What happens after a grassland fire: how do grasslands and firebreaks recover?

In our recently published paper, we investigated grassland recovery following wildfire and firebreak establishment.

Citation:

Deák B., Süveges K., Gőri Sz., Kapocsi I., Gál L. and Valkó O. (2026): Trade-offs between fire suppression and biodiversity: vegetation recovery in burnt grasslands and firebreaks under different restoration treatments. Fire Ecology, 22: 128.

The study is freely available to read and download here.

Fire has been part of grassland ecosystems in the Carpathian Basin since historical times. Together with flooding and grazing animals, it has shaped the landscape and contributed substantially to maintaining open habitats. Today, however, climate change, frequent droughts and the accumulation of dry plant biomass are increasing the risk of larger and less predictable fires. Such fires may threaten not only natural values but also human safety, as they can spread to farmland, farms and other infrastructure.

Fire in the Hortobágy (photo by Sándor Borza)

Wildfire in the grassland (photo by Sándor Borza)

Fire has been part of grassland ecosystems in the Carpathian Basin since historical times. Together with flooding and grazing animals, it has shaped the landscape and contributed substantially to maintaining open habitats. Today, however, climate change, frequent droughts and the accumulation of dry plant biomass are increasing the risk of larger and less predictable fires. Such fires may threaten not only natural values but also human safety, as they can spread to farmland, farms and other infrastructure.

To suppress rapidly spreading fires, it may be necessary to establish firebreaks that interrupt the continuity of combustible plant material and can thus slow or stop the advancing flames. Firebreaks can therefore play an important role in fire suppression. In grasslands, however, their establishment usually involves soil disturbance, often by disk-harrowing. In protected areas, their location and method of establishment should consequently be selected with care. It is also important to understand how vegetation recovers on firebreaks and which treatments can support the restoration of the original vegetation.

In collaboration with the Hortobágy National Park Directorate, we investigated how vegetation recovered after an extensive but low-intensity grassland fire in the summer of 2022. Our study included both pristine and restored loess grasslands. For three years, we monitored vegetation changes in the burnt areas and in disk-harrowed firebreaks, comparing them with adjacent unburnt reference areas.

Some sections of the firebreaks were left to recover without further intervention after disk-harrowing. Elsewhere, we used a ring roller to level and compact the rough soil surface. In a third treatment, rolling was followed by sowing seeds of locally sourced Festuca rupicola. This allowed us to compare spontaneous recovery, the effects of soil-surface levelling and active grassland restoration.

The firebreak and the three treatments

Our results showed that the low-intensity fire caused only moderate and temporary changes in grassland vegetation. Grassland species recovered well during the first year, and no substantial weed encroachment occurred in the burnt areas over the longer term. One reason is that many perennial dry-grassland plants are adapted to occasional fires: although their above-ground shoots may burn, they can resprout from below-ground organs and stored reserves.

Recovery also began quickly on the firebreaks. Vegetation cover increased rapidly, and grassland species appeared from the first year onwards. Nevertheless, their cover had still not reached the levels observed in the surrounding grasslands after three years. Disk-harrowing removed the original vegetation, while soil disturbance promoted the germination of weed and disturbance-tolerant species present in the soil seed bank. Consequently, weeds and disturbance-tolerant species still accounted for a considerable proportion of the vegetation on spontaneously recovering and rolled firebreaks after three years. These findings show that, although recovery begins quickly, the development of vegetation resembling the surrounding grasslands may take considerably longer.

Rolling alone had only a moderate effect on the rate of recovery, whereas sowing Festuca rupicola substantially suppressed weeds. This vigorous perennial grass rapidly formed a continuous grass matrix that left progressively less space for weed species. At the same time, a dense Festuca stand may also slow the establishment of other valuable grassland species. The most appropriate method for restoring firebreaks should therefore be selected according to the condition of the surrounding grassland, the abundance of weeds and the potential for natural colonisation by grassland species.

Our research highlights the importance of considering fire-safety and biodiversity-conservation objectives together. Firebreaks can play an important role in suppressing wildfires, but in grasslands they should be planned and established with care. After their creation, vegetation recovery should also be monitored over the longer term. Regular monitoring makes it possible to identify persistent weed encroachment or stalled recovery at an early stage and, where necessary, support the development of grassland vegetation through targeted management, such as removing weeds before seed set or applying appropriate mowing, grazing or seed sowing.

It is important to emphasise that our results concern a single summer fire of relatively low intensity. Grassland species may not be able to withstand frequent or high-intensity fires without damage. As the climate becomes drier, uncontrolled fires therefore require increasing attention because they can rapidly cause both conservation and safety problems. Our study focused on vegetation, but extensive fires may affect some groups of animals, such as arthropods and ground-nesting birds, much more severely than plants.

The abstract of the paper is provided below:

Abstract

Background: Wildfire is an important component of many grassland ecosystems, but it is often suppressed in modern landscapes to protect infrastructure and human safety. Disk-harrowed firebreaks are frequently used to stop wildfire spread; however, this method represents a severe soil disturbance that may alter grassland species composition and structure. We studied the effects of a low-intensity growing-season wildfire on the vegetation of pristine and restored Central European dry grasslands, and evaluated vegetation recovery on firebreaks for three years post-fire. Firebreaks were subjected to passive restoration (disk-harrowing), assisted natural regeneration (rolling) or active restoration (rolling combined with grass seed sowing). In total, 180 permanent vegetation plots were surveyed for three years.

