Urban waterfowl are important seed dispersers for native and alien plants

Our park ponds typically hold good numbers of mallards, and urban grassy areas often hold concentrations of geese. In the UK, Canada Geese are an abundant and widespread alien species, well known for fouling parks with their faeces. Until now, no attention had been paid to their role in seed dispersal, a major ecosystem service. Indeed, in the UK there has been surprisingly little attention paid to the role of wildfowl (ducks, geese and swans) in the spread of native or alien plants, a role of ever greater importance under climate change.

A new study from the Centre for Ecological Research in Hungary, in collaboration with the Doñana Biological Station in Spain, and the Wildfowl & Wetlands Trust and Liverpool John Moores University and University of Lincoln in the UK, compares the plants dispersed by mallards and Canada geese found together in 18 different urban and rural wetlands in north-west England (covering Merseyside, Greater Manchester, and the Lake District). In total 507 droppings were collected from the waterside, and examined for seeds and other plant propagules (i.e. dispersal units, that can include whole plants such as duckweeds) in the laboratory. Over 900 intact seeds were recovered, many of which were then germinated in the lab to prove they had survived gut passage.

“Although Darwin recognized the importance of migratory waterbirds in dispersing aquatic plants, this is the first detailed study of seed dispersal by ducks ever to be conducted in the UK, as well as the first European study to compare coexisting ducks and geese” said Andy J. Green, co-author of the paper. Over 33 plant species were identified, most of which were terrestrial plants, including trees and four alien species.

“We found that mallards and Canada geese have complementary roles” said Ádám Lovas-Kiss, senior author of the study. “Mallards disperse relatively more aquatic plants, and those with larger seeds, whereas Canada geese disperse more terrestrial plants”.

Both ducks and geese dispersed mainly plants that do not have a fleshy-fruit, and these have previously been assumed to have no or limited ability to disperse via animals, with no mechanism of moving more than a few metres. However, wildfowl provide perfect plant vectors, due to their long-distance flights, so they can help plants to reach new habitats, and to maintain connectivity between isolated plant populations, including different urban parks. For example, even wind-dispersed trees such as the Silver Birch, whose seeds were common in the faeces of both birds, will be dispersed much farther by wildfowl than by wind.

The study also found that the birds can continue to move seeds months after they have been produced on the plants, so for example migrating mallards can move seeds northwards in spring, which can help plants to adjust their distributions under climate change. Canada geese are relatively sedentary in the UK, although occasional movements of hundreds of km have been recorded. Alien plants were only recorded in wildfowl faeces in urban sites, but the study provides important evidence that they could also be spread from parks into natural habitats by wildfowl.

“We have been wrong to assume that only the 8% of European flowering plants with a fleshy-fruit are dispersed inside birds’ guts” says Lovas-Kiss. “Our study shows that many other plants are dispersed by birds, and that we need to pay much more attention to the role of ducks and geese as vectors of dispersal in urban ecology, as well as in natural ecosystems. Even alien geese can provide an important service by dispersing native plants”.


Meta-analysis identifies native priority as a mechanism that supports the restoration of invasion-resistant plant communities

Biological invasion is considered to be one of the main drivers of biodiversity loss with potential negative socio-economic impacts. Invasive alien plant species are well adapted to rapid establishment and exploitation of the resources of disturbed environments, therefore disturbed and intensively managed habitats may support high levels of invasive species. Ecological restoration – defined by the Society for Ecological Restoration as the process of assisting the recovery of an ecosystem that has been degraded, damaged or destroyed – is increasingly recognized as a relevant tool to combat land degradation and biodiversity loss, and also invasive alien species. As the invasion problem becomes increasingly serious, there is an urgent need to develop more innovative, effective and proactive strategies to help improve the resistance of restored communities to invasion, limiting the establishment and further spread of invasive alien species.

Based on a systematic review and meta-analysis of published studies on seed-based ecological restoration experiments, a research team led by Melinda Halassy (National Laboratory for Health Security Invasion Biology Division, Centre for Ecological Research, Hungary) aimed to demonstrate the potential of functional similarity, seeding density and priority effects in increasing invasion resistance.

In order to develop a prevention and mitigation strategy, it is necessary to understand the processes underlying biological invasion and resistance to invasion. The success of invasive alien species can be explained by the invasiveness of the species, the invisibility of the resident community and propagule pressure. The susceptibility of community to invasion, or its opposite, the ability of communities to resist invasion depends on the competitive ability of the resident community. Several factors can be responsible for the invasion resistance, such as the diversity or, more importantly, the functional diversity of resident communities, the presence of competitive dominant or rapidly developing native species that can exploit resources more fully or rapidly, limiting the potential for invaders to establish. Recently, functional similarity, propagule pressures and priority effects have become the focus of attention in attempts to explain resistance to invasion and to promote the restoration of invasion-resistant communities.

According to the limiting similarity hypothesis, species that use the same resources similarly cannot coexist stably, thus, in theory, integrating native species into restoration that are functionally more similar to known high-risk invasive alien species could lead to better resistance to invasion. High propagule pressure increases the chances of establishment, niche occupation and resource acquisition, therefore, density-driven suppression of invasive alien species is possible by increasing the seeding density of native species to match the propagule pressure of invasive alien species. Finally, priority of arrival has the advantage of early resource acquisition, which can strongly influence competition and survival, and thus ensuring the priority of native species; for example, by assisted dispersal, can be used to create communities that are more resistant to invasion.

The quantitative review of 48 papers indicate the potential of seed-based ecological restoration in controlling the establishment and growth of invasive alien species. Giving priority to native species was found to be the best approach in increasing invasion resistance that can reduce the performance of invasive alien species by more than 50%. Even a short-term advantage (as little as one week) can strongly favor native species, but the priority effect can be strengthened by increasing the time advantage. Seeding functionally similar species generally had a neutral effect on invasive alien species. High-density seeding is effective in controlling invasive alien species, but there can be thresholds above which further increases in seeding density may not result in increased invasion resistance.

Native perennial grass Festuca vaginata and invasive annual grass Tragus racemosus grown together in a greenhouse experiment studying the potential of limiting similarity, seeding density and priority effects to increase the competitive advantage of native species over invasive alien species.

Based on these results, the first step to prevent and mitigate the spread of invasive alien species is to create priority for the establishment of native species. This requires minimizing disturbance, reducing the propagule pressure and entry of invasive alien species, and introducing native species as soon as possible after disturbance. Native priority can be best increased by the early introduction of early-emerging, fast-growing native species and high-yielding communities. Seeding of a single species with high functional similarity to invasive alien species is unpromising, and instead, preference should be given to high-density multifunctional seed mixtures, possibly including native species favored by the priority effect. It is important to note that even combining the best methods to increase invasion resistance would not result in the complete elimination of invasive alien species, but would limit their biomass and seed production, reducing the risk of further invasion.

The study also highlights the need to integrate research across geographical regions, global invasive species and potential resistance mechanisms to improve the predictive capacity of invasion ecology and to identify best restoration practices to prevent and control invasive alien species.


Nature restoration

Council and Parliament reach agreement on new rules to restore and preserve degraded habitats in the EU

Today, the Council presidency and European Parliament representatives reached a provisional political agreement on a regulation on nature restoration. The proposal aims to put measures in place to restore at least 20% of the EU’s land and sea areas by 2030, and all ecosystems in need of restoration by 2050. It sets specific, legally binding targets and obligations for nature restoration in each of the listed ecosystems — from agricultural land and forests to marine, freshwater and urban ecosystems.

The regulation is an integral part of the Biodiversity Strategy for 2030 and will help the EU reach its international commitments, in particular the UN Kunming-Montreal global biodiversity framework agreed at the 2022 UN biodiversity conference (COP15).
he provisional agreement will have to be endorsed and formally adopted by the co-legislators before entering into force.

Informal meeting of tele­communications, transport, energy ministers, 27 Feburary. Maria Teresa Ribera Rodriguez Minister for the Ecological Transition and Demographic Challenge, Spain.
Photo: Josefine Stenersen

“We are faced with an increasingly dramatic reality: EU’s nature and biodiversity are in danger and need to be protected. I am proud of today’s indispensable agreement between the Council and Parliament on a nature restoration law, the first of its kind. It will help us rebuild healthy biodiversity levels across member states and preserve nature for the future generations, while fighting climate change and remaining committed to our climate goals.”

Teresa Ribera Rodríguez, acting third vice-president of the government and minister for the ecological transition and the demographic challenge of Spain

Scope and targets of the regulation
The new rules will help to restore degraded ecosystems across member states’ land and sea habitats, achieve the EU’s overarching objectives on climate mitigation and adaptation, and enhance food security. The regulation requires member states to establish and implement measures to restore at least 20% of the EU’s land and sea areas by 2030.

