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.”
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
A new study that sheds light on the extraordinary sensitivity of freshwater ecosystems and the long-term negative consequences of human impacts on biodiversity has been published in the most prestigious scientific journal, Nature. The research is based on a comprehensive dataset of 1,816 time series of freshwater invertebrate communities between 1968 and 2020 from 22 European countries, comprising 714,698 individuals of 2,648 taxa from 26,668 samples. Two Hungarian researchers, Dr. Gábor Várbíró from the Institute of Aquatic Ecology of the ELKH Centre for Ecological Research (CER), and Dr. Zoltán Csabai from the University of Pécs (PTE) also took part in the compilation and analysis of the data. Due to the persistent and newly emerging threats posed by climate change, invasive species, and new pollutants, the study calls for an immediate and intensified focus on mitigation strategies to rejuvenate the recovery of freshwater biodiversity.
Freshwater ecosystems hold significant significance in the context of global biodiversity. These water bodies provide habitat for numerous plant and animal species, and they play a crucial role in maintaining food chains and preserving ecological balance. Mitigation measures including wastewater treatment and hydromorphological restoration have historically shown promise in improving environmental quality and supporting the recovery of freshwater biodiversity.
Together with a large international team the study’s first author, Prof. Dr. Peter Haase of the Senckenberg Research Institute and Natural History Museum in Frankfurt and Dr. Ellen A. R. Welti of the Smithsonian’s Conservation Ecology Center in the US analysed a comprehensive dataset of 1,816 time series of freshwater invertebrate communities between 1968 and 2020 from 22 European countries, comprising 714,698 individuals of 2,648 taxa from 26,668 samples. The analysis reveals a plateauing trend in the gains achieved.
714,698 observations of 2,648 species from 26,668 samples were analyzed by the research team. Dr. Gábor Várbíró, one of the Hungarian team members
The study indicates notable increases in taxon richness (0.73% per year), functional richness (2.4% per year), and abundance (1.17% per year) of freshwater organisms. These positive trends were prominent up until the 2010s, after which the recovery rates have significantly slowed down. Alarming patterns emerged in communities located downstream of dams, urban areas, and croplands, where the prospects for recovery appear grim. Moreover, sites experiencing higher rates of warming demonstrated fewer biodiversity gains, underlining the impact of climate change on freshwater ecosystems.
The study underscores the vulnerability of inland waters to a range of anthropogenic pressures, including pollution, urbanization, and the impacts of climate change. Despite past regulatory efforts, including landmark legislations like the ‘US Clean Water Act’ of 1972 and the EU Water Framework Directive of 2000, the researchers emphasize that more needs to be done to counteract the increasing stressors that threaten these vital ecosystems.
The researchers suggest that while the gains witnessed in the 1990s and 2000s could be attributed to successful water-quality enhancements and restoration endeavours, the observed deceleration in the 2010s suggests a diminishing effectiveness of the current measures. These measures led to a significant reduction in organic pollution and acidification, beginning around 1980. Over the past 50 years, these steps have contributed to the containment of wastewater pollution and resulted in improvements in freshwater biodiversity. Unfortunately, as the number and impact of stressors continue to increase worldwide, the improvements resulting from past legislation are lessening and freshwater systems remain degraded in many places. With the persistent and emerging threats posed by climate change, invasive species, and new pollutants, the study calls for an immediate and intensified focus on mitigation strategies to rejuvenate the recovery of freshwater biodiversity.
Biodiversity in river systems from 22 European countries increased significantly over a period from 1968 to 2020 – but this trend has stagnated since the 2010s
The involvement of two Hungarian scientists. Dr. Gábor Várbíró from CER and Dr. Zoltán Csabai from PTE adds a significant layer of expertise to this critical research effort. Their collaboration within the international team has shed light on the status of European freshwater biodiversity and underscored the urgent need for actionable conservation measures.
Dr. Gábor Várbíró said, “Our findings raise a critical alarm for the health of European freshwater ecosystems. The slowdown in recovery rates demands a comprehensive re-evaluation of existing mitigation measures and the implementation of new, adaptive strategies. Time is of the essence, and we must act swiftly to protect these essential ecosystems.”
The study underscores the necessity of a multi-faceted approach, engaging policymakers, scientists, and communities at large, to ensure the long-term vitality of freshwater ecosystems. As Europe and the world face increasingly complex environmental challenges, collaborative and immediate actions are crucial to reverse the trend of stagnating freshwater biodiversity recovery.
With the decisive participation of Eörs Szathmáry, Member of the HAS and Research Professor at the Institute of Evolution of the Centre for Ecological Research, an international team of researchers has achieved a major new breakthrough in the study of the origin of life. The paper was published in Nature Chemistry, one of the world’s leading chemistry journals.
Eörs Szathmáry Photo: HAS/Tamás Szigeti
The discipline of systems chemistry deals with the analysis and synthesis of various autocatalytic systems and is therefore closely related to the study of the origin of life, since it investigates systems that can be considered as a transition between chemical and biological evolution: more complex than simple molecules, but simpler than living cells.
Tibor Gánti described the theory of self-replicating microspheres as early as 1978. These still lacked genetic material, but concealed within their membranes an autocatalytic metabolic network of small molecules, isolated (compartmentalised) within their membranes. As the autocatalytic process takes place, the membrane-building material is also produced, leading to the division of the sphere. This system may appear to be a living cell, and although it lacks genetic material, this can only be verified experimentally. These microspheres can be considered as ‘infrabiological’ chemical systems, since they do not reach the level of biological organisation, but they exceed the complexity of normal chemical reactions.
Tibor Gánti / Painting by László Gulyás
Years ago, we started to think about the possibility of experimentally realising the process whereby the growth of a small molecule metabolic network leads to the growth of the compartments that enclose the network, to the effect that they can divide. Already Tibor Gánti has described that one of the most promising candidates for this system is the formose reaction, an autocatalytic sugar-producing reaction that consumes formaldehyde and involves the circular transformation and propagation of glycolaldehyde molecules. The reaction does not require enzymes.
The experiment on which the study is based was carried out in the biochemistry laboratory of the École Supérieure de Physique et de Chimie Industrielles (ESPCI) in Paris by Professor Andrew Griffiths and his colleagues. The experiment involved creating tiny water droplets in an oil medium that did not fuse and therefore acted as artificial cells. Some of the ‘cells’ were given glycolaldehyde as an autocatalyst (in addition to formaldehyde as a nutrient), others were not. In the former group, the formose reaction was triggered and, by osmosis, it sucked water away from compartments that did not contain glycolaldehyde. This allowed them to grow and to divide under external influence. Many researchers have suggested that before the emergence of regulated cell division, the initial cells divided in response to external influences such as turbulent flow.
The significance of this study is that we are the first in the world to show that the operation of a network of small-molecule autocatalytic reactions, without genetic material and enzymes, leads to the growth and division of compartments, i.e. the formation of new generations. This has never been demonstrated before, so the result is fundamental to the experimental verification of the principles of systems chemistry and points the way forward in the study of the origin of life.
Szathmáry Eörs evolúcióbiológus, az MTA rendes tagja, az MTA Fenntartható Fejlődés Elnöki Bizottság elnöke. Kutatásai során az élet keletkezésétől kezdve az emberi nyelvkészség kialakulásáig számos evolúciós folyamatot vizsgált és modellezett. John Maynard Smithszel közösen írt könyvét, az Az evolúció nagy lépéseit a modern evolúcióbiológia alapműveként tartják számon.
