livelihoods and communities and hampering progress towards a just and equitable world. Currently, biological invasions are not adequately recognised and included in the UN Agenda 2030. Using a literature review conducted in Web of Science, we highlight the bias in available literature of biological invasions related to the UN Agenda 2030 and its Sustainable Development Goals. We find abundant scientific literature towards environmental and biodiversity related sustainability targets while other especially provisioning targets are less well represented. Subsequently, we discuss the risks of neglecting biological invasions within sustainable development and how invasive alien species can have changing and adverse effects through time counteracting the intended benefits at the time of introduction. Finally, we provide key recommendations for action at the international scale to ensure that biological invasions are adequately considered in sustainable development. Those recommendations include (1) acknowledgement of biological invasions as a key threat to sustainable development, (2) a call for stronger multilateral exchange under the umbrella of an adequately financed coordinating body and (3) appropriate implementation and resource provisioning for international monitoring, data infrastructure, data exchange and use of adequate indicators of biological invasions to streamline decision making based on a solid evidence base. Read the free Plain Language Summary for this article on the Journal blog.

Abstract A large number of non‐native trees (NNTs) have been introduced globally and widely planted, contributing significantly to the world's economy. Although some of these species present a limited risk of spreading beyond their planting sites, a growing number of NNTs are spreading and becoming invasive leading to diverse negative impacts on biodiversity, ecosystem functions and human well‐being. To help minimize the negative impacts and maximize the economic benefits of NNTs, Brundu et al. developed eight guidelines for the sustainable use of NNTs globally—the Global Guidelines for the Use of NNTs (GG‐NNTs). Here, we used an online survey to assess perceptions of key stakeholders towards NNTs, and explore their knowledge of and compliance with the GG‐NNTs. Our results show that stakeholders are generally aware that NNTs can provide benefits and cause negative impacts, often simultaneously and they consider that their organization complies with existing regulations and voluntary agreements concerning NNTs. However, they are not aware of or do not apply most of the eight recommendations included in the GG‐NNTs. We conclude that effectively managing invasions linked to NNTs requires both more communication efforts using an array of channels for improving stakeholder awareness and implementation of simple measures to reduce NNT impacts (e.g. via GG‐NNTs), and a deeper understanding of the barriers and reluctance of stakeholders to manage NNT invasions. Read the free Plain Language Summary for this article on the Journal blog.

Effective long-term management of invasive non-native species (INNS) in South America is a pressing yet complex task. Critically, the environmental, historical, cultural, and economic idiosyncrasies of the region call for the inclusion of a plurality of views from those sectors of society receiving the negative and positive impacts of INNS. This is a multifaceted, and often daunting, task that can be aided by an early identification of stakeholders – those affected by or with an interest in INNS and their management – accompanied by targeted stakeholder engagement. Here, we report the procedures and results of a stakeholder mapping activity aimed at identifying stakeholders and designing engagement strategies. Using expert knowledge procedures, we compiled comprehensive lists of stakeholders for six case-studies in South America: (i) invasive grasses (Urochloa spp.) in Brazil; (ii) glossy privet (Ligustrum lucidum) in Argentina; (iii) lodgepole and Monterey pines (Pinus contorta and P. radiata) in Argentina; (iv) American mink (Neogale vison) in Argentina and Chile; (v) lodgepole and Monterey pines in Chile; and (vi) German yellow-jacket (Vespula germanica) in Chile. Overall, we identified 250 stakeholders, which, based on their interest and influence, were classified into “context settlers” (2%), “key players” (47%), “crowd” (5%), and “subjects” (49%). We outlined strategies to engage with each of these four groups and for each of our six case-studies. Across case studies, communication with stakeholders was the most common engagement strategy proposed (27%; 19 of 70 strategies), followed by active involvement of stakeholders in INNS research and management (23%). Our results highlight the importance of considering power imbalances, as those stakeholders more likely to benefit from INNS were assessed to have more influence over INNS management relative to local and indigenous communities. Our work illustrates how to identify stakeholders in a rigorous and rapid manner, which should be complemented with the involvement of the stakeholders themselves.

