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Climate change and biological invasions are two of the most significant challenges facing ecological restoration efforts today. In the sand grasslands of Hungary, these pressures interact in complex ways, affecting how restored ecosystems develop over time. Researchers from the HUN-REN Centre for Ecological Research, Invasion Biology Division of the National Laboratory of Health Security, conducted a long-term study to understand how drought severity and restorative mowing influence the recovery and vulnerability of sand grassland ecosystems.

The research focused on three locations within the Kiskunság region, where invasive black locust stands (Robinia pseudoacacia) were removed between 1994 and 1995, and regular mowing was applied until 2001 to prevent regrowth. Using comprehensive vegetation data collected from 1995 to 2019, alongside long-term weather data, the team analysed the dynamics of native target species, invasive species, and drought-tolerant C4 plants under changing drought conditions.

The findings reveal that native sand grassland species demonstrated notable resistance to drought, maintaining stable populations even as summer droughts became more frequent and severe. In contrast, invasive species tended to decline during severe droughts, while C4 species, which are more tolerant of heat and dryness, became more dominant. Although mowing — commonly used to aid grassland restoration — effectively prevented the reinvasion of the targeted black locust, it did not enhance the recovery of native sand grassland species. Instead, it facilitated the spread of invasive herbaceous species, particularly under drought conditions. This unintended consequence highlights the complexity of restoration practices: interventions that control one problem may inadvertently create new vulnerabilities. In fragmented landscapes, where nearby habitats serve as reservoirs for invasive species, this risk is even greater.

The study emphasises that sand grasslands are naturally resilient to many disturbances, but their long-term stability depends on considering multiple ecological factors. Restoration strategies must go beyond local-level interventions and should consider landscape-scale dynamics and climatic impacts. The research underscores the need for adaptive, flexible restoration practices that anticipate future climatic stresses and invasion risks. It also highlights the importance of frequent, long-term monitoring to capture the delayed and sometimes subtle responses of ecosystems to environmental change.

The raccoon is one of the most widespread invasive mammal species in Europe. Its expansion on the continent dates back to 1934, when the first few individuals were released in Germany. Since then, their numbers have grown to several hundred thousand, and they are becoming increasingly common in many other European countries, including Hungary.

The 3^rd EURORACCOON Meeting was recently held, where raccoon researchers presented their latest work and discussed the management of the species. Three of us from the Hungarian University of Agriculture and Life Sciences participated in the event and gave presentations about our work in the Invasion Biology Division of the National Laboratory for Health Security, Hungary. We presented the raccoon wildlife camera trap studies, which confirmed the nest predation effect of the species, and described the annual occurrence of raccoons in their most important habitat in Hungary; our results on the condition and reproductive biology of raccoons in Hungary; and the experiences of the first local eradication program of the country, implemented for the species.

The conference took place at the Seminarzentrum Edersee event venue in the Kellerwald-Edersee National Park, Germany – at the historic site where the raccoon’s European conquest began.

During the three-day event, in addition to the professional activities, the researchers visited natural habitats, including a primeval beech forest, where raccoons are becoming an increasingly significant part of the ecological community, and also took an evening raccoon-watching tour in the nearby “raccoon capital” of Kassel, where they witnessed the species in large numbers and discussed their management in the city. For those who were up to some culinary adventures, the program was also enriched with a “raccoon barbecue”.

One of the important findings of the meeting was that although the raccoon is an extremely successful predator with a diverse diet and can also spread infections, there is hardly any research that would prove its actual significant impact. Therefore, there is a great need for such targeted research. In some places, the complete eradication of the species seems hopeless, but its spread to areas not yet occupied can be prevented. In Hungary, its population could still be kept under control with well-organized interventions.

Participants of the event would like to see next year’s conference on the Gödöllő Campus of the Hungarian University of Agriculture and Life Sciences, in Hungary.

Participants from the Division of Invasion Biology of NLHS: Dr. Krisztián Katona, Dr. Zsolt Biró, Balázs Bócsi

The “first of its kind” conference in Hungary enabled nationwide and international discussion on invasive alien species – a cohesive action plan is finally on the horizon

The conference took place in Sarlóspuszta, Hungary between 26 and 28 February 2025, organised by the HUN-REN Centre for Ecological Research and the Invasion Biology Division of NLHS. It was aimed to foster knowledge exchange and proactivity among researchers, practitioners, and policymakers on managing invasive species through the interdisciplinary “One Biosecurity” framework. This approach integrates plant, animal, human, and environmental health to mitigate the impacts of biological invasions.

