Month: May 2023

News

Katalin Mázsa

The resilience of aquatic ecosystems to heatwaves and their ability to recover from changes caused by temperature-induced stress

Researchers from the Institute of Aquatic Ecology of the ELKH Centre for Ecological Research (CER) led by Csaba Vad, conducted a study in an international collaboration to explore the resilience of aquatic ecosystems to the negative impacts of heatwaves. They also investigated whether dispersal from surrounding habitats, i.e., the arrival of other species, could accelerate ecosystem recovery. During their experiment on plankton communities in mesocosms, the researchers found that the heatwave drastically reduced the biomass of plankton due to the negative impact on primary consumer zooplankton, such as water fleas. Dispersal from surrounding habitats had limited effect in this study, somewhat positively influencing only the growth of phytoplankton. As a result of the heatwave, both the composition and trophic structure of the communities changed, which could have long-term implications for ecosystem functioning. The study presenting the results was published in one of the leading international ecological journals, Global Change Biology.

The increasingly frequent and intense heatwaves associated with global climate change pose a significant threat to biodiversity, ecosystem functioning, and the ecosystem services provided to humans. Consequently, it becomes crucial to understand the mechanisms that affect the resilience of communities in the face of extreme temperature events, including their resistance to temperature stress and their subsequent recovery. This knowledge is essential for improved prediction and mitigation of biodiversity loss and its far-reaching implications. Moreover, it enables the application of effective strategies to adapt to climate change.

In a research led by Csaba Vad, researcher at the Institute of Aquatic Ecology of CER, an international research group investigated whether connectivity through dispersal facilitates ecosystem adaptation to heatwave-induced stress (“spatial insurance hypothesis”). The study, conducted over a period of one and a half months, took place in artificial lakes known as mesocosms. In these experimental systems, the processes occurring in natural ecosystems can be modeled much more realistically compared to laboratory conditions. Moreover, they allow for the isolated examination of individual stressors and underlying mechanisms, which would not be feasible in natural habitats due to their complexity.

The Austrian WasserCluster Lunz research institute’s mesocosm system,
where the experiment was conducted

According to the results, the heatwave led to a decrease in plankton biomass, primarily due to its negative impact on zooplankton, such as water fleas. In the case of a natural lake, for example, this could lead to temporary reduction in food sources available for fish or even the development of algae blooms, as these small microscopic organisms play an important role in regulating algae levels. The effect of dispersal from surrounding habitats in this experiment was relatively minor, and it was only evident in the faster post-heatwave growth of phytoplankton. The results showed that the community biomass returned to the undisturbed level regardless of dispersal. However, the composition and trophic structure of the community changed, which could potentially result in long-term alterations in ecosystem functioning.

Based on the experiment, it can be concluded that even a short heatwave of about one week can alter the species composition and interactions within aquatic ecosystems, potentially leading to long-term consequences. These effects can be further aggravated by the fragmentation of ecosystems resulting from habitat loss, increasing spatial isolation of remaining habitats and reducing the dispersal of organisms. Ecologists urge for further long-term research to understand the impacts of heatwaves and develop possible adaptation strategies.

The research was carried out within the framework of the H2020 AQUACOSM project, with the support of H2020 AQUACOSM-plus and the National Multidisciplinary Laboratory for Climate Change.

Photos: Zsófia Horváth

Publication: 

Vad Cs. F., Hanny-Endrédi A., Kratina P., Abonyi A., Mironova E., Murray D. S., Samchyshyna L., Tsakalakis I., Smeti E., Spatharis S., Tan H., Preiler C., Petrusek A., Bengtsson M. M. & Ptacnik R. (2023). Spatial insurance against a heatwave differs between trophic levels in experimental aquatic communities. Global Change Biology 29: 3054–3071. (IF2021: 13.211 | SCimago2022: D1)

News

Katalin Mázsa

The Invasion Biology Division of the National Health Security Laboratory has been established with the leadership of CER as the new center for domestic research on biological invasion