Invasive plant species (IPs) are widespread in forests and cause substantial environmental, economic and social impacts. They occupy native ecological niches, causing local extinctions to the detriment of native biodiversity and disrupting ecosystem services provision. How landscape characteristics may determine the success of IPs remains unclear and, more importantly, how land-use and land-cover changes may result in spatial shifts in the invasion risk. Furthermore, the study of how landscape factors may influence biological invasions has focused on particular species, but not the IPs’ community. In this study, we identify and assess landscape variables that influence the presence and distribution of the IPs’ community in temperate forests of a global biodiversity hotspot in south-central Chile. We fitted spatially explicit models, combining field-sampling information and landscape variables related to land-use/land-cover, topography, climate, soil characteristics and anthropogenic factors to explain and predict the presence and distribution of the IPs’ community. From the whole sampling of plant species, we identified eight plant species classified as IPs: three trees and five shrubs. We used field data from 125 500 × 2 m-transects, in which we registered species richness, abundance and basal area of IPs’ community. Distance to forest plantations was the landscape variable with the most substantial influence on IPs’ presence and distribution. Richness, abundance and basal area of IPs’ trees were higher at shorter distances from forest plantations. The basal area of IPs’ trees was the best model explaining the relationship between IPs’ community and landscape variables. All descriptors of the IPs’ community showed similar spatial patterns: species richness, abundance and tree basal area are higher in more disturbed areas. Our findings contribute to increasing our understanding of the distribution patterns of IPs in forest landscapes. Our models can be suitable tools for designing strategies to prevent, mitigate or make integrated control of the impacts of invasive species in forest landscapes.

Unprecedentedly large areas were burned during the 2016/17 and 2022/23 fire seasons in south-central Chile (34-39°S). These seasonal-aggregated values were mostly accounted for human-caused wildfires within a limited period in late January 2017 and early February 2023. In this paper, we provide a comprehensive analysis of the meteorological conditions during these events, from local to hemispheric scales, and formally assess the contribution of climate change to their occurrence. To achieve this, we gathered monthly fire data from the Chilean Forestry Corporation and daily burned area estimates from satellite sources. In-situ and gridded data provided near-surface atmospheric insights, ERA5 reanalysis helped analyze broader wildfire features, high-resolution simulations were used to obtain details of the wind field, and large-ensemble simulations allowed the assessment of climate change's impact on extreme temperatures during the fires. This study found extraordinary daily burned area values (>65,000 ha) occurring under extreme surface weather conditions (temperature, humidity, and winds), fostered by strong mid-level subsidence ahead of a ridge and downslope winds converging towards a coastal low. Daytime temperatures and the water vapor deficit reached the maximum values observed across the region, well above the previous historical records. We hypothesize that these conditions were crucial in exacerbating the spread of fire, along with longer-term atmospheric processes and other non-climatic factors such as fuel availability and increasing human-driven ignitions. Our findings further reveal that climate change has increased the probability and intensity of extremely warm temperatures in south-central Chile, underscoring anthropogenic forcing as a significant driver of the extreme fire activity in the region.

Multifunctional landscapes offer an integrated approach to production, conservation, and human well-being. However, the challenges of implementing them in territories where plantations dominate are yet not well understood. This is the case in Chile, where plantations of non-native pines and eucalypts are extensively planted in its South-Central regions for timber and pulp. The resulting landscape homogenization, environmental degradation, and increased wildfire risk have caused and exacerbated conflicts, impacting biodiversity and the well-being of local communities and the Indigenous Mapuche Peoples.After the mega-wildfires in the region in 2023, science-policy discourse promoted the multifunctional landscapes model as a way to increase resilience. But what does this multifunctionality mean in challenging social-ecological contexts? Here, we aim to explore and deconstruct the multifunctional landscapes model in the context of the complex social-ecological systems of South-Central Chile. In this study, a review of the literature and semi-structured interviews with regional experts were used to better understand the challenges and opportunities presented by multifunctional landscapes.The results show a need to deepen the knowledge of how to move the model into practice, such as how to identify and decide compatible activities in the landscape. The thematic analysis of the interviews showed that restoration and water security are shared goals across the diverse actors in South-Central Chile. However, there were significant differences in knowledge, experiences and resources. While a number of landscape initiatives exist in the region, significant work is needed to build a common vision before the potential of multifunctional landscapes can be realized.

