FUT4 | Exploring the risks and opportunities of non-native species for the future of biodiversity
Exploring the risks and opportunities of non-native species for the future of biodiversity
Convener: Martin Schlaepfer | Co-conveners: Jens-Christian Svenning, Erick Lundgren
Orals
| Wed, 17 Jun, 10:30–12:00, 16:30–18:00|Room Flüela
Posters
| Attendance Wed, 17 Jun, 13:00–14:30 | Display Wed, 17 Jun, 08:30–Thu, 18 Jun, 18:00
Orals |
Wed, 10:30
Wed, 13:00
The accelerating impacts of climate change compel conservation biology to rethink traditional approaches, including the rigid dichotomy between native and non-native species. Conservation efforts increasingly require adaptive, forward-looking strategies that acknowledge biotic novelty and prioritize ecosystem function and human well-being.

Non-native species, long viewed primarily as threats, may play vital roles in maintaining biodiversity and ecosystem services under future climatic regimes. Some are more likely to persist than native species, providing safeguards against extinctions and ensuring continued provisioning of ecosystem functions such as pollination, carbon sequestration, or habitat structure. Novel ecosystems shaped by non-native species may also assist in species survival through processes like hybridization or novel mutualisms.

However, these potential benefits must be carefully weighed against substantial risks. Non-native species can reduce ecosystem resilience, alter trophic dynamics, and contribute to native species decline. The value of nonnative species must be considered alongside common concerns about them such as, the loss of ecological integrity and cultural values.

In this session we seek speakers who advocate for nuanced assessments that incorporate both scientific evidence and diverse societal values. This proposed session will create space for critical discussion of these emerging perspectives, facilitate the sharing of empirical evidence and case studies, and help shape a pragmatic, ethically grounded conservation paradigm. By addressing the dual roles of non-native species as both potential allies and threats, the session will foster more adaptive and inclusive conservation strategies suited to a rapidly changing world.

Orals: Wed, 17 Jun, 10:30–18:00 | Room Flüela

Chairpersons: Martin Schlaepfer, Erick Lundgren, Jens-Christian Svenning
FUT-4, Part I
10:30–10:45
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WBF2026-15
Jens-Christian Svenning

Human-driven environmental change has set in motion the largest global biotic reorganization in millions of years. Climate shifts, land-use transformation, defaunation, and species translocations are collectively reshaping ecological networks and altering the equilibria that have historically maintained biodiversity. In this changing biosphere, non-native species—long viewed primarily as threats—are integral to emerging ecological dynamics, acting through fundamental mechanisms that both erode and sustain diversity.

Across ecosystems, introduced organisms influence trophic interactions, resource use, and disturbance regimes, thereby affecting the basic mechanisms shaping biodiversity. These processes unfold amid profound climatic disequilibria and persistent human legacies, driving an expansion of self-organizing ecosystems without historical precedent. The question is no longer whether non-native species will shape future biodiversity, but how their roles will interact with changing environmental and ecological conditions to define the composition, structure, and function of tomorrow’s ecosystems.

Understanding these transitions requires a mechanistic focus—on competition, facilitation, trophic regulation, hybridization, and mutualistic reassembly—rather than on species’ origins. Global synthesis reveals that interacting novelty drivers, including climate change, defaunation, and floristic reconfiguration, now affect most of the terrestrial biosphere. Within this context, ecosystem functioning and evolutionary potential increasingly depend on the adaptive capacity of mixed assemblages. Whether this transformation leads to homogenization and biodiversity loss, or to diversification and new stable states, will hinge on how geographic dynamics, functional complementarity, and environmental heterogeneity are maintained.

Looking forward, biodiversity stewardship must emphasize process persistence and disequilibrium management over static composition—sustaining the flows of energy, materials, and information that underpin ecological and evolutionary renewal, along with mechanisms promoting biodiversity maintenance. Integrating macroecological foresight, long-term experimentation, and adaptive restoration can help steer ecosystems along trajectories that maintain high diversity and functional resilience. Non-native species are part of this reality—not as categorical enemies, but as agents whose roles must be understood, anticipated, and directed to sustain life’s diversity in the deep future.