The Invasion Biology Division of the National Health Security Laboratory (NHSL) has recently been established with the leadership of the ELKH Centre for Ecological Research (CER). The primary mission of the participating experts is to assess the level of threat posed by invasive species in Hungary, develop a comprehensive ecological framework to address the issue, and provide practical recommendations to decision-makers based on scientific findings, in order to support the development of effective invasion defense strategies. Additional consortium members of the project include the University of Pécs (UP), the ELKH Centre for Agricultural Research (ATK), the Hungarian University of Agriculture and Life Sciences (MATE), the University of Veterinary Medicine Budapest (UNIVET), and the ELKH Veterinary Medical Research Institute (ÁTKI).

The plant and animal life on Earth has evolved over millions of years. Populations were separated by oceans, mountain ranges, seas, and rivers, allowing each continent and their various geographic units to develop their unique biodiversity characteristics specific to that particular area. Throughout its history, humanity, especially during the age of great geographical discoveries, has intentionally or accidentally introduced and transported plant and animal species to areas where they were not originally native. In recent decades, globalization has led to a significant increase in the intentional introduction of non-native species for economic purposes, as well as the accidental introduction through transportation, travel, or tourism. Some of these species, once escaping human control, start spreading in their new habitats, causing harm to native flora and fauna. The introduction of new species leads to rearrangements in the ecological relationships among members of the original communities, resulting in damage to the composition and functioning of natural ecosystems, and the decline or extinction of numerous native species.

Articles on topics such as the naturalization of introduced plants began to appear as early as the 19th century. However, by the 20th and 21st centuries, the issue had reached such a magnitude that a new field of study, invasion biology or invasion ecology, emerged to address these questions.

Today, terrestrial ecosystems face a dual crisis of climate change and rapid biodiversity loss. One of the main causes of biodiversity loss, alongside systematic habitat destruction and fragmentation, is the spread of invasive species. The typical case of invasion phenomena occurs when a plant or animal species introduced for economic or aesthetic reasons, escapes from its breeding or cultivation area and becomes an “invasive species”, overwhelms the previously diverse native ecosystem. Examples of this include the planting of common milkweed (Asclepias syriaca) or giant goldenrod (Solidago gigantea) as bee pastures, which have caused severe degradation and destruction of our protected and natural grassland areas by today.

However, the range of invasion phenomena is much broader than that. Nowadays, we are familiar with numerous examples where introduced or spontaneously established species act as vectors, carrying new pathogens that can cause previously nonexistent diseases in the given area and potentially lead to epidemics. In recent years, for instance, several invasive mosquito and tick species have appeared in Europe, capable of transmitting various pathogens, including viruses and nematodes, that pose risks to both humans and domestic animals, causing a range of human diseases and conditions, as well as for example heartworm in dogs. The agricultural sector faces a new challenge with the impact of invasive plants on pollinator communities or the appearance and damage caused by invasive sucking pests, mites, and bugs, for example in vineyards and orchards, significantly reducing the efficiency of agricultural production.

Biological invasion is therefore a complex issue that not only directly affects biodiversity loss, but also has a direct impact on various segments of the economy and society, the decline of natural habitats, the reduction and disappearance of native species, the efficiency of agricultural and forestry practices, and ultimately, human health. It leads to the loss of natural and healthy environments and directly contributes to the emergence of new pathogens or allergens.

The severity of the impacts occurring on multiple levels is indicated by the fact that the European Union spends over 12 billion euros annually on combating invasive species and mitigating the damages caused by them, and this amount continues to increase year after year. According to the latest global assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the number of invasive species per country has increased by 70 percent since 1970, and over one-third of the currently recorded invasive species have appeared for the first time in a biogeographic region outside their native range in the past four decades. Globally, Europe and North America have the highest number of invasive species, and Hungary is also considered an invasion hotspot. Hundreds of new species have emerged in the past century in the country, many of which have caused significant ecological changes.