Terminology for the invasion status of alien species has typically relied either on ecological- or policy-based criteria, with the former emphasising species’ ability to overcome ecological barriers and the latter on species’ impacts. There remains no universal consensus about definitions of invasion. Without an agreement on definitions, it is difficult to combine data that comes from a range of sources. In Australia, information on plant invasions is provided by a collection of independent jurisdictions. This has led to inconsistencies in terminology used to describe species invasion status at the national level, impeding efficient management. In this paper, we review and discuss the steps taken to harmonise the different terminologies used across Australia’s states and territories. We identified mismatches in definitions and records of invasion status for vascular plant taxa across different jurisdictions and propose prioritisation procedures to tackle these mismatches and to integrate information into a harmonised workflow at the national scale. This integration has made possible the creation of a standardised dataset at the Australian national scale (the Alien Flora of Australia). In Australia, having an integrated workflow for referring to and monitoring alien flora will aid early warning and prevent species introduction, facilitate decision-making and aid biosecurity measures.

Abstract Invasive alien species are one of the major threats to global biodiversity, ecosystem integrity, nature's contributions to people and human health. While scenarios about potential future developments have been available for other global change drivers for quite some time, we largely lack an understanding of how biological invasions might unfold in the future across spatial scales. Based on previous work on global invasion scenarios, we developed a workflow to downscale global scenarios to a regional and policy‐relevant context. We applied this workflow at the European scale to create four European scenarios of biological invasions until 2050 that consider different environmental, socio‐economic and socio‐cultural trajectories, namely the European Alien Species Narratives (Eur‐ASNs). We compared the Eur‐ASNs with their previously published global counterparts (Global‐ASNs), assessing changes in 26 scenario variables. This assessment showed a high consistency between global and European scenarios in the logic and assumptions of the scenario variables. However, several discrepancies in scenario variable trends were detected that could be attributed to scale differences. This suggests that the workflow is able to capture scale‐dependent differences across scenarios. We also compared the Global‐ and Eur‐ASNs with the widely used Global and European Shared Socioeconomic Pathways (SSPs), a set of scenarios developed in the context of climate change to capture different future socio‐economic trends. Our comparison showed considerable divergences in the scenario space occupied by the different scenarios, with overall larger differences between the ASNs and SSPs than across scales (global vs. European) within the scenario initiatives. Given the differences between the ASNs and SSPs, it seems that the SSPs do not adequately capture the scenario space relevant to understanding the complex future of biological invasions. This underlines the importance of developing independent but complementary scenarios focussed on biological invasions. The downscaling workflow we implemented and presented here provides a tool to develop such scenarios across different regions and contexts. This is a major step towards an improved understanding of all major drivers of global change, including biological invasions. Read the free Plain Language Summary for this article on the Journal blog.

Non-native conifers have been planted widely because of their growth potential and wood quality. However, many of them have become invasive in the introduced ranges. In Chile, the initial introduction of non-native conifers helped the recovery of degraded land, but today some pine species present a high invasion risk when they are not properly managed, leading to detrimental impacts on natural ecosystems and biodiversity. Such is the case of Douglas fir (Pseudotsuga menziesii), a species listed as invasive in south-central Chile, as well as in many other countries, when it establishes beyond the original plantation range. The main goal of this research was to characterize the invasion pattern of P. menziesii within a recently-declared protected area nearby the Conguillío National Park in the Andes Cordillera. We aimed at determining the key factors that promote the invasion of P. menziesii outside the original plantations. We established five 1,000 m2 sampling transects (i.e., 100×10 m), considering two invasion conditions: (i) within the native forest and (ii) far into open scrub areas, both adjacent to P. menziesii plantations. We measured forest structure, soil nutrients, the floristic composition and pine regeneration before and after controlling the invasion within each study conditions. We found that P. menziesii density and soil nutrient availability in the soil decreased with the distance from the plantation. In addition, an increase in native species cover was found after removing pines, but also noted the ability of P. menziesii to readily re-invade the native forest after removal. These results indicate the need for continuous control of P. menziesii, especially inside the native forest at the early stages of invasion. We discuss the need for better plantation management to prevent its spread into natural areas and protect native forests from non-native conifers invasion.

