Better understanding the endozoochorous dispersal of alien and invasive fishes and plants

Dispersal is a crucial process in community ecology, through which individuals of a species can move into new and often different habitats. Species spread can happen actively, with individuals moving on their own, or passively, aided by dispersal agents. Understanding the dynamics and constraints of dispersal is a key to predict how species will adapt to changing environments, and can indirectly support biodiversity conservation and ecosystem stability.

The study of alien species dispersion is an important though relatively under-studied aspect of biological invasions. The colonisation of isolated wetlands and the introduction of pioneer and alien species are observable phenomena, but the underlying mechanisms are largely speculative. Researchers from the Institute of Aquatic Ecology at the HUN-REN Centre for Ecological Research have undertaken experiments on fish and plants to test hypotheses related to alien species dispersion. Previously, it was widely believed that waterbirds played an important role in the dispersal of fish in isolated water bodies, with fish eggs surviving passage through birds’ digestive tracts (i.e. endozoochory). Researchers at HUN-REN CER recently confirmed this hypothesis—the first such confirmation globally. However, questions persist regarding its prevalence among bony fishes and the variability in dispersal capacities across species.

In a series of feeding experiments with mallards, the researchers investigated the passive dispersal abilities of several common native (Wels Catfish, Common carp, Pike perch, Tench) and alien (Hybrid African catfish, Grass carp, Pumpkinseed, Amur sleeper, Stone moroko) fish species. In their paper, published in the journal Ecography, they reported the recovery of viable embryos of five fish taxa in the faeces of mallard, with successful hatching into larvae in one native (Tench) and one alien (Stone moroko) species. This result provide evidence that endozoochorous dispersal might be a widespread but likely rare phenomenon among bony fishes, with significant variability between species likely due to unique egg characteristics.

Herbivorous birds are known to play a significant role in seed dispersal, dietary studies from Europe showed that waterbirds can disperse hundreds of plant species, including many aliens. Moreover, passage through their digestive system can affect seeds’ germination rates. In a similar feeding experiment, researchers from HUN-REN CER compared the endozoochorous dispersal ability of six pairs of closely related (i.e. congeneric) alien and native wetland plant species. In their study, published in Freshwater Biology, they found that alien plant species can disperse more efficiently, with significantly higher seed passage rates.

However, these seeds germinated more slowly after gut passage compared to native species. Higher seed passage contributes to higher “propagule pressure” in new habitats, increasing the likelihood of establishing new populations of alien species. The delayed germination of aliens’ seeds also can offer a competitive edge to non-native species, particularly if they exhibit a fast growth rate and higher trait plasticity. Considering that mallards typically move several kilometres per day and even longer during migrations long-distance dispersal might be common and important for all studied plant species. Mallards also make shorter daily movements between wetlands, which might assist alien species to become fully established after their introduction to an area.


Diverse native wildflower plantings for pollinators in farmlands

Pollinators are declining rapidly, largely due to land conversion and intensification of agriculture. To mitigate their crisis, low-disturbance habitats, such as sown wildflower plantings (commonly known forms are wildflower strips at the edges of arable fields), could promote pollinators by restoration of their resources (food, sheltering and nesting habitats). However, comprehensive knowledge is lacking on how landscape context, spatial configuration and age of wildflower plantings, seasonality and flower composition affect pollinator communities, especially from East-Central Europe. 

To understand these effects, researchers from the HUN-REN Centre for Ecological Research established diverse native wildflower plantings within heterogeneous and homogeneous agricultural landscapes, by two spatial configurations: one large field or three smaller strips. Floral resources and wild pollinator insects (wild bees, hoverflies, butterflies) were sampled, in early and mid-summer, for two years after establishment (2020-21).

Flower resources of the sown plant species increased continuously, and were complemented at high rate by flowering plant species from the soil seed bank, especially in the first year. Both flower abundance and diversity increased the abundance of pollinators, highlighting the important role of using diverse seed mixtures. Wild bee abundance and species richness increased year by year and season by season, while butterfly abundance also demonstrated a yearly increase after establishment. Hoverfly abundance and species richness, however, showed an opposite trend, possibly due to the inter-annual variation. Wild bee and butterfly abundance was higher in the heterogeneous than in the homogeneous landscapes. Researchers did not observe any significant local effects of spatial configuration itself on pollinator populations.

Field-work photos from the transect walk method and the flower resources assessment from the four years of the study Photos: Borbála Bihaly (top left, buttom right) and Áron Bihaly (buttom left, middle and top right)


Our results emphasize that to support pollinators effectively, future wildflower plantings should be maintained for multiple years, in order to maximize floral diversity and ensure continuously available flower resources throughout the entire season.

Further results from the upcoming years and similar long-term and landscape-scale experimental studies are needed to understand all the benefits and ecological processes of diverse native wildflower plantings especially in understudied European regions.

The diverse floral resource of wildflower plantings in the second and third years and the pollinator insects visiting the flowers
Photos: Viktor Szigeti (top left and middle left) and Borbála Bihaly (bottom row, top right and middle right)






Researchers show that increase in water salinity can drive evolution in planktonic organisms

Researchers at the HUN-REN Centre for Ecological Research (HUN-REN CER) are continuously studying the effects of changing environment on ecosystems, caused by human activity and climate change, and how animals respond to it. They recently showed that the increase of salinity of ponds can drive the evolution of planktonic organisms, and this process can be observed in the Daphnia (water flea) populations in the sodic water of World War II bomb craters in Hungary. The paper presenting their latest discoveries has been published in the flagship biological journal of the Royal Society, Proceedings of the Royal Society B.