The phenomena related to biological invasion are intensively studied by representatives of various disciplines, including ecologists, virologists, plant protection experts and medical professionals. However, there are still numerous unanswered questions in each subfield. Currently, it is not yet possible to predict invasive processes in the same way as, for example, different climate scenarios show the expected outcomes under varying conditions.

As part of the Széchenyi Plan Plus program, the Invasion Biology Division of the National Health Security Laboratory has recently been established with the support of project RRF-2.3.1-21-2022-00006. The Invasion Biology Division, operated by a consortium led by CER and comprising PTE, ATK, MATE, UNIVET, and ÁTKI, aims to assess and address the actual threat posed by invasive species by developing a unified ecological framework and providing effective practical solutions based on scientific findings.

During the research, experts map and document the appearance and spread of – what based on their societal impact are considered – key invasive species in Hungary, including invasive plants, mosquitoes, plant pests, and wildlife. Understanding the process and driving forces of invasion is crucial for comprehending the effects, predicting invasions, and developing defense strategies. The properties determining the spread success of invasive species, including the contribution of human mobility to their spread, are investigated integratively in experimental systems. The impacts of invasive species on native species, ecosystem functioning, and ecosystem services are also studied. To understand the social and economic consequences of invasion, participating experts collaborate with relevant stakeholders to examine the effects on agriculture, forestry, game management, as well as plant, animal, and human health. A key objective of the project is to develop new technologies based on research findings, using predictive models, artificial intelligence, and molecular methods, to identify and forecast critical invasive events. The development and testing of new methods for invasive species control are also part of the plan.

The members of the Invasion Biology Division of NHSL consider providing continuous comprehensive information on the scope of invasion and the actual level of risks to the wider public, as well as formulating recommendations for decision-makers to develop invasion defense strategies, as their key task.

News

Katalin Mázsa

Researchers do not recommend planting blanketflower in gardens due to its invasive potential

The researchers of the ELKH Centre for Ecological Research (CER) investigated the spread of the non-native great blanketflower in Hungary within the framework of the National Laboratory for Health Security project. The aim of the research was to evaluate the impact of the species on the local plant community and determine its invasive potential through its functional traits. Based on the results, the great blanketflower does not currently appear to be a strong ecosystem-transforming species, but there is a risk that due to climate change, the local environment in Hungary will become more suitable for it in the future, leading to strong speading and becoming invasive. Therefore, the researchers do not recommend planting blanketflower species in gardens. They also suggest surveying non-native ornamental plant populations, conducting long-term monitoring and a more detailed assessment of the traits that influence their spread. The publication presenting the results was published in the scientific journal NeoBiota.

Ornamental plants are one of the main sources of species becoming invasive. During their planting, they are introduced to new habitats where humans create favourable living conditions through irrigation and maintenance. Later, in natural habitats, they can easily occupy open niches created by human disturbances and the warming effects of climate change. The blanketflower has followed this path as well, and its ecological impacts were studied by researchers of CER along with several other new, potentially dangerous species within the recently initiated National Laboratory for Health Security project.

The great blanketflower and its relative, the Indian blanket, along with their hybrid, are globally planted ornamental plant species. Reports have already been made in several countries about the great blanketflower escaping from gardens and naturalizing in various new habitats, but its invasive behavior has been relatively unknown until now. However, it seems that in the past few decades, this species has found suitable habitats in Hungary and from a naturalized species it has become invasive in several locations. “Our aim was to map the distribution of the great blanketflower in Hungary, evaluate its impact on the local plant community, and determine the species’ invasive potential through its functional traits,” summarized Gabriella Süle, Phd, a assistant research fellow at CER.