Results: Several grassland specialist species were associated with burnt grasslands during the first two post-fire years, but these patterns disappeared by the third year and did not affect overall specialist richness or cover. Fire did not promote disturbance-tolerant or weed species in the long run. Grassland specialists were able to re-establish in disk-harrowed and rolled firebreaks from the seed bank and seed rain; however, their cover remained substantially lower than in reference grasslands. Sowing seeds of the competitive perennial grass Festuca rupicola accelerated the development of a continuous grass cover and substantially reduced the proportion of weeds. Even in the third year after disturbance, firebreak vegetation remained dominated by disturbance-tolerant and weed species. Recovery of specialists was faster in restored grasslands, characterised by species typical of mid-successional stages, than in pristine grasslands.

Conclusion: Low-intensity growing-season wildfire had moderate and temporary effects on dry grasslands, indicating that fire represents an endogenous disturbance to which these communities respond with a short-term internal reorganisation. In contrast, mechanical soil disturbance associated with firebreak establishment represented an exogenous disturbance with longer-lasting effects on vegetation composition and structure. Although species richness of target grassland species recovered quickly, their cover remained lower than in reference grasslands even for the third year. Sowing a dominant perennial grass effectively suppressed weeds, but increased competition may limit the establishment of other grassland species. Our results highlight a trade-off between short-term fire safety and long-term biodiversity conservation, suggesting that firebreak establishment should be cautiously applied and accompanied by appropriate monitoring and targeted management.

Life on the burial mounds of southern Italy – ancient stone mounds as refuges for Mediterranean flora

Our latest article, with Rocco Labadessa as the first author, has been published. Here we were able to indulge our passion for the biodiversity sustained by ancient burial mounds in a new biogeographic region: the Mediterranean :)

The citation of the paper:

Labadessa, R., Vicario, S., Tarantino, C., Valkó, O., & Deák, B. (2026). Life in the graveyard: ancient stone burial mounds as refuges for Mediterranean grassland vegetation. Global Ecology and Conservation, e04361.

The paper is freely available on the journal’s homepage (please click here).

In the Mediterranean landscapes of southern Italy, stone-built mounds preserve the memory of the past. The nearly one hundred burial mounds of the San Magno necropolis were constructed around 2,700–2,800 years ago, between the Late Bronze Age and the Early Iron Age. However, these ancient structures are valuable not only from an archaeological and cultural perspective.

Ancient stone mound in the San Magno necropolis, from the birdseye view.

In a joint Italian–Hungarian study led by Rocco Labadessa (Institute of Environmental Intelligence and Technologies at the Italian National Research Council), we explored the potential role of these stone mounds in conserving threatened species of the Mediterranean flora. This question is particularly important because the region’s semi-natural dry grasslands have declined considerably and become increasingly fragmented over recent decades and centuries. The remaining habitats are further threatened by the abandonment of formerly widespread grazing practices and by the growing populations and increasing disturbance of wild boar.

We found that the rocky surfaces of the burial mounds provide excellent refuges for grassland species that prefer open habitats, while also protecting the soil from severe disturbance, as the stony ground is not particularly attractive to rooting wild boar. The small and varied habitats among the stones create distinctive microclimatic conditions that may also buffer the effects of heat and drought.

As a result, the mounds support more grassland plant species than the surrounding grasslands, including numerous perennial and habitat-specialist species. We also found species on the mounds that were entirely absent from their immediate surroundings. These included the southern Italian endemic feather grass Stipa austroitalica, which is recognized as a species of particular conservation importance under the European Union’s Habitats Directive. This suggests that the burial mounds may have preserved elements of formerly more extensive natural grassland vegetation over long periods of landscape change.

This picture shows very nicely the striking differences between the vegetation of the stone mound and the surrounding grassland matrix.

Although less than a metre high, these ancient structures now function as habitat islands in a profoundly transformed landscape. Protecting them therefore contributes to the conservation of both archaeological heritage and biodiversity. However, the mounds alone cannot safeguard nature: appropriate management of the surrounding grasslands and the maintenance of connections between habitats are equally essential.

The burial mounds of San Magno clearly demonstrate that monuments inherited from humanity’s distant past can also play an important role in nature conservation today.

Resilience of sown grasslands - our new paper in Ecological Solutions and Evidence

Our recent study by Réka Kiss  about the resilience of restored grasslands has recently been published in Ecological Solutions and Evidence.

Kiss, R., Lukács, K., Tóth, K., Tóth, Á., Godó, L., Deák, B., Valkó, O. (2026): Early sowing of multiple species supports the recovery potential of restored grasslands. Ecological Solutions and Evidence 7: e70247. https://doi.org/10.1002/2688-8319.70247

The paper is open access and can be freely downloaded from the journal website (please click here).

In this article, we explore why sowing grasses alone is not sufficient when aiming to establish species-rich grasslands, and why the early introduction of forb species is essential following land abandonment or sowing grass seeds. We examine all this from the perspective of restored grasslands, by evaluating the role of disturbance (i.e. ploughing) in grassland recovery. Our study has a clear practical implication: our results show that we can restore more resilient grasslands if the target forb species are sown together with the grasses, as early as possible.

