Invasive plant species pose a major threat to biodiversity and ecosystem health worldwide. However, predicting the exact impact of these invasions is challenging due to the complexity of interactions between invading species, native communities, and impacted ecosystems.
Outlined in a study published in the open-access journal NeoBiota, the framework combines new technologies and techniques to learn and predict how invasive plants alter ecosystems over time and in different environments.
Animated model visualisation of spatial-temporal dynamics of invader impacts. Click here to download a detailed explanation of the model.
The new framework integrates several modern advancements:
Environmental mapping: Progress in remote sensing and ecological monitoring allow researchers to capture detailed information about the environmental conditions of invaded areas. Drones, satellites, and advanced sensory networks can be used to create detailed ecosystem maps, which show how invasive species interact with their environment.
Functional tracers: These are specific indicators that reflect changes in ecosystem functions caused by invasive species. For example, researchers can track the impact of nitrogen-fixing invasive plants on ecosystems using nitrogen isotopes.
Spatio-temporal modelling: By combining environmental data with new modelling techniques, such as AI, researchers can create detailed models showing the spread and impact of invasive species on ecosystems over time. Such models can predict how changes in environmental conditions, such as climate change, might influence an invasive species’ success.
Mechanisms determining plant invasion impact.
Beyond scientific analysis, novel technologies also facilitate communication of ecological impacts, as the authors demonstrate in an animated 3D-video visualisation.
“The framework we’ve introduced offers researchers deeper insights into how invasive plant species interact with their environments, enabling more targeted management to lessen their ecological impact. We advocate for stronger collaboration between ecologists and technical experts to refine and expand these methods.
“Going forward, further research and integration of the wide range of recent methods and tools are needed to enhance the framework’s effectiveness.”
The research team behind the new framework: Christiane Werner, Christine Hellmann and André Große-Stoltenberg.
Original source
Werner C, Hellmann C, Große-Stoltenberg A (2024) An integrative framework to assess the spatio-temporal impact of plant invasion on ecosystem functioning. NeoBiota 94: 225-242. https://doi.org/10.3897/neobiota.94.126714
As climate change continues its relentless march, the world faces not only rising temperatures and extreme weather, but also an insidious threat to our homes: invasive termites. And the bill could be steep – invasive termites currently cost over 40 billion USD annually.
In a new study published in the open-access journal Neobiota, PhD student Edouard Duquesne and Professor Denis Fournier from the Evolutionary Biology & Ecology lab (Université libre de Bruxelles) unveil the unsettling reality of invasive termites’ potential expansion into new territories.
Their research reveals that as temperatures rise and climate patterns shift, cities worldwide, from tropical hotspots like Miami, Sao Paulo, Lagos, Jakarta or Darwin to temperate metropolises like Paris, Brussels, London, New York or Tokyo, could soon find themselves under siege by these tiny yet destructive pests.
But how do termites, typically associated with tropical climates, find their way into cities far beyond their natural habitat? The answer lies in the interconnectedness of our modern world. Urbanisation, with its dense populations and bustling trade networks, provides the perfect breeding ground for termite invasions.
Moreover, the global movement of goods, including wooden furniture transported by private vessels, offers unsuspecting pathways for these silent invaders to hitch a ride into our homes.
“A solitary termite colony, nestled within a small piece of wood, could clandestinely voyage from the West Indies to your Cannes apartment. It might lurk within furniture aboard a yacht moored at the Cannes Film Festival marina.”
“Mating is coming. Termite queens and kings, attracted by lights, may initiate reproduction, laying the groundwork for new colonies to conquer dry land.”
Researchers Edouard Duquesne and Denis Fournier.
Duquesne and Fournier’s research emphasises the need for a paradigm shift in how we approach invasive species modelling. By integrating connectivity variables like trade, transport, and population density, their study highlights the importance of understanding the intricate interactions that facilitate termite spread.
In light of these findings, the researchers urge swift action from policymakers and citizens alike. Major cities, regardless of their climate zone, must implement strict termite control measures to protect homes and infrastructure.
“Citizens can play a crucial role by leveraging technology, such as AI-assisted apps like iNaturalist, to detect and report potential termite sightings, turning ordinary residents into vigilant guardians of their environment,” say the researchers.