How to cite: Svenning, J.-C.: Non-Native Species, Novel Ecosystems, and the Future of Biodiversity in a Transforming Biosphere, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-15, https://doi.org/10.5194/wbf2026-15, 2026.

10:45–11:00
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WBF2026-27
Weihan Zhao, Trevor S. Fristoe, Amy J.S. Davis, Wayne Dawson, Franz Essl, Holger Kreft, Jan Pergl, Petr Pysek, Patrick Weigelt, Marten Winter, and Mark van Kleunen

Human actions pose threats to numerous native plant species. At the same time, humans have introduced many plant species beyond their native ranges, where some of these plants have become naturalized or even invasive. Invasive plant species are listed as one of the main threats to many threatened native plants. Interestingly, however, there are also plant species that are threatened in their native range but have become naturalized or even invasive elsewhere. Such threatened-but-naturalized plants species constitute a conservation paradox. The number of threatened-but-naturalized plants species and what characteristics distinguish them from other threatened species remains unknown. Here, we combined databases of global threat status and naturalization success of the world’s vascular plants, and added information on growth forms, economic uses and their native and non-native ranges. We found that among the 26,036 species assessed as threatened by the IUCN, only 238 (ca. 1%) have become naturalized elsewhere, and 21 of those are considered invasive in at least one country. If we extrapolate from the number of IUCN-assessed species to the entire extant global vascular flora, we estimate that between 1000 to 2000 plant species might be threatened at home but naturalized elsewhere. Most of the threatened-but-naturalized species are trees or shrubs with economic uses such as provisioning of materials and use for landscaping. More threatened species than expected have naturalized in Europe from nearly all other continents. Furthermore, although Africa is the largest donor of threatened-but-naturalized species in absolute numbers, the numbers are nevertheless lower than expected due to the continent’s overall large number of threatened species. Our study shows that, although the number is relatively low, some threatened plant species have managed to become naturalized outside their native range, and deviate in some of their characteristics from the other threatened species. Future studies should assess the potential conservation value of the naturalized populations of threatened species.

How to cite: Zhao, W., Fristoe, T. S., Davis, A. J. S., Dawson, W., Essl, F., Kreft, H., Pergl, J., Pysek, P., Weigelt, P., Winter, M., and van Kleunen, M.: The conservation paradox of plants that are threatened at home but naturalized elsewhere, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-27, https://doi.org/10.5194/wbf2026-27, 2026.

11:00–11:15
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WBF2026-39
Willem Goossens, Christian Ledergerber, Stef Haesen, Marijke Geuskens, Senne Spreij, Irena Axmanová, Idoia Biurrun, François Gillet, Florian Jansen, Borja Jiménez-Alfaro, Veronika Kalusová, Jonathan Lenoir, Gabriele Midolo, Jens-Christian Svenning, Jürgen Dengler, and Koenraad Van Meerbeek and the EVA contributors

Human activities have introduced alien plant species far beyond their native ranges around the globe. Although only a fraction of these alien plants becomes harmful to ecosystems, alien species are often treated as a uniform group, irrespective of their actual ecological effects. Using over half a million vegetation plots across Europe, we conducted the first large-scale analysis of how alien vascular plants impact local plant species richness, disentangling the role of species origin, dominance and environmental context. To ensure a fair assessment, we compared the impacts of alien species with those of natives and distinguished between intracontinental (European) and extracontinental (non-European) introductions.

Our results show that both European and non-European alien species tend to be more dominant than natives, albeit less frequent. However, alien plants were only associated with lower species richness compared to natives at low cover, with no significant difference in impact between biogeographic origins at higher cover levels. Furthermore, non-European aliens exhibited stronger average impacts and higher likelihood of reaching dominance when present than European aliens, underscoring the potential influence of shared evolutionary history to limit ecological impacts. We further observed that alien plant richness is primarily associated with anthropogenic disturbances and proxies for eutrophication and acidification. Hence, the reduced species richness in plots with low alien cover likely reflects environmental degradation preceding alien establishment, rather than competitive exclusion, suggesting that most alien species act as passengers and not drivers of ecological change. Indeed, plot-level species richness was mostly reduced by human pressures, while alien plant prevalence explained relatively little variation in native species richness – respectively 0.9% and 1.9% for European and non-European aliens.