The regulation covers a range of terrestrial, coastal and freshwater ecosystems, including wetlands, grasslands, forests, rivers and lakes, as well as marine ecosystems, including seagrass and sponge and coral beds (listed in Annexes I and II). It requires member states to put measures in place, by 2030, to restore at least 30% of the habitats types listed in both Annexes that are in poor condition. Until 2030, the co-legislators agreed that member states need to prioritise Natura 2000 sites when implementing the restoration measures set out in the regulation.

Member states must also establish measures to restore at least 60% of habitats in poor condition by 2040 and at least 90% by 2050. An additional flexibility was added for very common and widespread habitats.

Non-deterioration requirement
The text includes a requirement to prevent significant deterioration of areas subject to restoration that have reached good condition and of areas where the terrestrial and marine habitats listed in Annexes I and II occur. The co-legislators agreed to make this requirement effort-based. The requirement will be measured at habitat type level.

Restoring pollinators
In recent decades, the abundance and diversity of wild insect pollinators in Europe have declined dramatically. To address this, the regulation introduces specific requirements for member states to set out measures to reverse the decline of pollinator populations by 2030 at the latest. Based on delegated acts adopted by the Commission to establish a science-based method for monitoring pollinator diversity and populations, member states will have to monitor progress in this respect, at least, every six years after 2030.

Ecosystem-specific obligations
The regulation sets out specific requirements for different types of ecosystems.

Agriculture ecosystems
The text requires member states to put measures in place aiming to achieve increasing trends in at least two of the following three indicators:

  • the grassland butterfly index
  • the share of agricultural land with high-diversity landscape features (HDLFs)
  • the stock of organic carbon in cropland mineral soil
  • It also sets timebound targets to increase the common farmland bird index at national level.

The co-legislators agreed to provide flexibility to member states when rewetting peatlands, as some will be disproportionately impacted by these obligations. The text sets targets to restore 30% of drained peatlands under agricultural use by 2030, 40% by 2040 and 50% by 2050, although member states that are strongly affected will be able to apply a lower percentage. Restoration measures include the rewetting of organic soils constituting drained peatlands, which helps increase biodiversity and reduce greenhouse gas emissions. The co-legislators also agreed that the achievement of the rewetting targets does not imply an obligation for farmers and private landowners.

Forest ecosystems
Under the agreed text, member states will be required to put measures in place to enhance the biodiversity of forest ecosystems and achieve increasing trends at the national level of certain indicators, such as standing and lying deadwood and the common forest bird index, taking into account the risk of forest fires.

The co-legislators also added a provision calling on member states to contribute to the planting of at least three billion additional trees by 2030 at the EU level.

Urban ecosystems and river connectivity
For urban ecosystems, the Council and Parliament agreed that member states should achieve an increasing trend in urban green areas until a satisfactory level is reached. They also agreed that member states should ensure that there is no net loss of urban green space and urban tree canopy cover between the entry into force of the regulation and the end of 2030, unless urban ecosystems already have over 45% of green space.

The provisional agreement includes an obligation for member states to identify and remove man-made barriers to the connectivity of surface waters, in order to turn at least 25 000 km of rivers into free-flowing rivers by 2030, and maintain restored natural river connectivity.

National restoration plans
Under the new rules, member states must regularly submit national restoration plans to the Commission, showing how they will deliver on the targets. They must also monitor and report on their progress.

The co-legislators opted for a stepwise approach. Member states would first submit national restoration plans covering the period until June 2032, with a strategic overview for the period beyond June 2032. By June 2032, member states would submit restoration plans for the ten years until 2042 with a strategic overview until 2050, and by June 2042 they would submit plans for the remaining period to 2050.

The text allows member states to take into account their diverse social, economic and cultural requirements, regional and local characteristics and population density, including the specific situation of outermost regions, when establishing their plans.

Financing restoration measures
The provisional agreement introduces a new provision tasking the Commission with submitting a report, one year after the entry into force of the regulation, with an overview of the financial resources available at EU level, an assessment of the funding needs for implementation, and an analysis identifying any funding gaps. Where appropriate, the report would also include proposals for adequate funding, without prejudging the next multiannual financial framework (MFF, 2028–2034).

The co-legislators also agreed to introduce a provision encouraging member states to promote existing private and public schemes to support stakeholders implementing restoration measures, including land managers and owners, farmers, foresters and fishers. The text also clarifies that national restoration plans do not entail an obligation for countries to re-programme the common agricultural policy (CAP) or the common fisheries policy (CFP) funding under the 2021–2027 MFF in order to implement this regulation.

Review and emergency brake
The provisional agreement sets the date of 2033 for the Commission to review and assess the application of the regulation and its impacts on the agricultural, fisheries and forestry sectors, as well as its wider socio-economic effects.

The text also introduces a possibility to suspend the implementation of those provisions of the regulation related to agricultural ecosystems for up to one year via an implementing act, in the event of unforeseeable and exceptional events outside of the EU’s control and with severe EU-wide consequences for food security.

Infographic – What is the state of nature in the EU?

The infographic presents the state of nature in the EU based on the latest scientific reports. See full infographic

Next steps
The provisional agreement will now be submitted to the member states’ representatives within the Council (Coreper) and to the Parliament’s environment committee for endorsement. If approved, the text will then need to be formally adopted by both institutions, following legal-linguistic revision, before it can be published in the EU’s Official Journal and enter into force.

The European Commission proposed a nature restoration law on 22 June 2022, under the EU biodiversity strategy for 2030, which is part of the European Green Deal. Over 80% of European habitats are in poor shape. Past efforts to protect and preserve nature have not been able to reverse this worrying trend.

This is why, for the first time ever, the proposal sets out to adopt measures to not only preserve but to restore nature. The proposal aims to improve the state of nature by setting binding targets and obligations across a broad range of ecosystems on land and at sea.

Member states would have to put in place effective and area-based restoration measures in order to reach the ecosystem-specific targets. In order to assess the measures, member states would have to plan ahead by developing national nature restoration plans, in close cooperation with scientists, interested stakeholders and the public. The proposal would also define biodiversity indicators to measure progress.

The Council reached an agreement (‘general approach’) on the proposal on 20 June 2023 at the Environment Council meeting, while the European Parliament adopted its position on 12 July.

Council general approach on the nature restoration law
Nature restoration (background information)
Biodiversity: how the EU protects nature (background information)
European Green Deal (background information)


Senescence can accelerate evolution

Using a computer model, evolutionary biologists at the HUN-REN Centre for Ecological Research — including András Szilágyi, Tamás Czárán, and Mauro Santos, under the leadership of Eörs Szathmáry, a member of the Hungarian Academy of Sciences — have demonstrated that under the right circumstances, senescence can support the response to the directional selection and assist the adaptation to the changed environmental factors. The study’s findings were featured in a paper published in the journal BMC Biology. Senescence is therefore not necessarily an adverse by-product of natural selection but can also be advantageous for organisms. This represents major progress in explaining senescence, which remains one of the greatest unsolved problems in evolutionary biology.

The mystery of aging has fascinated people for millennia, with many willing to do anything to halt or reverse this process, because aging is typically associated with gradual deterioration of most body functions. While senescence is a natural part of life, biologists understand surprisingly little about the emergence of this process during evolution. It is not clear whether aging is inevitable, because there are organisms that seemingly do not age at all, moreover, the phenomenon known as negative aging, or rejuvenation, does exist: some turtles’ vital functions improve with age.

Researchers of the Institute of Evolution led by Academician Eörs Szathmáry have endeavoured to prove the validity of a previously proposed but still unproven theory of aging. The theory suggests that under the right circumstances, evolution can favour the proliferation of genes controlling senescence.

To test the hypothesis, the researchers used a computer model they had developed. This model is an algorithm capable of simulating long-term processes in populations of organisms and genes under circumstances controlled by the scientists. Essentially, with such models, evolutionary scenarios can be run, yielding results in a few hours rather than over millions of years. Modern evolutionary research would be inconceivable without computer modelling.

The fundamental question of the research was simple: Is there any meaning of aging? Does it serve any evolutionary function, or is it indeed a bitter and fatal by-product of life? “Aging can have an evolutionary function if there is a selection for senescence. In our research, we aimed to uncover this selection”, says Eörs Szathmáry. “According to classical explanations, aging emerges in the populations even without selection. That is because individuals would die sooner or later without aging as well (as a consequence of illness or accidents), therefore the force of natural selection in the population would get weaker and weaker. This creates an opportunity for the genes which have an adverse effect for chronologically old individuals (thus causing senescence) to accumulate. Which would mean aging is only a collateral consequence of evolution and has no adaptive function.”