Natural ecosystems are exposed to a multitude of stressors including climate change, urbanisation, or the rising salinity of aquatic habitats. These stressors change the environmental conditions, which determine the success of organisms. The emerging spatial variation in environmental factors is called a gradient. The Plankton Ecology Research Group at HUN-REN CER, led by research fellow Csaba Vad, studies the effects of environmental change on the functioning, species composition, and evolution of planktonic communities.
“Organisms have to adapt to environmental stress, otherwise they go extinct,” the researcher says. “Sensitive species can be replaced by other more stress-tolerant species, or the resident populations can also adapt to the changing environment. In other words, an evolutionary adaptation occurs in the population, and this provides an opportunity to survive in the habitat.”

Salinisation, the increasing salinity levels of aquatic ecosystems, is a global threat. The salinity of large lakes is rising as well, but the change can be much more dramatic in shallow temporary ponds. Salinisation is caused by many factors, but one of the most important drivers is increasing evaporation (as a result of warming). Meanwhile, pollution from mining or other industrial activities, or the environmental effects of urbanisation can also lead to salinisation.

Soda pan in the Seewinkel area, Austria (Oberer Stinkersee, photo: Horváth Zsófia)

Soda pans are naturally saline habitats in the lowlands of Carpathian Basin. The researchers studied the plankton communities and salinity of these soda pans and compared them to the communities of ~80-year-old sodic bomb crater ponds in the Great Plains of Hungary. Their exact origin is somewhat uncertain, but some sources suggest that during World War II, American bombers bombed the plains instead of the nearby airport, creating more than 100 explosion craters in an 800 m diameter circle. These craters were filled with sodic water and have since become very useful model systems for ecological research.

The salinity of the bomb crater ponds varies widely, so ecologists were able to compare their Daphnia populations and find out whether they are adapted to this environmental factor. Water fleas, such as the object of this study, Daphnia magna, are large-bodied zooplankton species, which are common model organisms in ecological and evolutionary research, because they play important roles in aquatic communities and can be kept easily in laboratories. “We wanted to find out whether the salinity tolerance of Daphnia originating from ponds with low and high salinity levels is different”, tells Csaba Vad. “We also studied soda pans, which are also sodic and hold similar zooplankton communities to the bomb craters. Both types of these habitats are naturally saline, and can be used as model systems, because their clusters consist of several ponds with different salinity levels in close proximity to each other.”

If local adaptation occurs, the salinity tolerance of the populations is matching with the salinity levels of their home ponds. This means that water fleas from more saline ponds will have a higher salinity tolerance compared to the Daphnia from less saline waters. In theory, local adaptation could be more prominent in more isolated habitats (in ponds more distant in space), because the mixing of their populations with others is less likely in the case of more distant habitats. The soda pans are kilometres apart, while bomb crater ponds are only a few metres away from each other. So, based on merely the position of ponds, more intense evolutionary patterns could be expected to be found in soda pans. But this was not the case.

Local adaptation (adaptation to the local salinity concentrations) was only found in the bomb crater ponds, which are very close to each other in space. There are some possible reasons underlying this observation. For example, salinity levels in soda pans are usually higher and more variable within and across years than in the bomb crater ponds. Soda pans are also shallower and larger, while bomb craters are deeper and smaller in diameter. When soda pans dry up, the resting eggs of water fleas can be easily blown to another pond by the wind. In contrast, bomb craters dry up more rarely (only in years with extreme weather conditions), their salinity level fluctuates less, and during the explosion, a prominent rim was created along their edges. Thus, Daphnia eggs cannot be as easily transported among the neighbouring ponds, and the more stable salinity levels allow for local adaptation to this stressor.

The researchers found adaptation to salinity in the soda pans as well, but this occurred on a regional level. Soda pans have a higher average salinity level than bomb craters, therefore the water flea populations from soda pans have higher overall salinity tolerance than those from the bomb crater ponds.

“Despite soda pans being more distant from each other, because of their more frequent drying-up, the gene flow among their Daphnia populations is more intense,” argues Csaba Vad. “Furthermore, many waterbirds visit soda pans, which transport several aquatic organisms from one pond to another. These circumstances overall reduce the possibility for local adaptation in this habitat type. In contrast, we found strong local adaptation in bomb crater ponds, which are sometimes only a few metres apart. Our results show that the response of aquatic communities to salinity may be influenced by several factors.”

Opening image: The model organism of the study, the water flea Daphnia magna Photo: Zsófia Horváth


Numerical models for a better understanding of long-term effects on lake ecosystems

Nowadays we hear a lot about climate change impacts in general, however, we still lack in-depth knowledge about how climate change might modify the processes determining the ecological status of lakes and the structure and functioning of aquatic communities. This is largely because these processes are intertwined in a complex manner, making any estimation regarding these changes challenging. In their latest study, researchers of the HUN-REN CER Institute of Aquatic Ecology used model simulations to analyse warming effects on phytoplankton dynamics based on field and experimental observations.

Although numerous lakes around the world have been showing an increase in annual mean temperature over the last few decades, it still remains difficult to assess long-term warming-related impacts in water bodies with various physical and chemical properties and diverse communities. Exploring these impacts is crucial not only for fishes, macroinvertebrates or aquatic macrophytes, but also for planktonic organisms, which form the basis of the aquatic food web and have a substantial influence on material cycles. Despite the broad range of sophisticated techniques developed to study this important group, elucidating how interrelated environmental factors drive plankton functioning is still a hard task due to the typically rapid dynamics of these communities. Monitoring based on regular field work is a crucial part of research on aquatic systems, but it is also time-consuming and lab-intensive, making any sampling effort limited in both space and time. In a sense, this is like following a streaming series with several seasons by only looking at a few snapshots from each episode, trying to guess what the actual story is.