“As we confront the challenges of a rapidly changing climate, awareness and proactive measures are our best defence against the creeping menace of invasive termites,” they conclude.
Original source
Duquesne E, Fournier D (2024) Connectivity and climate change drive the global distribution of highly invasive termites. NeoBiota 92: 281-314. https://doi.org/10.3897/neobiota.92.115411
Invasive species spread through human activities are one of the main causes of the ongoing biodiversity crisis.
Even on South Georgia, a remote island located in the very south of the Atlantic Ocean, exotic species are present. Many of which were inadvertently introduced by whalers and sealers in the 19th and early 20th century.
The invasive carabid ground beetle, Merizodus soledadinus, is present on sites that have been recently exposed by melting glaciers.
In a new study published in the open-access journal Neobiota and funded by Darwin Plus, researchers explored how living organisms colonise new ground provided by melting glaciers.
Like other cold regions of the world, South Georgia is losing its glaciers because of climate change, leaving behind large areas of newly uncovered bare ground.
Invasive annual meadow grass colonising ground only a few years after the glacier disappeared.
Researchers surveyed the foreland biodiversity of six glaciers, creating an inventory of the flora and fauna that colonise forelands at different stages of glacial retreat.
A survey site near a former whaling station (Grytviken).
They found that, just a few years after bare ground is exposed by a glacier melting, pioneer plants arrive, progressively covering more ground with time, followed by an increasing number of species.
Rocky terrain by Glacier Col.
Native and exotic plants, as well as invertebrates, take advantage of this opportunity. Surprisingly, two temperate plant species from the Northern Hemisphere, annual meadow grass and mouse-ear chickweed, colonise sites faster than any other species.
The team suggests their results indicate invasive species will likely spread on South Georgia as fast as glaciers are retreating. Whether this has or will have negative consequences on local species needs to be investigated to help protect this unique ecosystem.
Original Source
Tichit P, Brickle P, Newton RJ, Convey P, Dawson W (2024) Introduced species infiltrate recent stages of succession after glacial retreat on sub-Antarctic South Georgia. NeoBiota 92: 85-110. https://doi.org/10.3897/neobiota.92.117226
An attempt to explore the history of the spread of four non-indigenous invasive tree species in one of the most important Hungarian forest-steppe forests of high conservation value.
Guest blog post by Arnold Erdélyi, Judit Hartdégen, Ákos Malatinszky, and Csaba Vadász
Today, almost everyone is familiar with the term “biological invasion”. Countless studies have been carried out to describe the various processes, and explore the cause and effect, and several methods have been developed in order to control certain invasive species. However, one of the biggest puzzles is always the question of how it all happened. It is not always easy to answer, and, in general, the smaller the area, the more difficult or even impossible it is to answer. In the course of our work, we attempted to explore the history of the spread of four, non-indigenous invasive tree species in one of the most important Hungarian forest-steppe forests of high conservation value, the Peszér Forest (approximately 1000 ha). Last week, we published our study in the journal One Ecosystem.
An open formation of the Eurosiberian steppic woods with Quercus spp., a priority natural habitat type of Community interest under the European Union’s Habitats DirectiveA closed formation of steppic oak forest with a dense shrub layer and a herb layer dominated by the lily of the valley (Convallaria majalis).
The Far Eastern tree of heaven (Ailanthus altissima), as well as the North American black cherry (Prunus serotina), the box elder (Acer negundo) and the common hackberry (Celtis occidentalis) are among the worst invasive plant species in Hungary. They are also responsible for serious conservation and economic problems in the Peszér Forest.
Invasion of tree of heaven (top left) and common hackberry (top right) in poplar stands, carpet of seedlings of black cherry (bottom left), and monodominant stand of box elder, regrown from stump after cutting (bottom right)
Historical reconstructions of the spread of invasive species are most often based on only one, or sometimes a few aspects. We used six approaches simultaneously:
we reviewed the published and grey literature,
extracted tree species data from the National Forest Database since 1958,
conducted a field survey with full spatial coverage (16,000 survey units (25×25 m quadrats)) – instead of sampling,
recorded all the largest (and presumably the oldest) individuals for annual ring counts,
performed hotspot analyses on the field data
collected local knowledge.
