Study reveals crowberry expansion and bilberry decline in Arctic tundra

University of Oulu, Finland

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Crowberry is taking over the fells, where it has conquered areas covered by bilberry and heather vegetation types, as well as open, wind-swept areas. These changes are affecting the sensitive ecosystems of the fells. Photo: Tuija Maliniemi, University of Oulu

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Credit: Photo: Tuija Maliniemi, University of Oulu

Researchers at the University of Oulu, Finland have observed significant vegetation changes in the treeless heath and tundra regions of northern Finland and Norway over recent decades, marked by the expansion of crowberry (Empetrum nigrum) and the decline of bilberry (Vaccinium myrtillus).

A new study indicates that the primary vegetation types in these areas—bilberry, crowberry, dwarf birch, and heather -dominated tundra—are becoming increasingly homogenized. This shift is particularly evident in bilberry-dominated landscapes, where crowberry proliferation coincides with bilberry decline. While bilberry remains a dominant species, its reduction could impact local ecosystems and alter the visual landscape, especially during autumn foliage.

The research, covering areas from Riisitunturi in northern Finland to Finnmark in Norway, utilized long-term data sets, a rarity in vegetation studies that often focus on shorter time frames and smaller regions. "Over the past decade, we've re-surveyed tundra heathlands initially mapped by Matti Haapasaari in the 1960s and 1970s. Such meticulously collected historical data are invaluable for detecting long-term vegetation changes. We plan to continue monitoring these areas in the future," says Academy Research Fellow Tuija Maliniemi.

The greening of the Arctic region also affects Lapland

Arctic regions are experiencing rapid warming, leading to increased greening and shrub expansion. However, in Finnish Lapland and northern Norway, this trend is decelerated by extensive reindeer grazing, which suppresses the growth of mountain birch and other taller shrubs. Consequently, the greening manifests as the spread of dwarf shrubs, notably crowberry.

The decline of bilberry, which is not expanding into new areas, raises concerns among researchers. "The reasons behind bilberry's decline have not been extensively studied. The unique and locally variable nature of tundra ecosystems suggests multiple factors, such as changes in snow conditions, the proliferation of evergreen plants, and reindeer grazing, may be contributing," notes Doctoral Researcher Petteri Kiilunen from the University of Oulu.

The study Long-term homogenization of Fennoscandian heathland and tundra vegetation is connected to the expansion of an allelopathic dwarf shrub was published in the Ecography scientific journal on October 10th, 2025.

Learn more

• Climate change and forest management can threaten blueberry microbes – differences between northern and southern blueberries 
• Researchers discuss the blueberry situation in a video
• Reindeer grazing can mitigate the impacts of winter climate change on forest carbon release
• Physical Geography Research Group at the University of Oulu

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DOI

10.1002/ecog.07921 

Article Title

Long-term homogenization of Fennoscandian heathland and tundra vegetation is connected to the expansion of an allelopathic dwarf shrub

Article Publication Date

10-Oct-2025

Instagram photos help scientists track invasive plant flowering patterns

Invasive succulent that smothers native plants shows extended flowering in new territories, where it can dominate coastlines

University of Galway

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Carpobrotus invasion at Duna do Caldeirão, Vila Praia de Âncora, Portugal. Credit: Jonatan Rodríguez, University of Santiago de Compostela.

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Credit: Credit: Jonatan Rodríguez, University of Santiago de Compostela.

That vibrant carpet of pink and yellow flowers blanketing Mediterranean cliffs might look beautiful in holiday photos on a social media feed. But scientists have discovered these same Instagram snapshots are revealing how one of the world's most destructive coastal plants is taking over new environments by extending its flowering season and threatening native biodiversity.

 

An international team of researchers analysed more than 1,700 photographs from social media and citizen science platforms to track Carpobrotus species - commonly known as ice plants or sour fig – across South Africa, Argentina, New Zealand, Portugal, Spain and the US.

 

These fleshy evergeen succulent plants are native to South Africa but now smother coastal ecosystems from California to the Mediterranean and transform ecosystems.