Overall, our study challenges normative classifications of invasiveness, since many species labelled as invasive exhibited neutral or even positive overall effects on plant species richness. These findings highlight the need to manage plant species based on demonstrated ecological impact rather than on biogeographic origin or expert-based assessments and emphasize the central role of anthropogenic stressors in shaping European plant communities.

How to cite: Goossens, W., Ledergerber, C., Haesen, S., Geuskens, M., Spreij, S., Axmanová, I., Biurrun, I., Gillet, F., Jansen, F., Jiménez-Alfaro, B., Kalusová, V., Lenoir, J., Midolo, G., Svenning, J.-C., Dengler, J., and Van Meerbeek, K. and the EVA contributors: Passengers, not drivers of change: Rethinking alien impacts in a human-shaped world, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-39, https://doi.org/10.5194/wbf2026-39, 2026.

11:15–11:30
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WBF2026-112
Martin Schlaepfer

The accelerating impacts of climate change compel conservation biology to rethink traditional approaches, including the rigid dichotomy between native and non-native species. Conservation efforts increasingly require adaptive, forward-looking strategies that acknowledge biotic novelty and prioritize ecosystem function and human well-being.

Non-native species, long viewed primarily as threats, may play vital roles in maintaining biodiversity and ecosystem services under future climatic regimes. Some are more likely to persist than native species, providing safeguards against extinctions and ensuring the continued provision of ecosystem functions such as pollination, carbon sequestration, or habitat structure. Novel ecosystems shaped by non-native species may also assist in species survival through processes such as hybridization or novel mutualisms.

In this presentation, I will address two related questions: (1) Can we identify distribution characteristics of non-native species that are desirable or undesirable? In other words, what might be the “ideal” distribution (presence and abundance) of non-native species in a rapidly changing world—both in absolute terms and relative to native species? (2) Empirically, what are the current distribution and abundance of non-native species at various spatial scales?

Most conservation strategies are silent about desired outcomes or implicitly use a “pristine” world as a benchmark. In addition, conservation biologists generally assume that the addition of non-native species to local ecosystems is undesirable because of the risk that some non-native species could become problematic or because they alter the “natural equilibrium.” Such benchmarks are increasingly obsolete in a rapidly changing world. I outline several alternative outcomes for the distribution of non-native species (relative to native species) and discuss their value in light of different worldviews or normative lenses (intrinsic, instrumental, relational values). I then quantify the relative abundance of non-native species at local and regional scales (numbers not available at the time of abstract submission) and discuss the empirical results in light of different theoretical and normative considerations.

How to cite: Schlaepfer, M.: Exploring the role of normative benchmarks when gauging forthcoming effects of non-native species, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-112, https://doi.org/10.5194/wbf2026-112, 2026.

11:30–11:45
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WBF2026-114
Bart Steen

 

Invasive alien species (IAS), meaning the fraction of non-native species that cause harm to ecological processes and/or economy and/or public health, present a major threat to biodiversity and ecosystem services. Managing and controlling them is of paramount importance. To guide conservation efforts, detailed maps of potential distributions of IAS, as for instance produced by species distribution models (SDMs), are very useful, but lacking in the dimension of probability of invasion success. An important barrier to the successful establishment of IAS is climate. The Niche Margin Index (NMI) provides a measure of (dis)similarity between the native climatic niche of IAS and the environmental conditions in another site (which, for these purposes, would be a (potential) invasion site). This measure was shown to be positively correlated with invasion success in invasive vertebrates. However, special caution is advised to pick the method to define the native climatic niche, as Species Distribution Modelling outputs have been advised over expert-based maps to support conservation decisions. This study therefore examines the effect on NMI of using three different methods to define the native range: the full native range polygons, the geographical occurrences of the species inside the native range, and a binarized SDM of the native range. The last method occupies the middle ground between the first and second, which present the highest and lowest NMI, respectively (i.e. occurrences < SDMs < range polygons). This has implications for nature conservation and invasion science, as it points out new considerations that must be made before the probability of invasion success is assessed. These include decisions on when (at what dispersal distance) the climatic barriers become important, and whether different barriers must be considered when an invasion has moved beyond the first stage. Finding the right questions to answer is a critical prerequisite for finding the right answers, which in turn allows us to determine the right areas to target for conservation.