Cutting down the oldest common hackberry trees in order to count the annual rings from trunk discs
Our results show that each approach provided some new information, and without any of them the story revealed would have been much shorter and more uncertain. We have also highlighted that at the local level, the use of one or two aspects can be not only inadequate but also misleading.
From the literature it was possible to determine the exact place and date of the first occurrence of the tree of heaven and the black cherry. However, in the case of black cherry, for example, it was only possible to piece together the circumstances of the first plantings by combining three different sources. The first occurrences of box elder were found in forestry data. Finally, in the case of the common hackberry, searching for old individuals and determining their age gave the best results.
Common hackberry in the Peszér forest according to the recent forestry data (2016) and the field survey (2017-2019). The difference is clear: in the official forestry database, the tree species is underrepresented several times over
A well-explored story of a biological invasion can go a long way in making more and more people understand that controlling these non-indigenous species can only be beneficial. On the other hand, it can also help to strengthen conservation efforts, for example by increasing the volunteer workforce, which can be a major factor in the reduction of certain species. We hope that our work and the approaches we have taken will serve as a good model for exploring other invasion stories around the world.
Winter snapshot from the Peszér Forest, a diverse forest edge habitat along an inner road.
Research article:
Erdélyi A, Hartdégen J, Malatinszky Á, Vadász C (2023) Historical reconstruction of the invasions of four non-native tree species at local scale: a detective work on Ailanthus altissima, Celtis occidentalis, Prunus serotina and Acer negundo. One Ecosystem 8: e108683. https://doi.org/10.3897/oneeco.8.e108683
A research team led by Jacob Maher discovered thousands of online advertisements for weeds that are prohibited in Australia due to their harmful impact on the country’s environment and agriculture.
Hundreds of weeds have been found advertised on a public online marketplace in Australia. Cacti and pond plants were among the most frequently advertised illegal weed species. These weeds are prohibited in Australia due to their harmful impact on the country’s environment and agriculture. Despite this, a research team led by Jacob Maher discovered thousands of online advertisements for these weeds. Their study is published in the open access journal NeoBiota.
Water hyacinth, a notorious invader that was found traded online.
Trade of ornamental plants, the kind grown in homes and gardens, is the major way weeds are introduced to new places. Some ornamental plants can make their way into the environment and become invasive, negatively impacting native species and agriculture. Increasingly, plants are traded on the internet, allowing a wide variety of plants to be introduced to more distant places. A lack of surveillance and regulation of this trade has resulted in the wide trade of invasive species.
In response, scientists from the University of Adelaide have utilised specialised software called ‘web scrapers’ to monitor trade on public classifieds websites. These web scrapers automate the collection of online advertisements. This allowed the researchers to detect thousands of advertisements for weeds over a 12-month period.
Opuntia, a notorious invader that was found traded online.
Despite Australia’s laws banning the trade of harmful weeds, advertisements were observed across the country. Some of the weeds advertised were associated with uses by traders, including food and medicine. The most popular uses were associated with pond and aquarium plants such as filtering water and providing fish habitat.
The researchers recommend that governments adopt web scraping technology to assist in regulating online trade of plants. They also highlight increasing public awareness and seeking cooperation from online marketplaces as solutions to this growing problem.
“Currently, these online marketplaces allow people to advertise and purchase invasive species, whether they are aware of it or not,” says Maher. “Regulation is needed, but we also need to cultivate awareness of amongst plant growers of this issues and we need help from marketplaces to regulate trade on their end.”
The technology developed in this study is now being utilised by biosecurity agencies in Australia to monitor and regulate the illegal trade of plants and animals online.
Microplastics forming the disproportionate amount of plastic garbage, and catfish have become numerically dominant in some ecosystems thanks to their tolerance to pollution and anoxic environments.
Armored catfish (Pterygoplicthys spp.) and microplastics, as invasive species and emerging contaminants, respectively, represent two socio-environmental problems in the globalized world, since both have negative effects on faunistic communities and freshwater habitats, as well as on rural community fisheries and public health.