The researchers of the Functional Algology Research Group, operating at the Tisza Research Department of the Institute of Aquatic Ecology of the ELKH Centre for Ecological Research (CER), in collaboration with experts from the Department of Environment, Nature Protection and Waste Management of the Győr-Moson-Sopron County Government Office, investigated whether one-off drought events and trend-like precipitation decrease result in similar changes in the composition of diatom assemblages of the Rába River, one of the largest rivers in Hungary. The results clearly highlighted that the continuous decrease in annual precipitation has a much more significant impact on the composition and biodiversity than a single dry year. The paper presenting the research was published in the prestigious scientific journal Ecological Indicators.
Weather extremes and the impact of drought are immediately noticeable, for example, in agricultural areas or forests, and although perhaps less perceptible, they also have significant consequences for the ecosystems of rivers.
Reimeria sinuata: one of the diatom species indicating the effects of drought in the Rába River
The researchers of the Functional Algology Research Group, operating at the Tisza Research Department of the Institute of Aquatic Ecology of the ELKH Centre for Ecological Research (CER), in collaboration with experts from the Department of Environment, Nature Protection and Waste Management of the Győr-Moson-Sopron County Government Office, investigated the long-term changes in the composition of the benthic diatom assemblage of the Rába River.
The Rába is the third largest river in Hungary and the most important domestic tributary of the Danube. Over the past five years, environmental protection experts have observed a significant decrease in precipitation within its catchment area. They applied to CER researchers with the observation that the trend-like, continuous decrease in precipitation likely affects the composition of the benthic diatom assemblages.
During the joint work, they sought to find the answer to whether one-off drought events and trend-like precipitation decrease result in similar changes in the composition of the river’s benthic diatom assemblages. It has been shown in other ecosystems that the resilience of the assemblages can vary depending on whether drought occurs regularly, for extended periods, or only intermittently.
Maintaining the good condition of our rivers and reducing harmful effects, such as nutrient load, are important societal interests. The legal framework for this is determined by the EU Water Framework Directive, which Hungary also follows. In order to characterize and monitor the ecological status of our surface watercourses, experts regularly monitor the river ecosystems, in which benthic diatoms play a key role. These tiny organisms have a significant function in the food web and primary production.
Although microscopic in size, the biofilm they create is visible to the naked eye and can be felt, for example, on the steps of beaches, on rocks, and on shoreline and aquatic plants. Perhaps few people are aware of the wonders hidden within this film. When magnified, it reveals a micro-world resembling a small forest, where, similar to the ground level of a forest, there are species adhering on the surface, often very small, as well as prominent, branching species that resemble trees. Just as forests, the biofilm is also shaped by the environment. The number of species and individuals present, as well as the species with specific characteristics that can occur in a given biofilm, greatly depend on the influences affecting the water. Besides nutrient load, other threatening factors such as the increase in pharmaceutical residues, rising water temperature, changes in water residence time, drastic decrease in water level and flow, or the receding of flash floods significantly influence the composition of this tiny forest. Ultimately, this will also have an impact on higher taxonomic groups, such as aquatic invertebrates and fish,” said Viktória B-Béres, one of the lead authors of the study.
In order to understand these processes, the analysis and evaluation of long-term datasets are of paramount importance. For the investigation, the authors of the study utilized datasets available for the Rába River, covering a period of fifteen years. The period from 2007 to 2021 was divided into two groups based on annual precipitation. Between 2007 and 2016, fluctuating years of both drier and wetter conditions alternated, while from 2017 onwards, consistently decreasing annual precipitation was characteristic.
“Our results showed that one-off dry events had little influence on the composition and biological diversity of benthic diatom assemblages. In contrast, continuously decreasing precipitation ‒ dry periods ‒ significantly reduced species-level and functional diversities, the latter based on individual characteristics. Using the previous analogy, it was as if our tiny forest transformed into a barren landscape. Small-sized species that strongly adhere to the substrate, such as Amphora pediculus and Reimeria sinuata, became dominant, while the proportion of larger tree-like species decreased significantly. This is problematic because this type of algae plays an important role in the river’s food web as a food source for snails and macroinvertebrates. Therefore, their absence or decline in population size can have detrimental effects on the larger organisms inhabiting the river,” added Viktória B-Béres.
In a recently published study, researchers analyzed for the first time the differences in the effects between one-off dry weather events and trend-like changes in precipitation on the benthic diatom assemblages of a large river. The results clearly highlighted that the continuous decrease in annual precipitation has a much more significant impact on the composition and biodiversity than a single dry year. Climate scenarios project extreme water balance conditions in the near future, including longer periods of low precipitation. Therefore, any knowledge that can predict changes in the microscopic river ecosystems can assist in the development of action plans by authorities to preserve the functional and structural characteristics of riverine ecosystems, and thus maintain the ecosystem services provided by benthic algal assemblages. The study indirectly draws attention to the vulnerability of even large, perennial riverine ecosystems during dry periods, emphasizing the importance of responsible water management. The researchers are asking the public to report any incidents of extraordinary water pollution, untreated wastewater discharge, shoreline littering, or large amounts of mussel or fish carcasses to the environmental protection departments of e.g. the Győr-Moson-Sopron County or Hajdú-Bihar County Government Offices.
The members of the ‘Lendület’ Seed Ecology Research Group of the ELKH Centre for Ecological Research (CER) examined the human factors behind animal-vehicle collisions through a questionnaire survey. The researchers pointed out that there are significant correlations between the frequency of collisions, driver attitudes, and driving habits. The paper presenting the results was published in the Journal of Environmental Management.
The rapidly developing road network places a significant burden on terrestrial ecosystems, increasing the number and severity of conflicts between humans and wildlife, which are most often manifested in animal-vehicle collisions. Collisions with animals raise serious problems from both a conservation and traffic safety perspective. If we want to express this in numbers, it can be said that hundreds of millions of vertebrate animals are victims of vehicle collisions worldwide every year. This results in significant financial damage and personal injury. The problem is not new, researchers have been aware of it for decades, and numerous studies have been conducted. Most of these were based on field surveys. With their help, a list of affected species was compiled, conservation damage estimated, and “hotspots” identified, i.e., road sections where the frequency of collisions is higher than average.
“Our research is novel in that it targets the social strata traveling on the road, so it captures the problem from the other end. The experience and opinions of drivers contain a lot of useful information for accident prevention, which can be collected and evaluated in this way,” explained Sándor Borza, one of the first authors of the article, a PhD student in the Cooperative Doctoral Program.
It is very important to consider how interested the affected social stratum is in the topic, how conservation or financial damage affects them, and what solutions they consider good or acceptable to reduce the problem.
“Many people were interested in the survey, a total of 2123 people completed our questionnaire, which is an outstanding number worldwide!” emphasized Sándor Borza. “We were curious about what animals drivers had hit during their lifetime, whether they had suffered financial damage, and, most importantly, whether their driving habits and attitudes affected the likelihood of collision.”