This is the second study resulting from our common garden experiment that we established in 2014, and we run it until 2022. Between 2014 and 2019 we studied vegetation recovery after nine restoration treatments (combinations of grass and forb sowing, with joint and delayed sowing) and published the first results in Kiss et al. (2022). Then we introduced a severe experimental disturbance – ploughing – to the sown parcels to study resilience of the grasslands restored by different methods.

This was a very interesting study, but also one of our most demanding studies: besides the long-term survey (survey of the 144 plots twice per year for 8 years), we needed to do the yearly maintenance of the experimental site. This involved multiple mowing, raking, sowing, soil preparation. This was a huge work and many thanks to all the people who took part in that!

Restored grassland with large cover of Salvia nemorosa - before ploughing

Grassland restored by grass seed sowing - before ploughing.

The maintenance of this experiment was highly demanding, sometimes mowing was very challenging

EASAC report “Changing Wildfires in Europe” presented at the Cyprus Institute

On 22 January 2026 the Cyprus Institute, the Cyprus Academy of Sciences, Letters and Arts, and the European Academies Science Advisory Council (EASAC) organized a public lecture and presentation of the EASAC report entitled Changing Wildfires - Policy Options for a Fire-literate and Fire-adapted Europe.

In the public lecture, we discussed the main findings of the EASAC report, emphasised the importance of preventive measures in wildfire governance, and also focused on the specific challenges of the Mediterranean region. The lectures were followed by fruitful discussion on these topics and on the relevance on the EU decision of establishing a Wildfire Hub in Cyprus. Many thanks to the organizers for making this super-important and interesting event possible!

The event was live-streamed and can be watched here (from 10:30). 

Please find below some brief information about the panel and the abstract of the event.

Convenor: Prof. Costas N. Papanicolas, President Emeritus, The Cyprus Institute, Director, Research Unit of Climate Crisis and Sustainable Development; The Cyprus Academy of Sciences, Letters and Arts

Panelists:

Prof. Thomas Elmqvist, Professor, Stockholm Resilience Center, Stockholm University, Sweden and EASAC Environment Director

Dr. Orsolya Valkó, Research Group Leader, HUN-REN Centre for Ecological Research, Hungary

Prof. Efthymis Lekkas, Professor of Dynamic, Tectonic, Applied Geology, and Natural Disaster Management, National and Kapodistrian University of Athens

Mr. Kostakis A. Papageorgiou, Chief Conservator of Forests, Ministry of Agriculture, Rural Development & Environment, Department of Forests

Abstract

“Suppressing fires alone is not sufficient. We need to address the root causes, strengthen efforts to combat climate change, invest in resilient landscapes, and actively engage society in learning to live with fire,” says Dr. Cathelijne Stoof, Co-Chair of EASAC’s Wildfires Working Group.

 

According to the newly published EASAC report Changing Wildfires in Europe, many regions across Europe are experiencing multi-year droughts, significantly increasing the likelihood of extreme wildfire events. On average, wildfires in the European Union currently burn approximately half a million hectares each year—an area roughly equivalent to half the size of Cyprus.

 

The event will examine the escalating wildfire risks across Europe, with a particular focus on the Mediterranean, and assess their implications for Cyprus, the Eastern Mediterranean region, and the proposed European Wildfire Hub. Topics covered will include wildfire risk reduction, prevention strategies, and building fire-resilient societies in Europe, the Eastern Mediterranean, and Cyprus. Experts, policymakers, and stakeholders will convene to explore how EU and regional strategies can transition from reactive fire suppression toward proactive, risk-based land and landscape management. 

Session on Grasslands and Pastoralists at the InterAcademy Partnership (IAP) conference

The 2025 Triennial Conference and General Assembly ofthe InterAcademy Partnership (IAP) took place 8-11 December 2025 in Cairo, Egypt, hosted by the Academy of Scientific Research and Technology (ASRT). This is a very interesting and prestigious international conference with the aim to discuss how science can help advancing sound policies, improve public health, promote science excellence and achieve other critical development goals. It was our great honour that one of the sessions of this conference was dedicated to grasslands and pastoralists, and together with excellent colleagues we could show the beauty of these unique ecosystems and pastoral communities as their stewards. We had a very diverse and interesting session and panel discussions.

You can read the abstract and the program of the session below.

Pastoralism and Grasslands: Science and Policy for Regenerative Rangeland Management

Moderator: Thomas Elmqvist, Programme Director EASAC

Rapporteur: Georg Bërveniku-Brunner, Executive Director, EASAC secretariat

Speakers

Gregorio Velasco Gil, Coordinator of the Pastoralist Knowledge Hub, FAO: International Year of Rangelands and Pastoralists 2026

Orsolya Valkó, Scientific advisor, HUN-REN Centre for Ecological Research, Institute of Ecology and Botany, Hungary: Biodiversity conservation of European grasslands: challenges and opportunities

Batgelder Gantuya, Mongolian Academy of Sciences, Mongolia: Rangelands and pastoralists in Asia

Zsolt Molnár, Scientific advisor, HUN-REN Centre for Ecological Research, Institute of Ecology and Botany, Hungary: Transdisciplinary research and knowledge systems: who’s knowledge counts

Abstract

The UN General Assembly has declared 2026 the International Year of Rangelands and Pastoralists (IYRP) to increase worldwide understanding of the value of grasslands and pastoralism for food security, economy, environment and cultural heritage. Semi-natural grasslands are among the most species-rich ecosystems on Earth, offering a unique example of how long-term, low-intensity human activities can enhance biodiversity.