We need complementary approaches to improve our ability to assess, estimate or forecast the ecological effects of climate change. Numerical models are promising candidates for this role, gradually gaining importance in ecological research. Generally speaking, such models describe fundamental relationships in the form of mathematical equations based on current data and scientific knowledge. Such relationships include e.g. species growth as a function of food item availability or the dependence of plant photosynthetic activity on light intensity. The strength of modelling lies in the possibility to create computer-generated simulations about changes in a population, community or ecosystem and their environment through space and/or time, helping to find causality behind natural phenomena. Thus, while field and experimental observations provide data about a series of temporary states and conditions, modelling aims at the processes that induce temporal change in those states and conditions.

In a Hungarian-Greek collaboration, Károly Pálffy, researcher of the institute’s Plankton Ecology Group, studied the dynamics of planktonic algae (phytoplankton, major primary producers of aquatic habitats) using an ecological modelling approach. While analysing a data series on Lake Balaton, Hungary in his previous study he found that the long-term rise in annual mean water temperature was accompanied by increasing seasonal fluctuations in phytoplankton composition (increasing seasonal variability), which might suggest a decline in ecosystem stability. He and his colleagues also managed to demonstrate something highly similar in a mesocosm experiment, raising the question of whether there is a more general connection between warming and the dynamics of planktonic algae.

A typical graphical output of a model simulation of one year run under different seasonal temperature scenarios (daily temperature values characteristic at present and increased with 1, 2 or 3˚C). Curves with different colours represent seasonal changes in the abundance of different species of algae. The modelling of temporal dynamics in multiple randomly assembled phytoplankton communities under different nutrient load and temperature combinations added up to more than 100,000 simulations. The study focussed on both short-term (one year) and long-term (30 years) changes and impacts.

The newly developed model made it possible to simulate changes in phytoplankton on the species level under various temperature scenarios. The output of the simulations was in agreement with the previous observations, elevated mean temperature caused more pronounced seasonal changes in phytoplankton composition, but the degree of this impact was also highly dependent on how the communities received inorganic nutrients essential for their growth. Accordingly, the ratio of the two most important ones, nitrogen and phosphorus as well as the temporal fluctuations in nutrient supply had significant influence on the effect of warming. This is in close agreement with recent studies that suggest the importance of considering nutrient load conditions (the so-called trophic state of a water body) when assessing the effect of climate change on aquatic ecosystems. Besides nutrients, initial species richness of the simulated communities also affected their response to warming. From a methodological point of view, this is an important finding, since it suggests that choosing an adequate number of species can be crucial in the planning of community-scale climate change experiments.

The recent paper published in Limnology and Oceanography also sheds light on what long-term consequences an increase in the seasonal variability of phytoplankton can have in terms of stability. At higher mean temperatures, seasonal extremes in community composition became more prominent, shifting the communities toward lower overall evenness. On a longer time scale, elevated temperatures also increased the probability of species loss, providing a mathematical explanation for the role of warming in reducing plankton community stability and thus modifying aquatic ecosystem functioning. The research group has plans for further extending the model, facilitating the simulation of climate change impacts in a spatial context as well as on the level of the planktonic food web.

Numerical models nowadays have an increasingly important role in the interpretation of field observations


Interview with Corrado Alessandrini about apple orchards in Trentino, white-winged snowfinch and the National Botanical Garden of Vácrátót.

Corrado Alessandrini is an Italian PhD student visiting HUN-REN Centre for Ecological Research, and lives inside the National Botanical Garden in Vácrátót. He studies the agro-ecology of apple orchards in Trentino, and Europe’s most alpine birds, the snowfinch. He discovered that the climate change is destroying the unique microhabitats which are essential for the survival of this unique species. Corrado feels great about being connected to the nature literally every minute in the Garden, with all the trees and flowers blooming, and the birds calling, greeting the spring.

– Why are you visiting the Centre for Ecological Research?

– My Phd is upon the EU-funded National Recovery and Resilience Plan (PNRR), which requires to have a period abroad during the PhD (to make science more interconnected at the European level). I already knew Péter Batáry, head of the Lendület Landscape and Conservation Ecology research group, for his several works on agro-ecology and – since my supervisor, Mattia Brambilla, personally knew him, we thought that he could be a good teacher for my period abroad. He kindly accepted me in Vácrátót for a 6-months stay. I have been now here for five months, sadly time is running out! During my stay here, I have been basically studying my own data, but by applying and learning the techniques that the research group uses here, basically within the fields of Landscape and Community Ecology.

– Please tell me about yourself and your studies first. What’s your background and what are you studying?

– I’m a naturalist from Rome, Italy. I started a bachelor in natural science, so I integrate animals, plants, rocks, and ecosystems in my studies. This gave me an holistic view that I really enjoy having in my background. After the BSc, I kept studying in Rome for a master’s degree in Ecology and Conservation. As a master thesis I contacted Mattia Brambilla from University of Milan and together we studied the foraging ecology of the white-winged snowfinch (Montifrigilla nivalis), an alpine bird species endangered by climate change, by using innovative methodes of remote sensing. Thanks to this, we’ve disclosed new aspects of the species’ ecology and reaffirmed its dependence on climate-sensitive habitats, which poses a threat on the species. After that, I went to Oviedo (Spain), to keep studying this bird with Maria del Mar Delgado, again integrating field studies with remote sensing, which is very helpful in such harsh environments like mountains.