 

How to cite: Steen, B.: How much do out-of-the-native range occurrences of invasive alien species reflect their native niche?, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-114, https://doi.org/10.5194/wbf2026-114, 2026.

11:45–12:00
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WBF2026-363
Erick Lundgren

Novel ecosystems are rapidly becoming dominant across the world due to globalization, changing land use and abiotic conditions, and climate change. Dominant paradigms to understand novel ecosystems, and introduced organisms more broadly, consider them to be drivers of biodiversity loss and ecosystem degradation because introduced organisms did not coevolve with native communities. If this is true, then native and introduced species should have measurably different effects and one should be able to empirically determine whether a species is native or introduced by their impacts without historic knowledge. I will report on meta-analytic results stemming from >10,000 effect sizes and ~400 articles where I compared the effects of introduced and native megafauna and found that introduced and native megafauna generally have similar impacts on vegetation, soils, and other animals. These results suggest that nativeness—at least for megafauna—may not be as important as usually considered. I will contextualize these results in relation to other similar meta-analytic tests and widely used frameworks for assessing the impacts of introduced organisms, such as the Environmental Impact Classification for Alien Taxa (EICAT) and suggest that the majority of literature on the effects of introduced organisms is rooted in tautological comparisons that do not use the proper controls to understand the effects of introduced organisms.

I will then discuss how alternative lenses towards introduced species can help reveal overlooked ecological patterns and processes, especially in the context of Earth’s history, and can provide new opportunities to prevent extinctions. Including introduced species in conservation decision making is not simple and requires broader and more pluralistic value systems towards non-human life. I will outline how these values can provide robust guideposts for conservation action and how they can also reduce the bias of our science, make our discipline more culturally inclusive, and help us navigate a time of rapid environmental change.

How to cite: Lundgren, E.: Is nativeness measurable? , World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-363, https://doi.org/10.5194/wbf2026-363, 2026.

FUT-4, Part II
Lunch break
Chairpersons: Jens-Christian Svenning, Martin Schlaepfer, Erick Lundgren
16:30–16:45
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WBF2026-609
Daniel Ramp, Rosalie Chapple, Laura McLauchlan, and Erick Lungren

Debates over introduced species remain a persistent fault line in conservation biology. While some view them as major threats to biodiversity, others argue these concerns are overstated and advocate for more inclusive, pragmatic approaches to extinction prevention. These disagreements stem not only from empirical uncertainty but also from deep ontological and epistemological differences about ecosystem function and problem framing. Consequently, trust and communication have eroded, limiting scientific progress.

Adversarial collaboration, which facilitates structured cooperation between individuals with opposing views, offers a promising way to resolve empirical disputes. However, success requires groundwork to establish shared understanding, clarified values, and conditions for productive disagreement. We focus on constructive discussion as this precursor, a process enabling participants to articulate perspectives, surface assumptions, and explore differences without collapsing them.

To lay this foundation, we conducted semi-structured interviews with 16 stakeholders involved in introduced species research and management in Australia. Participants included researchers, land managers, hunters, policy advocates, and representatives from conservation and Indigenous communities across university, government, and non-government sectors. Interviews explored how introduced species are understood and acted upon; perceived successes and limitations of invasion biology; experiences shaping positionalities; and tensions around concepts such as nativeness and coevolution.

Thematic analysis revealed patterns in language, framing, and normative commitments. Stakeholders were receptive to engaging with divergent views and called for nuanced, mature conversations that embrace complexity rather than binary positions. While all agreed change is needed, interviews exposed deep ontological differences about what the issue is, underscoring the need for constructive dialogue addressing these fundamentals.

This groundwork will inform future facilitated workshops, bringing interviewees together for structured discussion and co-design of research questions. These workshops will initiate adversarial collaboration to rigorously interrogate contested empirical claims and advance inclusive, transparent, and trustworthy conservation science. Ultimately, the project seeks to foster adaptive, inclusive responses to introduced species and greater acceptance of novel ecosystems.