Abstract Biological invasions are a major threat to Australia. Information on alien flora in Australia is collated independently by different jurisdictions, which has led to inconsistencies at the national level, hampering efficient management. To harmonise different information sources, we present the Alien Flora of Australia (AFA), a nationally unified dataset. To create the AFA, we developed an R script that compares existing data sources (the Australian Plant Census and state and territory censuses), identifies mismatches among them and integrates the information into unified invasion statuses at the national scale. The AFA follows the taxonomy and nomenclature adopted for the Australian Plant Census, introduction status and impact of plants known to occur in Australia. The up-to-date information presented in this dataset can aid early warning of alien species invasions, facilitate decision-making at different levels, and biosecurity at national scale. The associated script is ready to be implemented into new versions of the AFA with updated releases of any of the data sources, streamlining future efforts to track of alien flora across Australia.

Abstract Islands have unique vulnerabilities to biodiversity loss and climate change. Current Nationally Determined Contributions under the Paris Agreement are insufficient to avoid the irreversible loss of critical island ecosystems. Existing research, policies, and finance also do not sufficiently address small islands’ social-environmental challenges. For instance, the new Global Biodiversity Framework (GBF) mentions islands in the invasive species management target. This focus is important, as islands are at high risk to biological invasions; however, this is the only GBF target that mentions islands. There are threats of equal or greater urgency to small islands, including coastal hazards and overexploitation. Ecosystems such as coral reefs and mangroves are crucial for biodiversity, coastal protection, and human livelihoods, yet are unaddressed in the GBF. While research and global policy, including targeted financial flows, have a strong focus on Small Island Developing States (SIDS), the situation of other small islands has been largely overlooked. Here, through a review of policy developments and examples from islands in the Philippines and Chile, we urge that conservation and climate change policies place greater emphasis on acknowledging the diversity of small islands and their unique governance challenges, extending the focus beyond SIDS. Moving forward, global policy and research should include the recognition of small islands as metacommunities linked by interacting species and social-ecological systems to emphasize their connectivity rather than their isolation. Coalition-building and knowledge-sharing, particularly with local, Indigenous and traditional knowledge-holders from small islands, is needed to meet global goals on biodiversity and sustainable development by 2030.

Understanding the likely future impacts of biological invasions is crucial yet highly challenging given the multiple relevant environmental, socio-economic and societal contexts and drivers. In the absence of quantitative models, methods based on expert knowledge are the best option for assessing future invasion trajectories. Here, we present an expert assessment of the drivers of potential alien species impacts under contrasting scenarios and socioecological contexts through the mid-21st century. Based on responses from 36 experts in biological invasions, moderate (20%-30%) increases in invasions, compared to the current conditions, are expected to cause major impacts on biodiversity in most socioecological contexts. Three main drivers of biological invasions-transport, climate change and socio-economic change-were predicted to significantly affect future impacts of alien species on biodiversity even under a best-case scenario. Other drivers (e.g. human demography and migration in tropical and subtropical regions) were also of high importance in specific global contexts (e.g. for individual taxonomic groups or biomes). We show that some best-case scenarios can substantially reduce potential future impacts of biological invasions. However, rapid and comprehensive actions are necessary to use this potential and achieve the goals of the Post-2020 Framework of the Convention on Biological Diversity.