Their ecological value is closely tied to traditional management practices, such as grazing and mowing, which help maintain their open structure and biodiversity. Steppes and other drylands also harbour outstanding biodiversity that is shaped by the herders and the one billion people living in these ecosystems globally. Today, grasslands are rapidly disappearing in many regions of the world, due to climate change in combination with land use changes including abandonment that leads to secondary succession toward shrubs or forests, or, through intensification (use of fertilizers, frequent mowing, or sowing monocultures) causing biodiversity loss. This session will contribute to the aims of the IYRP and through taking a global view of grasslands and focussing on how to bring multiple knowledge systems together at the table to discuss what policy options and actions are available in different regions for reversing current trends.

Many thanks for EASAC, the European Academies Science Advisory Council for supporting my participation at the conference, for the organizers, and to everyone who made this possible.

How Can Small Grasslands Help Protect Biodiversity in Agricultural Landscapes?

We are very grateful for the support of the National Research, Development and Innovation Office (NKFIH) for supporting our project entitled “How Can Small Grasslands Help Protect Biodiversity in Agricultural Landscapes?” (PI: Balázs Deák), that provides an excellent possibility for studying the importance of small habitat islands (covered with pristine and recovering grasslands) in preserving grassland biodiversity and ecosystem services in intensively used landscapes.

While the primary role of agricultural landscapes is food production, they also hold significant biodiversity potential. Small, pristine grasslands and recovering grassland habitats embedded in agricultural parcels can help maintain populations of several grassland species, thus, they support ecosystem stability and agricultural sustainability. However, these habitats are increasingly threatened by weed and woody encroachment, and by isolation, leading to time-delayed species loss. We investigate the impacts of these processes on grassland biodiversity using ancient burial mounds (so called kurgans) involved into the system of agricultural subsidies (functioning as out-of-production sites). We study the effects of both local- and landscape-level factors such as soil characteristics, microclimate, habitat structure, and the surrounding landscape matrix.

Our main research questions include:

(i) How do weeds spread in recovering grasslands, and can diverse weed communities suppress harmful weeds hindering restoration and agricultural production?

(ii) What happens when woody species encroach grasslands, and how capable are these habitats of self-recovery when woody vegetation is removed?

(iii) How does the biodiversity in isolated grasslands change over time, and what actions can prevent further species loss?

Beyond advancing scientific knowledge, our findings help conservationists, farmers, and policymakers make informed decisions about biodiversity protection and sustainable land use. By understanding the underlying ecological processes, we can improve the design of agri-environmental schemes, support sustainable farming, and restore valuable habitats. This research aligns with EU conservation and restoration objectives and provides scientific evidence to support policies that balance food production with nature conservation. The four-year-long project starts on 1 Jan 2026, we are looking forward to this new and exciting challenge!

Fire in Central European Ecosystems - a very interesting conference

Last week, the first Central European fire ecology conference, entitled 'Fire in Central European Ecosystems', was held in Decin, Czech Republic. The conference presentations dealt with the consequences of forest and grassland fires, post-fire regeneration, and the nature conservation opportunities of prescribed burning. The event was prompted by a huge forest fire in Bohemian Switzerland National Park in July 2022, which burned down 1,200 hectares of land. Many presentations focused on post-fire regeneration and the responses of individual groups of organisms, and we were able to see the burned areas for ourselves during a field trip. It was a very interesting and informative conference with excellent presentations — it was great to see that more and more people are working on fire ecology in Central Europe as well!

We presented two presentations at the conference:

Deák, B., Süveges, K., Gőri, Sz., Kapocsi, I., Valkó, O. (2025): The legacy of wildfires: Grassland vegetation recovery in burned grasslands and differently managed firebreaks.

Valkó, O, Stoof, C, Akala, T, Arianoutsou, M, Arsava, K, Ascoli, D, Bengtsson, J, Castro, R, Engelbrecht, J, Fra Paleo, U, Granström, A, Ibisch, P, Kalabokidis, K, Kandárová, H, Marinšek, A, Knottnerus, A, Metallinou, M, Müller, M, Oliviera, T, Pereira, J, Plieninger, T, Palaiologou, P, Pulido Diaz, J, Saražin, J, Stoyanov, T, Thacker, FN, van der Werf, G, Zerefos, C., Elmqvist, T. (2025): Living with Fire: Policy Recommendations from the EASAC Report on Changing Wildfires in Europe. (keynote talk)

Many thanks to the organizers for the wonderful conference and excursion!

Birch trees grow higher than three metres in some of the areas burned in 2022.

Burned mushroom.

Life has found a way to thrive in the scorched area.

The weather was a bit rainy during the field program ...

The Conference was held at the beautiful Decin castle.

The way up to the castle.

View from the castle to the brewery.

The lecture room was also very nice.

Ancient mounds, modern refuges: Out-of-production sites on kurgans support rare weeds in agricultural landscapes

It is a sad but evident fact that the expansion of agricultural areas over the past centuries has led to an enormous loss of natural habitats worldwide. However, it is perhaps less well known that the unprecedented intensification of agriculture in the decades following the Second World War has also caused the disappearance of many weed species traditionally associated with extensively managed farmland. These rare weeds used to inhabit arable fields, oldfields, and pastures, but many have now become endangered.

