An international research team led by scientists from the University of Vienna, together with colleagues at BOKU University and the Austrian Academy of Sciences, analysed vegetation records from 62 European mountain summits that were surveyed four times between 2001 and 2022. The plots form part of GLORIA, the Global Observation Research Initiative in Alpine Environments, a worldwide monitoring network coordinated from Austria that uses standardised multi-summit plots to track vegetation change across elevation gradients. Because every summit in the network is revisited on the same schedule and with the same methods, the dataset offers an unusually clear window into how alpine plant communities respond to a warming climate in near real time.

The underlying mechanism is straightforward. Until a few decades ago, short growing seasons, low accumulated warmth and the risk of frost at any time of year made Europe’s alpine landscapes effectively impenetrable to many lowland and montane species. Accelerating climate warming has relaxed these constraints, allowing plants to expand their ranges upward. Summit vegetation has consequently become more species-rich, a pattern documented repeatedly across mountain ranges on several continents. What the new analysis adds is the other side of the ledger: an explicit, quantified account of the species that vanish from these same summits, and of how quickly those disappearances are accelerating.

The data show that the percentage of species not re-detected on a given summit increased with each successive survey period. In other words, local extinctions are not a rare background process but a growing one, and the trend has strengthened over the past two decades. Crucially, the losses were not distributed randomly across the flora. Species whose centres of distribution lie above the elevation of the focal summit were significantly overrepresented among those that disappeared. These are the cold-adapted specialists of the highest zones, the cushion plants, mosses and rosette herbs that have nowhere higher to go and that give alpine ecosystems their distinctive character.

The study’s statistical analysis points unambiguously to warming as the driver. First author Johannes Wessely of the University of Vienna notes that species were more likely to disappear from summits that experienced stronger warming, and that this correlation with the magnitude of temperature increase was even stronger than the simple passage of time. That distinction matters scientifically: if extinctions merely tracked the calendar, any number of unrelated processes could be responsible. The fact that the loss rate scales with the degree of warming experienced at each site identifies rising temperatures as the proximate cause of the accelerating disappearances.

Position within a species’ overall range turned out to be a second powerful predictor. The likelihood of local extinction increases towards the lower elevational margin of a species’ current distribution. Harald Pauli, coordinator of the GLORIA network at the Austrian Academy of Sciences and BOKU University, explains the implication plainly: when species already grow on warmer-than-average sites, they become more sensitive to further temperature increases. Populations at the warm edge of a range are, in effect, living closest to their physiological limits, so each additional fraction of a degree pushes them closer to the threshold beyond which they can no longer persist on a given summit.

One of the most conceptually important findings concerns timing. The specialists of high elevations tend to be particularly stress-tolerant and long-lived. Individual plants of some alpine species can survive for many decades, and their populations can persist in declining condition long after the environmental conditions that once sustained them have gone. This means local extinction can lag far behind the onset of the environmental changes that ultimately trigger it, a phenomenon ecologists describe as an extinction debt. Biological communities accumulate invisible losses that will only become apparent years or decades later, when the last surviving individuals of a doomed population finally die out.

This lag effect has long been the leading explanation for an asymmetry in alpine vegetation records: colonisations by new species arriving from below have been documented far more frequently than extinctions of established residents. The new results fit that interpretation closely. The analysis found that local extinctions are typically preceded by longer phases of population decline, meaning that the disappearances recorded between surveys are the end point of processes that began much earlier. Stefan Dullinger, project coordinator of the study, emphasises that the elevated extinction rates observed today could therefore indicate that an extinction debt accumulated over past decades is now starting to be paid off, although he cautions that whether this interpretation holds true needs further investigation.

The implications of that possibility are sobering. If current extinction rates reflect warming that occurred or at least began decades ago, then the losses already locked into alpine communities exceed what the monitoring record shows today. The full cost of twentieth-century and early twenty-first-century warming may still be working its way through populations of long-lived mountain plants, with further disappearances inevitable even under optimistic emissions scenarios. At the same time, the accelerating trend means that new debts continue to accumulate, stacking future losses on top of those already in the pipeline. For the cold-adapted specialists of Europe’s highest summits, there is little room for upward retreat: many already occupy the top of their mountains, and the regional species pool offers no replacement flora adapted to the harshest summit conditions.