– Your PhD topic is about the connections between agriculture and wildlife communities. Why is this topic interesting to you?

– Yes, I’m currently a PhD student at University of Milan, with a field project in the Non Valley (Trentino, north of Italy), one of the most productive areas for apples in all Europe. There, farmers are trying to make the production more sustainable, so they wanted us to study the biological communities that live inside the apple orchards to try to understand whether their activities are impacting these communities and how such communities can provide valuable ecosystem services for the apple production. So, last year we started this project by firstly focussing on three taxa: birds, pollinators (especially insect pollinators), and rodents. These taxa are involved in the supply of important ecosystem services, basically insect-pest control (insectivorous birds feeding on apple pests), pollination (by bees and other wild pollinators), and weed control (whose spread is controlled by granivorous birds and rodents). Richer biological communities (and especially the occurrence of rare bird or butterfly species) can also be very attractive for nature-based tourism, which is an important asset for the whole Trentino province.

– You are accommodated inside the National Botanical Garden in Vácrátót. How does it feel?

– Definitely great! I lived in Milan this past year. And Milan is a very crowded, “hyper-urban” city, I would say, with very few green areas. While here I’m all the time connected with nature. Literally every single minute I can hear some bird calling. For instance, now birds are “warming up” for the breeding season, and many have already started singing. Trees are sprouting after the winter, and the first flowers are shyly colouring the Garden. Few weeks ago, squirrels came out of dormancy, they really looked sleepy! Well, every day you can find something going on when you have so much life around. And for me, as a naturalist, this is precious.

– In Italy, you cooperate with the apple farmers. Is there any conflict between the ecologists and farmers because of their different interests?

– We work with a farmer’s association that started to push towards a more sustainable agriculture 20 years ago by adopting integrated management. Their practices are not pure conventional, indeed, and they do intend to be more sustainable in their production. This makes our cooperation much easier. Of course, we come from very different perspectives, but we need one another, because we do love apples, and they do want to hear blackbirds singing in their orchards. The main goal of agriculture is to produce food, not to save birds, and we do acknowledge that we all need this food. On the same time, we all know that conventional intensive agriculture is driving farmland birds to extinction and that it severely impacts wildlife (and human) health. Here we are trying a new way. Sometimes (and my supervisor Mattia Brambilla proved this in previous works in vinyards), very little things can make a huge difference for biodiversity. For example, by slightly shifting the timing of mowing the grasses inside the orchards we could sustain much richer pollinator communities (that forage on those herbs and flowers). You see, this alternative management doesn’t really affect farmer’s production, but it does help biodiversity. Solutions like this is what we are all looking for.

– You conducted a lot of studies on the snowfinch. Why is this bird so important to you?

– The white-winged snowfinch has quite a large distribution area. It is found originally in the highest mountains of the Himalaya, but, as the only species from its genus (Montifringilla), came to Europe as well, following all the mountains: Caucasus, Balkans, Alps, and Pyrenees. Nowadays it’s the most cold-adapted species in Europe. This is the most alpine bird we have: in fact, it’s the only one that can survive above the tree line (which means roughly above 2000 m), even during winter. They can live with all snow around in very harsh conditions. Because they are adapted to cold, they are one of the most endangered species in the age of climate change, and note that mountains are warming up twice faster than lowlands. This is why we are so concerned about studying its European population. We have already found evidence of population declines (e.g. in Switzerland), and we found that they depend on climate-sensitive habitats. We focussed on their breeding ecology: this is a critical period, when the adults forage for the newborn chicks. We saw that they forage in specific microhabitats (namely snow patches, snow margins, and low-sward grasslands) which are all predicted to disappear in a very near (warmer) future. We expect that, as in a few years they would have more problems in finding suitable microhabitats for feeding their chicks, this would hamper their survival and therefore the fitness of the whole population.

How do you study the snowfinches and their habitat?

– I wanted to assist the current research with the potential of remote sensing, which is nowadays able to capture at high resolution what’s going on Earth’s surface. We use satellites to describe the environment where the birds live, so we don’t need to go up there to see whether vegetation is blooming or to estimate snow cover during the breeding season. By using satellites, we can record such changes remotely, every 3 to 5 days, in a very uniform way, and simultaneously over very large extents. We found that remote sensing can be a useful conservation tool. Once you know the area where they live, for instance, a national park, you can keep tracking the evolution of those critical habitats (snow patches and short grasslands) across the breeding season, and eventually act if conditions become critical.

– Is the climate change affecting the whole bird community or there are some species which are affected most?

– In general, it starts by affecting specialist species (which are less capable to face environmental changes due to their high degree of ecological specialization), but later its effects propagate to the whole community. Communities are constantly adapting to changes in the environment (this mechanism is called “homeostasis”). But climate change is now stressing them at an unprecedented level, by disrupting many ecological dynamics at the same time. This results in a general loss of the resilience of bird (or any other animal) populations, and their ability to cope with other environmental changes also declines. In high mountains, for instance, we now know that climate and ski tourism (another important – anthropogenic – source of environmental change), are synergically impacting on our bird communities.

– What are your plans after you go back to Italy?