During the last century, using different biological mechanisms, several evolutionary theories were formulated for the explanation of inevitable aging, which has no positive function. Several scientists accepted this assumption as fact, but when non-aging organisms were discovered, more and more researchers questioned the inevitability of senescence, and suggested perhaps aging could have some advantages as well.

“It has become accepted in the evolutionary biology community that the classical non-adaptive theories of aging cannot explain all the aging patterns of nature, which means the explanation of aging has become an open question once again”, says Szathmáry. “Alternative adaptive theories offer solutions for this problem by suggesting positive consequences of senescence. For example, it is possible that in a changing environment, aging and death are more advantageous for individuals, because this way the competition, which hampers the survival and reproduction of the more adaptable progeny with better gene compositions, can be decreased.”

However, this scenario holds true only if individuals are predominantly surrounded by their relatives. Otherwise, during sexual reproduction the non-aging individuals “steal” the better (that is better suited for changed environment) genes from the members of the aging population, and therefore the significant senescence disappears.

After running the model, the Hungarian biologists found that aging can indeed accelerate evolution. This is advantageous in a changing world because the faster adaptation can find the adequate traits more quickly, thereby supporting the survival and spread of descendent genes. This means that senescence can become a really advantageous characteristic and be favoured by natural selection.

Related link(s):

BMC biology

Source: BMC Biology - Directional selection coupled with kin selection favors the establishment of senescence - 2023-10-23


Eörs Szathmáry is an evolutionary biologist, a member of the Hungarian Academy of Sciences, and the chairman of the Sustainable Development Committee of the Hungarian Academy of Sciences. In his research, he studied and modeled many evolutionary processes from the origin of life to the development of human language skills. His book, The Great Steps of Evolution, co-authored with John Maynard Smith, is considered a cornerstone of modern evolutionary biology.


SEEN Hungary 2024 – Citizen Science Conference and Workshop

The Centre for Ecological Research is organising a Citizen Science Conference and Workshop on 18-19 January 2024. The main purpose of the SEEN (Social Engagement in Ecology Network) conference is to create a genuine connection between Hungarian community science projects and the researchers involved. The conference will be followed by workshops, in order to provide an opportunity for more detailed scientific discussion. The conference will take place at the Öreg-tó Hotel and Event Center. The conference will be held in English.

Date: 18-19 January 2024.
Location: Tata
Application deadline: 10th of December, 2023
Registration and further information:

Presentations and workshops

The titles and abstracts of the presentations can be submitted on the application form. We will try to include everyone, but in case of over-registration, priority will be given to those who submit their application early. The duration of the presentations will be determined when the scientific programme is finalised, but we plan with presentations of approximately 15 minutes.

Proposals for workshop topics are also welcome via the application form. We are serious about the title of the conference (SEEN, Social Engagement in Ecology Network). Our main goal is to launch a network of citizen science researchers, where real collaborations could form around common themes and common goals. For the workshops we are therefore looking for topics that are potentially relevant to any citizen science project. These could be strategic or methodological issues, or even broad scientific questions that require cross-project collaboration. From the proposals received, the scientific committee will select the final workshop topics.

Accommodation and meals

Please make your accommodation and meal reservations individually with the venue. Unfortunately we are not in a position to charge a registration fee, and the hotel will only accept bookings from those who will make the payment.

During the conference, the hotel will only be open to participants, so reservations can be made by emailing by 15 December, indicating that the reservation is for the conference. Further information on accommodation can be found on the Old Lake Hotel website.

The room price includes a breakfast buffet. In addition, a buffet lunch and dinner can be requested at a price of HUF 6900 per person per meal. (We would appreciate if the meals could provide an opportunity for further discussions!) Meals can be requested together with (or in the same way than) the accommodation, emailing

Conference organisers: László Zsolt Garamszegi and Zsóka Vásárhelyi

Scientific committee: Gábor Földvári, Attila Lengyel, Zsuzsanna Márton, Zoltán Soltész, Beáta Szabó, Éva Szabó and Tamara Szentiványi.


The contribution of habitat diversity to the maintenance of benthic diatom diversity

Diverse macrovegetation can provide heterogeneous habitats for benthic diatoms. Researchers from the CER Institute of Aquatic Ecology and the University of Debrecen, together with specialists from the Middle-Tisza Water Authority studied the importance of microhabitat heterogeneity (emergent, submerged and floating macrophytes) in maintaining diverse periphytic diatom assemblages. Their results were published in the journal Hydrobiologia.

Human well-being and good quality of life are based on the biodiversity of ecosystems and there is an increasing demand to reduce the knowledge gap on the variety of life on Earth. At the same time, an “invisible tragedy” is taking place in freshwater habitats that are highly threatened by the loss of diversity with species disappearing, threatening the functioning of the ecosystem. While relatively more information is available on the processes occurring in plant, animal or microbial communities that are important to human communities, much less is known about the vulnerability and exposure of other groups, including microalgae, which play a key role in ecosystem services. The situation is further complicated by the fact that there is a delicate balance between protecting and “exploiting” multipurpose freshwaters that take a lead in the daily life of human communities. While good ecological condition is essential for the maintenance of diverse communities, water management works such as water level regulation, thinning of macrophyte communities or sediment dredging are important for human recreation in these multipurpose lakes and reservoirs.

This is no different in the largest artificial, multipurpose shallow reservoir of the Carpathian basin, Lake Tisza, which is a UNESCO World Heritage Site. As in other lakes, the composition and biomass of the macrophyte communities form a complex system with benthic and metaphytic microflora assemblages. However, the extensive macrophyte vegetation needs to be thinned at least once a year. In the study, researchers highlighted that the macrovegetation belonging to different life form types, i.e. emergent, submerged and floating, contributes to the taxonomic and trait diversity of the microflora in a different but equally important way. Almost one-third of the benthic diatoms occurred on only one type of aquatic plant, pointing to the unique microhabitat that these macrophytes can provide for microalgae. Besides the microhabitats, however, the regular water level control of the lake also affected the biodiversity of the microalgae, promoting the spread of diatoms between the basins.

These results highlighted that the protection and maintenance of benthic microalgae biodiversity in multipurpose lakes requires delicate water management planning and implementation, but at the same time it is unavoidable for the functioning of a healthy ecosystem.


Assembly Theory links physics and evolution

An international team of researchers has developed a new theoretical framework that bridges physics and biology to provide a unified approach for understanding how evolution and complexity emerge in nature. This new work on “Assembly Theory,” was published on October 4th in Nature.

As Dániel Czégel, the co-first author of the paper from Arizona State University and the Institute of Evolution at the Centre for Ecological Research in Budapest explained, “we have a language for physics, a language for chemistry, and a language for biology and evolution, but they are almost mutually incomprehensible, like as if we were at the early days of Babel. This makes the transition between them very difficult to study. We need something like a lingua franca of medieval port towns, to bridge cultures and languages. But these lingua francas often turn to fully developed languages, separate from their ancestors. Assembly theory is neither physics or chemistry or biology but a mathematical language to talk about historically contingent systems, systems where the existence of current forms are strongly determined by what existed in the past, like the products of biological or technological evolution. It turns out that a coordinate system for such complex objects are nothing like a coordinate system in physics, but it’s more like a space determined by combinatorics and recursivity. The most peculiar thing is that an object is not a point but a series of causes and effects, like a story of the origin of the object. And it’s not even the “real” history, but a fictional one, like an origin myth, but it’s mathematically well-defined within the assembly universe. It’s a counterfactual causal history. But then when we treat objects as their own fictional origin story, we can start to talk about the entangled web of stories of all objects and measure things like the amount of selection and historical contingency that caused those objects to exist. It’s a bit like the particle-wave duality of quantum physics, but for complex objects: sometimes it’s better to think of them as three dimensional structures, sometimes as interrelated construction histories. We have to speak the language of this coordinate system if we assume that life that we’d like to make in the lab or life elsewhere in the universe are not like ours, chemically.”


Urbanisation generates multiple trait syndromes for terrestrial animal taxa worldwide

More than 50% of the world’s population currently lives in cities, yet cities can be home to significant biodiversity that provides important ecosystem services to urban populations. An international team of researchers, including Andrew J. Hamer, Senior Research Fellow at the Institute of Aquatic Ecology at the Centre for Ecological Research, has shown that urbanisation causes different changes in trait composition between animal groups through a systematic review of databases and publications on six terrestrial fauna groups (amphibians, bats, bees, birds, beetles and reptiles) in 379 cities on six continents. The study was published in Nature Communications.