The researchers found that nearly half of drivers have had at least one collision with an animal during their lifetime and one in four drivers suffered property damage as a result. Male drivers, drivers who cover longer distances annually, use secondary roads more frequently, and drive larger vehicles were more likely to collide with animals. However, driving style, whether someone drives slower or more dynamically, did not affect the likelihood of an animal-vehicle collision. “This does not mean that the two things are not related at all, as research supports that at certain speeds, it is not possible to slow down enough to avoid a collision,” added Sándor Borza. The drivers’ attitude towards the importance of nature conservation and traffic safety in relation to animal-vehicle collisions was significantly influenced by whether they had hit something before in their lives. More than a third of drivers shared their opinions on possible ways to improve traffic safety. The most popular form of action was the installation of protective devices (wildlife fences, wildlife crossings), but many also pointed out the usefulness of warning signs and the greater responsibility of hunting associations, including control of the number of large game animals.
Researchers from the Institute of Aquatic Ecology of the ELKH Centre for Ecological Research (CER) led by Csaba Vad, conducted a study in an international collaboration to explore the resilience of aquatic ecosystems to the negative impacts of heatwaves. They also investigated whether dispersal from surrounding habitats, i.e., the arrival of other species, could accelerate ecosystem recovery. During their experiment on plankton communities in mesocosms, the researchers found that the heatwave drastically reduced the biomass of plankton due to the negative impact on primary consumer zooplankton, such as water fleas. Dispersal from surrounding habitats had limited effect in this study, somewhat positively influencing only the growth of phytoplankton. As a result of the heatwave, both the composition and trophic structure of the communities changed, which could have long-term implications for ecosystem functioning. The study presenting the results was published in one of the leading international ecological journals, Global Change Biology.
The increasingly frequent and intense heatwaves associated with global climate change pose a significant threat to biodiversity, ecosystem functioning, and the ecosystem services provided to humans. Consequently, it becomes crucial to understand the mechanisms that affect the resilience of communities in the face of extreme temperature events, including their resistance to temperature stress and their subsequent recovery. This knowledge is essential for improved prediction and mitigation of biodiversity loss and its far-reaching implications. Moreover, it enables the application of effective strategies to adapt to climate change.
In a research led by Csaba Vad, researcher at the Institute of Aquatic Ecology of CER, an international research group investigated whether connectivity through dispersal facilitates ecosystem adaptation to heatwave-induced stress (“spatial insurance hypothesis”). The study, conducted over a period of one and a half months, took place in artificial lakes known as mesocosms. In these experimental systems, the processes occurring in natural ecosystems can be modeled much more realistically compared to laboratory conditions. Moreover, they allow for the isolated examination of individual stressors and underlying mechanisms, which would not be feasible in natural habitats due to their complexity.
The Austrian WasserCluster Lunz research institute’s mesocosm system, where the experiment was conducted
According to the results, the heatwave led to a decrease in plankton biomass, primarily due to its negative impact on zooplankton, such as water fleas. In the case of a natural lake, for example, this could lead to temporary reduction in food sources available for fish or even the development of algae blooms, as these small microscopic organisms play an important role in regulating algae levels. The effect of dispersal from surrounding habitats in this experiment was relatively minor, and it was only evident in the faster post-heatwave growth of phytoplankton. The results showed that the community biomass returned to the undisturbed level regardless of dispersal. However, the composition and trophic structure of the community changed, which could potentially result in long-term alterations in ecosystem functioning.
Based on the experiment, it can be concluded that even a short heatwave of about one week can alter the species composition and interactions within aquatic ecosystems, potentially leading to long-term consequences. These effects can be further aggravated by the fragmentation of ecosystems resulting from habitat loss, increasing spatial isolation of remaining habitats and reducing the dispersal of organisms. Ecologists urge for further long-term research to understand the impacts of heatwaves and develop possible adaptation strategies.
The research was carried out within the framework of the H2020 AQUACOSM project, with the support of H2020 AQUACOSM-plus and the National Multidisciplinary Laboratory for Climate Change.
The researchers of the ELKH Centre for Ecological Research (CER) investigated the spread of the non-native great blanketflower in Hungary within the framework of the National Laboratory for Health Security project. The aim of the research was to evaluate the impact of the species on the local plant community and determine its invasive potential through its functional traits. Based on the results, the great blanketflower does not currently appear to be a strong ecosystem-transforming species, but there is a risk that due to climate change, the local environment in Hungary will become more suitable for it in the future, leading to strong speading and becoming invasive. Therefore, the researchers do not recommend planting blanketflower species in gardens. They also suggest surveying non-native ornamental plant populations, conducting long-term monitoring and a more detailed assessment of the traits that influence their spread. The publication presenting the results was published in the scientific journal NeoBiota.
Ornamental plants are one of the main sources of species becoming invasive. During their planting, they are introduced to new habitats where humans create favourable living conditions through irrigation and maintenance. Later, in natural habitats, they can easily occupy open niches created by human disturbances and the warming effects of climate change. The blanketflower has followed this path as well, and its ecological impacts were studied by researchers of CER along with several other new, potentially dangerous species within the recently initiated National Laboratory for Health Security project.
The great blanketflower and its relative, the Indian blanket, along with their hybrid, are globally planted ornamental plant species. Reports have already been made in several countries about the great blanketflower escaping from gardens and naturalizing in various new habitats, but its invasive behavior has been relatively unknown until now. However, it seems that in the past few decades, this species has found suitable habitats in Hungary and from a naturalized species it has become invasive in several locations. “Our aim was to map the distribution of the great blanketflower in Hungary, evaluate its impact on the local plant community, and determine the species’ invasive potential through its functional traits,” summarized Gabriella Süle, Phd, a assistant research fellow at CER.
Based on the distribution data collected here, the great blanketflower occurs in Hungary mainly as casual escapes yet. This species, which blooms profusely throughout the year and is extremely colorful, requires little to no care. Therefore, owners allow it to spread, and we can often see it occupying more and more space in front of gardens. However, it became naturalized in recent years, and invasive populations have also been found in significant numbers within the country. The species is mainly observed near gardens and disturbed habitats, but it has also appeared in natural and semi-natural grasslands. It successfully spreads in disturbed, species-poor, sandy, open habitats. Its spread affects the composition of the local plant community, reducing, for example, the species richness of local plants. Based on its functional traits, its well germination capacity, extremely long flowering period, the large absorbing and adhering surface provided by its roots, and its spread by grazing animals’ fur, mainly sheep, can promote its invasive spread. Currently, the great blanketflower does not appear to be a strong ecosystem-transforming species, but more attention needs to be paid to it because there is a risk that the local environment in Hungary will become increasingly suitable for it due to drier weather caused by climate change, leading to strong spread and becoming invasive, primarily in sandy soils.
“Due to all of these, we do not recommend planting blanketflower species in gardens, as they can easily escape and establish in natural plant communities. Furthermore, we suggest considering banning their distribution in seed mixes. To control invasive populations in natural habitats, there is a need to develop an effective eradication method” emphasized Gabriella Süle, Phd.
Assessing the great blanketflower and similar non-native ornamental plant populations, conducting long-term monitoring, and performing a more detailed evaluation of the traits influencing their spread would be important in order to prevent the escape of species planted in gardens into the natural habitats on time.
Assessing and managing the ecological, economic, and societal threats posed by invasive species similar to the great blanketflower is one of the focuses of the Division of Invasion Biology within the National Laboratory for Health Security project. The research is being carried out within the framework of the Széchenyi Plan Plus program with the support of the RRF-2.3.1-21-2022-00006 project.