– We will continue investigating the birds in the Non Valley. From the data we collected last year, we noted very low densities of great tits, an insectivore species that is very important for controlling the outbreaks of pest insects in orchards. Hence, we now want to test whether providing them with nest boxes (where they can breed) can help increasing their population inside the apple orchards, therefore maximising the supply of the pest-control ecosystem service. Besides this, on a longer term, I think I will keep doing the same: studying nature to provide solutions for better policies, which is what conservation biology does. No matter where, in the agro-ecosystems or up on the mountain tops, always trying to push us all to be a little bit “softer” with our Earth.

Corrado Alessandrini Fofo: Márton Kállai


Internationally recognised visiting researcher arrives this year at the Institute of Evolution of the HUN-REN Centre for Ecological Research

In the framework of the Hungarian Academy of Sciences (MTA) Distinguished Guest Scientists Fellowship Programme, ten internationally renowned visiting professors will arrive at the research centres and supported research groups of the HUN-REN Hungarian Research Network in 2024. Applications for the calls for proposals were received from all three major disciplines: the humanities and social sciences, the life sciences and mathematics and natural sciences. Out of a total support budget of 100 million HUF, successful applicants were awarded grants ranging from 4.7 million to 9 million HUF.

Mauro Santos, a professor at the Autonomous University of Barcelona, will join the Institute of Evolution of the HUN-REN Centre for Ecological Research. The joint research aims to explore the potential for evolving univariate and multivariate adaptive phenotypic plasticity to increase the probability of persistence in response to continuous, controlled environmental change (e.g. global warming) accompanied by random environmental fluctuations within generations. The results will inform the empirical evidence needed to draw robust conclusions about the role of phenotypic plasticity in evolution. The aim is also to explore the role of different types of epistasis – synergistic or antagonistic – in the evolution of early genetic systems, starting from first principles and using theoretical model systems.

Professor Mauro Santos has worked with evolutionary biologists at the Centre for Ecological Research before. Then they demonstrated that, under the right circumstandes, senescens can support the response to the directional selection, i.e. evolutionary adaptation to changing environmental conditions. In doing so, the researchers have added an important and new aspect to the question of ageing, which has been an elusive and poorly understood phenomenon in evolutionary biology for more than a century and a half.


National mapping and assessment of ecosystem services in Hungary

The nature surrounding us, the living world, and the ecosystem provide us with the means to produce food. They play an essential role in regulating the climate by absorbing carbon dioxide, storing carbon, or protecting the soil from erosion. In recent decades, the concept of ecosystem services has gained ground. Its spread is due to the opportunity it offers to explore the complex interrelationships between the natural and socio-economic systems. It highlights how society and the economy are based on ecosystems and how human activities modify the natural environment. There is a clear link between the state of ecosystems and the well-being, health and happiness of people through ecosystem services.

Hungary’s current National Biodiversity Strategy to 2030 (3rd National Biodiversity Strategy) was adopted in August 2023. Its objectives are creating a coherent network of protected areas, improving the condition of different protected areas and restoring degraded ecosystems. The above objectives can only be achieved based on proper information and a thorough situation assessment. For this, we need a comprehensive understanding of the current state of our habitats.

Over the past five years, extensive cooperation has been established between sectoral experts and nearly 250 researchers and conservationists in a project coordinated by the Ministry of Agriculture (KEHOP-4.3.0.-VEKOP-15-2016-00001). One project element is the National Ecosystem Services Mapping and Assessment (MAES-HU), which aims to assess and map the extent of ecosystems, ecosystem condition and ecosystem services nationwide. The extensive collaboration resulted in several studies, which amounted to about 2,400 pages overall. The most important results are highlighted in a book titled ‘The Assessment and Mapping of Ecosystem services in Hungary’.

“One of the tasks was to assess ecosystem condition. However, what someone means by the condition of an area or habitat can be very varied,” says Eszter Tanács, one of the project researchers and a research fellow at the HUN-REN Ecological Research Centre. “Each stakeholder defines ‘good condition’ from their own perspective. They usually focus on factors that directly affect the state of the habitat or group of organisms that are especially important to them. For example, the health of plants (whether trees or crops of some kind) is an important indicator. If this is not in order, everyone pays attention. However, there may also be indirect links between condition and services that are more difficult to identify. For example, the diversity of wildlife in an area may be closely linked to its condition and thus indirectly to what services may be provided by the particular ecosystem type and in what quality.”

“To inform nationwide decisions, we need to produce maps that try to reflect the state of the environment and habitats nationally. This scale represents a particular challenge because the ‘goodness’ of large-scale maps depends to a large extent on the data we can base them on. However, how much detailed data we have for a given area is often arbitrary in space and time. Information on different types of habitat is not uniformly available. In the case of forests, where management means that we have to think in terms of decades or centuries, a lot of data are available at the national level. This is also true for agricultural land, partly due to the different subsidy schemes. For grasslands and wetlands, however, there is little information at the national level based on accurate measurements, although many sectors could make good use of such. Generally, more related information is available on very valuable protected areas, but these cover only a small part of the country’s territory,” said Eszter Tanács, explaining the difficulties of the task.

“Where there are insufficient sources of information, i.e. little measured data, the researchers have tried to indirectly estimate the extent of environmental pressures and mapped them. They have built on previous research and knowledge of responses to such pressures. Maps based on such relationships can also be used to estimate current condition and suitability for wildlife. Still, they have a relatively high degree of uncertainty because they represent risk. There are cases where only rough estimates can be provided through multi-step analyses – for example, flower abundance is estimated based on the presence of pollinators, and flower abundance is estimated based on what habitat is being discussed. The usefulness of such maps is more limited than those based on measured data. Therefore, an important element of our research is to investigate how well such maps reflect the condition according to more detailed, fine-scale data where they are available. This is a prerequisite for producing better and more accurate maps over time,” said Eszter Tanács.