Non-native invasive species of armored catfish have become numerically dominant in some ecosystems, with efforts to eradicate them a seemingly endless task. Due to this, a possible scenario of biological homogenization in Mesoamerica can be expected, mainly given by the wide dispersion of the Pterygoplichthys species, added to the introduction of other non-native catfish species.
Photo: Miguel Ángel Salcedo. Drawing: Diana Ríos-Hernández.
The omnipresence of plastics in terrestrial and aquatic environments is caused by their excessive use and inadequate management of waste. The discarded plastics are fragmented, degraded, and dissolved by solar radiation, wind, and water, among other agents, to be incorporated into the food web in aquatic environments.
Microplastics found in the digestive tract of armed catfish (Pterygoplichthys spp.)
Both persist in the aquatic environment, microplastics forming the disproportionate amount of plastic garbage, and catfish thanks to their tolerance to pollution and anoxic environments, and their ability to survive for several hours breeding atmospheric oxygen. What is the relationship between the two? Microplastics, depending on their origin and composition, are sedimented in the wetlands, where they can be ingested by detritus feeders, such as armored catfish, mainly in areas where there is runoff or discharge of liquid waste.
In this context, we ask ourselves, can armored catfish be used as biomonitors of microplastics deposited in wetlands? Taking the above into consideration, the doctoral student Gabriela Angulo-Olmos under the guidance of the researchers Nicolás Álvarez-Pliego, Alberto J. Sánchez, Rosa Florido, Miguel Ángel Salcedo, Allan K. Cruz-Ramírez and Arturo Garrido Mora from the Laboratorio de Humedales, from the División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, decided to answer the aforementioned question based on the numerical dominance of armored catfish recorded in the aquatic ecosystems of the Metropolitan Area of Villahermosa (MAV) in the coastal plain of the Gulf of Mexico.
A) Study area; Metropolitan Area of Villahermosa. Map modified from INEGI (2021). B) La Pólvora lake (Satélite Airbus 2023).
The stomach contents of the specimens from a lake located in the MAV were reviewed and the results showed that all the specimens had consumed microfibers. This result corroborated that these organisms can ingest sedimented microplastics due to their benthophagous habits.
The use of armored catfish as a resource in the food industry has had positive results, but is still insufficient. Therefore, we propose that another option to control their populations is to subtract and use this organism to verify which are the most frequent and abundant emerging contaminants deposited in the bottoms of urban wetlands.
Research article:
Angulo-Olmos G, Alvarez-Pliego N, Sánchez AJ, Florido R, Salcedo MÁ, Garrido-Mora A, Cruz-Rámirez AK (2023) Microfibers in the gut of invasive armored catfish (Pterygoplichthys spp.) (Actinopterygii: Siluriformes: Loricariidae) in an urban lake in the floodplain of the Grijalva River basin, Mexico. Acta Ichthyologica et Piscatoria 53: 81–88. https://doi.org/10.3897/aiep.53.102643
“The lydemapr package will aid researchers, managers and the public in their understanding, modelling and managing of the spread of this invasive pest,” says Dr. De Bona, the lead author of the study.
“Stomp, squash, smash” has been the accompanying soundtrack to the expansion of an odd-looking bug through the Eastern US. The spotted lanternfly, a large planthopper native to Asia, has been popularized in media outlets as the most recent enemy one ought to kill on sight.
Spotted lanternflies. Photo by Matthew Helmus
This charismatic insect was first discovered in the US in Berks county, Pennsylvania, in 2014, likely the result of an accidental introduction alongside shipments of landscaping materials. Since then, the invasive pest has spread throughout the country, fueled by its ability to hitch rides undetected on cargo and passenger vehicles, and aided by the widespread presence of one of its favorite food sources, the tree of heaven, another invasive in North America. As of 2023, it has been found in 14 US states.
Unfortunately, this species is not picky when it comes to the plants it consumes, favoring both crops and ornamentals, and showing a particular preference for cultivated grape. This dietary choice has impacted several wine-making areas throughout Pennsylvania and New York state, and is threatening important wine hubs on the Western coast of the US.