Based on the distribution data collected here, the great blanketflower occurs in Hungary mainly as casual escapes yet. This species, which blooms profusely throughout the year and is extremely colorful, requires little to no care. Therefore, owners allow it to spread, and we can often see it occupying more and more space in front of gardens. However, it became naturalized in recent years, and invasive populations have also been found in significant numbers within the country. The species is mainly observed near gardens and disturbed habitats, but it has also appeared in natural and semi-natural grasslands. It successfully spreads in disturbed, species-poor, sandy, open habitats. Its spread affects the composition of the local plant community, reducing, for example, the species richness of local plants. Based on its functional traits, its well germination capacity, extremely long flowering period, the large absorbing and adhering surface provided by its roots, and its spread by grazing animals’ fur, mainly sheep, can promote its invasive spread. Currently, the great blanketflower does not appear to be a strong ecosystem-transforming species, but more attention needs to be paid to it because there is a risk that the local environment in Hungary will become increasingly suitable for it due to drier weather caused by climate change, leading to strong spread and becoming invasive, primarily in sandy soils.

“Due to all of these, we do not recommend planting blanketflower species in gardens, as they can easily escape and establish in natural plant communities. Furthermore, we suggest considering banning their distribution in seed mixes. To control invasive populations in natural habitats, there is a need to develop an effective eradication method” emphasized Gabriella Süle, Phd.
Assessing the great blanketflower and similar non-native ornamental plant populations, conducting long-term monitoring, and performing a more detailed evaluation of the traits influencing their spread would be important in order to prevent the escape of species planted in gardens into the natural habitats on time.

Assessing and managing the ecological, economic, and societal threats posed by invasive species similar to the great blanketflower is one of the focuses of the Division of Invasion Biology within the National Laboratory for Health Security project. The research is being carried out within the framework of the Széchenyi Plan Plus program with the support of the RRF-2.3.1-21-2022-00006 project.

Publication:
Süle G, Miholcsa Z, Molnár C, Kovács-Hostyánszki A, Fenesi A, Bauer N, Szigeti V (2023) Escape from the garden: spreading, effects and traits of a new risky invasive ornamental plant (Gaillardia aristata Pursh). NeoBiota 83: 43-69. https://doi.org/10.3897/neobiota.83.97325

Related link(s):

elkh.org

News

Katalin Mázsa

Researchers have revealed the multi-level effects of invasion on plant-pollinator communities

Researchers from the ELKH Centre for Ecological Research (CER) and Babeș-Bolyai University (BBE) in three recent papers have described the effects of twelve invasive plant species with different traits on vegetation (Fenesi et al. 2023), pollinator communities (Kovács-Hostyánszki et al. 2022), and the traits of pollinating insects (Szigeti et al. 2023). During their field studies they assessed and compared the plant and pollinator communities of invaded and semi-natural habitats in Hungary and Romania. In order to facilitate proper comparisons and conduct detailed exploration, the researchers employed uniform field methods while utilizing diverse ecological indicators, ranging from the height of indigenous vegetation, honeybee abundances, depth of flowers to tongue length of pollinator insects.

Bees and other pollinator species play an extremely important role in most terrestrial ecosystems, including agriculture. Increasingly, studies report the drastic decline of pollinating insects, one reason being the reduced availability of their food resources. The strong spread of invasive species is one of the five most important causes of biodiversity loss, that is why the Invasion Biology Division was established under the leadership of the Ecological Research Center within the National Laboratory for Health Security, where researchers investigate the complex effects of invasion. Where invasive plant species appear and are able to spread, they inundate and dominate the given area, reducing diversity and making habitats more homogeneous. In many cases, they also reduce the range of available flowers, thus helping some compatible pollinator species while displacing the food resources of others from the landscape. In general, it can be stated that the impacts of invasive plant species on native vegetation and pollinator insects are often varied and dependent on their specific traits.