On the first day, the “One Biosecurity” concept was introduced by the day’s plenary speaker, Dr. Philip Hulme, a distinguished professor of plant biosecurity at Lincoln University, New Zealand. He highlighted its potential to unify decision-making across sectors for better biosecurity outcomes while emphasizing its holistic approach to biosecurity threats. Speakers of the day presented their studies on such threats imposed by human, animal and plant parasites and their vectors, such as alien mosquito species and their spread diseases or fungal diseases of plants, as well as invasive species with a high risk to native animals and environmental health, i.e., the raccoon and the raccoon dog, or released exotic pet fish and reptile species.

The second day featured scientific presentations on invasion biology topics such as spread mechanisms, monitoring and control, ecological roles, and socio-economic impacts. Dr. Petr Pyšek, a senior research scientist at the Czech Academy of Sciences, and Dr. Piero Genovesi, chair at the IUCN SSC Invasive Species Specialist Group, delivered plenary talks on cutting-edge research and control methods. Dr. Petr Pyšek’s presentation focused on mechanisms of species invasiveness and global biogeography of alien floras. Whereas Dr. Piero Genovesi discussed strategies for controlling invasive species and related policymaking. Some of the highlights from other speakers were mapping the spread of invasive plant species and using AI technology for maximising efficiency; unintentional dispersal of plant seeds; targeted control of invasive trees; biological control of insect pests; the control issues with the coypu and alien aquatic macrofauna, the damage they cause, and the potential to reduce the impact of invasive fish with the reintroduction of beavers.

Finally, the third day was comprised of a day-long workshop that facilitated collaboration between researchers and practitioners from various fields, focusing on co-producing actionable knowledge for managing invasive species effectively. One of their conclusions was that involving and helping the lay public in reporting and managing invasions is as important as cooperating with farmers, foresters, gardeners, and other related professionals. Understanding and mitigating the spread of alien species requires a combined effort from all layers of society, and finding the appropriate channels of communication to each layer is a key factor in doing so.

In summary, the conference emphasized the importance of prioritising invasive species management efforts on high-risk, early-stage invasions. Geographic context was highlighted as crucial, with island nations better focusing on border controls and mainland countries with open borders, like Hungary, are advised to prioritise nationwide monitoring focusing on high-risk hubs of travel and trade. Key recommendations included legislative improvements, increased government support and investment, multi-stakeholder and sectorial collaboration, education on biosecurity in schools, and the use of clear terminology in media.

A key conference goal was translating the One Biosecurity concept into Hungarian to ensure effective communication through media channels. The result is “ökobiztonság” which translates to “Eco-Security” in English – a much more widely understood term in Hungarian that, with the right contextualisation, can also cover the unified concept of the protection of plant, animal, human, and environmental health.

Book of Abstracts »
One Biosecurity workshop, Mentimeter results »

The loss of biodiversity on our planet is partly due to the presence and spread of alien invasive species. Once an invasive species has established in a new habitat, it can alter the structure and function of the ecosystem to such an extent that it has an impact even after removal, making it very difficult to control and eradicate. Ecological restoration, when carried out in an effective and sustainable way, contributes to biodiversity conservation and climate change mitigation, resilience and adaptation, and has proven to be an effective method of controlling invasive species. At the same time, the presence of invasive species in the landscape can compromise restoration objectives. The aim of this study is to assess how the abundance of annual and perennial invasive species varies with location, direction and distance around the restoration site, and which factors should be considered when planning restoration interventions.