Although urban environments cause significant habitat loss and alter the spatial structure of the landscape, it is crucial to conserve the remaining urban biodiversity and even increase the role of cities in reducing the current biodiversity extinction crisis. Understanding how different groups of animals respond through their functional traits to the impacts of urban environments worldwide is essential for developing effective strategies to promote biodiversity in urban environments.

Significant progress has been made in understanding the impacts of urbanisation on global biodiversity, there are still many gaps in research. Previous studies has focused geographically on major metropolitan areas in the northern hemisphere and Australia. However, the majority of the areas of greatest biodiversity value are in the tropics and the southern hemisphere, and these areas have been less investigated. Urban landscape structure has largely been characterised by negative indicators such as the proportion of impermeable surfaces, while biodiversity-enhancing indicators such as the proportion and spatial distribution of vegetation cover have received relatively less attention, particularly at the global level. Studies on urban biodiversity have so far mainly focused on plants and birds. Urbanisation also affects other species-rich and functionally important animal groups that have been little studied, such as insects, amphibians, bats and reptiles. Most studies on urban biodiversity continue to focus on taxonomic diversity, despite the growing importance of functional traits in the ecological literature.

In the Nature Communications study, six groups of terrestrial fauna (amphibians, bats, bees, birds, beetles and reptiles) from 379 cities on six continents were reviewed and shown that urbanisation causes taxon-specific changes in trait composition, with traits related to reproductive strategy showing the strongest response. The study results suggest that the impact of urbanisation on functional traits results in a set of four urban traits related to animal mobility and food preference, which can be classified into four types: mobile generalists, site specialists, central foragers and mobile specialists.

Mobile generalists includes taxa such as bats and carabid beetles are highly mobile species with more generalist diets and reproductive strategies that are better able to exploit available resources in urban environments. The urban trait syndrome associated with site specialists was characterised by reduced mobility, increased dietary specialism and a shift towards smaller clutch sizes. These traits are advantageous to species that are reliant on highly localised life cycles, such as amphibians and reptiles. Central place foragers establish a home base location from which they undertake daily movements to forage for additional resources. The taxa that displayed this urban trait syndrome were bees and birds. Mobile specialists are characterised by species that are able to meet their resource needs by being dietary specialists that are highly mobile and can move between spatially isolated food sources without having to return to a central place. Wetland birds can be regarded as mobile specialists, where their distribution is tightly linked to a specific resource (waterbodies), but they have the capacity to easily move between locations when resources fluctuate.

Frogs are site specialists – they are are reliant on highly localised life cycles
(Photo: Shutterstock)

These findings are in contrast to the hypothesis that there is one single global ‘urban trait syndrome’ as a species response to urbanisation. The results therefore reassess previous ideas about ecological community dynamics and biotic homogenisation of urban ecosystems. It is crucial for the survival of different animal groups that conservation and urban development regulations and plans for cities and their environments take into account the different needs of different animal groups, as this may underpin the increasing role of cities in mitigating global biodiversity loss.

Lead photo: Julia Horanyi: An urban wetland that is habitat for species covered by all four urban trait syndromes


New study with the involvement of Hungarian researchers calls for urgent action due to halt in the recovery of European freshwater biodiversity

A new study that sheds light on the extraordinary sensitivity of freshwater ecosystems and the long-term negative consequences of human impacts on biodiversity has been published in the most prestigious scientific journal, Nature. The research is based on a comprehensive dataset of 1,816 time series of freshwater invertebrate communities between 1968 and 2020 from 22 European countries, comprising 714,698 individuals of 2,648 taxa from 26,668 samples. Two Hungarian researchers, Dr. Gábor Várbíró from the Institute of Aquatic Ecology of the ELKH Centre for Ecological Research (CER), and Dr. Zoltán Csabai from the University of Pécs (PTE) also took part in the compilation and analysis of the data. Due to the persistent and newly emerging threats posed by climate change, invasive species, and new pollutants, the study calls for an immediate and intensified focus on mitigation strategies to rejuvenate the recovery of freshwater biodiversity.

Freshwater ecosystems hold significant significance in the context of global biodiversity. These water bodies provide habitat for numerous plant and animal species, and they play a crucial role in maintaining food chains and preserving ecological balance. Mitigation measures including wastewater treatment and hydromorphological restoration have historically shown promise in improving environmental quality and supporting the recovery of freshwater biodiversity.

Together with a large international team the study’s first author, Prof. Dr. Peter Haase of the Senckenberg Research Institute and Natural History Museum in Frankfurt and Dr. Ellen A. R. Welti of the Smithsonian’s Conservation Ecology Center in the US analysed a comprehensive dataset of 1,816 time series of freshwater invertebrate communities between 1968 and 2020 from 22 European countries, comprising 714,698 individuals of 2,648 taxa from 26,668 samples. The analysis reveals a plateauing trend in the gains achieved.

714,698 observations of 2,648 species from 26,668 samples were analyzed by the research team. Dr. Gábor Várbíró, one of the Hungarian team members

The study indicates notable increases in taxon richness (0.73% per year), functional richness (2.4% per year), and abundance (1.17% per year) of freshwater organisms. These positive trends were prominent up until the 2010s, after which the recovery rates have significantly slowed down. Alarming patterns emerged in communities located downstream of dams, urban areas, and croplands, where the prospects for recovery appear grim. Moreover, sites experiencing higher rates of warming demonstrated fewer biodiversity gains, underlining the impact of climate change on freshwater ecosystems.

The study underscores the vulnerability of inland waters to a range of anthropogenic pressures, including pollution, urbanization, and the impacts of climate change. Despite past regulatory efforts, including landmark legislations like the ‘US Clean Water Act’ of 1972 and the EU Water Framework Directive of 2000, the researchers emphasize that more needs to be done to counteract the increasing stressors that threaten these vital ecosystems.

The researchers suggest that while the gains witnessed in the 1990s and 2000s could be attributed to successful water-quality enhancements and restoration endeavours, the observed deceleration in the 2010s suggests a diminishing effectiveness of the current measures. These measures led to a significant reduction in organic pollution and acidification, beginning around 1980. Over the past 50 years, these steps have contributed to the containment of wastewater pollution and resulted in improvements in freshwater biodiversity. Unfortunately, as the number and impact of stressors continue to increase worldwide, the improvements resulting from past legislation are lessening and freshwater systems remain degraded in many places. With the persistent and emerging threats posed by climate change, invasive species, and new pollutants, the study calls for an immediate and intensified focus on mitigation strategies to rejuvenate the recovery of freshwater biodiversity.

Biodiversity in river systems from 22 European countries increased significantly over a period from 1968 to 2020 – but this trend has stagnated since the 2010s

The involvement of two Hungarian scientists. Dr. Gábor Várbíró from CER and Dr. Zoltán Csabai from PTE adds a significant layer of expertise to this critical research effort. Their collaboration within the international team has shed light on the status of European freshwater biodiversity and underscored the urgent need for actionable conservation measures.
Dr. Gábor Várbíró said, “Our findings raise a critical alarm for the health of European freshwater ecosystems. The slowdown in recovery rates demands a comprehensive re-evaluation of existing mitigation measures and the implementation of new, adaptive strategies. Time is of the essence, and we must act swiftly to protect these essential ecosystems.”
The study underscores the necessity of a multi-faceted approach, engaging policymakers, scientists, and communities at large, to ensure the long-term vitality of freshwater ecosystems. As Europe and the world face increasingly complex environmental challenges, collaborative and immediate actions are crucial to reverse the trend of stagnating freshwater biodiversity recovery.

Haase, P., Bowler, D. E., Baker, N. J. … Csabai, Z., Várbíró, G. et al. (2023). The recovery of European freshwater biodiversity has come to a halt. Nature. DOI: 10.1038/s41586-023-06400-1

Photos: Gabriella Bodnár, – Centre for Ecological Research


Small-molecule autocatalysis drives compartment growth, competition and reproduction

With the decisive participation of Eörs Szathmáry, Member of the HAS and Research Professor at the Institute of Evolution of the Centre for Ecological Research, an international team of researchers has achieved a major new breakthrough in the study of the origin of life. The paper was published in Nature Chemistry, one of the world’s leading chemistry journals.

Eörs Szathmáry Photo: HAS/Tamás Szigeti

The discipline of systems chemistry deals with the analysis and synthesis of various autocatalytic systems and is therefore closely related to the study of the origin of life, since it investigates systems that can be considered as a transition between chemical and biological evolution: more complex than simple molecules, but simpler than living cells.