The study reframes a widely cited indicator of climate change impact. Rising species richness on mountain summits has often been presented as evidence that alpine biodiversity is, for now, benefiting from warming. The new analysis shows that this metric is misleading on its own, because it counts arrivals while ignoring departures and because the departures disproportionately remove the species that are most characteristic of alpine ecosystems. Biodiversity change, the authors argue, must be assessed on both sides of the ledger simultaneously. The research was funded by the European Research Council under the European Union’s Horizon 2020 research and innovation programme, grant agreement number 883669, and the long-term GLORIA monitoring that made it possible continues across summit sites worldwide, providing the observational foundation needed to test whether the extinction debt now visible on Europe’s mountaintops will continue to grow.

Subject of Research: Accelerating climate-driven local extinctions of high-elevation specialist plants on European mountain summits

Article Title: Rising plant extinction rates on European mountain summits

Article References: Rising plant extinction rates on European mountain summits. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: alpine plants, mountain summits, climate warming, local extinction, extinction debt, GLORIA, biodiversity monitoring, species range shifts, high-elevation specialists, European Alps, vegetation change, Science journal

An international team led by Juliano Palacios-Abrantes of the Institute for the Oceans and Fisheries at the University of British Columbia, together with colleagues from Fundación MarViva, the Charles Darwin Foundation and partner institutions across the region, set out to answer a deceptively simple question. If the countries of the Eastern Tropical Pacific improve their fisheries management and conservation enforcement, can they buffer their marine ecosystems against the impacts of a warming ocean? The answer, drawn from an unusually detailed modelling exercise, is a qualified yes, with an important caveat: neither conservation nor fisheries management alone is enough, and the two must advance in parallel.

The scientific challenge is formidable. The Eastern Tropical Pacific is a region of high endemism and extraordinary migratory species, from tunas and billfishes to scalloped hammerhead sharks that move between island sanctuaries. It is also a region where climate stressors converge. Surface temperatures are projected to rise by up to 0.96 degrees Celsius by 2050 under a high-emission scenario, while oxygen minimum zones, already a defining feature of the region, are expected to expand and shoal. Warmer, less oxygenated water compresses the vertical habitat available to pelagic species, disrupts trophic interactions across the food web and shifts species distributions, often poleward toward the Humboldt Current system. On top of these pressures, illegal, unreported and unregulated fishing has historically undermined the conservation benefits that the protected areas were designed to deliver.

To explore how these forces might interact, the researchers built their analysis around a dynamic bioclimate envelope model, or DBEM, operating on a half-degree grid across the exclusive economic zones of the four member countries, ten marine protected areas and the adjacent high seas. The model ingests spatially explicit outputs from three Earth System Models contributed to the sixth phase of the Coupled Model Intercomparison Project, from the Geophysical Fluid Dynamics Laboratory, the Institut Pierre-Simon Laplace and the Max Planck Institute. These inputs, including temperature, oxygen, salinity, net primary production and ocean currents, are translated into habitat suitability indices for each of 42 species identified as priorities during stakeholder workshops held in December 2023 and May 2024. The model then simulates population growth, adult and larval dispersal through advection-diffusion-reaction equations, and even the effect of warming and oxygen loss on individual growth through a generalized von Bertalanffy growth sub-model.

What makes the study distinctive is its treatment of management. Rather than assuming regulations on paper translate into protection at sea, the team co-developed five scenarios with regional stakeholders, capturing everything from the status quo, in which fishing mortality runs roughly 30 percent above sustainable levels and protected cells still experience 20 percent of that pressure, to a future in which all rules are respected and fishing everywhere occurs at maximum sustainable yield. Intermediate scenarios tested the consequences of implementing only conservation measures or only fisheries reforms, and of abandoning enforcement altogether, which the model represented as fishing mortality 50 percent above sustainable levels inside and outside protected areas.