How to cite: Ramp, D., Chapple, R., McLauchlan, L., and Lungren, E.: Laying the groundwork for constructive discussions on introduced species, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-609, https://doi.org/10.5194/wbf2026-609, 2026.

16:45–17:00
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WBF2026-950
Arnau Bosch Guiu, Julian W Zeller, Pablo González-Moreno, and Ana Novoa Pérez

Alpine and montane regions globally hold key biodiversity, yet they are threatened by various human pressures that are projected to increase during the 21st century. Invasive species are considered one of the main drivers of biodiversity loss globally. Nevertheless, until recently, alpine and montane systems were among the few ecosystems where invasive plant pressure remained limited. However, recent assesments and reports suggest that this situation is currently changing, as climate warming, land use change, pollution and higher rates of introductions expand species distributions into previously less disturbed mountain habitats. High-elevation habitats can therefore be used as valuable model systems to study invasion patterns and mechanisms. As a result, mountain ecosystems provide valuable model systems for studying invasion patterns and underlying mechanisms, particularly for plants, whose distributions and dynamics have been extensively monitored across regions, to better understand these species future impacts.
In this study, we assess the magnitude and mechanisms of the negative environmental impacts caused by alien plant species occurring in mountain ecosystems worldwide. Specifically, we compiled a list of 564 species recorded as naturalized in 18 mountain regions based on standardized road surveys along elevational gradients conducted by the Mountain Invasion Research Network (MIREN). We evaluated these species using the Environmental Impact Classification for Alien Taxa (EICAT), an objective and transparent method recognized by the IUCN to classify alien species according to the severity of their impacts on native species populations and the mechanisms driving these impacts. Assessments included impacts occurring in both mountain and non-mountain ecosystems.
Our preliminary results suggest that empirical evidence on the environmental impacts of most alien plant species remains limited or entirely lacking, particularly in mountain environments. For the species with available information, the most frequently reported impact mechanisms include competition with native species, indirect effects mediated through interactions with other organisms, and allelopathic effects, such as disruption of pollinator networks.

How to cite: Bosch Guiu, A., Zeller, J. W., González-Moreno, P., and Novoa Pérez, A.: Evaluating impacts of plant invasions in mountains, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-950, https://doi.org/10.5194/wbf2026-950, 2026.

17:00–17:15
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WBF2026-565
David Havlick and Christine Biermann

Coldwater fisheries around the world face an array of challenges, ranging from warming temperatures to habitat modification and introduced species. Recent advances in genetic and genomic analyses are also reordering long-standing conceptions of fish taxonomy and range, leading to new questions about which organisms belong in particular watersheds as true or “historic” natives, which might be considered “near-natives,” and which are introgressed hybrids or interlopers brought in through human activity (e.g. Lemoine and Svenning, 2022). While these changes are often seen as threats to salmonid and coldwater fish conservation, they also present opportunities to manage biodiversity in new and potentially adaptive ways. In this paper we critically examine efforts in the US Rocky Mountain West to strike a balance between privileging native species, managing near-natives as ecological cognates that may carry advantages of resilience or reproduction, and introducing non-natives as part of managed novel ecosystems that cater to ecological or cultural interests. We focus in particular on two cases of coldwater fish conservation that highlight these dynamics: 1) the management of native cutthroat trout species (Oncorhynchus clarkii) that recent genetic assays have found to be taxonomically different than previously thought, whether due to trans-basin relocations and/or hybridization; and 2) the intentional introduction of sterile, hybrid tiger muskies (a cross between muskellunge [Esox masquinongy] and northern pike [Esox lucius]) to a high-elevation reservoir to control the proliferation of an earlier introduced species, the white sucker (Catostomus commersonii). Both cases illustrate how shifting scientific knowledge and emergent novel ecosystems create new ecological and social dynamics for conservation efforts to negotiate as we turn toward forward-looking strategies that account for biotic novelty, ecosystem function, and cultural interests.