When it comes to controlling the spread of this pest, two of the main challenges for researchers and field managers alike are to 1) know where this species is today so that eradication campaigns can be targeted and 2) predict where it will be tomorrow, to invest in prevention practices. Both efforts rely on accurate and extensive knowledge of its past and present distribution.
Many state and federal agencies, as well as individual research institutions, have been involved in conducting surveys to detect this bug in the field. In addition, a campaign to raise public awareness has fostered the development of self-reporting tools citizens can use to track sightings of this insect. Unfortunately, given the different practices adopted by these parties, the data on the presence of spotted lanternfly are scattered and hard to access, which makes it harder to assess and manage its spread.
Spotted lanternflies. Photo by Matthew Helmus
The need to put together a current, comprehensive, consistent and openly available dataset pushed researchers at Temple University to take action. A research group led by Dr. Matthew Helmus has been closely monitoring the spread of this invasive pest since its inception, contacting institutions and collecting data. In a recent work published in the journal NeoBiota, Dr. Helmus and Dr. Sebastiano De Bona, together with collaborators across several agencies, put together an anonymized and comprehensive dataset that collected all records of spotted lanternfly in the US to date. These records come from a plethora of sources, from control actions, citizen-science projects, and research efforts. The resulting dataset contains highly detailed data (at 1 km2 resolution) with yearly information on the presence or absence of spotted lanternflies, the establishment status of this pest, and estimated population density, across over 650,000 observations.
“The lydemapr package will aid researchers, managers and the public in their understanding, modelling and managing of the spread of this invasive pest,” says Dr. De Bona, the lead author of the study.
The scientists hope that this package will make forecasting the spread of the spotted lanternfly easier and foster more effective collaboration between agencies and researchers.
Research article:
De Bona S, Barringer L, Kurtz P, Losiewicz J, Parra GR, Helmus MR. 2023. lydemapr: an R package to track the spread of the invasive Spotted Lanternfly (Lycorma delicatula, White 1845)(Hemiptera, Fulgoridae) in the United States. NeoBiota 85: 151–168, DOI: 10.3897/neobiota.86.101471
A new approach compared characteristics of species that succeeded or failed to establish after probably following the same historical introduction route.
Plant species become exotic after being accidentally or deliberately transported by humans to a new region outside their native range, where they establish self-perpetuating populations that quickly reproduce and spread. This is a complex process mediated by many factors, such as plant traits and genetics, which challenges the creation of general guidelines to predict or manage plant invasions. Scientists from Spanish and Australian institutions have now defined a new framework to find the predictors of invasiveness, investigating species that have succeeded or failed to establish abroad after following similar historical introduction routes.
Ancient agricultural landscape dominated by plant species introduced in other Mediterranean regions (Parque Natural de Los Alcornocales, Andalucía, Spain). Photo by Dr Javier Galán Díaz
“While current policies exert strong control on the import and export of living organisms, including pests, across countries, until only a few decades ago, very little attention was paid to this issue. This means that many species were translocated to new regions without any consideration of their potential impacts,” says Dr Javier Galán Díaz.
An example of this is the massive plant exchange among Mediterranean‐type regions as a consequence of European colonialism: crops and cattle were exported, along with tools and materials, potentially bringing along the seeds of many plant species.
Agricultural landscape dominated by exotic species of European origin (Merced Vernal Pool and Grassland Reserve, California, U.S.A.). Photo by Dr Javier Galán Díaz
“So far, most studies on plant invasions have tried to explain the success of exotic species by comparing their traits with those of the native plant communities where they arrive, or by comparing the traits of plant species that have achieved different levels of invasion in the same region. But, if we take into account that the most common plant species from European agricultural landscapes have been in contact with humans and have therefore had the potential to be inadvertently transported to other Mediterranean regions, then only those that have successfully invaded other regions have something different in them that allowed them to establish and spread abroad,” Dr Galán Díaz explains.
Following this approach, the scientists found that, when comparing plant species transported from the Mediterranean Basin to other Mediterranean-climate regions (California, Central Chile, the Cape Region of South Africa and Southwestern and South Australia) in the search of predictors of invasiveness, only those species with large distribution ranges that occupy climatically diverse habitats in their native region became exotic. Also, species with many dispersal vectors (for instance those that have seeds dispersed by animals, water or wind), long bloom periods and acquisitive above- and belowground strategies of resource use are most likely to become exotic. Most of this plant information is readily available or easy to obtain from free and open-access repositories.