Publication:
Süle G, Miholcsa Z, Molnár C, Kovács-Hostyánszki A, Fenesi A, Bauer N, Szigeti V (2023) Escape from the garden: spreading, effects and traits of a new risky invasive ornamental plant (Gaillardia aristata Pursh). NeoBiota 83: 43-69. https://doi.org/10.3897/neobiota.83.97325
Researchers from the ELKH Centre for Ecological Research (CER) and Babeș-Bolyai University (BBE) in three recent papers have described the effects of twelve invasive plant species with different traits on vegetation (Fenesi et al. 2023), pollinator communities (Kovács-Hostyánszki et al. 2022), and the traits of pollinating insects (Szigeti et al. 2023). During their field studies they assessed and compared the plant and pollinator communities of invaded and semi-natural habitats in Hungary and Romania. In order to facilitate proper comparisons and conduct detailed exploration, the researchers employed uniform field methods while utilizing diverse ecological indicators, ranging from the height of indigenous vegetation, honeybee abundances, depth of flowers to tongue length of pollinator insects.
Bees and other pollinator species play an extremely important role in most terrestrial ecosystems, including agriculture. Increasingly, studies report the drastic decline of pollinating insects, one reason being the reduced availability of their food resources. The strong spread of invasive species is one of the five most important causes of biodiversity loss, that is why the Invasion Biology Division was established under the leadership of the Ecological Research Center within the National Laboratory for Health Security, where researchers investigate the complex effects of invasion. Where invasive plant species appear and are able to spread, they inundate and dominate the given area, reducing diversity and making habitats more homogeneous. In many cases, they also reduce the range of available flowers, thus helping some compatible pollinator species while displacing the food resources of others from the landscape. In general, it can be stated that the impacts of invasive plant species on native vegetation and pollinator insects are often varied and dependent on their specific traits.
Based on the research results, there is no universal effect of plant invasion, except for a few general patterns there are differences among invasive plant species in almost every ecological indicator studied. Perhaps the most important message is that as many invasive plant species and traits as there are, there can be a variety of effects on invaded plant-pollinator communities. The three publications highlight that the cover of invasive plant species strongly influences the composition, diversity, and height of the remaining native vegetation, among other factors. As the invasive plant species displaces native plants in a given area, fewer of the original or potential communities remain. Perennial invasive plant species have an even stronger negative impact on flower availability and pollinators than annual species. This is likely due to their stronger invasive capacity, dominance, different growth and flowering strategies, and presence in later successional stages of habitats. Timing is extremely important in plant-pollinator systems. Invaded areas are similar to crop fields such as rapeseed or sunflowers: during their blooming period, they provide significant amounts of food for the pollinating insects, while beyond of their flowering period, these areas are extremely poor in resources of pollinators. Where invasive plant species appear, they eventually become dominant. They cover the area with green vegetation mass for most of the year, but only bloom for a short period of time. As indicated by the studies, natural areas have more and more diverse resources along the year. The researchers also found important and interesting relations when comparing the traits of invasive flowers and the traits of wild bees. For example, the sites invaded by two invasive species with deep flowers had more long-tongued and also larger-bodied bees, while a species with shallow flowers had more smaller-bodied bees. This indicates a strong size determination between flowers and their pollinators, meaning that the invasion of a particular trait (such as deep flowers in invasive plants) affects the functional characteristics of the remaining pollinator community in the invaded area (i.e., only long-tongued pollinators that can feed on deep flowers will remain).
Proper nature conservation management of (semi)natural habitats and effective control of invasive plant species are important for the protection of pollinators, but some invasive plants can also provide valuable foraging resources for pollinator insects. Therefore, instead of uniformly eradicating all invasive species, it is recommended to consider the best approach on a case-by-case and location-specific basis, taking also into account the needs of protected pollinator insects. For example, efforts to combat plant invasion could incorporate the nutritional requirements of pollinators. Some of the costs associated with invasive plant eradication could be redirected towards providing alternative nutrition sources, such as sowing native seed mixes in or in the neighborhood of invaded areas. Overall, the factors and impacts important in the plant-pollinator systems are complex and interrelated, hence further detailed studies are needed to uncover the specific relationships between species and to develop effective conservation solutions.
Over the past two centuries, in Hungary and globally, the area of natural and semi-natural forests shrunk dramatically, while at the same time some of the economic functions of forests have been taken over by tree plantations, which cover a significant area (3.8% of Europe’s forests but in Hungary in some region e.g. Kiskunság this proportion exceeds 80%). Plantations are intensively managed forests, mainly composed of one or two tree species, which mainly perform economic functions (e.g. timber and firewood production). There is a long-standing controversy about the evaluation of tree plantations, depending on whether the economic or the nature conservation values of the forest are regarded as a primary role. While tree plantations can also provide some important ecosystem services alongside the economic benefits of timber production, in these ‘forests’ taxonomic diversity decreases radically or the plantations become a hot spot for biological invasions.
A paper of the researchers of the University of Szeged and the Centre for Ecological Research, published in Forest Ecology and Management, represents a significant step forward in the more accurate ecological assessment and evaluation of Hungarian tree plantations. The sample area was the Kiskunság Sand Ridge, a lowland region in the center of the Pannonian biogeographic region between the rivers Danube and Tisza in Hungary, where semi-natural forests survived almost exclusively in the forest-steppe mosaics of protected areas, but tree plantations are widespread in the landscape. The analysis compared four types of forest habitat: near-natural poplar forest Junipero-Populetum albae and three types of tree plantation: native deciduous white poplar (Populus alba), the non-native deciduous black locust (Robinia pseudoacacia), and the non-native evergreen Austrian pine (Pinus nigra) plantation. The study assessed the diversity of the vegetation, not only in terms of species diversity, but also in terms of functional and phylogenetic diversity indicators, i.e., how diverse the vegetation is in each type in terms of plant traits (pollination type, seed dispersal, life form, flowering date, etc) and phylogenetic lineages. Each type of habitat was assessed from an ecological and conservation point of view based on the occurrence of protected, endemic and red-listed species, i.e. the rarest and most valuable species from a conservation point of view.
László Erdős, a research fellow at the Centre for Ecological Research and one of the lead authors of the paper, says that each forest type has a unique species composition, but semi-natural forests are the richest in native species, while tree plantations are dominated by weeds and non-native species. The semi-natural forest is also characterized by the frequent occurrence of native shrub species such as Berberis vulgaris, Ligustrum vulgare, and Rhamnus catharticus. In the case of tree plantations, shrubs disappear as a result of the forestry activities (mechanical site preparation and mechanical weed control) to protect the saplings. The planted tree species also have an impact on the forest floor, e.g. in Robinia pseudoacacia stands weed species that tolerate high nitrogen levels appear, or in pine forests, the deep layer of slowly decaying leaf litter results in a special species composition.
The analysis also showed that low taxonomic diversity in tree plantations does not necessarily imply low functional or phylogenetic diversity, as several different diversity indicators provide a more complex characterization of the plant diversity of a habitat. Among the tree plantations, native poplar plantation and pine forest were found to be more favorable habitats for plant diversity than black locust stands. Black locust was also the most degraded of the habitats studied in terms of naturalness indicators.
The study provides a more accurate assessment of the different types of tree plantations in the region and has important implications for forest management and conservation. From an ecological and conservation point of view, the remnants of semi-natural forest are much more valuable than any of the tree plantations, and therefore conservation and restoration programs should focus primarily on these areas. Of the tree plantations, the planting of native white poplar (Populus alba) should be preferred when further tree plantations are to be established. In the longer term, reducing the area of black locust and pine plantations is inevitable, and the establishment of a mosaic of grassland and forest, in keeping with the semi-arid climate of the Kiskunság, is appropriate for the forest-steppe region.