 

Citation: Lemoine, R. T., & Svenning, J. C. (2022). Nativeness is not binary – a graduated terminology for native and non‐native species in the Anthropocene. Restoration Ecology30(8), e13636.

How to cite: Havlick, D. and Biermann, C.: Non-Natives, Near-Natives, and Coldwater Fisheries Conservation, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-565, https://doi.org/10.5194/wbf2026-565, 2026.

17:15–17:30
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WBF2026-538
Giovanni Vimercati, Anna Frances Probert, Sabrina Kumschick, and Sven Bacher

Despite their well-documented negative impacts on human well-being and biodiversity, alien species outside domestication or cultivation can also generate socio-economic benefits. Recognizing these benefits is important for identifying stakeholder conflicts and for informed decision-making by managers and policymakers. Such benefits may arise from enhancements of ecosystem services—such as the provision of food, timber, and other natural resources—or from reductions of ecosystem disservices, for example through the control of agricultural or medical pests. Although these positive impacts are broadly acknowledged, no unified framework yet exists to classify them in a way that enables systematic and rigorous comparisons across species and contexts. A key challenge is the absence of a common metric for evaluating the magnitude of diverse socio-economic benefits of alien species. Monetary assessments can capture some benefits—such as revenue from timber extraction or avoided damage due to biocontrol programs—but they struggle to account for non-market values, including natural resources (e.g. clean air), cultural contributions and health-related outcomes. Frameworks based on Ecosystem Services (ES) or Nature’s Contributions to People (NCP) offer broader perspectives but often rely on context-specific or non-comparable metrics. We argue that conceptualizing the human benefits of alien species through the lens of the capability approach—evaluating changes in people’s preferred activities and states of being as proxies for well-being—provides a holistic framework and a practical, relevant, and comparable metric for socio-economic impact assessment. We introduce SEICAT+ (the positive Socio-Economic Impact Classification for Alien Taxa), a framework designed to capture beneficial impacts of varying magnitude across all constituents of human well-being: basic materials for a good life, security, health, good social relations, and freedom of choice and action. We show how SEICAT+ can complement existing approaches based on monetary valuation, ES, and NCP, and how it can integrate with other similarly structured alien-species impact assessment frameworks—thus improving their scope, comparability, and robustness.

How to cite: Vimercati, G., Probert, A. F., Kumschick, S., and Bacher, S.: SEICAT+: a conceptual assessment framework for positive socio-economic impacts of alien species on human well-being, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-538, https://doi.org/10.5194/wbf2026-538, 2026.

17:30–17:45
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WBF2026-623
Vincent Fehr, Matteo Tonellotto, Gloria Guidotti, Chiara Benedetti, Bruno Cerabolini, Michele Dalle Fratte, Ira Tanya Handa, Marcel Hunziker, Andrea Minetti, Guido Maspoli, Robert Buitenwerf, Sergio Rasmann, Jens-Christian Svenning, Marco Conedera, Marco Moretti, and Gianni Boris Pezzatti

Novel ecosystems driven by non-native species increasingly challenge classical conservation and management paradigms, particularly when ecological change intersects with cultural values. In the lake-rich Insubric region along the Swiss–Italian border in the southern European Alps, the naturalization of the iconic Chinese windmill palm (Trachycarpus fortunei) is part of an ongoing biome shift toward mixed evergreen, laurophyllous forests. To understand the multi-dimensional implications of this process, we synthesized results from complementary ecological, functional, and socio-cultural studies.

We surveyed forest vegetation, quantified arthropod communities in paired invaded and non-invaded stands, measured litter decomposition, assessed fire behavior and post-fire stand dynamics, documented the establishment of the palm borer moth Paysandisia archon, and conducted a nationwide public perception survey. Together, these approaches allowed us to evaluate how T. fortunei reshapes biodiversity, ecosystem processes, disturbance interactions, and social attitudes.