The projections are sobering. Under continued status quo management, biomass of the region’s key species holds roughly steady through 2030 under the low-emission SSP1-2.6 pathway but begins declining by 2050 under the high-emission SSP5-8.5 pathway. Regional patterns diverge sharply from this overall trend. Panama’s exclusive economic zone fares worst, with projected biomass losses of around 13 percent by 2030 and losses reaching 20 percent around Coiba by 2050, while Ecuador’s insular waters and the Galápagos Marine Reserve show near-zero change, albeit with low confidence across the climate models. By mid-century, most sub-regions are projected to lose between 7 and 15 percent of their biomass relative to a 1951 to 2014 baseline.

The statistical analysis, a generalized additive model explaining 85 percent of the deviance in projected biomass change, identified management scenario as the strongest lever. Implementing fisheries regulations alone produced the largest single improvement relative to the unimplemented scenario, followed closely by full implementation of both conservation and fisheries rules. The high-emission climate pathway and the later 2050 time frame both depressed biomass independently, and MPA area exerted a strong but non-linear influence, suggesting that size alone does not determine a reserve’s climate resilience. Latitude mattered too, with biomass declining linearly as one moves northward through the corridor.

One of the most intriguing findings concerns the Galápagos, where implementing conservation rules alone sometimes appeared to yield slightly worse percentage outcomes than the status quo. The authors attribute this to what conservation scientists call the relative abundance protection paradox. Because the Galápagos reserve has already succeeded in rebuilding biomass, its baseline is higher, so climate-driven losses appear proportionally larger even though the reserve maintains more absolute biomass than less-protected areas. The pattern is a reminder that percentage comparisons can mislead, and that well-protected areas may be quietly doing exactly what they were designed to do.

The study also highlights the double-edged role of upwelling systems. Regions such as the Galápagos, which show the smallest projected losses, benefit from upwelling that delivers cool, nutrient-rich water to the surface, potentially acting as thermal refugia. Yet the same process can lift the upper boundary of the oxygen minimum zone closer to the surface, compressing habitat for tunas and billfishes that already face declining suitability in the region. Stronger currents projected under climate change may also scatter primary productivity offshore, weakening the food web that upwelling is supposed to sustain. The authors argue these zones should be managed as dynamic systems requiring continuous monitoring of oxygen and productivity rather than treated as stable sanctuaries.

The policy implications are direct. Fisheries management, the study finds, delivers a larger buffering effect than conservation because it regulates activity across entire exclusive economic zones rather than within smaller reserve boundaries, and reforms need not rely solely on effort limits. Shifting from high-bycatch gears such as longlines toward selective, low-impact methods, including the green-stick technique for tunas, would reduce mortality of sharks, billfishes and turtles while potentially raising economic returns for coastal communities. In Costa Rica, where the small but strictly protected Cocos Island coexists with the larger Bicentenario area that still lacks a management plan, targeted low-impact fisheries and stronger traceability measures could substantially amplify conservation gains. The authors also urge CMAR to move beyond its current non-binding structure, establishing a dedicated fisheries management body and thematic working groups on fisheries and tourism, the two most influential human uses in the region. Even under the most optimistic combination of mitigation and management, some biomass decline is inevitable, but the modelling makes clear that coordinated, enforced, transboundary action can meaningfully offset climate losses, offering a template as nations race to meet the Kunming-Montreal Global Biodiversity Framework’s 30-by-30 target.

Subject of Research: Climate change impacts and management resilience of marine biomass in the Eastern Tropical Pacific marine protected area corridor

Article Title: Climate change and ocean management shape marine biomass resilience in the Marine Corridor of the Eastern Tropical Pacific

Article References: Palacios-Abrantes, J., Clarke, T. M., Jiménez, A. B., Romero-Chaves, R., Villalobos-Rojas, F., Sánchez-Godínez, C., Viteri-Mejía, C., Martínez-Fernández, D., Moity, N., Ramírez, J., & Cheung, W. W. L. (2026). Climate change and ocean management shape marine biomass resilience in the Marine Corridor of the Eastern Tropical Pacific. Discover Oceans, 3(1), Article 38. https://doi.org/10.1007/s44289-026-00151-3

Image Credits: AI Generated

DOI: 10.1007/s44289-026-00151-3

Keywords: marine protected areas, climate change, fisheries management, Eastern Tropical Pacific, CMAR, ocean warming, oxygen minimum zones, biomass projections, Galápagos, transboundary conservation, species range shifts, ecosystem modelling