Publication:
Khanh Vu Ho, György Kröel-Dulay, Csaba Tölgyesi, Zoltán Bátori, Eszter Tanács, Miklós Kertész, Péter Török, László Erdős: Non-native tree plantations are weak substitutes for near-natural forests regarding plant diversity and ecological value Forest Ecology and Management, Volume 531. 2023.
https://doi.org/10.1016/j.foreco.2023.120789.
Alkaline soda pans of Hungary are special representatives of inland saline waters in the interior of the continents. The largest number of soda pans in Eurasia is found in the Carpathian Basin, and these lakes are also important resting and feeding areas for migratory birds in the European-African bird migration routes. Evidence is mounting that globally, aquatic habitats and waterbird populations are being rapidly declined by the land-use and land cover changes of recent decades (drainage, run-off), and climate change: rising temperatures and changing rainfall patterns. Waterbird populations play an important role in trophic- and host-parasite networks, and their cultural and recreational role is also important, but as bird populations and habitats decline, these ecological services are also declining.
Emil Boros, Senior Research Fellow at the Centre for Ecological Research, Institute of Aquatic Ecology, has been studying the interaction between waterbird populations and soda pans for many years. In an earlier publication in the Science of the Total Environment they found that waterbirds contribute high phosphorus loading (P) to the shallow saline lakes through their droppings, i.e. birds act as vectors of external phosphorus sources, a process called guanotrophication (bird-induced nutrient enrichment). Waterbirds, such as large-bodied herbivores (goose and duck species) and medium-bodied omnivores (e.g. gulls) have been shown to be 64% responsible for the extremely high phosphorus content of natural soda pans. However, it was also found that, the hypertrophic state of water was in contradiction with the limited primary production of natural soda pans due to the characteristics of the lakes: shallow water depth, high alkalinity (PH ≥ 9), and intermittent hydrological cycle.
Lake Balkhash
In a further investigation about the interaction between inland saline aquatic ecosystems and waterbirds the aim was to show whether the ecological/trophic attributes of saline water bodies could be predicted on multi spatial-scales by different groups (guilds) of waterbirds. Also published in the prestigious journal Science of the Total Environment, Emil Boros and colleagues studied a vast area of 1700 km by 1000 km at different spatial scales in the steppe and semi-desert region of Kazakhstan, where 63 sample area were selected. Nearly 100 waterbird species occurred in the sample areas and were classified into three groups according to their role in nutrient cycling and nutrient turnover: net-importers (large herbivores e.g. geese, cranes), importer-exporters (omnivorous ducks and gulls) and net-exporters (various herbi-, omni- and piscivorous species), based on Boros’s classification method. The abundance, biomass and diversity of these bird groups (guilds) were compared with the attributes of the inland waters on multi spatial scales e.g. water depth, chlorophyll content, and at larger spatial scales, with the land cover data found in the 1 and 10 km radius around the ponds e.g. grassland or agricultural land.
Their results showed that the occurrence of the above waterbird groups was strongly correlated with the attributes of the saline aquatic ecosystems on multi-spatial scale. Water cover and salinity are the main attributes predicting of the type of bird group that occurs in a given environment. The importer-exporter and net exporter bird groups showed positive correlations with productivity metrics and water depth of the waters, while the importers were predicted by the surrounding pond environment e.g. grassland.
The practical significance of this study is that it quantifies this ecosystem services provided by waterbirds, their role in nutrient cycling, which is essential for systematic monitoring and habitat management. The classification system and methodology described in this study can be used to estimate certain environmental attributes of inland water bodies for large geographic regions by counting waterbird populations. In the future, this will provide an opportunity to use birds to estimate ecosystem function and services of aquatic systems, which in turn will require further methodological studies.
Publications:
Emil Boros, Zarina Inelova, Zsuzsanna Lánczos, Zsolt Végvári: Waterbird guilds predict environmental attributes of inland saline aquatic ecosystems on multi-spatial scales,
Science of the Total Environment, Volume 855, 2023.
https://doi.org/10.1016/j.scitotenv.2022.158845. https://www.sciencedirect.com/science/article/pii/S0048969722059447
Emil Boros, Anita Takács, Péter Dobosy, Lajos Vörös: Extreme guanotrophication by phosphorus in contradiction with the productivity of alkaline soda pan ecosystems,
Science of the Total Environment, Volume 793, 2021.
https://doi.org/10.1016/j.scitotenv.2021.148300. https://www.sciencedirect.com/science/article/pii/S0048969721033714
Photos: Emil Boros – Red-necked Phalarope and Lake Balkas
The understanding and importance of traditional ecological knowledge systems is increasingly recognised worldwide as a means to develop more effective policies in today’s crises, e.g. in nature conservation or grassland management. Zsolt Molnár, scientific advisor at the Centre for Ecological Research, has been researching the traditional ecological knowledge of pastoralists for more than 20 years. His Iranian student is the first author of a joint publication with European, Asian and African authors in the Journal of Environmental Management.
Unusual for academic publications, the publication is a collaboration between researchers and practising pastoralists. “Since the holders of traditional knowledge are mostly not researchers but herders, farmers, fishermen, when a researcher works with their knowledge, the ethical approach is for these ‘non-scientific’ professionals to also become co-authors. After all, the new publication is the result of collective thinking, knowledge co-production. Such recognition of traditional knowledge is now, fortunately, becoming more and more common” – said Zsolt Molnár.
Herders often graze in landscapes that are less suitable for crop production due to climatic extremes or soil conditions. Traditional grazing systems exist in very different natural environments, such as tundra, steppe, savannah, desert, mountainous areas. Pastoralist communities have locally relevant, multi-generational traditional ecological knowledge of pasture plants on which they base the utilisation of their pastures.
During the research, the authors collected the knowledge of herders on pasture (and hay meadow) plants and plant-livestock interactions in a review article. They analysed 24 of the 372 relevant scientific articles and 18 of the 105 videos about herders and their pastures. In addition, semi-structured interviews were conducted with practising herders in Iran, Mongolia, Kenya, Poland and Hungary to discuss the findings and conclusions.
Thirty-five indicators were identified in the scientific papers and documentaries of how herders ‘see’ forage plants. These indicators described both the botanical features of the plants and the livestock behaviour during grazing, as well as the impact of forage plants on the condition and health of livestock. The indicators were used by herders in management decisions to optimise grazing, the availability and quality of fodder grasses, and the appropriate way of grazing. Although herders around the world are very different, their knowledge of pasture grasses and the relationship between livestock and forage plants is remarkably similar. The researchers identified ten general principles that were common globally, almost regardless of location or habitat type. Such a global synthesis has never been done before.
Perhaps the most important key global principle is the livestock-centred approach explained Zsolt Molnár: “herders see plants through the “mouth of the livestock”. While in the pasture together, herders and livestock reciprocally learn from each other. The condition of the pasture grasses is closely monitored by the herders, who graze each patch in a targeted way, while often planning livestock movements with surprisingly strategic attention to detail, on a daily, weekly and monthly basis. The aim is to make the best use of the available grass as a resource and to ensure also the long-term ‘well-being’ of the pastures (see more details in this film). The lexical details of this knowledge are of course highly specific to the place, but the principles are globally general. You might ask that it’s good, but why is it important? It may come as a surprise, but even in cases where the state or a national park develops supporting measures and regulatory systems for pastoral grazing, it is easy to develop rules that have harmful effects. Because decision-makers often do not sufficiently understand the pastoral world, which is so different from our own. Our article points out that there are general principles that we can build on, and that we can take into account to create better policies, both ecologically and culturally.”