Vegetation surveys revealed that high palm densities markedly reduce the richness of native recruiting tree species in alluvial forests, whereas effects on mixed broadleaved forests on slopes remain minimal. Arthropod communities shifted, with herbivore richness declining, likely due to reduced understory plant diversity and the low nutritional quality of palm foliage. Despite the slow decomposition of palm leaves, overall litter decomposition increased with palm abundance, suggesting microclimatic or decomposer-mediated changes. Filamentous palm roots likely provide limited slope reinforcement, offering little protection against shallow landslides. Fire assessments showed that adult palms are highly fire-resistant, yet their flammable stem-attached fuels and dry leaves can increase fire intensity and channel flames upward, causing greater damage to neighboring deciduous trees than to the palms themselves. Meanwhile, P. archon established in southern Switzerland, posing a threat to cultivated palms and potentially limiting the spread of naturalized T. fortunei. Public perception data revealed strong regional differences in attitudes toward palms, with cultural associations in southern Switzerland reducing support for control measures, although this changed markedly when ecological impacts were communicated.

Together, these studies provide a holistic assessment of the ecosystem functions and disservices of an iconic but invasive species at the center of a regional biome shift, underscoring the need for adaptive, context-specific, and socially informed management strategies for novel ecosystems.

How to cite: Fehr, V., Tonellotto, M., Guidotti, G., Benedetti, C., Cerabolini, B., Dalle Fratte, M., Handa, I. T., Hunziker, M., Minetti, A., Maspoli, G., Buitenwerf, R., Rasmann, S., Svenning, J.-C., Conedera, M., Moretti, M., and Pezzatti, G. B.: Behind the scenes of the palm invasion in Southern Switzerland: ecological, functional and societal dimensions of a banned iconic species in a shifting biome, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-623, https://doi.org/10.5194/wbf2026-623, 2026.

17:45–18:00
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WBF2026-963
Ninad Avinash Mungi and Jens-Christian Svenning

As ecological novelty accelerates worldwide, conservation debates continue to be dominated by historical baselines largely derived from sparsely populated regions of the Earth. Yet the ecological future of the planet is already visible across the Global South, where megafauna persist within some of the most densely populated, modified, and socially complex landscapes on Earth. Drawing on long-term empirical evidence from India, this talk synthesizes findings on megaherbivores and large carnivores living amidst invasive species, altered vegetation states, intensive human use, and prevalent poverty and asks what these systems reveal about managing biodiversity under irreversible change.

Across multiple ecosystems, large herbivores demonstrably reduce invasive plant dominance, maintain native plant richness, and restructure vegetation in ways that mechanical or chemical interventions rarely achieve at scale. These functional effects persist within highly novel plant communities, indicating that ecosystem function can be restored even when historical composition cannot. Parallel evidence from carnivore recovery shows that large predators can rebound and stabilize populations despite high human density, provided governance, tolerance, and livelihood contexts are addressed - challenging assumptions that novelty inevitably erodes trophic integrity.

Crucially, these outcomes are not accidental. Management decisions in novel ecosystems often emerge from collaboration with local communities who prioritize present-day utility, risk reduction, and cultural values over strict historical fidelity. In practice, novel ecosystem thinking already guides decisions on grazing, invasive species control, and habitat use, enabling coexistence with flagship megafauna while sustaining ecosystem services.

Theoretically, these findings call for shifting conservation benchmarks from historical states to empirically demonstrable functions. Applied lessons suggest that megafaunal recovery can be actively leveraged to manage invasions, regulate ecosystems, and deliver nature-based solutions in human-dominated landscapes. The broader implication is hopeful: systems long labeled “degraded” are not ecological dead ends but predictive models of the Anthropocene. Learning from megafauna already thriving within novelty may be essential for sustaining biodiversity in a rapidly transforming world.

How to cite: Mungi, N. A. and Svenning, J.-C.: Megafauna amidst rising ecological novelty: Rethinking management in the Anthropocene, World Biodiversity Forum 2026, Davos, Switzerland, 14–19 Jun 2026, WBF2026-963, https://doi.org/10.5194/wbf2026-963, 2026.

Posters: Wed, 17 Jun, 13:00–14:30

Display time: Wed, 17 Jun, 08:30–Thu, 18 Jun, 18:00
Chairpersons: Martin Schlaepfer, Erick Lundgren, Jens-Christian Svenning
WBF2026-222
Native = natural, and neither are useful concepts for conservation 
(withdrawn)
Yasha Rohwer and Emma Marris