Hungarian team applies game theory to determine how a government can fight novel pathogen

Current Science Daily talked with co-author Ádám Kun how the researchers came up with using game theory as a way to help a government most efficiently deal with an epidemic caused by a new pathogen. Kun is at the Institute of Evolution, Centre for Ecological Research and Eötvös Loránd University in Budapest.
The work appears in Nature’s Scientific Reports, Sept. 30.

Two findings of note.
• First, the study found that the “presence and length of a pre-symptomatic infectious state of the disease” has the “greatest effect” on the probability of the pathogen to cause a pandemic.
• Second, surprisingly, the research showed that even if a nation (or state) wants to provide care for everyone who needs it and “minimize the cost of lockdowns,” it should not “strive for the great expansion of its health care capacities….”

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Source: currentsciencedaily.com

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Appointment of Deputy Director

On the recommendation of the Director of the Institute of Aquatic Ecology, the Director-General of the Centre for Ecological Research appointed Péter Dobosy as Deputy Director of the Institute of Aquatic Ecology from 1 November 2022. His areas of expertise include the chemical analysis of sediment and water in river, lake, wastewater and drinking water, and the study of the effects of trace element-enriched irrigation water on plant cultivation through soil-plant interactions.

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International Meeting for PhD students in Botany organized by the CER IEB researchers

Between 22-25 September 2022, the researchers of the Centre for Ecological Research Institute of Ecology and Botany (CER IEB), and members of the Hungarian Ecological Society (HES) organized an International Meeting for PhD students in vegetation ecology in Poroszló, Hungary. This meeting was first initiated by Milan Chytrý and Zoltán Botta-Dukát about twenty years ago, and it has been a very nice tradition since then. Every second year, PhD students in botany meet somewhere in Central Europe and they share their research plans and results, and they can get advice from each other and from senior scientists in a friendly atmosphere.

After a break of few years due to the pandemic, finally this nice event could be organized in person. We were very happy that this year, researchers from the IEB CER – Zoltán Botta-Dukát, Balázs Deák, and Orsolya Valkó – had the possibility to organize this event.

There was a huge interest as there were almost 70 participants, from 16 countries. The scientific program was very intensive, but also very interesting; the PhD students gave very impressive and high-quality presentations, followed by fruitful discussions. The venue of the conference was in Poroszló, in the Tisza-Lake Ecocentrum, which is a wonderful place for such an event. During the coffee breaks, we could visit the nice indoor and outdoor exhibitions and aquariums, which was a nice and refreshing activity. After dinner, there were two very interesting topical discussions about ‘How can we translate the scientific results into practice?’ and whether ‘Quality or quantity counts more in science?’, followed by a lively social program. On Sunday, Balázs Deák led a half-day long excursion, where we showed the participants the natural beauties of the Hortobágy National Park, the alkaline grasslands and wetlands, loess grasslands, and kurgans.

The event was co-organized by Centre for Ecological Research Institute of Ecology and Botany and the Hungarian Ecological Society and supported by the Hungarian Academy of Sciences; we are grateful for its support. We are thankful to all the participants for their enthusiasm and active participation in all the events. We are thankful for all the colleagues from IEB who helped us in the organization, especially József Nagy, Attila Lengyel, and Miklós Kertész. We are thankful to the Hortobágy National Park Directorate for supporting the field trip.

Organizers: Zoltán Botta-Dukát, Orsolya Valkó and Balázs Deák

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New ’Forefront’ project at the Centre of Ecological Research

The research project of Orsolya Valkó (CER, IEB, ‘Lendület’ Seed Ecology Research Group) was one of the ten funded Forefront projects by the National Research, Development and Innovation Office in 2022. The research funding will enable the applicants to carry out a world-class research project in Hungary over the next five years, and support the participation in the European Research Council (ERC) research funding programmes. The current project is the third Forefront project at the CER, after the projects of Eörs Szathmáry and Péter Batáry.

The title of the project is ‘Grassland restoration based on nature-based solutions in agricultural landscapes: drivers at micro- and macro-scales’. The topic of the project align well to the current global and European policies, that have ambitious plans for supporting habitat restoration in agricultural landscapes. The Frontline project aims to provide a comprehensive framework for utilizing nature-based solutions in the restoration of semi-natural grasslands and in creating multifunctional agricultural landscapes. The ambition is a multi-scale and multi-site research program that by answering theoretical ecological questions provides evidence-based solutions for strategic restoration planning and for fine-tuning the agri-environmental schemes. The novelty of the work is that the researchers will combine approaches of large-scale multi-site vegetation surveys with landscape ecology, seed ecology and historical ecology. First, they use a multi-site chronosequence approach and study the spontaneous and assisted grassland recovery in agricultural landscapes. They sample the vegetation in 300 recovering sites and evaluate diversity and species composition patterns as a function of small-scale environmental heterogeneity, landscape context and recovery time. In Second, they analyze the temporal (seed bank) and spatial (seed rain) components of seed dispersal and test the effect of the local and landscape factors on the availability of seed sources. Finally, they study whether seeds from the seed sources can achieve successful establishment in the aboveground vegetation and test the importance of plant functional traits, landscape- and environmental filters in the establishment process from the seed sources in the recovery process. They aim to develop and test seed-based restoration methods for overcoming establishment limitation. The research will identify optimal settings of local and landscape factors where recovery is the most promising and support restoration prioritization by determining where we can rely on spontaneous recovery processes and where we need active restoration measures.

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Zsolt Molnár elected member of Academia Europaea

Zsolt Molnár, DSc, ethno-ecologist, scientific advisor of the Centre for Ecological Research and head of the Traditional Ecological Knowledge research group, has been elected a member of Academia Europaea.
The Academia Europaea is a non-governmental association acting as an Academy. Its mission is to promote excellence in the humanities, law, economics, social and political sciences, mathematics, medicine and natural sciences and technology. Founded in 1988, it currently has 4,500 members, including 72 Nobel laureates.

Source: Academia Europaea membership

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A research group led by fellows from the Centre for Ecological Research summarized spatial priorities for freshwater biodiversity in Europe

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).

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The role of microbial cooperation in the development of higher level organisation

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

Source: elkh.org

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The Ecology of Spider Sociality: A Spatial Model

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.

Source: elkh.org

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Spectral sensitivity transition in the compound eyes of a twilight-swarming mayfly and its visual ecological implications

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.

Photo: Imre Potyó

Source: elkh.org

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Eurasian crane (Grus grus) as ecosystem engineer in grasslands

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