Researchers hope that a better understanding of pastoralists’ knowledge of grasslands and livestock grazing will help not only to maintain the biodiversity and economic benefits of less productive semi-natural grasslands, but also to innovatively preserve the traditional pastoral way of life.
The members of the ‘Lendület’ Seed Ecology Research Group of the Centre of Ecological Research followed the vegetation dynamics of artificially created grassland patches for several years. The researchers found that in the course of grassland-restoration the efforts at the beginning pay off: the simultaneous sowing of grasses and forbs in fallow lands leads to the development of species-rich grassland communities and efficient weed control.
The aim of ecological restoration is to recreate something lost or deteriorated. Grassland restoration aims to recreate grassland ecosystems and communities. In many cases recreation of the original ecosystem is not a possibility, but restoration still can help to cover landscape scars created by human activities. Restored grasslands not only improve landscape aesthetics but offer many different ecosystem services as well (e.g., forage for the livestock, nectar for pollinators, effective carbon capture and storage, and soil erosion control).
When grassland restoration is done with seed sowing, the success of restoration depends on many factors, such as the identity of sown species, the timing of sowing, the quantity, quality and proportion of sown seeds. In the current study the researchers aimed to find the best timing to sow grasses and forbs to achieve the highest possible species richness, to enhance forb-establishment and to hamper weed encroachment.
„The matrix of the grasslands is composed by grasses. Previous works found that sowing grass seeds certainly results in a closed grass sward within a few years, and also hampers weed encroachment. That is why grass sowing is preferred in landscape-scale restoration works. But it also has its feedbacks: the new grassland will be species-poor, as the closed grass sward hampers the establishment of other grassland species.” – explained Réka Kiss, the first author of the manuscript published in the Nature- Scientific Reports.
To create species-rich grasslands the use of diverse forb seed mixtures is needed. However, the compilation or production of such seed mixtures requires more efforts (seeds of more species are needed in good quality and high quantity). Due to these reasons diverse seed mixture is less likely to be used in the early stages of restoration. In later stages, however, it will need more effort from the practitioners to secure the successful establishment of species.
„We were curious of the most suitable timing: If we want to sow both grasses and forbs in a fallow for a species rich grassland, which is the time-lag when with the least effort we can achieve the most?” – explained Réka Kiss – „At the beginning of the experiment we created 36 patches in a recently abandoned land. We sow exclusively grass seeds, exclusively diverse forb seed mixture (20 species) or both of them into the patches. When we combined the grass with the forb seed mixture we sown them simultaneously (at the same time), or the diverse seed mixture was sown with a delay of 1, 2 or 3 years.”
Following the development of the patches for several years the researchers found that the best results were achieved when seeds were sown simultaneously, without time-lag. In such patches the species richness of species was the highest, the weeds were less successful and the establishment success of sown forb species was the highest. This is the most cost-effective and most successful method among the studied sowing regimes. If simultaneous sowing is not a possibility, sowing forbs one year later than grasses is still effective. However, after one year the advantage received by grasses cannot be outcome by the forbs, their successful establishment in later stages can be promoted only by active interventions.
A research group led by fellows from the Centre for Ecological Research created a comprehensive analysis on the freshwater biodiversity of Europe. They prioritised water catchments based on the conservation value of the species living there. They found that most of the catchments with high conservation priority are located in the Mediterranean Peninsulas but Hungary is also in the top. The study was published in the journal PLOS ONE.
Although freshwaters cover only one percent of the Earth’s surface they host ten percent of the known species. Freshwater ecosystems provide many ecosystem services such as food production, carbon sequestration or water purification. At the same time, freshwater biodiversity declines much faster than terrestrial and marine biodiversity due to habitat destruction, hydromorphological alteration, hydropower construction, pollution or climate change. These processes are further aggravated with the phenomenon that freshwaters are less involved in protected area designation.
For the more efficient protection of freshwater biodiversity, an international research group led by fellows from the Centre for Ecological Research created a comprehensive analysis ranking water catchments by their priority level. They also investigated priority values in the light of spatial protectedness. They used 18816 freshwater catchments as planning units in the analysis and summed the number of species living in them based on the database of the International Union for the Conservation of Nature (IUCN). There were 512 fish, 656 mollusc, 124 dragonfly and 339 plant, namely a total of 1631 species used in the study. The species were ranked differently based on their IUCN Red List Status and range-restrictedness.
The researchers used methods from the area of systematic conservation planning (SCP). The reason for SCP is to give a scientifically sound basis for the designation of protected areas. One important part of this process is spatial conservation prioritisation where planning units, such as standard sized cells or water catchments are prioritised based on their conservation or other socio-economic importance. In the dawn of nature conservation most of the protected areas were created in scenic, but otherwise hardly cultivatable places such as the World’s first national park, the Yellowstone, or Hungary’s first national park, Hortobágy. In recent times the focus shifted towards the conservation value of species and ecosystems and it is possible to prioritise a large set of planning units with algorythms. One such example is Marxan which was developed to help the rezoning the Great Barrier Reef National Park in Australia. This method is also useful in the validation of existing protected areas.
In this analysis the researchers also used Marxan to prioritise catchments in Europe. They revealed that higher priority values are occuring in the Mediterranean Peninsulas and as well as along major rivers, such as the Danube, while values are decreasing towards north. They also investigated priorities with the involvement of catchment connectivity. In river conservation it is important to give emphasis on connectivity as different influences and threats can react elsewhere from its source due to the connectedness of river sections. They found that although it is important to involve river connectivity it may follows a decreased attention towards lakes and lake species when there is a limited possibility for conservation. When they analysed the relation between areal protection and priorities they found that correspondence is good in Western and Northern Europe mostly due to the Natura 2000 network in the European Union. In contrast, protection level is low in the Non-EU states in the Balkan Peninsula and large parts in the Ukraine and Russia.
Fig 1: Conservation priority of catchments in Europe without connectivity (A) and with connectivity (B). Catchments with orange are more valuable while with grey are less valuable.
Fig 2: Average conservation priority of European countries.
Fig 3: Correspondence between the priority of catchments and their protectedness without connectivity (A) and with connectivity (B).
Photo: A river with high priority values but low protection, Shala in Albania (photo: Márton Szabolcs).
István Zachar and Gergely Boza, researchers of the Institute of Evolution, ELKH Centre for Ecological Research (ÖK) investigated the role of cooperative interactions among microbial cells in the development of higher levels of organisation. They identified the selection forces that facilitate or inhibit microbial community formation, reproduction and the possible emergence of higher levels of selection and evolution. The study of their results has been published in the prestigious international journal Frontiers in Ecology and Evolution.
Microbial communities consist of unicellular organisms, often of species from different domains eukaryotes, bacteria or archaea. Examples are biofilms, the common lifeform of prokaryotes, that form on any surface, on rocks in riverbeds, on the roots of plants, on the skin of animals and humans, or on the inner surface of the digestive system. These communities are usually highly diverse but interactions are mostly limited to the immediate neighbourhood of cells.