The Ecosystem Map of Hungary, completed in 2019 (with a baseline year of 2015), was a major milestone in the implementation of the project. Although there were significant data gaps in some of the maps used for compiling it, a detailed, wall-to-wall land cover database has been developed. It is currently the best available for Hungary in terms of spatial and thematic resolution.

Proportion (%) of seminatural habitat types (based on the Ecosystem Map of Hungary) within a 300 m radius of each point

Researchers from the HUN-REN ÖK Lendület Ecosystem Services Research Group have reviewed European ecosystem services mapping projects using national experience in a recent prestigious international publication. The paper, published in the journal Ecosystem Services and first authored by Ágnes Vári, reviews the ecosystem mapping process in 13 European countries, presenting the results of a survey of project participants. The publication reviews the types of methods used, the ecosystem services assessed, the problems identified, and possible ways forward at the European level.

Ágnes Vári, Cristian Mihai Adamescu, Mario Balzan, Kremena Gocheva, Martin Götzl, Karsten Grunewald, Miguel Inácio, Madli Linder, Grégory Obiang-Ndong, Paulo Pereira, Fernando Santos-Martin, Ina Sieber, Małgorzata Stępniewska, Eszter Tanács, Mette Termansen, Eric Tromeur, Davina Vačkářová, Bálint Czúcz: National mapping and assessment of ecosystem services projects in Europe – Participants’ experiences, state of the art and lessons learned
Ecosystem Services, Vol.65, 2024,


Boross Gábor joins HUN-REN CER to establish a new cancer evalution research group within HUN-REN’s excellence programme

Gábor Boross, an evolutionary and systems biologist, returns to Hungary as part of the HUN-REN Welcome Home and Foreign Researcher Recruitment Programme, following his postdoctoral research on lung cancer evolution in mice at Stanford University in the United States. At the Institute of Evolution of the HUN-REN Centre for Ecological Research, he will establish a new research group to investigate how the ‘driver’ mutations responsible for cancer interact with each other, ultimately leading to the growth of cancerous tumours.

Gábor Boross used the Tuba-seq technology developed at Stanford University. This technology primarily involves the utilisation of CRISPR genome engineering techniques to induce specific mutations in mouse lung epithelial cells. Tumours originating from these mutations are marked with DNA barcodes. By sequencing these short DNA segments, the size of the tumours can be determined, thereby providing insights into how specific mutations impact tumour growth or even how they influence the response to various therapies.

While conducting research in the United States, the young researcher further developed the Tuba-seq technology, considering that human tumours typically result from multiple mutations occurring concurrently. The objective was to enhance the system making it suitable to handle combinations of mutations in a highly scalable manner, allowing for cost-effective measurements of a large number of mutations with minimal experiments. With the backing of the HUN-REN grant, he is now bringing this technology to Hungary and applying it to create high-coverage interaction maps and describe adaptive landscapes that determine the progression of cancer.

As part of the HUN-REN Welcome Home and Foreign Researcher Recruitment Programme, which was announced for the first time in 2023 by the HUN-REN HQ, six Hungarian researchers and one foreign researcher from the international elite are coming to Hungary to form research groups at HUN-REN research sites to undertake their outstanding scientific projects as part of the winning proposals.


Workshop on how the Convention on Biological Diversity works in practice

The diversity of life on our planet is declining at an unprecedented rate, as confirmed by a series of international scientific studies, evaluations and assessments. Recognising this process and mitigating the damage is the subject of a series of international conventions, the most significant of which is the Convention on Biological Diversity (CBD), adopted at the 1992 Earth Summit in Rio de Janeiro. The CBD is significant in that it takes a position at the highest international policy level on the relationship between human society and biodiversity. The Convention not only defines principles and tasks, but also contains measures on the functional, organisational and financial aspects of implementation.

As it is a global agreement, the implementation of the measures is extremely complex and demanding. The CO-OP4CBDCooperation for the Convention on Biological Diversity project’s objective is to improve coordination within the European Union (EU) in the implementation of the Convention, to identify the appropriate knowledge base for each issue addressed and to use it appropriately and effectively. The Centre for Ecological Research (CER) as project partner organised a two-day expert workshop with the collaboration of the Biodiversity and Gene Conservation Department of the Hungarian Ministry for Agriculture. The event took place on 15–16 January 2024 in Budapest, in the Ministry for Agriculture.

The meeting was attended by 56 participants from 7 countries, representing various government agencies, research institutes, universities, national parks and conservation NGOs. The first day focused on the technical processes of the Convention on Biological Diversity (CBD), at international, European Union and national level. The objectives of the workshop were outlined by Kinga Öllerer (CER), Pierre Spielewoy (National Museum of Natural History – MNHN, France) presented the draft of further training activities for Central and Eastern European professionals within the CO-OP4CBD project, and Ditta Greguss (Biodiversity and Gene Conservation Department, Ministry for Agriculture, Hungary) spoke about Hungary’s commitments, in particular with a view to the 16th meeting of the Conference of the Parties to the CBD (COP 16) to be organised under the Hungarian Presidency of the Council of the European Union in  2024. Didier Babin (French Agricultural Research Centre for International Development – CIRAD) and Hendrik Segers (Royal Belgian Institute of Natural Sciences – RBINS) presented the functioning, decision-making and professional processes of the CBD, while Eliška Rolfová (Ministry of the Environment, Czech Republic) presented the functioning of the CBD from the perspective of the European Union.