Tibor Gánti described the theory of self-replicating microspheres as early as 1978. These still lacked genetic material, but concealed within their membranes an autocatalytic metabolic network of small molecules, isolated (compartmentalised) within their membranes. As the autocatalytic process takes place, the membrane-building material is also produced, leading to the division of the sphere. This system may appear to be a living cell, and although it lacks genetic material, this can only be verified experimentally. These microspheres can be considered as ‘infrabiological’ chemical systems, since they do not reach the level of biological organisation, but they exceed the complexity of normal chemical reactions.

Tibor Gánti / Painting by László Gulyás

Years ago, we started to think about the possibility of experimentally realising the process whereby the growth of a small molecule metabolic network leads to the growth of the compartments that enclose the network, to the effect that they can divide. Already Tibor Gánti has described that one of the most promising candidates for this system is the formose reaction, an autocatalytic sugar-producing reaction that consumes formaldehyde and involves the circular transformation and propagation of glycolaldehyde molecules. The reaction does not require enzymes.
The experiment on which the study is based was carried out in the biochemistry laboratory of the École Supérieure de Physique et de Chimie Industrielles (ESPCI) in Paris by Professor Andrew Griffiths and his colleagues. The experiment involved creating tiny water droplets in an oil medium that did not fuse and therefore acted as artificial cells. Some of the ‘cells’ were given glycolaldehyde as an autocatalyst (in addition to formaldehyde as a nutrient), others were not. In the former group, the formose reaction was triggered and, by osmosis, it sucked water away from compartments that did not contain glycolaldehyde. This allowed them to grow and to divide under external influence. Many researchers have suggested that before the emergence of regulated cell division, the initial cells divided in response to external influences such as turbulent flow.

The significance of this study is that we are the first in the world to show that the operation of a network of small-molecule autocatalytic reactions, without genetic material and enzymes, leads to the growth and division of compartments, i.e. the formation of new generations. This has never been demonstrated before, so the result is fundamental to the experimental verification of the principles of systems chemistry and points the way forward in the study of the origin of life.


Szathmáry Eörs evolúcióbiológus, az MTA rendes tagja, az MTA Fenntartható Fejlődés Elnöki Bizottság elnöke. Kutatásai során az élet keletkezésétől kezdve az emberi nyelvkészség kialakulásáig számos evolúciós folyamatot vizsgált és modellezett. John Maynard Smithszel közösen írt könyvét, az Az evolúció nagy lépéseit a modern evolúcióbiológia alapműveként tartják számon.

Other publications on this topic:


The first aquatic ecology experiment is launched at the experimental site of the Centre for Ecological Research in Vácrátót

The Institute of Ecology and Botany and the Institute of Aquatic Ecology have been working together to establish new experimental infrastructure in Vácrátót. In parallel with the greenhouse experimental system, two mesocosm infrastructures are also being established, which will be used for short- and long-term experiments. The first of these, called the CER Mesocosms has been completed and is already hosting the first experiment, in which researchers from the Institute of Aquatic Ecology are investigating the combined effects of climate change (heat waves) and fragmentation as part of an OTKA project.

Establishment of simplified experimental ecosystems (mesocosms) in the experimental area

The Transnational Access programme of the H2020 AQUACOSM-plus project has provided the opportunity for a group of international researchers and trainees to participate in the experiment. The main objective of the programme, in addition to provide networking possibilities between researchers, is to create opportunities for students and young researchers to become familiar with the tools of experimental aquatic ecology and to gain practical experience through active participation in mesocosm experiments at the project partners’ sites. The Centre for Ecological Research will thus host a total of 10 international guests from Greece, Serbia, Spain, the UK, Chile, Uruguay, who will be joined by an Erasmus+ student from Turkey and several Hungarian university trainees over the next two months.

The CER Mesocosms (together with the Hungarian Pond Network, which is still under construction) is recognized as “Emerging Research Infrastructure” by the National Research, Development and Innovation Office (NKFIH)


Continuous precipitation loss causes severe damage to the diatom assemblages in large rivers

The researchers of the Functional Algology Research Group, operating at the Tisza Research Department of the Institute of Aquatic Ecology of the ELKH Centre for Ecological Research (CER), in collaboration with experts from the Department of Environment, Nature Protection and Waste Management of the Győr-Moson-Sopron County Government Office, investigated whether one-off drought events and trend-like precipitation decrease result in similar changes in the composition of diatom assemblages of the Rába River, one of the largest rivers in Hungary. The results clearly highlighted that the continuous decrease in annual precipitation has a much more significant impact on the composition and biodiversity than a single dry year. The paper presenting the research was published in the prestigious scientific journal Ecological Indicators.

Weather extremes and the impact of drought are immediately noticeable, for example, in agricultural areas or forests, and although perhaps less perceptible, they also have significant consequences for the ecosystems of rivers.

Reimeria sinuata: one of the diatom species indicating the effects of drought in the Rába River

The researchers of the Functional Algology Research Group, operating at the Tisza Research Department of the Institute of Aquatic Ecology of the ELKH Centre for Ecological Research (CER), in collaboration with experts from the Department of Environment, Nature Protection and Waste Management of the Győr-Moson-Sopron County Government Office, investigated the long-term changes in the composition of the benthic diatom assemblage of the Rába River.

The Rába is the third largest river in Hungary and the most important domestic tributary of the Danube. Over the past five years, environmental protection experts have observed a significant decrease in precipitation within its catchment area. They applied to CER researchers with the observation that the trend-like, continuous decrease in precipitation likely affects the composition of the benthic diatom assemblages.

During the joint work, they sought to find the answer to whether one-off drought events and trend-like precipitation decrease result in similar changes in the composition of the river’s benthic diatom assemblages. It has been shown in other ecosystems that the resilience of the assemblages can vary depending on whether drought occurs regularly, for extended periods, or only intermittently.

Maintaining the good condition of our rivers and reducing harmful effects, such as nutrient load, are important societal interests. The legal framework for this is determined by the EU Water Framework Directive, which Hungary also follows. In order to characterize and monitor the ecological status of our surface watercourses, experts regularly monitor the river ecosystems, in which benthic diatoms play a key role. These tiny organisms have a significant function in the food web and primary production.

Although microscopic in size, the biofilm they create is visible to the naked eye and can be felt, for example, on the steps of beaches, on rocks, and on shoreline and aquatic plants. Perhaps few people are aware of the wonders hidden within this film. When magnified, it reveals a micro-world resembling a small forest, where, similar to the ground level of a forest, there are species adhering on the surface, often very small, as well as prominent, branching species that resemble trees. Just as forests, the biofilm is also shaped by the environment. The number of species and individuals present, as well as the species with specific characteristics that can occur in a given biofilm, greatly depend on the influences affecting the water. Besides nutrient load, other threatening factors such as the increase in pharmaceutical residues, rising water temperature, changes in water residence time, drastic decrease in water level and flow, or the receding of flash floods significantly influence the composition of this tiny forest. Ultimately, this will also have an impact on higher taxonomic groups, such as aquatic invertebrates and fish,” said Viktória B-Béres, one of the lead authors of the study.

In order to understand these processes, the analysis and evaluation of long-term datasets are of paramount importance. For the investigation, the authors of the study utilized datasets available for the Rába River, covering a period of fifteen years. The period from 2007 to 2021 was divided into two groups based on annual precipitation. Between 2007 and 2016, fluctuating years of both drier and wetter conditions alternated, while from 2017 onwards, consistently decreasing annual precipitation was characteristic.

“Our results showed that one-off dry events had little influence on the composition and biological diversity of benthic diatom assemblages. In contrast, continuously decreasing precipitation ‒ dry periods ‒ significantly reduced species-level and functional diversities, the latter based on individual characteristics. Using the previous analogy, it was as if our tiny forest transformed into a barren landscape. Small-sized species that strongly adhere to the substrate, such as Amphora pediculus and Reimeria sinuata, became dominant, while the proportion of larger tree-like species decreased significantly. This is problematic because this type of algae plays an important role in the river’s food web as a food source for snails and macroinvertebrates. Therefore, their absence or decline in population size can have detrimental effects on the larger organisms inhabiting the river,” added Viktória B-Béres.

In a recently published study, researchers analyzed for the first time the differences in the effects between one-off dry weather events and trend-like changes in precipitation on the benthic diatom assemblages of a large river. The results clearly highlighted that the continuous decrease in annual precipitation has a much more significant impact on the composition and biodiversity than a single dry year. Climate scenarios project extreme water balance conditions in the near future, including longer periods of low precipitation. Therefore, any knowledge that can predict changes in the microscopic river ecosystems can assist in the development of action plans by authorities to preserve the functional and structural characteristics of riverine ecosystems, and thus maintain the ecosystem services provided by benthic algal assemblages. The study indirectly draws attention to the vulnerability of even large, perennial riverine ecosystems during dry periods, emphasizing the importance of responsible water management. The researchers are asking the public to report any incidents of extraordinary water pollution, untreated wastewater discharge, shoreline littering, or large amounts of mussel or fish carcasses to the environmental protection departments of e.g. the Győr-Moson-Sopron County or Hajdú-Bihar County Government Offices.