Seeds of plant species are often dispersed unintentionally on our clothes, which thanks to the increasing mobility of people, can be important events in the process of biological invasions. Researchers from the HUN-REN Centre for Ecological Research, ‘Lendület’ Seed Ecology Research Group, investigated this topic, and published their results in the D1-ranked scientific journal Journal of Environmental Management. This study provides critical insights into the unintentional spread of plant species through human-vectored dispersal via clothing, a pathway that has received limited attention so far. Their findings show that most seeds remain viable after typical household washing, even at common temperatures and a wide range of detergent types, highlighting a largely overlooked vector of plant dispersal. Since most of the plants that are capable of cloth-dispersal are weeds and invasive species, the results have important implications for invasion control. They emphasize the need for targeted biosecurity measures, especially among those working outdoors, to mitigate the spread of invasive species. The results also offer actionable strategies for environmental management by integrating behavioural changes and public awareness to reduce the environmental impact of human-vectored dispersal. According to their questionnaire survey, raising awareness is especially important for nature conservation professionals who are among the most important potential vectors.

Citation of the paper:

Lukács, K., Kiss, R., Tóth, Á., Godó, L., Deák, B., Valkó, O. (2025): Effects of laundry washing on germination of cloth-dispersed seeds depends on washing intensity not on detergent type. Journal of Environmental Management 375: 124345.

Invasive mosquito species already established in Hungary can pose a significant threat to human and animal health due to their potential role in the pathogen transmission. Researchers from the HUN-REN Ecological Research Centre and the University of Pécs, part of the Invasion Biology Division of the National Laboratory for Health Security, and ELTE have published their results in the D1-ranked scientific journal ‘Journal of Pest Science’. In this study the researchers evaluated the effect of environmental factors reflecting climate, habitat type, food supply, traffic, and interspecific competition on the distribution of three invasive tiger mosquito species in Hungary. They trained species distribution models using citizen science observations and then predicted the potential distribution of the species. The researchers uncovered species-specific patterns and found that different predictor sets were selected for the three different species, however, only predictions for Asian tiger mosquito could be validated with direct trapping data. They concluded that citizen science informed distribution maps can be used to identify environmental predictors that determine the spread of invasive mosquitoes.

Researchers of the National Laboratory for Health Security’s Mosquito Monitor program created a new laboratory to breed invasive mosquitoes and to study their acoustic ecology. Adult individuals of the tiger mosquito (Aedes albopictus), which is bred here, feed on nectar in the wild, but get sugar-water instead in the lab. In order to produce eggs, females are fed with sterile cow blood via the Hemotek system, a device designed specifically for feeding blood sucking insects. The lab follows the arthropod containment guidelines, in order to prevent any potential escapes.

The researchers built a soundproof box with camera and microphones inside, with which they are able to record high quality footage even of low sound intensity. Audio recordings can be analysed using a specialised software, thus several acoustic variables can be extracted. The variation in sound can also be linked to the mosquito behaviour, recorded using the video camera.

Two projects are currently running in the lab. The first one is the identification of mosquito species based on sound, with the help of artificial intelligence. The second project aims to better understand the acoustic communication of the female and male tiger mosquitoes during the mating sequence. In some other mosquito species it has been shown that the male and female converge toward the same sound frequency right before mating together. This capacity of changing the flying sound and to adjust to the potential mate could play a significant role in mate choice and sexual selection. A better understanding of this phenomenon could help develop efficient techniques in mosquito control.

Ground-nesting bees are highly sensitive to changes in vegetation, flower supply and soil properties caused by plant invasions. The direct and indirect effects of twelve alien invasive plant species were investigated under field conditions. Invasion generally reduced flower resources, increased vegetation height and affected some soil properties. While invasion had a negative effect and the amount and diversity of flowers had a positive effect on ground-nesting bees, but no relationship was found between the soil properties and bees. Our findings suggest that it would be worth exploring the issue in more depth, for example using more specific field methods to explore the role of additional soil parameters. Our present publication is a first step towards future research exploring the role of soil properties on bees.

Biological invasions are a growing challenge around the world. Meanwhile, it is now widely recognised and acknowledged that indigenous peoples’ territories play a key role in global biodiversity conservation. On the one hand, their land-use practices are often more nature-friendly than conventional land-use practices, and on the other hand, their territories, like protected areas, are in more remote locations, away from urbanisation and transport infrastructure. Our article, for the first time in the world, examined the extent to which indigenous peoples’ territories are threatened by invasive species compared to the rest of the world’s landscapes. We used our previously published global map. We calculate that, on average, there are 30% fewer invasive species in indigenous peoples’ landscapes than in other parts of the world. If we take into account differences in sampling intensity, distance of sites from roads, major land cover types, etc., the difference is reduced but remains significant. In the rare cases where the number of invasive species was higher in the indigenous areas, propagule pressure from neighbouring, e.g. urban areas, could be assumed as a cause.
Our article is part of a series of articles examining the contribution that indigenous peoples’ territories can make to the maintenance of the world’s natural heritage.