Formerly widespread weed species have declined due to multiple factors: changes in landscape structure (due to land consolidation), altered tillage systems (for example, changes in the timing of ploughing), the increasing use of chemicals in agro-ecosystems, the disappearance of fallows and oldfields, and the abandonment or overgrazing of pastures. Importantly, rare weeds do not threaten crop yields. Instead, they contribute to agro-biodiversity and provide valuable ecosystem services. Their preservation is therefore important both for nature conservation and, indirectly, for agricultural production.

One promising refuge for rare weeds is kurgans – ancient burial mounds scattered across Central, Southeastern and Eastern Europe and beyond. When embedded in agricultural fields and covered with grasslands of various ages, these small, elevated sites often escape intensive management and host diverse vegetation.

In an intensive field survey covering approximately 21,500 km² in Eastern Hungary, we set out to identify which site- and landscape-specific factors (such as geographic position, habitat area, soil properties, vegetation age, and environmental heterogeneity) influence the occurrence and species richness of rare weeds. Altogether, we surveyed 216 kurgans: 24 covered with ancient grasslands and 192 with successional grasslands, ranging in age from one to 144 years. All were out-of-production sites surrounded by agricultural fields.

We recorded 38 weed species that have become rare in the region in recent decades, including 15 red-listed and two legally protected species. Rare weeds were present on more than half of the kurgans (50.9%), showing that even small, abandoned patches of land can provide important refuges for species once common in arable lands, oldfields, and pastures.

Several ecological factors shaped their occurrence. Environmental heterogeneity – linked to the topographic variation of kurgans – proved to be the strongest predictor of whether rare weeds were present at a site. And species richness of rare weeds was also considerably higher on mounds with larger environmental heterogeneity. Species richness was generally lower in northern sites, which reflects the Mediterranean origin of many rare arable weeds and their association with warmer climates in southern regions. High soil CaCO₃ content supported species-rich weed communities. While high soil phosphorus content suppressed them, likely by increasing the level of competition in nutrient rich environments. Sites with more diverse vegetation harboured more oldfield and grassland-related rare weeds, probably due to reduced competitive pressure typical of species rich grassland assemblages.

Interestingly, we also found that smaller kurgans hosted more rare weed species. At first glance, this seems paradoxical: for habitat specialists, larger areas usually support more species because they contain larger undisturbed core zones. In contrast, as rare weeds depend on a certain level of disturbance, the high edge-to-core ratio of small kurgans appears to provide precisely the slightly disturbed conditions they need. As was found in our previous study, the presence of burrowing mammals (such as red foxes) on kurgans can also support the existence of disturbance tolerant species that require open gaps for establishment.

In summary: our study shows that small, island-like out-of-production sites on kurgans can play an outsized role in maintaining rare weed populations in intensively managed agricultural landscapes. Preserving such landscape features – a form of land sparing – can therefore make a major contribution to conserving biodiversity in farmland.

The full study, published in Agriculture, Ecosystems & Environment, provides further insights into factors supporting the existence of rare weeds on kurgans holding pristine or secondary grasslands.

The citation of the paper:

Deák, B., Bede-Fazekas, Á., Süveges, K., Tölgyesi, Cs., Kelemen, A., Bede, Á., Borza, S., Godó, L., Valkó, O. (2025): Ancient mounds, modern refuges: Out-of-production sites on kurgans support rare weeds in agricultural landscapes. Agriculture, Ecosystems & Environment, 394: 109902.

The paper is open access and can be downloaded from here:

https://www.sciencedirect.com/science/article/pii/S0167880925004347

Kurgans holding small grassland patches provide hotspots for medicinal plant and associated phytochemical diversity in agricultural landscapes

Our recent study published in the Plants, People, Planet journal revealed that ancient burial mounds – also known as kurgans – play a crucial role in preserving medicinal plant species and their phytochemical diversity within European agricultural landscapes. These mounds, constructed thousands of years ago by steppe nomadic cultures, are widely distributed across the Eurasian steppe biome. While their original grassland vegetation has often been destroyed by agricultural activities, in many cases they remain intact – often due to their spiritual, historical, or cultural significance. These intact mounds are commonly covered by natural or semi-natural grasslands, forming isolated ecological refuges in otherwise intensively cultivated areas. In other cases – thanks to agri-environmental schemes supporting the cessation of arable farming on mounds – these sites are now covered by spontaneously recovering grassland vegetation. Based on our former field observations, we assumed that kurgans have the potential to serve as habitats for medicinal plant species. However, this specific ecosystem function has not been previously studied in any region.

We surveyed 166 kurgans in Hungary to assess their role in conserving medicinal plants and the phytochemical compounds they produce. We identified over 160 species of medicinal plants, many of which are rarely found in the surrounding agricultural matrix. Importantly, kurgans harbour not only plant species diversity but also a broad spectrum of secondary metabolites, which contribute to ecosystem resilience. In total, we recorded 33 secondary metabolite groups in the vegetation of the mounds, 23 of which were associated with grassland-related medicinal plants. These compounds enable plants to survive drought, herbivory, and intense solar radiation – factors that are becoming increasingly common due to climate change and intensive land use. We found that the presence and diversity of certain secondary metabolites were strongly linked to environmental conditions and biotic interactions, which followed clear gradients based on vegetation age and level of landscape transformation.