 

A single Carpobrotus plant can cover up to 50m², suffocating everything beneath it. They change soil chemistry and monopolise pollinators with their showy flowers, disrupting local ecosystems.

 

The findings have been published in Ecological Solutions and Evidence.

 

They are the result of a global study conducted by University of Galway, Institute of Botany of the Czech Academy of Sciences, University of Santiago de Compostela in Spain, Experimental Station of Arid Zones in Spain, Charles University in the Czech Republic, Macquarie University in Sydney, Stellenbosch University in South Africa, and Penn State University.

 

            Dr Susan Canavan, lead author and Honorary Researcher with the College of Science and Engineering at University of Galway, said: "We realised thousands of people were unknowingly documenting these invasions in the background of their beach selfies and cliff-top sunset photos. This gave us observers across the globe, from California's Big Sur to New Zealand's coastlines to Portugal's tourist beaches.”

 

For the research team, California's tourist hotspots provided nearly three times more usable photos than other regions, while remote locations in South Africa and the Azores relied entirely on dedicated naturalist platforms like iNaturalist.

 

The team discovered that the Carpobrotus populations flower longer than native ones, potentially producing more seeds and increasing their spread. In their native South Africa, the plants show a short, concentrated flowering peak but in invaded regions, they bloom across extended periods. This reproductive advantage may help to explain their invasive success.

 

They also found that local environmental conditions override genetic differences in determining flowering timing. The plants adapt to bloom during the local spring season, such as October in New Zealand and May-June in California and Europe, rather than maintaining the flowering patterns from their native range.

 

For coastal managers battling these invaders, the findings offer practical guidance - by revealing peak flowering times in the invaded regions, the research will help them to time removal efforts to prevent seed production.

 

            Dr Canavan added: "Tourist destinations were goldmines of data. Every scenic overlook with Carpobrotus had hundreds of Instagram posts. But this also showed us the bias in social media data. Remote invaded areas remain invisible without citizen scientists actively documenting them.

“The study also demonstrates how the digital age is transforming ecological research. What began as vacation photos and nature observations has become a powerful tool for tracking biological invasions.”

 

            Dr Ana Novoa, co-author and project lead from the Institute of Botany of the Czech Academy of Sciences, said: "These plants are notoriously difficult to control because they spread both by seed and by fragments. Even a small piece can regrow into a new colony. Knowing exactly when they flower in each region means we can strike when they're most vulnerable, before they produce the thousands of seeds that ensure next subsequent invasions."

  

Open flower and a bud of Carpobrotus in the Tower of Hércules Natural Reserve, A Coruña, Spain. 

Carpobrotus plants competing for space and pollinators with the native gorse Ulex europaeus in the Tower of Hércules Natural Reserve, A Coruña, Spain.

Credit

Jonatan Rodríguez, University of Santiago de Compostela.

The full study, published in Ecological Solutions and Evidence, is available at https://doi.org/10.1002/2688-8319.70122.

 

Ends

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Journal

Ecological Solutions and Evidence

DOI

10.1002/2688-8319.70122 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

iEcology reveals the importance of geography and genetic makeup in the flowering phenology of invasive Carpobrotus taxa

Article Publication Date

13-Oct-2025

METAL ALCHEMY

Novel metal alloy withstands extreme conditions

A new high-temperature resistant material exhibits great potential for applications such as energy-efficient aircraft turbines

Karlsruher Institut für Technologie (KIT)

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Alloy production by means of arc melting in the material synthesis lab of the Institute for Applied Materials – Materials Science and Engineering. (Photo: Chiara Bellamoli, KIT)

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Credit: Chiara Bellamoli, KIT

High-temperature-resistant metallic materials are required for aircraft engines, gas turbines, X-ray units, and many other technical applications. Refractory metals such as tungsten, molybdenum, and chromium, whose melting points are around or higher than 2,000 degrees Celsius, can be most resistant to high temperatures. Their practical application, however, has limitations: They are brittle at room temperature and, in contact with oxygen, they start to oxidize causing failure within short time already at temperatures of 600 to 700 degrees Celsius. Therefore, they can only be used under technically complex vacuum conditions – for example as X-ray rotating anodes.