Based on the research results, there is no universal effect of plant invasion, except for a few general patterns there are differences among invasive plant species in almost every ecological indicator studied. Perhaps the most important message is that as many invasive plant species and traits as there are, there can be a variety of effects on invaded plant-pollinator communities. The three publications highlight that the cover of invasive plant species strongly influences the composition, diversity, and height of the remaining native vegetation, among other factors. As the invasive plant species displaces native plants in a given area, fewer of the original or potential communities remain. Perennial invasive plant species have an even stronger negative impact on flower availability and pollinators than annual species. This is likely due to their stronger invasive capacity, dominance, different growth and flowering strategies, and presence in later successional stages of habitats. Timing is extremely important in plant-pollinator systems. Invaded areas are similar to crop fields such as rapeseed or sunflowers: during their blooming period, they provide significant amounts of food for the pollinating insects, while beyond of their flowering period, these areas are extremely poor in resources of pollinators. Where invasive plant species appear, they eventually become dominant. They cover the area with green vegetation mass for most of the year, but only bloom for a short period of time. As indicated by the studies, natural areas have more and more diverse resources along the year. The researchers also found important and interesting relations when comparing the traits of invasive flowers and the traits of wild bees. For example, the sites invaded by two invasive species with deep flowers had more long-tongued and also larger-bodied bees, while a species with shallow flowers had more smaller-bodied bees. This indicates a strong size determination between flowers and their pollinators, meaning that the invasion of a particular trait (such as deep flowers in invasive plants) affects the functional characteristics of the remaining pollinator community in the invaded area (i.e., only long-tongued pollinators that can feed on deep flowers will remain).

Proper nature conservation management of (semi)natural habitats and effective control of invasive plant species are important for the protection of pollinators, but some invasive plants can also provide valuable foraging resources for pollinator insects. Therefore, instead of uniformly eradicating all invasive species, it is recommended to consider the best approach on a case-by-case and location-specific basis, taking also into account the needs of protected pollinator insects. For example, efforts to combat plant invasion could incorporate the nutritional requirements of pollinators. Some of the costs associated with invasive plant eradication could be redirected towards providing alternative nutrition sources, such as sowing native seed mixes in or in the neighborhood of invaded areas. Overall, the factors and impacts important in the plant-pollinator systems are complex and interrelated, hence further detailed studies are needed to uncover the specific relationships between species and to develop effective conservation solutions.

Publications:

Fenesi, A., Botta-Dukát, Z., Miholcsa, Zs., Szigeti, V., Molnár, Cs., Sándor, D., Szabó, A., Kuhn, T., Kovács-Hostyánszki, A. (2023). No consistencies in abundance-impact relationships across herbaceous invasive species and ecological impact metrics. Journal of Ecology. DOI: 10.1111/1365-2745.14085

Kovács-Hostyánszki, A., Szigeti, V., Miholcsa, Zs., Sándor, D., Soltész, Z., Török, E., Fenesi, A. (2022). Threats and benefits of invasive alien plant species on pollinators. Basic and Applied Ecology, 64:89–102. DOI: 10.1016/j.baae.2022.07.003

Szigeti, V., Fenesi, A., Botta-Dukát, Z., Kuhlmann, M., Potts, S. G., Roberts, S., Soltész, Z., Török, E., Kovács-Hostyánszki, A. (2023). Trait-based effects of plant invasion on floral resources, hoverflies and bees. Insect Conservation and Diversity. DOI: 10.1111/icad.12640

Related link(s):

elkh.org

Other publications on this topic:

News

Katalin Mázsa

Invasion Biology website launched

The website of the Division of Invasion Biology, part of the National Laboratory for Health Security, has been launched at https://invaziobiologia.hu/.

The main mission of the Division is to investigate the ecological causes and consequences of the establishment and spread of invasive species through a unified concept, which requires a systemic and cross-disciplinary investigation of the processes at the system level and in distant specialist areas. In total, 16 research groups from six institutions are involved in this work, and one of the main aims of the website is to present the groups and the research topics they investigate, as well as to provide regular updates on the latest scientific publications and professional events published within the Division of Invasion Biology. We consider it important to make our latest scientific results in the field of invasion biology easily accessible in one place and in a suitable format for both professional and civil audiences, thus ensuring their further exploitation.