(a) Kurgan with a pristine grassland, (b) old field and (c) young fallow; The most frequent grassland-related medicinal plants on kurgans: (d) Achillea collina (102 mounds), (e) Podospermum canum (79 mounds), (f) Tragopogon dubius (66 mounds), (g) Galium verum (64 mounds), (h) Epilobium tetragonum (42 mounds) (photos by Balázs Deák a, b, c, d and Attila Lengyel e, f, g, h).

For example, mounds covered with older, recovering grasslands were characterized by a higher abundance of species producing iridoids and diterpenes. This is likely due to that, in later successional phases, the shading effect of tall-growing weedy species (that are suppressed by time) decreases, exposing medicinal plants to higher solar radiation, which in turn stimulates the production of these protective compounds. In kurgans surrounded by croplands, medicinal plants frequently produced a wide array of nitrogen-containing compounds, such as alkaloids, saponins, and plant steroids. These function as antifeedant chemicals and may deter crop-feeding pests like rodents – making these small grassland patches valuable not only for biodiversity conservation but also for pest management in adjacent farmlands.

Although plant collection is not permitted on protected kurgans, these sites offer valuable opportunities for conservation, ecological restoration, and environmental education. As natural seed banks, they may help restore medicinal plant populations in degraded landscapes. Our findings underscore the importance of integrating cultural heritage with biodiversity conservation. Once valued solely for their historical significance, kurgans now emerge as key elements of ecological infrastructure, helping to preserve “nature’s pharmacy” in modern agricultural regions.

The full study, published in Plants, People, Planet, provides further insights into the links between land use history, soil conditions, and medicinal plant diversity.

The citation of the paper:

Engel, R., Valkó, O, Lengyel, A., Bede, Á, Deák, B. (2025): Small grassland patches are hotspots for medicinal plants and associated phytochemical diversity in European agricultural landscapes. Plants People Planet DOI: 10.1002/ppp3.70074

The paper is open access and can be downloaded from here: https://nph.onlinelibrary.wiley.com/doi/10.1002/ppp3.70074

Kurgan "Bio-blitz" Day in the Hortobágy Nature Conservation Research Camp

We were very happy to visit the Hortobágy Nature Conservation Research Camp again this year after a very long time :) This wonderful camp was 51 years old this year, and many Hungarian ecologists and conservationists got to know the beauty and diversity of the lowland landscape for the first time here - including me more than 20 years ago :) This year we finally made it back to the camp, unfortunately only for one day - but it was still a great experience. The day was dedicated to kurgans, and in the morning Balázs Deák gave a comprehensive lecture on the natural and cultural heritage of the mounds, and then we visited the kurgans near Nádudvar. This year's drought (and the droughts of previous years) have left their mark on the vegetation, unfortunately most of the perennial grassland species have now also dried up, and the mass of the plumeless thistle (Carduus acanthoides) on the mounds has increased several times compared to our 2017 surveys.

On our way to the Tök-halom (Pumpkin-mound).

Thanks to the enthusiastic group, we could search every square meter of the mounds very effectively looking for plants :)

On the Pumpkin-mound, crop production was ceased in 2012 and spontaneous grassland recovery started thereafter. This year we found some specimens of the protected yellow starthistle (Centaurea solstitialis) which probably established spontaneously from the seed rain.

On our way to the Hegyes-halom (Pointy mound), another kurgan, where arable farming was abandoned.

The name "Pointy mound" is adequate, it is a spectacular landmark in the yellow sea of the large grassland.

Many thanks to the camp organizers, Sára Csiha and Csaba Tóth for their kind hospitality, and we hope to see you next time :)

European cities need ambitious nature restoration targets – our new comment paper published in npj Urban Sustainability

In a nice international team led by Valentin Klaus we have recently published a comment paper about the potential of the EU Nature Restoration Law in making our cities more resilient, biodiverse and liveable.

The paper is open access and can be downloaded from the journal homepage (please click here).

Klaus, V. H., Řehounková, K., Valkó, O., Degtjarenko, P., & Schelfhout, S. (2025). Countries need ambitious urban biodiversity targets under the EU Nature Restoration Law. npj Urban Sustainability, 5(1), 1-4. https://doi.org/10.1038/s42949-025-00218-8

The European Union’s Nature Restoration Law is a great opportunity and a much needed step in tackling climate change and protecting biodiversity in Europe. Cities make up over 20% of EU land, and restoring urban ecosystems is a great opportunity to make cities greener, healthier, and more sustainable. But right now, the law mostly measures how much green space a city has, not how good that space is for nature. In fact, cities with already high green space may not be required to do much more under the law.

Many city green spaces look nice, but they often lack the variety of native plant and animal species, and those natural features that support a healthy environment. Poor design and pollution can limit their benefits to people, i.e., the ecosystem services provided. This matters because urban nature is crucial – not just for wildlife, but for people’s health, well-being, and protection from heatwaves and floods.

Therefore, we believe that European cities need even more ambitious nature restoration targets. Urban green spaces must be ecologically rich and diverse, not just large or leafy. That means planting native species, protecting rare habitats, avoiding too much mowing or paving, and adding features like dead wood or ponds to support insects and birds.

Biodiverse and aestethically appealing tallgrass meadow in an urban park in Gödöllő, Hungary.