 

Due to these challenges, superalloys based on nickel have been used for decades in components that are exposed to air or combustion gases at high temperatures. They are used, for example, as standard materials for gas turbines. “The existing superalloys are made of many different metallic elements including rarely available ones so that they combine several properties. They are ductile at room temperature, stable at high temperatures, and resistant to oxidation,” explains Professor Martin Heilmaier from KIT’s Institute for Applied Materials – Materials Science and Engineering. “However – and there is the rub – the operating temperatures, i.e. the temperatures in which they can be used safely, are in the range up to 1,100 degrees Celsius maximum. This is too low to exploit the full potential for more efficiency in turbines or other high-temperature applications. The fact is that the efficiency in combustion processes increases with temperature.”

 

A Chance for a Technological Leap

This limitation existing with the materials available today was the starting point for Heilmaier’s working group. Within the “Materials Compounds from Composite Materials for Applications in Extreme Conditions” (MatCom-ComMat) research training group funded by the German Research Foundation (DFG), the researchers succeeded in developing a new alloy made of chromium, molybdenum, and silicon. This refractory metal-based alloy, in whose discovery Dr. Alexander Kauffmann, now professor at the Ruhr University Bochum, played a major role, features hitherto unparalleled properties. “It is ductile at room temperature, its melting point is as high as about 2,000 degrees Celsius, and – unlike refractory alloys known to date – it oxidizes only slowly, even in the critical temperature range. This nurtures the vision of being able to make components suitable for operating temperatures substantially higher than 1,100 degrees Celsius. Thus, the result of our research has the potential to enable a real technological leap,” says Kauffmann. This specifically remarkable as resistance to oxidation and ductility still cannot be predicted sufficiently to allow a targeted material design – despite the great progress that has been achieved in computer-assisted materials development.

 

More Efficiency, Less Consumption

“In a turbine, even a temperature increase of just 100 degrees Celsius can reduce fuel consumption by about five percent,” explains Heilmaier. This is particularly relevant to aviation, as airplanes powered by electricity will hardly be suitable for long-haul flights in the next decades. Thus, a significant reduction of the fuel consumption will be a vital issue. Stationary gas turbines in power plants could also be operated with lower CO₂ emissions thanks to more robust materials. In order to be able to use the alloy on an industrial level, many other development steps are necessary,” says Heilmaier. “However, with our discovery in fundamental research, we have reached an important milestone. Research groups all over the world can now build on this achievement.” 

 

Original publication

Frauke Hinrichs, Georg Winkens, Lena Katharina Kramer, Gabriely Falcão, Ewa M. Hahn, Daniel Schliephake, Michael Konrad Eusterholz, Sandipan Sen, Mathias Christian Galetz, Haruyuki Inui, Alexander Kauffmann, Martin Heilmaier: A ductile chromium–molybdenum alloy resistant to high-temperature oxidation. Nature, 2025. DOI: 10.1038/s41586-025-09516-8

 

Being “The Research University in the Helmholtz Association”, KIT creates and imparts knowledge for the society and the environment. It is the objective to make significant contributions to the global challenges in the fields of energy, mobility, and information. For this, about 10,000 employees cooperate in a broad range of disciplines in natural sciences, engineering sciences, economics, and the humanities and social sciences. KIT prepares its 22,800 students for responsible tasks in society, industry, and science by offering research-based study programs. Innovation efforts at KIT build a bridge between important scientific findings and their application for the benefit of society, economic prosperity, and the preservation of our natural basis of life. KIT is one of the German universities of excellence.

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Journal

Nature

DOI

10.1038/s41586-025-09516-8 

Article Title

https://www.nature.com/articles/s41586-025-09516-8

Article Publication Date

8-Oct-2025

Satellite images reveal ancient hunting traps used by South American social groups 

University of Exeter

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An illustration of a chacu, courtesy of Gerald Díaz-Vigil

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Credit: Gerald Díaz-Vigil

Satellite images have revealed an ancient system of elaborate, funnel-shaped mega traps likely built by hunters and pastoralists to catch prey in the high altitudes of northern Chile.