On the second day, two group leaders of CER, scientific advisor Zsolt Molnár and András Báldi, corresponding member of the Hungarian Academy of Sciences, presented the functioning of the Intergovernmental Science–Policy Platform on Biodiversity and Ecosystem Services (IPBES) and that of the CBD from a researcher’s point of view. Joachim Töpper (Norwegian Institute for Nature Research – NINA) spoke about the indicators of the Kunming–Montreal Global Biodiversity Framework.



A bombcrater pond network demonstrates the importance of connectivity for aquatic biodiversity

Habitat fragmentation poses a growing global threat to our natural ecosystems, making it one of the greatest challenges in biodiversity conservation. Among the most vulnerable of these ecosystems are ponds, due to their small sizes and intricate networks. Ponds have experienced global declines in numbers and extent, making them a critical focus for conservation efforts. Once a pond loses its neighbors, it becomes isolated, which can lead to biodiversity decline. A new study, conducted in Hungary, sheds light on the importance of connectivity among ponds in these small-scaled habitat networks and its impact on the biodiversity of ponds.

Situated in the heart of the Pannonian Plain on the interfluve of the Danube and Tisza rivers, Hungary’s Kiskunság region is a diverse landscape, encompassing a variety of aquatic and terrestrial habitats. From shallow lakes, soda pans, and swamps to dry and wet meadows, semi-arid sand dunes, and grasslands, the region supports a unique array of flora and fauna, including numerous rare and endemic species. Large parts of the region belong to the Kiskunság National Park and are parts of a UNESCO Biosphere reserve, while a number of aquatic habitats are listed under the Ramsar Convention. Here, a cluster of 112 bomb crater ponds form a network with ponds differing in their distances, and therefore their relative connectivity to their neighbors. This so-called ‘pondscape’ was likely created during World War II by mistargeted bombing on a sodic meadow of the nearby airport.

Bomb craters may be scars on our Earth and reminders of devastating history but these ponds are thriving with life and providing habitat for a range of aquatic species today. They hold sodic water mostly dominated by sodium carbonates and hydrocarbonates and they vary in environmental and morphological characteristics. The ponds host a variety of species, including Pannonian endemic fairy shrimp (Chirocephalus carnuntanus), protected amphibians, pond turtles, and a range of invertebrates such as dragonflies, mayflies, aquatic beetles, and microcrustaceans. Beside its importance for conservation, the pondscape offers a unique setting for investigating scientific questions in a natural laboratory. The ponds are small and easy to sample and they form a well-delineated network far from other waterbodies. Therefore, they represent an excellent model system to understand how pond networks sustain biodiversity, and form a metacommunity, i.e., multiple separate habitat patches potentially connected through the dispersing organisms.

The ponds are not physically connected by waterways thus the dispersal of organisms is expected to occur mainly via wind or by the active movement of the organisms. The prevailing assumption has been that such small-scaled habitat networks lack structuring by spatial processes, i.e. we cannot observe diversity gradients in the network due to differential dispersal rates because all organisms could potentially spread to all habitats.

However, the findings of a study carried out by researchers from HUN-REN Centre for Ecological Research in Hungary challenge this notion. The researchteam investigated the influence of both space, i.e., the arrangement of the habitat patches and the local environmental variables (e.g. water nutrient content, depth, salinity) on species richness and community composition in an international collaboration led by Barbara Barta. These were tested in a range of organism groups including the tiniest microscopic creatures to ones as large as amphibians. They are expected to respond differently to the environmental conditions and connectivity.

“The findings showed that besides environmental conditions which certainly play a significant role in shaping community composition, the spatial position of ponds in the network is also important, particularly for passively dispersing organism groups. These are the organisms (e.g. microbes, plankton) that rely on dispersal agents, such as wind to move them across the landscape. For these species, it is better to be in the centre of the network where their pond is surrounded by many other ponds from which conspecifics can easily arrive. This leads to higher diversity of these groups in the centre of the pondscape.” explains Barbara Barta, the lead author of this study. This discovery highlights the importance of the central-peripheral connectivity gradient within pond networks.

“These findings underscore the significance of studying and conserving ponds as integral components of a network, rather than as isolated entities. It is crucial that the network as a whole is protected with all the connections which ensures that the biodiversity is sustained. Understanding the impact of connectivity on biodiversity in fragmented ecosystems like ponds is vital for the preservation of these unique habitats.” summarises Barbara Barta.

Photo: Horváth Zsófia
A network of bombcrater ponds on a meadow in Apaj, Central Hungary


Project RestPoll: Restoring Pollinator habitats in Europe

RestPoll is a new project which aims to permanently restore and connect pollinator habitats in Europe. The project began in October 2023 and will run for 4 years. The project is led by the Chair of Nature Conservation and Landscape Ecology at the University of Freiburg. It aims to provide society with tools to reverse wild pollinator declines and to position Europe as a global leader in pollinator restoration.

Butterfly on twig, rename to: “Butterfly drinking plum juice” the butterfly is Vanessa atalanta – Felix Fornoff

Restoring pollinator habitats
To counteract the decline of pollinators and thus pollination services, it is important to restore their flowering and nesting habitats. This is important for biodiversity in general and for agricultural yields and food security.
RestPoll will, together with stakeholders ranging from individual land managers to governments, focus on measures and cross-sectoral approaches to restore pollinators and their services. Central to RestPoll is the establishment of a Europe-wide network of pollinator restoration case-study areas and Living Labs (LL), which are unique hubs for experimentation, demonstration, and mutual learning. Restoration activities in the eighteen case-study areas in fourteen European countries are partly already set up by stakeholders in cooperation with RestPoll researchers or vice versa.
The RestPoll consortium combines expertise from sixteen countries ranging from natural and social scientists, twenty-three research institutions, one NGO, three businesses, three ministries and one national park. Stakeholders along the food value chain will be engaged through newly developed participatory approaches at diverse social, ecological, and political scales. The project partners are a team of smart and passionate creatives.