Related publications:

Fa, JA, Watson, JEM, Leiper, I., Potapov, Evans, Burgess, Molnár, Z., Fernández-Llamazares, Duncan, Wang, Austin, Jonas, Robinson, Malmer, Zander, Jackson, Ellis, Brondizio, Garnett (2020): Importance of Indigenous Peoples’ lands for the conservation of intact forest landscapes. Frontiers in Ecology and the Environment 18(3), 135-140.
Garnett, S.T., Burgess, N.D., Fa J.E., Fernández-Llamazares, Á., Molnár, Zs., Robinson, C.J., Watson, J.E.M., Zander, K.K. et al. (2018): A spatial overview of the global importance of Indigenous lands for conservation. Nature Sustainability 1: 369–374.
O’Bryan CJ, Garnett, ST, Fa, JE, Leiper, I., Rehbein, J, Fernández-Llamazares, Á, Jackson, MV, Jonas, HD, Brondizio, ES, Burgess, ND, Robinson, CJ, Zander, KK, Molnár, Z, Venter, O, Watson, JEM (2021): The importance of indigenous peoples’ lands for the conservation of terrestrial mammals. Conservation Biology, 35: 1002-1008.
Seebens, H., Niamir, A., Essl, F., Garnett, S.T., Kumagai, J.A., Molnár, Zs., Saeedis, H., Meyerson, L.A. (2024): Biological invasions on Indigenous peoples’ lands. Nature Sustainability (nyomdában) https://doi.org/10.1038/s41893-024-01361-3

The invasion of North American sand dropseed (Sporobolus cryptandrus) in Hungary mainly threatens vulnerable open sandy grasslands. As there is already considerable field experience and research on the species in Hungary, and as this has shown that we are facing a very serious problem, it has become necessary to organise a large-scale professional meeting to discuss the most pressing issues of the invasion of sand prairie grass in Hungary.

On 27 March 2024, the HUN-REN Ecological Research Centre, Experimental Vegetation Ecology Research Group and the Kiskunság National Park Directorate organised this professional meeting in Kecskemét. The event was attended by experts from the research centres (University of Debrecen, University of Sopron, University of Szeged and HUN-REN Ecology Research Centre) and the national parks concerned (Kiskunság NP and Hortobágy NP). The primary aim of the meeting was to establish a link between researchers and conservation practitioners.

The first session presented research on North American sand dropseed in Hungary. Dr. Csaba Tölgyesi talked about the possibilities of controlling prairie grass with semi-parasites and competitors, Dr. Attila Torma presented the effects of prairie grass on arthropod communities, while Dr. György Kröel-Dulay (the main organizer and moderator of the meeting) presented the results of the mapping of the species in the Kiskunság region and the long-term monitoring and experimental studies that have been initiated. In the next session, participants discussed in a moderated discussion how they see the invasion of prairie grass in the coming decades and what possible ways of control could be. The next session opened with a presentation by Attila Rigó, who described possible ways to collect coordinated occurrence data and discussed the possibility of involving the public (citizen science), followed by a talk by Dr. Eszter Tanács on the possible use of remote sensing methods in monitoring the spread of prairie grass in Hungary. Afterwards, Dr. Ferenc Sipos, Deputy Director of the KNP, presented the National Park’s experience with the species, from its ecology to the practical challenges of eradication. Finally, the participants attempted to synthesise the knowledge gained so far and agreed on the way forward.

As a result of the meeting, an informal “Sporobolus working group” was formed, and the participants agreed to discuss ongoing and planned research and results, and to report back to each other once a year in a similar meeting. They also drew up a list of the most important research tasks and identified the most important non-research tasks. The possibility to join the group is open to all, with the explicit aim of bringing together researchers and conservationists working on the species and coordinating research and conservation interventions.

Contact Attila Rigó (rigo.attila@ecolres.hu) and György Kröel-Dulay (kroel-dulay.gyorgy@ecolres.hu)