To help make this happen, we propose nine key actions:

• Make biodiversity a key part of urban planning – treat nature as essential, not decorative.
• Set bold targets for restoring native species and ecosystem health.
• Include urban biodiversity in national restoration plans with strong monitoring and long-term goals.
• Show cities as leaders in nature restoration and teach the public about its benefits.
• Give cities expert support and real-life examples to follow.
• Protect rare urban habitats – don’t let infrastructural development or tree planting destroy open areas that are already rich in wildlife.
• Train city staff in ecology, not just landscape design.
• Ensure social fairness – restoration must benefit all residents, not push out poorer communities.
• Measure the current state of urban biodiversity and act quickly to protect what's left.

Cities have a unique chance to help solve the biodiversity crisis. Unlike farmland or forests, city spaces don’t usually compete with agriculture or timber production. Restoring nature in cities can bring big rewards – from better mental health to cleaner air and even economic benefits like tourism and reduced healthcare costs.

In our comment paper, we call on EU countries to use the momentum of the new law to do more – not just create green-looking spaces, but to restore truly biodiverse and resilient urban ecosystems. That’s how we can make our cities better for nature and people.

Good practices in public greenspaces can inspire people to introduce nature into their gardens.

New EASAC report on Changing Wildfires is published

 Over the last two years we have been working on a very interesting and topical issue in an international research group, resulting in the publication of the latest study by the European Academies Science Advisory Council (EASAC) entitled Changing Wildfires: Policy Options for a Fire-literate and Fire-adapted Europe. A total of 22 international researchers participated in the project, with Thomas Elmqvist as project manager and Orsolya Valkó and Cathelijne Stoof as working group leaders.

Our study warns that vegetation fires have also reached a new level in Europe. Climate change, land-use change and social factors are combining to create conditions that are making vegetation fires more frequent and destructive. In addition, the risk is increasing in regions, including central Europe, where it was not particularly prevalent before.

The full report is freely availanble at EASAC's homepage (please click here). 

The EASAC press release can be read here.

The launch of our  report took place in Brussels in 19 May 2025, with scientists from all over Europe, discussing their findings with EU policymakers and stakeholders across Europe. The event was webstreamed and the presentations and panel discussions can be watched here.

The EASAC infographic summarizing some of the key messages of our report.

New review paper on the soil seed banks of drylands

Our latest article a review of the soil seed bank of drylans, has been published with the first authorship of Abdubakir Kushbokov.

Kushbokov, A., Deák, B., Valkó, O. (2025): Characteristics of soil seed bank in global drylands – A review. Arid Land Research and Management 39: https://doi.org/10.1080/15324982.2025.2467728 

The pdf of the article is available from the authors (please click here).

Drylands cover a large part of the Earth and are unique in terms of their biodiversity and the ecosystem services they provide. Understanding the characteristics and restoration potential of the soil seed bank is key to maintaining and restoring ecosystem biodiversity. In our review article, we looked at the characteristics of the soil seed bank in global drylands and analysed the key factors influencing seed bank density and composition, including soil and climatic characteristics, woody vegetation, topography, and grazing. In our article, we have shown that soil seedbank can contribute to some extent to the restoration of degraded dry habitats, but in many regions and in highly degraded and overgrazed environments, the restoration potential of seedbank is limited.

Map showing the locations of the reviewed studies and the studied treatments.

Please see the abstract of the paper below.

Abstract

Drylands, covering 45.4% of the global land area, are vital ecosystems that support 38% of the world’s population and approximately 35% of global biodiversity. However, they face increasing threats from desertification, land degradation, and unsustainable management practices. Soil seed banks (SSBs) play a critical role in vegetation recovery, resilience, and biodiversity conservation in drylands. This review synthesizes evidence from 58 studies to evaluate the effects of grazing, topography, and woody plants on SSB dynamics and restoration potential. Grazing impacts on SSBs are highly variable, ranging from depletion under heavy grazing to enhanced seed density and diversity under moderate grazing or intermediate-term exclusion. Topographical features, such as dune tops and leeward slopes, and shrubs significantly influence SSB density and diversity by creating seed-rich microsites. While passive restoration using SSBs shows promise, especially in sandy grasslands, it is often slower than active interventions and limited by insufficient seed resources in severely degraded areas. The findings highlight the need for tailored grazing management and integrated restoration strategies to optimize the restoration potential of SSBs. Future research should address knowledge gaps related to underrepresented regions, deeper soil layers, long-term processes, and the combined effects of multiple drivers to enhance dryland ecosystem resilience and functionality.

A picture from our study site in the Kyzyl-Kum drylands, where we started investigating soil seed bank composition.

Effects of laundry washing on the germination of cloth-dispersed seeds: our new paper in Journal of Environmental Management

Our new paper by Katalin Lukács et al. has recently been published in Journal of Environmental Management.

The citation of the paper is:

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. https://doi.org/10.1016/j.jenvman.2025.124345

It is an open access paper that can be freely downloaded from the journal's homepage (please click here).

In this study, we investigated a simple, everyday process - laundry washing. This seems a bit odd, why ecologists study this process - but our study revealed that indeed, it can have very interesting effects on the dispersal of plant species :)

What is the importance of our clothing in the dispersal of plant species? Unintentional human-vectored dispersal (HVD) is a special form of epizoochory, in which the seed dispersal vectors are humans, with seeds attaching to clothing or footwear during various outdoor activities. Due to the increasing human mobility, large quantities of seeds can be spread over long distances on a daily basis. It is important to emphasize, that, to date, mostly weeds and invasive species have been documented as capable of spreading on clothing. Despite HVD is part of everyday life, most people remain unaware of this phenomenon. In many cases, people do not pay attention to clean their clothes from seeds or may not even notice their presence. Unnoticed seeds on clothes can end up in washing machines regularly.