Photo: Sampling from the Rába River


Zsuzsanna Nemes-Kókai, Krisztián Kovács, Gábor Borics, Rezső Mayer, Zoltán Novák, Ákos Gábor Robotka, Júlia József, Károly Érczes, Áron Lukács, Viktória B-Béres (2023). Continuous precipitation loss induced more pronounced compositional and diversity changes in the lotic phytobenthos than one-off drought events. Ecological Indicators, Volume 148, 2023. 110051, ISSN 1470-160X. DOI: 10.1016/j.ecolind.2023.110051.


CER research group examines possibilities to prevent animal-vehicle collisions focusing on human factors

The members of the ‘Lendület’ Seed Ecology Research Group of the ELKH Centre for Ecological Research (CER) examined the human factors behind animal-vehicle collisions through a questionnaire survey. The researchers pointed out that there are significant correlations between the frequency of collisions, driver attitudes, and driving habits. The paper presenting the results was published in the Journal of Environmental Management.

The rapidly developing road network places a significant burden on terrestrial ecosystems, increasing the number and severity of conflicts between humans and wildlife, which are most often manifested in animal-vehicle collisions. Collisions with animals raise serious problems from both a conservation and traffic safety perspective. If we want to express this in numbers, it can be said that hundreds of millions of vertebrate animals are victims of vehicle collisions worldwide every year. This results in significant financial damage and personal injury. The problem is not new, researchers have been aware of it for decades, and numerous studies have been conducted. Most of these were based on field surveys. With their help, a list of affected species was compiled, conservation damage estimated, and “hotspots” identified, i.e., road sections where the frequency of collisions is higher than average.

“Our research is novel in that it targets the social strata traveling on the road, so it captures the problem from the other end. The experience and opinions of drivers contain a lot of useful information for accident prevention, which can be collected and evaluated in this way,” explained Sándor Borza, one of the first authors of the article, a PhD student in the Cooperative Doctoral Program.

It is very important to consider how interested the affected social stratum is in the topic, how conservation or financial damage affects them, and what solutions they consider good or acceptable to reduce the problem.

“Many people were interested in the survey, a total of 2123 people completed our questionnaire, which is an outstanding number worldwide!” emphasized Sándor Borza. “We were curious about what animals drivers had hit during their lifetime, whether they had suffered financial damage, and, most importantly, whether their driving habits and attitudes affected the likelihood of collision.”

The researchers found that nearly half of drivers have had at least one collision with an animal during their lifetime and one in four drivers suffered property damage as a result. Male drivers, drivers who cover longer distances annually, use secondary roads more frequently, and drive larger vehicles were more likely to collide with animals. However, driving style, whether someone drives slower or more dynamically, did not affect the likelihood of an animal-vehicle collision. “This does not mean that the two things are not related at all, as research supports that at certain speeds, it is not possible to slow down enough to avoid a collision,” added Sándor Borza. The drivers’ attitude towards the importance of nature conservation and traffic safety in relation to animal-vehicle collisions was significantly influenced by whether they had hit something before in their lives. More than a third of drivers shared their opinions on possible ways to improve traffic safety. The most popular form of action was the installation of protective devices (wildlife fences, wildlife crossings), but many also pointed out the usefulness of warning signs and the greater responsibility of hunting associations, including control of the number of large game animals.


Réka Kiss among the winners of the HAS Environmental Science Youth Prize

The Environmental Science Youth Prize was established in 2010 to recognise the achievements of young scientists in the field of environmental research. The awards were presented by Eörs Szathmáry, Chairman of the Presidential Committee on Sustainable Development of the Hungarian Academy of Sciences on 12 June 2023 at the HAS Headquarters in Budapest. Réka Kiss, researcher at the Centre for Ecological Research ‘Lendület’ Seed Ecology Research Group, is one of the 2023 winners.

Réka Kiss was awarded the prize for her research on the development and testing of grassland restoration methods and increasing the biodiversity of grassland vegetation. In their research, Réka and her colleagues aimed to create species-rich grasslands with the lowest possible energy and cost inputs. The grasslands were created using grass seeds and a diverse seed mix of forb species. They were looking for the time window in the sowing of the two mixtures when the most species-rich grasslands could be established with the least energy and cost investment. The results of the research underline the fact that the higher amount of labour invested in the early stages of grassland reconstruction pays off: simultaneous sowing results in the highest species richness, the most successful establishment of sown forb species and the lowest weed infestation rates. This is therefore the most cost-effective method of the options considered, while later, non-coordinated sowings are less effective and require additional interventions.

Recent publications related to the award

Kiss, R., Deák, B., Tóth, K., Lukács, K., Rádai, Z., Kelemen, A., Miglécz, T., Tóth, Á., Godó, L., Valkó, O. (2022): Co-seeding grasses and forbs supports restoration of species-rich grasslands and improves weed control in ex-arable land. Scientific Reports 12: 21239. https://doi-org/10.1038/s41598-022-25837-4

Kiss, R., Deák, B., Tóthmérész, B., Miglécz, T., Tóth, K., Török, P., Lukács, K., Godó, L., Körmöczi, Zs., Radócz, Sz., Kelemen, A., Sonkoly, J., Kirmer, A., Tischew, S., Švamberková, E., Valkó, O. (2021): Establishment gaps: biodiversity hotspots to support the colonization of target species in species-poor grasslands. Restoration Ecology 29(S1): e13135. doi: 10.1111/rec.13135

Kiss, R., Deák, B., Tóthmérész, B., Miglécz, T., Tóth, K., Török, P., Lukács, K., Godó, L., Körmöczi, Z., Radócz, S., Borza, S., Kelemen, A., Sonkoly, J., Kirmer, A., Tischew, S., Valkó, O. (2021): Zoochory on and off: A field experiment for trait-based analysis of establishment success of grassland species. Journal of Vegetation Science 32: e13051. doi: 10.1111/JVS.13051

Photo: Hungarian Academy of Sciences communication – Tamás Szigeti


Péter Batáry elected member of Academia Europea

Péter Batáry, DSc, landscape ecologist, scientific advisor of the Centre for Ecological Research and head of the Lendület Landscape and Conservation Ecology research group, has been elected to be a member of Academia Europaea.

The Academia Europaea is a non-governmental association acting as an Academy. Its mission is to promote excellence in the humanities, law, economics, social and political sciences, mathematics, medicine and natural sciences and technology. Founded in 1988, it currently has more than 5100 members, including several Nobel laureates.

Source: Academia Europaea membership


The resilience of aquatic ecosystems to heatwaves and their ability to recover from changes caused by temperature-induced stress

Researchers from the Institute of Aquatic Ecology of the ELKH Centre for Ecological Research (CER) led by Csaba Vad, conducted a study in an international collaboration to explore the resilience of aquatic ecosystems to the negative impacts of heatwaves. They also investigated whether dispersal from surrounding habitats, i.e., the arrival of other species, could accelerate ecosystem recovery. During their experiment on plankton communities in mesocosms, the researchers found that the heatwave drastically reduced the biomass of plankton due to the negative impact on primary consumer zooplankton, such as water fleas. Dispersal from surrounding habitats had limited effect in this study, somewhat positively influencing only the growth of phytoplankton. As a result of the heatwave, both the composition and trophic structure of the communities changed, which could have long-term implications for ecosystem functioning. The study presenting the results was published in one of the leading international ecological journals, Global Change Biology.

The increasingly frequent and intense heatwaves associated with global climate change pose a significant threat to biodiversity, ecosystem functioning, and the ecosystem services provided to humans. Consequently, it becomes crucial to understand the mechanisms that affect the resilience of communities in the face of extreme temperature events, including their resistance to temperature stress and their subsequent recovery. This knowledge is essential for improved prediction and mitigation of biodiversity loss and its far-reaching implications. Moreover, it enables the application of effective strategies to adapt to climate change.

In a research led by Csaba Vad, researcher at the Institute of Aquatic Ecology of CER, an international research group investigated whether connectivity through dispersal facilitates ecosystem adaptation to heatwave-induced stress (“spatial insurance hypothesis”). The study, conducted over a period of one and a half months, took place in artificial lakes known as mesocosms. In these experimental systems, the processes occurring in natural ecosystems can be modeled much more realistically compared to laboratory conditions. Moreover, they allow for the isolated examination of individual stressors and underlying mechanisms, which would not be feasible in natural habitats due to their complexity.