One of the most common interactions among microbes and in microbial communities is metabolite-mediated cooperation, whereby cells leak various products into their environment, which can diffuse over small distances. These molecules may serve as food for others or antibiotics, enzymes or signal molecules, that may mediate higher-order interactions between cells, ultimately facilitating or inhibiting the partner’s reproduction.
Metabolic interactions based on mutual assistance and cooperation – such as syntrophy, or cross-feeding – are widespread among microbes and are crucial for the formation, functioning and maintenance of these communities, probably also responsible for the unculturabiolity of many prokaryotes. However, products are usually costly to produce and can easily be diluted or are subject to exploitation by free-riders.
The most effective form of metabolic cooperation between different species is symbiosis, in particular endosymbiosis, where one cell physically relocates into the other. While this is an obvious way of stabilising the mutually beneficial relationships so common among microbes, only one such (presumed) case is known so far. Mitochondria, a crucal eukaryotic acquisition, have evolved to cellular organelles via endosymbiosis, when a bacterium moved into an archaeal host, about 2 billion years ago. Some theories suggest that this highly successful relationship emerged from an already existing mutually beneficial metabolic syntrophy between partners. However, no syntrophic relationship approximating endosymbiosis is known at all among any two modern prokaryotes (unicells lacking a nucleus). The emergence of eukaryotes from prokaryotic ancestors was a major evolutionary transition, during which cells lost their autonomy and created a new evolutionary unit responsible for the macroscopic living world around us. Although syntrophy is extremely widespread in the prokaryotic world, we know of no demonstrable case leading to a major transition, syntrophic, endosymbiotic or other. Why is it that prokaryotes are seemingly not able to “level up”? Why do we not see more major transitions in the prokaryotic domain? Why do we not see a transiton in individuality in microbial biofilms, as it has happened multiple times independently in case of eukaryotic multicellularity?
In their studies, the researchers of ÖK have categorised selection forces according to which ones facilitate and which ones hinder the establishment, reproduction and possible higher organisation of microbial communities. They have taken into account the community characteristics: species composition, coupled metabolism, metabolic functions, community building and interaction patterns. Some of these can be stably maintained in by certain microbial communities, and may also reappear when new communities are formed. If communities can also transmit minor changes, it is capable of informational inheritanceing. If bacterial colonies have such an adaptive property, it may be stably maintained in the population, for example in new colonies that bud off from the parent colony. If this trait provides a selective advantage to the colony, it should be maintained through higher level, e.g. group selection. This would be the first step towards a prokaryotic major transition. However, due to the high variability of bacterial communities (and their composition), the chances of this happening are low, and we do not yet see convincing examples.
An alternative solution, the researchers suggest, is for the loose interaction network to lead to tight pairwise symbiosis through higher levels of selection. A textbook example of this is endosymbiosis, the engulfment of a cell by another cell, which is common in eukaryotes but unknown in the prokaryotic world except for the origin of the mitochondrion. Prokaryotes seem to have been given the opportunity to move to a higher level of organisation only once. It is this fruitful relationship that has led us to read these lines.
Publication:
Zachar, I. and Boza, G. (2022). The Evolution of Microbial Facilitation: Sociogenesis, Symbiogenesis, and Transition in Individuality. Front. Ecol. Evol. 10:798045. doi: 10.3389/fevo.2022.798045
Zsóka Vásárhelyi and István Scheuring, researchers at the Institute of Evolution, Centre for Ecological Research, and Leticia Avilés, a researcher at the University of British Columbia, studied the geographical distribution of spiders with varying levels of sociality by modelling the Eastern slopes of the Andes in a computer simulation. They have shown that the ecological characteristics of a given habitat fundamentally determine whether social or subsocial species live in that habitat. The study presenting the results was published in the journal American Naturalist.
Spiders are typically known as solitary and aggressive animals, yet there exists a handful of spider species in the tropics where closely related individuals live in a common web. They maintain their dense, three-dimensional web together, they subdue and consume their prey together, and they care for the offspring together. These species are called social spiders. Their study may contribute, among others, to a deeper understanding of the evolutionary and ecological background of social behaviour.
It was empirically observed that with increasing altitude and latitude social spider species are being replaced by less cooperative, subsocial species, which, although characterised by long maternal care, do not show extensive social behaviour. The question naturally arises, what factors shape these geographical species distributions.
In the corresponding literature two separate hypotheses were offered to explain this pattern. According to the Prey Size Hypothesis, a common web (and a social lifestyle) is only worth maintaining where a sufficient amount of large prey are available. Although the surface-volume ratio of the web decreases with the size of the colony, the size of the prey items, available only for cooperating collectives, can compensate for this effect.
In contrast, the Disturbance Hypothesis suggests that where the environment is strongly disturbed (by wind, rain, or predators), solitary individuals cannot reproduce stably. This is because the dense three-dimensional web, characteristic of these species, is very expensive to maintain. If the mother is unable to care for her offspring long enough, for example, because of the energy loss due to web maintenance, the offspring will die before maturing. Thus, the two hypotheses suggest that the distribution of social species is limited by the size of the prey and that of the subsocial species by the degree of disturbance.
The researchers in their latest study modelled the Eastern slopes of the Andes with a computer simulation, incorporating the respective environmental gradients (changes in the maximum size of prey animals and the degree of disturbance). They then placed several social and subsocial “virtual colonies” into this modelled habitat, and observed which species survived in which environment, with what success.
The model illustrates well that together the prey size and the level of disturbance can indeed re-generate the naturally occurring distribution patterns. The researchers have shown that high disturbance is not only responsible for destroying small colonies, but can also have a potentially stabilising effect, especially in the largest colonies. The results suggest that the ecological characteristics of a given habitat may have a significant impact on the social behaviour of the species living there.
Image: A social spider colony and some of its members (top right). The images show one of the species that inspired the study (Anelosimus eximius). The photo was taken by L. Aviles in Equador.
Researchers of the ELKH Centre for Ecological Research, Institute of Aquatic Ecology and the Institute of Biology of Eötvös Loránd University (ELTE) studied the spectral sensitivity of mayflies during their larval and adult life stages. Using electroretinography, they showed that the visual system of the virgin mayfly (Ephoron virgo), a protected species in Hungary, adapts to changes in light conditions during development.
The study, which presents their results, was published in Proceedings of the Royal Society B.
Larvae of the virgin mayflies hatch from the eggs around April, they feed on organic material in the river bottom and develop until the swarming period, which takes place late summer. Swarming starts after sunset during twilight. The larvae float to the surface, where they emerge. The males undergo an additional moult, and after mating, the
fertilized females fly a few kilometres upstream above the river so that the eggs become laid into the water approximately at the same place where the previous generations developed.
The swarming of the virgin mayfly is restricted to a relatively short time frame during twilight, when the environment is almost completely dark for the human eye, but the scattered light of the sun still dominates the sky. At this time the content ratio of blue and ultraviolet photons compared to longer wavelength components is the
highest in the skylight.
In their most recent study, the researchers measured the spectral sensitivity of the compound eyes of larvae and adults of the virgin mayfly with electroretinography and found significant differences between these life stages. “The larval eyes were mostly sensitive to the green spectral range, while the eyes of the adults had a sensitivity
maximum in the ultraviolet” said Ádám Egri, research fellow at the Institute of Aquatic Ecology, the first author of the study.