We designed a large experiment to study the effect of laundry washing on the germination potential of cloth-dispersed seeds, with particular attention to the effects of detergents and washing intensity. Since in our earlier study (Valkó et al. 2020 NeoBiota) we did not find a significant effect of detergent type, we sought to investigate this topic further to identify whether a specific detergent could significantly reduce the germination potential of cloth-dispersed seeds. To this end, we selected detergents based on their chemical composition, to represent the main types of detergents used in households (ranging from natural detergents to synthetic ones with varying concentrations of surfactants, enzymes, and soap). We aimed to cover the full spectrum of the detergent types and washing intensities most commonly used in households, and we had in total 21 treatment combinations.

The main idea of our experiment and the design of the treatments.

The findings show that most seeds remain viable after typical household washing, even at common temperatures and wide range of detergent types, highlighting a largely overlooked vector of plant dispersal. These results provided critical insights into the unintentional spread of plant species through human-vectored dispersal via clothing, a pathway that has received limited attention so far. Since most of the plants that are capable of cloth-dispersal are weeds and invasive species, the results have important implications for management. We 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 behavioral changes and public awareness to reduce the environmental impact of human-vectored dispersal. According to our questionnaire survey, raising awareness is especially important for nature conservation professionals who are among the most important potential vectors.

Abstract

Unintentional human-vectored seed dispersal (HVD) occurs when the seed dispersal vectors are humans, and the seeds are attached to clothing or footwear during various outdoor activities. Since most plant species spread by HVD are invasives or weeds, the process can have globally relevant adverse environmental effects due to the growing global tourism industry. Here we evaluated whether the germination capacity of seeds can be reduced by laundry washing treatments used in households, in order to decrease the chance of unintended dispersal of plant species by clothing. We experimentally tested the effects of seven types of detergents with different chemical composition and three washing intensities in a full factorial design on the germination capacity of 18 plant species. Washing at high intensity (60 0C) significantly decreased the germination capacity in 15 species, probably due to high temperatures and longer exposure times. Washing at low (30 0C) and medium intensities (40 0C) had no effect. Detergent type affected the germination capacity of only three species. The findings underscore the importance of laundry washing in seed dispersal, since the low and medium washing intensities and detergent types that are commonly used in households do not decrease the germination capacity of the cloth-dispersed seeds. We urge addressing the spread of HVD-dispersed seeds through combined biosecurity measures. Self-regulation, such as removing of seeds from clothes and disposing them properly, is crucial. Informing outdoor workers, who play the largest role in HVD, can encourage small behavioural changes to decrease the adverse effects of this process.

The graphical summary of the study in the graphical abstract.

Homage to kurgans - A conference celebrating the past 30 years of kurgan research and protection in Hungary

A very inspiring and successful conference entitled "Protecting the kurgans '30" was organised by the Government Office of Békés County, the Hungarian University of Agriculture and Life Sciences and the Körös-Maros National Park Directorate in Békéscsaba on 21 November 2024. The occasion of the event was that 30 years ago, in the same place, a professional conference on the protection of the kurgans was held, which drew the attention of nature conservation to these special landmarks. The 1994 event was a milestone in the conservation of the mounds, so the organisers of the conference, in celebrating this fine anniversary, have created an opportunity to look back in 2024 on the achievements, successes and experiences of the past 30 years of kurgan research and protection in Hungary. Kurgans are ancient millennia-old burial mounds characteristic of the Eurasian steppe and forest steppe zone, that have outstanding historical, cultural, and nature conservational importance. For more information on these special landmarks, please read our earlier blog posts (e.g. here, here, and here) and scientific publications.

News about the conference in 1994 on the pages of Békés County Days (Békés Megyei Nap) magazine.

It was so nice to hear the thoughts and the presentations of the speakers. It was good to see and hear that the conservation of kurgans is on the right track in Hungary, and that the natural condition of the mounds has generally improved in recent decades, thanks to the joined efforts of conservationists, government, farmers, and researchers. The contributions and presentations highlighted the most important achievements and experiences of 30 years of kurgan conservation and research in Hungary. It was a great honour for us that our research group was represented at the conference with two presentations:

Ádám Bede: The main results of the landscape archaeological survey of the kurgans in the Maros-Körös river basin

Balázs Deák, Orsolya Valkó: Natural values of mounds in agricultural landscapes

In addition to the lectures, visitors were also able to view Ádám Bede's exhibition about kurgans.

Ádám Bede talking about the landscape archaeological importance of kurgans.

Balázs Deák talking about the importance of kurgans in nature conservation.

Many thanks to the Organizers, especially Dr. Attila Rákóczi, Director General of the Békés County Government Office for making this inspiring event possible! We hope that there will be many more such events in the future, where professionals who love and know the Hungarian kurgans can meet and present the values of the mounds and the importance of their protection to the public. It is very important that as many people as possible learn about the historical heritage and the conservation importance of these millennia-old mounds, because as Dr. András Rácz, State Secretary emphasized at the conference, "No one will protect what he is not interested in, and no one will be interested in what he has never experienced." (David Attenborough) 

The iconic Gödény-halom (Pelican-mound) near Békésszentandrás: the largest kurgan in Hungary.

The press release about the conference can be read here (in Hungarian).