The Austrian WasserCluster Lunz research institute’s mesocosm system,
where the experiment was conducted

According to the results, the heatwave led to a decrease in plankton biomass, primarily due to its negative impact on zooplankton, such as water fleas. In the case of a natural lake, for example, this could lead to temporary reduction in food sources available for fish or even the development of algae blooms, as these small microscopic organisms play an important role in regulating algae levels. The effect of dispersal from surrounding habitats in this experiment was relatively minor, and it was only evident in the faster post-heatwave growth of phytoplankton. The results showed that the community biomass returned to the undisturbed level regardless of dispersal. However, the composition and trophic structure of the community changed, which could potentially result in long-term alterations in ecosystem functioning.

Based on the experiment, it can be concluded that even a short heatwave of about one week can alter the species composition and interactions within aquatic ecosystems, potentially leading to long-term consequences. These effects can be further aggravated by the fragmentation of ecosystems resulting from habitat loss, increasing spatial isolation of remaining habitats and reducing the dispersal of organisms. Ecologists urge for further long-term research to understand the impacts of heatwaves and develop possible adaptation strategies.

The research was carried out within the framework of the H2020 AQUACOSM project, with the support of H2020 AQUACOSM-plus and the National Multidisciplinary Laboratory for Climate Change.

Photos: Zsófia Horváth


Vad Cs. F., Hanny-Endrédi A., Kratina P., Abonyi A., Mironova E., Murray D. S., Samchyshyna L., Tsakalakis I., Smeti E., Spatharis S., Tan H., Preiler C., Petrusek A., Bengtsson M. M. & Ptacnik R. (2023). Spatial insurance against a heatwave differs between trophic levels in experimental aquatic communities. Global Change Biology 29: 3054–3071. (IF2021: 13.211 | SCimago2022: D1)


The Invasion Biology Division of the National Health Security Laboratory has been established with the leadership of CER as the new center for domestic research on biological invasion

The Invasion Biology Division of the National Health Security Laboratory (NHSL) has recently been established with the leadership of the ELKH Centre for Ecological Research (CER). The primary mission of the participating experts is to assess the level of threat posed by invasive species in Hungary, develop a comprehensive ecological framework to address the issue, and provide practical recommendations to decision-makers based on scientific findings, in order to support the development of effective invasion defense strategies. Additional consortium members of the project include the University of Pécs (UP), the ELKH Centre for Agricultural Research (ATK), the Hungarian University of Agriculture and Life Sciences (MATE), the University of Veterinary Medicine Budapest (UNIVET), and the ELKH Veterinary Medical Research Institute (ÁTKI).

The plant and animal life on Earth has evolved over millions of years. Populations were separated by oceans, mountain ranges, seas, and rivers, allowing each continent and their various geographic units to develop their unique biodiversity characteristics specific to that particular area. Throughout its history, humanity, especially during the age of great geographical discoveries, has intentionally or accidentally introduced and transported plant and animal species to areas where they were not originally native. In recent decades, globalization has led to a significant increase in the intentional introduction of non-native species for economic purposes, as well as the accidental introduction through transportation, travel, or tourism. Some of these species, once escaping human control, start spreading in their new habitats, causing harm to native flora and fauna. The introduction of new species leads to rearrangements in the ecological relationships among members of the original communities, resulting in damage to the composition and functioning of natural ecosystems, and the decline or extinction of numerous native species.

Articles on topics such as the naturalization of introduced plants began to appear as early as the 19th century. However, by the 20th and 21st centuries, the issue had reached such a magnitude that a new field of study, invasion biology or invasion ecology, emerged to address these questions.

Today, terrestrial ecosystems face a dual crisis of climate change and rapid biodiversity loss. One of the main causes of biodiversity loss, alongside systematic habitat destruction and fragmentation, is the spread of invasive species. The typical case of invasion phenomena occurs when a plant or animal species introduced for economic or aesthetic reasons, escapes from its breeding or cultivation area and becomes an “invasive species”, overwhelms the previously diverse native ecosystem. Examples of this include the planting of common milkweed (Asclepias syriaca) or giant goldenrod (Solidago gigantea) as bee pastures, which have caused severe degradation and destruction of our protected and natural grassland areas by today.

However, the range of invasion phenomena is much broader than that. Nowadays, we are familiar with numerous examples where introduced or spontaneously established species act as vectors, carrying new pathogens that can cause previously nonexistent diseases in the given area and potentially lead to epidemics. In recent years, for instance, several invasive mosquito and tick species have appeared in Europe, capable of transmitting various pathogens, including viruses and nematodes, that pose risks to both humans and domestic animals, causing a range of human diseases and conditions, as well as for example heartworm in dogs. The agricultural sector faces a new challenge with the impact of invasive plants on pollinator communities or the appearance and damage caused by invasive sucking pests, mites, and bugs, for example in vineyards and orchards, significantly reducing the efficiency of agricultural production.

Biological invasion is therefore a complex issue that not only directly affects biodiversity loss, but also has a direct impact on various segments of the economy and society, the decline of natural habitats, the reduction and disappearance of native species, the efficiency of agricultural and forestry practices, and ultimately, human health. It leads to the loss of natural and healthy environments and directly contributes to the emergence of new pathogens or allergens.

The severity of the impacts occurring on multiple levels is indicated by the fact that the European Union spends over 12 billion euros annually on combating invasive species and mitigating the damages caused by them, and this amount continues to increase year after year. According to the latest global assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the number of invasive species per country has increased by 70 percent since 1970, and over one-third of the currently recorded invasive species have appeared for the first time in a biogeographic region outside their native range in the past four decades. Globally, Europe and North America have the highest number of invasive species, and Hungary is also considered an invasion hotspot. Hundreds of new species have emerged in the past century in the country, many of which have caused significant ecological changes.

The phenomena related to biological invasion are intensively studied by representatives of various disciplines, including ecologists, virologists, plant protection experts and medical professionals. However, there are still numerous unanswered questions in each subfield. Currently, it is not yet possible to predict invasive processes in the same way as, for example, different climate scenarios show the expected outcomes under varying conditions.

As part of the Széchenyi Plan Plus program, the Invasion Biology Division of the National Health Security Laboratory has recently been established with the support of project RRF-2.3.1-21-2022-00006. The Invasion Biology Division, operated by a consortium led by CER and comprising PTE, ATK, MATE, UNIVET, and ÁTKI, aims to assess and address the actual threat posed by invasive species by developing a unified ecological framework and providing effective practical solutions based on scientific findings.

During the research, experts map and document the appearance and spread of – what based on their societal impact are considered – key invasive species in Hungary, including invasive plants, mosquitoes, plant pests, and wildlife. Understanding the process and driving forces of invasion is crucial for comprehending the effects, predicting invasions, and developing defense strategies. The properties determining the spread success of invasive species, including the contribution of human mobility to their spread, are investigated integratively in experimental systems. The impacts of invasive species on native species, ecosystem functioning, and ecosystem services are also studied. To understand the social and economic consequences of invasion, participating experts collaborate with relevant stakeholders to examine the effects on agriculture, forestry, game management, as well as plant, animal, and human health. A key objective of the project is to develop new technologies based on research findings, using predictive models, artificial intelligence, and molecular methods, to identify and forecast critical invasive events. The development and testing of new methods for invasive species control are also part of the plan.

The members of the Invasion Biology Division of NHSL consider providing continuous comprehensive information on the scope of invasion and the actual level of risks to the wider public, as well as formulating recommendations for decision-makers to develop invasion defense strategies, as their key task.


Researchers do not recommend planting blanketflower in gardens due to its invasive potential

The researchers of the ELKH Centre for Ecological Research (CER) investigated the spread of the non-native great blanketflower in Hungary within the framework of the National Laboratory for Health Security project. The aim of the research was to evaluate the impact of the species on the local plant community and determine its invasive potential through its functional traits. Based on the results, the great blanketflower does not currently appear to be a strong ecosystem-transforming species, but there is a risk that due to climate change, the local environment in Hungary will become more suitable for it in the future, leading to strong speading and becoming invasive. Therefore, the researchers do not recommend planting blanketflower species in gardens. They also suggest surveying non-native ornamental plant populations, conducting long-term monitoring and a more detailed assessment of the traits that influence their spread. The publication presenting the results was published in the scientific journal NeoBiota.