New research on the Andean landscape and the people who lived there has identified 76 stone ‘chacus’, often stretching hundreds of metres in length, that would have been used to capture vicuña, a wild relative of the alpaca.

Similar structures have been found in other arid regions of the world, including the Middle East, but this is the first time such a concentration has been discovered in the area, and it raises the possibility that they pre-date those known to have been used by the Inkas.

An archaeologist at the University of Exeter has also found evidence of settlements and outposts in the area known as the Western Valleys, establishing a high probability that it was home to foragers many centuries after it was believed people had adopted more settled agricultural social systems.

The study, by Dr Adrián Oyaneder, of Exeter’s Department of Archaeology and History, is published in the journal Antiquity, and is based on the research he conducted during his PhD.

“There has long been a discrepancy between what archaeological and ethnohistorical records have told us about life in the Western Valleys of northern Chile during the colonial period,” says Dr Oyaneder. “On the one hand, archaeological research has pointed to a gradual decline in hunting and gathering from 2,000 B.C. onwards with the introduction of domesticated plants and animals. But, historical sources, such as Spanish tax records from the 16th to the 19th centuries, refer to ‘Uru’ or ‘Uro’, which was a generic term for foraging populations who were of little economic interest to the colonisers.”

Using publicly available satellite data, Dr Oyaneder examined a 4,600 square-kilometre area of the Camarones River Basin, focusing on upland areas that had hitherto remained little studied. Over four months, he identified a huge number of new sites of archaeological interest.

Among them were 76 chacus, with the great majority being V-shaped traps formed by two ‘antennae’ built from dry-stone walls, around 1.5 metres in height and on average 150 metres in length. These funnelled down to an enclosure of around 95 square metres, which would have been dug or established to a depth of around two metres, sufficient to trap any animals driven into it by the hunters.

All the chacus were located on steep slopes, pointing downhill, with some employing natural topographical features to create one of the antennae. They were also at an altitude within the usual range of the vicuña.

“My reaction when I saw the first chacu was to double and even triple check it,” said Dr Oyaneder. “Initially, I thought it was a bit of a unique occurrence, but as I progressed with my survey, I realised that they were everywhere in the highlands and in a quantity never previously recorded in the Andes.

“And then when I began to read papers and books around the subject, particularly by Thérèse Bouysse-Cassagne and Olivia Harris, there was reference to the choquela, specialised vicuña hunting groups, and words referring specifically to chacu hunting people and chacu hunters.”

Dr Oyaneder identified almost 800 small-scale settlements, ranging from single buildings of no more than one square metre to groups of nine or more structures. These were plotted using GIS and grouped into likely clusters linked to nearby chacus and other settlements, all within a 5km distance.

“The picture that emerges is of a landscape occupied by a range of human groups from at least 6000 B.C. to the 18th century,” adds Dr Oyaneder. “These groups moved strategically across the highlands, tethered primarily to hunting resources, particularly vicuña. The evidence indicates overlapping lifeways, combining hunting-gathering with agropastoral practices, and a network of short-term seasonal settlements and outposts to help people move across rugged and difficult terrain.”

Dr Oyaneder is now conducting further research to date some of these sites and establish whether they represent the first examples of their kind in the Andean region.

A tethered hunting and mobility landscape in the Andean highlands of the Western Valleys, northern Chile is published in Antiquity and was funded by the Becas Chile-ANID doctoral scholarships programme and a FONDECYT project by the same agency, led by Dr Daniela Valenzuela (Universidad de Tarapacá).

Aerial photo of a double chacu

Credit

Dr Adrian Oyaneder

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Journal

Antiquity

DOI

10.15184/aqy.2025.10213 

Method of Research

Imaging analysis

Subject of Research

People

Article Title

A tethered hunting and mobility landscape in the Andean highlands of the Western Valleys, northern Chile

Article Publication Date

13-Oct-2025