The virgin mayfly develops underwater, where the short wavelength light is filtered out in the turbid water. This means that the green, yellow and red wavelengths are dominating this underwater world. Thus it is advantageous for the larvae to have eyes being primarily sensitive to the green spectral range.
Using webcams images, the researchers determined that the virgin mayfly typically swarms between solar elevations of 14 and 7 degrees below the horizon, when the content ratio of ultraviolet and green photons is the
highest in the skylight. Thus, the primarily ultraviolet-sensitive eyes of adults suggests adaptation to the light conditions of the twilight.
“We have previously shown that the virgin mayfly is mostly attracted to ultraviolet and blue light, which is in accordance with our new results” said György Kriska, associate professor at ELTE, who began to study the mass swarming and the streetlight-induced mass perishment of mayflies in 2012.
The mass perishment of the virgin mayfly at illuminated areas, e.g. bridges, is a well-known phenomenon, which can be reduced by the correct choice of the spectrum of outdoor lighting. Most short-wavelength light sources, such as the bluish cold-white LEDs, attract far more mayflies than the yellowish, warm-white LEDs which emit
light primarily in the longer-wavelength spectral range.
Thus, these results support the general agreement that long-wavelength artificial light cause the least ecological damage to the environment.
Ecosystem engineer organisms alter the local environmental conditions and resource distribution in a way that they create and maintain habitats or microhabitats for other organisms. The engineered patches are characterised by different structure and functioning compared to the surrounding habitats. Well-known ecosystem engineers include corals that create reef habitats or beavers that literally engineer whole landscapes. Among birds, woodpeckers are well-known engineers that create nesting places for many other birds. In grasslands, the ecosystem engineering effect of birds has been largely unknown. Members of the CER IEB ‘Lendület’ Seed Ecology Research Group studied this interesting phenomenon and published their results recently in the journal Land Degradation and Development.
They studied a large, iconic bird species, the Eurasian crane (Grus grus) which is a protected species across Europe. The global crane population – thanks to the conservation efforts, wetland restoration projects and to the ability of cranes to coexist with intensive agricultural practices –shows a growing trend. Because of this population increase, it is possible that the effects of cranes on natural ecosystems will also amplify, that is why it is timely and important to evaluate the effects of this large bird on the grassland ecosystems.
Hungary is an important stopover area during the migration of cranes. During autumn, 100,000 – 160,000 birds spend a few weeks in the lowland areas of East-Hungary. Cranes are usually foraging on maize stubbles on crop residue, but regularly visit grasslands where they forage on invertebrates. In grasslands they perform a special feeding habit called ‘crane-ploughing’: they heavily disturb the soil surface with their bill and remove the vegetation. The disturbed surface resembles to a ploughed area and their size range from a few square metres to a few hectares. These are characteristic landmarks in Hungarian alkaline grasslands, but until this recently published study, their ecological function was unknown.
The researchers compared the vegetation of crane-disturbed patches and undisturbed alkaline grasslands in the Hortobágy National Park. They found that the disturbed surfaces were characterised by different structure and function compared to the undisturbed patches. The pioneer vegetation on the disturbed patches sprouted earlier than in the undisturbed grasslands, and was characterised by short-lived plant species and forbs. The crane-ploughed patches harboured more species and a different species composition compared to the undisturbed grasslands.
There were important trade-offs between the positive and negative effects of the foraging activity of cranes on different structural and functional components of the ecosystems. The abundance and species richness of insect-pollinated plants increased on the disturbed patches which suggests that these areas offer important nectar sources for pollinators in the otherwise grass-dominated habitat. The early sprouting vegetation on the disturbed patches probably provides important forage source for the livestock early in the season, but in the dry summer period the forage quality value decreases considerably.
The study showed that foraging cranes have a fundamental effect on the structure and functioning of alkaline grassland ecosystems, by creating patches with altered vegetation composition and ecosystem functioning. This impressive ecosystem engineering is the result of a few-week long foraging, and even though the disturbance is temporal, its effect may last for many years.
Valkó, O., Borza, S., Godó, L., Végvári, Z., Deák, B. (2022) Eurasian crane (Grus grus) as ecosystem engineer in grasslands ‒ conservation values, ecosystem services and disservices related to a large iconic bird species. Land Degradation and Development https://doi.org/10.1002/ldr.4314
At least half of the insect species on our planet feed on plants (i.e., herbivores). Insect pests among them pose one of the greatest threats to both cultivated and naturally occurring plants. Regulating their numbers is therefore essential for both the economy and plant health. Unfortunately, pest control in most ecosystems relies primarily on the use of synthetic chemicals, which cause significant damage to the environment and human health. To mitigate these adverse effects, environmentally friendly methods are needed, especially in cities where more than half of the world’s population lives.
The biological defense mechanism is one of the most important features provided by biodiversity, with an estimated economic value of more than $ 400 billion annually worldwide. Biological control of pest insects is provided by natural enemies, helping to keep the size of their populations below a threshold where they can no longer be considered pests. Natural enemies can be predators that kill and consume their prey, such as ladybugs feeding on aphids, or so-called parasitoids whose larvae parasitize and thus kill the host, such as ichneumon wasps that lay eggs on caterpillars.
The impact of cities on this feature of the ecosystem was examined in a global study by an international research team from the Centre for Ecological Research (Hungary), the Technical University of Munich (Germany) and the National Agricultural Research Institute (France). Their results were published in the international journal Science of the Total Environment.
The researchers used a statistical method called meta-analysis, which combines the results of several scientific papers on the same issue. Fifty-two studies were conducted in different cities around the world. Compared to more natural rural areas, urban areas have been found to have higher numbers of insect pests that feed on plant sap ( that is, insects that suck plant sap with their piercing-sucking oral organs, such as aphids and shield lice) while the number of their natural enemies of arthropods with poor propagation was lower. Researchers have also shown that the level of biological regulation provided by arthropods has weakened as the rate of urbanization has increased.
Their results show that natural regulation of plant-sap-feeding pest populations is not effective enough in cities. The first author of the study, Dr. Dávid Korányi, a researcher at the Centre for Ecological Research, said: “These insects are one of the most problematic plant pests in cities, as they can severely degrade plants and produce large amounts of honeydew from plants that result in sticky sidewalks and other surfaces. The results suggest that natural enemies, in particular predators with poorer transmission capacity (such as earwigs and some beetles), may play a significant role in the effective biological defense against pest insects.
The leader of the study, Dr. Péter Batáry, a scientific advisor at the Centre for Ecological Research, said: “We can help these beneficial arthropods with more cohesive and less intensively treated, more natural green spaces in cities. For example, diverse vegetation (including trees, shrubs, and taller herbs), less mowing, preserving moorlands and dead trees provide them with hiding places and a suitable environment, contributing to their continued presence in urban areas as well.
Accordingly, this study urges the development of nature-based solutions and the reduction of artificial surfaces in cities to restore ecological communities and their functioning, thereby reducing the ecological footprint of urbanization.
Researchers from the Institute of Aquatic Ecology Centre for Ecological Research have been involved in setting global research priorities for freshwater salinisation. Their review article was published in Trends in Ecology and Evolution, one of the most prestigious journals in ecology.
Increasing salinity in freshwaters is one of the most pressing surface water problems facing the world today, threatening biodiversity and ecosystem services to society. To identify research gaps and future research priorities, an international team of researchers has now proposed a H2020 AQUACOSM-plus project with the Centre for Ecological Research.