Grass with yellow flowers rename to: “Bumblebee on spring flowers in vineyard” – Felix Fornoff

Kick-off in Lund, Sweden
The first meeting with all project partners will take place to kick-off the project and will be held on 28 and 29 November in Lund, Sweden. It is an opportunity for all project partners to discuss in person how to reach the ambitious project goals. The partners will share an overview of their work packages and certain topics related to data collection and policymaking will be discussed further. Alexandra-Maria Klein is coordinator of the project and currently a guest professor at the University of Lund. She is excited to launch the multi-actor restoration project.

“The project will support land-use transformation towards biodiversity-friendly and productive landscapes across Europe.”
– Alexandra-Maria Klein  

Pollinator on purple flower, rename to: “Hoverfly on purple flower” its Volucella bombylans on Thyme – Felix Fornoff

Launching RestPoll website
During the kick-off in Lund, the website for the project will also be launched: The website will stimulate knowledge exchange and include background information on the project and updates such as news, planned activities and milestones which have been reached.

This project has received funding from the European Union’s Horizon Europe Framework Programme under grant agreement No. 101082102.

Pollinator on yellow flower, that ok, it’s a hoverfly too (Syritta pipiens) – Felix Fornoff


A global running race – climate change and species range shifts

One of the effects of climate change is shifting the habitats of species. For example, warming is pushing upward the forest boundary in high mountains. The question is whether the species’ speed of spreading is fast enough to follow the suitable habitats. Dr. Beáta Oborny, a researcher from the Institute of Evolution at the Centre for Ecological Research and the Institute of Biology at the Eötvös Loránd University, together with her colleagues have developed a new method to investigate this. Their paper co-authored with Dániel Zimmermann was the editor’s choice in Ecography. (The editor’s choice is a paper highlighted as the most exciting and novel paper in the monthly journal issue.)

As our planet undergoes significant transformations due to climate change, habitats are being altered, appearing, disappearing, or changing in quality. Understanding the impact of these changes on the geographic distributions of species is of great significance. The shrinking ranges of protected organisms and the expanding ranges of noxious species, such as pests and pathogens, highlight the urgent need to monitor range movements precisely. However, this task poses challenges as the available observation time is often short compared to the pace of underlying population processes, making it difficult to distinguish between directional shifts and random fluctuations.

Addressing this challenge, a research team led by Dr. Beáta Oborny from Loránd Eötvös University and the Centre for Ecological Research in Budapest has developed a novel method to monitor range shifts. The team aimed to precisely and consistently delineate range edges, allowing for comparisons between different years, geographic locations, and species.
Delineating range edges accurately is a non-trivial task as they often exhibit complex patterns. Occupied peninsulas are interspersed with unoccupied bays, and isolated occurrences dot the landscape. While traditional methods rely on the outermost occurrences of a species, Oborny and her colleagues propose a different approach. They suggest marking the range edge at the boundary between connected and fragmented occurrences, known as the “hull.” By marking the average position of the hull, the “connectivity limit,” over time, the researchers offer a statistically more reliable method. This region has a higher population density and exhibits smaller fluctuations, enhancing the robustness of the approach.

An upper limit of Dwarf mountain pine (Pinus mugo) in the low Tatra Mountains, Slovakia. The inset shows a snapshot from simulated population dynamics. Dark/light green shows the connected/fragmented occurrence of the species. The hull is marked by red.
Photo: Courtesy of Konrád Lájer simulated image: Beáta Oborny

Oborny and her colleagues delved into the pattern-generating mechanisms using spatially explicit models. Unlike previous approaches based on general spatial statistical methods, their novel approach capitalizes on knowledge about the mechanisms governing the emergence of these patterns: birth, dispersal, and death within populations. Through computer simulations along environmental gradients (e.g., hillsides), the team explored the connectivity limits of different kinds of species. Remarkably, they discovered that the hull displayed a robust fractal structure with a dimension of 7/4. Further investigations conducted by Beáta Oborny and Dániel Zimmermann confirmed that this fractal structure remained consistent regardless of whether the range was rapidly advancing or retreating compared to the generation time. Notably, the method demonstrated particular robustness in the retreating (trailing) edge of species ranges. These findings highlight the applicability of the connectivity limit in tracking range shifts across diverse geographic scenarios, enabling a global perspective on these changes. For instance, the method allows for the comparison of treelines in different mountains, even when composed of different species, utilizing universal scaling laws.

The universal features uncovered in this study find their explanation in percolation theory, a field of research in statistical physics. This exemplifies the power of knowledge transfer between seemingly disparate scientific disciplines. The insights gained from these investigations deepen our understanding of the intricate relationship between environmental changes and species distributions. As scientists continue to refine and validate this method, it holds the potential to contribute to more robust assessments of biodiversity shifts and inform effective conservation strategies.

Image: An upper limit of Dwarf mountain pine (Pinus mugo) in the low Tatra Mountains, Slovakia. The inset shows a snapshot from simulated population dynamics. Dark/light green shows the connected/fragmented occurrence of the species. The hull is marked by red.
Photo: Courtesy of Konrád Lájer simulated image: Beáta Oborny


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