Ornamental plants are one of the main sources of species becoming invasive. During their planting, they are introduced to new habitats where humans create favourable living conditions through irrigation and maintenance. Later, in natural habitats, they can easily occupy open niches created by human disturbances and the warming effects of climate change. The blanketflower has followed this path as well, and its ecological impacts were studied by researchers of CER along with several other new, potentially dangerous species within the recently initiated National Laboratory for Health Security project.

The great blanketflower and its relative, the Indian blanket, along with their hybrid, are globally planted ornamental plant species. Reports have already been made in several countries about the great blanketflower escaping from gardens and naturalizing in various new habitats, but its invasive behavior has been relatively unknown until now. However, it seems that in the past few decades, this species has found suitable habitats in Hungary and from a naturalized species it has become invasive in several locations. “Our aim was to map the distribution of the great blanketflower in Hungary, evaluate its impact on the local plant community, and determine the species’ invasive potential through its functional traits,” summarized Gabriella Süle, Phd, a assistant research fellow at CER.

Based on the distribution data collected here, the great blanketflower occurs in Hungary mainly as casual escapes yet. This species, which blooms profusely throughout the year and is extremely colorful, requires little to no care. Therefore, owners allow it to spread, and we can often see it occupying more and more space in front of gardens. However, it became naturalized in recent years, and invasive populations have also been found in significant numbers within the country. The species is mainly observed near gardens and disturbed habitats, but it has also appeared in natural and semi-natural grasslands. It successfully spreads in disturbed, species-poor, sandy, open habitats. Its spread affects the composition of the local plant community, reducing, for example, the species richness of local plants. Based on its functional traits, its well germination capacity, extremely long flowering period, the large absorbing and adhering surface provided by its roots, and its spread by grazing animals’ fur, mainly sheep, can promote its invasive spread. Currently, the great blanketflower does not appear to be a strong ecosystem-transforming species, but more attention needs to be paid to it because there is a risk that the local environment in Hungary will become increasingly suitable for it due to drier weather caused by climate change, leading to strong spread and becoming invasive, primarily in sandy soils.

“Due to all of these, we do not recommend planting blanketflower species in gardens, as they can easily escape and establish in natural plant communities. Furthermore, we suggest considering banning their distribution in seed mixes. To control invasive populations in natural habitats, there is a need to develop an effective eradication method” emphasized Gabriella Süle, Phd.
Assessing the great blanketflower and similar non-native ornamental plant populations, conducting long-term monitoring, and performing a more detailed evaluation of the traits influencing their spread would be important in order to prevent the escape of species planted in gardens into the natural habitats on time.

Assessing and managing the ecological, economic, and societal threats posed by invasive species similar to the great blanketflower is one of the focuses of the Division of Invasion Biology within the National Laboratory for Health Security project. The research is being carried out within the framework of the Széchenyi Plan Plus program with the support of the RRF-2.3.1-21-2022-00006 project.

Süle G, Miholcsa Z, Molnár C, Kovács-Hostyánszki A, Fenesi A, Bauer N, Szigeti V (2023) Escape from the garden: spreading, effects and traits of a new risky invasive ornamental plant (Gaillardia aristata Pursh). NeoBiota 83: 43-69.

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Researchers have revealed the multi-level effects of invasion on plant-pollinator communities

Researchers from the ELKH Centre for Ecological Research (CER) and Babeș-Bolyai University (BBE) in three recent papers have described the effects of twelve invasive plant species with different traits on vegetation (Fenesi et al. 2023), pollinator communities (Kovács-Hostyánszki et al. 2022), and the traits of pollinating insects (Szigeti et al. 2023). During their field studies they assessed and compared the plant and pollinator communities of invaded and semi-natural habitats in Hungary and Romania. In order to facilitate proper comparisons and conduct detailed exploration, the researchers employed uniform field methods while utilizing diverse ecological indicators, ranging from the height of indigenous vegetation, honeybee abundances, depth of flowers to tongue length of pollinator insects.

Bees and other pollinator species play an extremely important role in most terrestrial ecosystems, including agriculture. Increasingly, studies report the drastic decline of pollinating insects, one reason being the reduced availability of their food resources. The strong spread of invasive species is one of the five most important causes of biodiversity loss, that is why the Invasion Biology Division was established under the leadership of the Ecological Research Center within the National Laboratory for Health Security, where researchers investigate the complex effects of invasion. Where invasive plant species appear and are able to spread, they inundate and dominate the given area, reducing diversity and making habitats more homogeneous. In many cases, they also reduce the range of available flowers, thus helping some compatible pollinator species while displacing the food resources of others from the landscape. In general, it can be stated that the impacts of invasive plant species on native vegetation and pollinator insects are often varied and dependent on their specific traits.

Based on the research results, there is no universal effect of plant invasion, except for a few general patterns there are differences among invasive plant species in almost every ecological indicator studied. Perhaps the most important message is that as many invasive plant species and traits as there are, there can be a variety of effects on invaded plant-pollinator communities. The three publications highlight that the cover of invasive plant species strongly influences the composition, diversity, and height of the remaining native vegetation, among other factors. As the invasive plant species displaces native plants in a given area, fewer of the original or potential communities remain. Perennial invasive plant species have an even stronger negative impact on flower availability and pollinators than annual species. This is likely due to their stronger invasive capacity, dominance, different growth and flowering strategies, and presence in later successional stages of habitats. Timing is extremely important in plant-pollinator systems. Invaded areas are similar to crop fields such as rapeseed or sunflowers: during their blooming period, they provide significant amounts of food for the pollinating insects, while beyond of their flowering period, these areas are extremely poor in resources of pollinators. Where invasive plant species appear, they eventually become dominant. They cover the area with green vegetation mass for most of the year, but only bloom for a short period of time. As indicated by the studies, natural areas have more and more diverse resources along the year. The researchers also found important and interesting relations when comparing the traits of invasive flowers and the traits of wild bees. For example, the sites invaded by two invasive species with deep flowers had more long-tongued and also larger-bodied bees, while a species with shallow flowers had more smaller-bodied bees. This indicates a strong size determination between flowers and their pollinators, meaning that the invasion of a particular trait (such as deep flowers in invasive plants) affects the functional characteristics of the remaining pollinator community in the invaded area (i.e., only long-tongued pollinators that can feed on deep flowers will remain).

Proper nature conservation management of (semi)natural habitats and effective control of invasive plant species are important for the protection of pollinators, but some invasive plants can also provide valuable foraging resources for pollinator insects. Therefore, instead of uniformly eradicating all invasive species, it is recommended to consider the best approach on a case-by-case and location-specific basis, taking also into account the needs of protected pollinator insects. For example, efforts to combat plant invasion could incorporate the nutritional requirements of pollinators. Some of the costs associated with invasive plant eradication could be redirected towards providing alternative nutrition sources, such as sowing native seed mixes in or in the neighborhood of invaded areas. Overall, the factors and impacts important in the plant-pollinator systems are complex and interrelated, hence further detailed studies are needed to uncover the specific relationships between species and to develop effective conservation solutions.


Fenesi, A., Botta-Dukát, Z., Miholcsa, Zs., Szigeti, V., Molnár, Cs., Sándor, D., Szabó, A., Kuhn, T., Kovács-Hostyánszki, A. (2023). No consistencies in abundance-impact relationships across herbaceous invasive species and ecological impact metrics. Journal of Ecology. DOI: 10.1111/1365-2745.14085

Kovács-Hostyánszki, A., Szigeti, V., Miholcsa, Zs., Sándor, D., Soltész, Z., Török, E., Fenesi, A. (2022). Threats and benefits of invasive alien plant species on pollinators. Basic and Applied Ecology, 64:89–102. DOI: 10.1016/j.baae.2022.07.003

Szigeti, V., Fenesi, A., Botta-Dukát, Z., Kuhlmann, M., Potts, S. G., Roberts, S., Soltész, Z., Török, E., Kovács-Hostyánszki, A. (2023). Trait-based effects of plant invasion on floral resources, hoverflies and bees. Insect Conservation and Diversity. DOI: 10.1111/icad.12640

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Invasion Biology website launched

The website of the Division of Invasion Biology, part of the National Laboratory for Health Security, has been launched at

The main mission of the Division is to investigate the ecological causes and consequences of the establishment and spread of invasive species through a unified concept, which requires a systemic and cross-disciplinary investigation of the processes at the system level and in distant specialist areas. In total, 16 research groups from six institutions are involved in this work, and one of the main aims of the website is to present the groups and the research topics they investigate, as well as to provide regular updates on the latest scientific publications and professional events published within the Division of Invasion Biology. We consider it important to make our latest scientific results in the field of invasion biology easily accessible in one place and in a suitable format for both professional and civil audiences, thus ensuring their further exploitation.