Lotus corniculatus, one of the species that the study identified as invasive in other Mediterranean-climate regions of the world. Photo by Teresa Grau Ros under a CC-BY 2 license
Rumex acetosella, one of the species that the study identified as invasive in other Mediterranean-climate regions of the world. Photo by Jakub T. Jankiewicz under a CC-BY 2 license
Carduus tenuiflorus, one of the species that the study identified as invasive in other Mediterranean-climate regions of the world. Photo by jacinta lluch valero under a CC-BY 2 license
Poa pratensis, one of the species that the study identified as invasive in other Mediterranean-climate regions of the world. Photo by AnneTanne under a CC BY-NC-SA 2 license
“Determining the factors that pre-adapt plant species to successfully establish and spread outside of their native ranges constitutes a powerful approach with great potential for management,” the researchers write in their paper. “This framework has the potential to improve prediction models and management practices to prevent the harmful impacts from species in invaded communities.”
“Using the existing information, we can identify the key species to monitor. This is especially encouraging in the era of Big Data, where observations from citizen science applications add to those of scientists, increasing the potential of screening systems,” Dr Galán Díaz says in conclusion.
Research article:
Galán Díaz J, de la Riva EG, Martín-Forés I, Vilà M (2023) Which features at home make a plant prone to become invasive? NeoBiota 86: 1-20. https://doi.org/10.3897/neobiota.86.104039
This happens more than you might think, with pet releases deemed responsible for 53% of invasive vertebrate species and one third of all aquatic invasive species. It has been shown that the more readily available a species is in the pet trade, the greater the risk of it being released, or escaping, into the wild.
Somewhat fascinatingly, this also puts the trade at the mercy of pop culture influences. 1970s animated series “Rascal the Raccoon” is commonly blamed for Japan’s invasive racoon population, and demand for Trachemys scripta pets is said to have boomed in the 1990s due to “Teenage Mutant Ninja Turtles.” Side note: the influence of movies highlighting the challenges of pet ownership, such as “Gremlins” or “Little Shop of Horrors”, warrants further study.
Hitchhikers
While invasion ecology has typically focused on these released species and the impacts that they cause, many species are sold with commensal organisms attached. These incidentally carried fauna are commonly known as “hitchhikers”.
Recent studies have found the protozoan Vorticella sp. and a species of bdelloid rotifer associated with two species of atyid shrimps, digenean larvae with the carnivorous snail Anentome helena, and an epibiont, Diceratocephala boschmai, on New Guinean ornamental Cherax crayfish.
Temnocephalid eggs located on thorax carapace (white arrow) of adult Cherax monticola. From Ložek F, Patoka J, Bláha M. 2021. Another hitchhiker exposed: Diceratocephala boschmai (Platyhelminthes: Temnocephalida) found associated with ornamental crayfish Cherax spp. Knowl. Manag. Aquat. Ecosyst., 422, 25.
A high-profile example emerged in 2021 when zebra mussels (Dreissena polymorpha) were detected in 21 US states on aquarium moss balls that had been imported from Ukraine, and subsequent searches revealed the species in 600 locations in Canada. Similar findings have since emerged from Europe. Having colonised both European and North American waters, the ease with which this Ponto-Caspian bivalve is being spread by the pet trade on both sides of the Atlantic is a major concern. Zebra mussels have been listed as one of the IUCN’s “100 of the Worst Invasive Species”, and their myriad ecological and economic impacts range from habitat alteration, to competition with native unionids, to disruption of food-web structure, to blocking industrial water intake pipes. They are also able to attach to boat hulls and other organisms, facilitating further spread.
The discovery
Zebra mussels, Dreissena polymorpha, found amongst ordered European pond snail, Viviparus viviparus
I remember the moment clearly. I had ordered seventy-five Viviparus viviparus – a common European pond snail species – for behavioural studies at GEOMAR Helmholtz Centre for Ocean Research Kiel where I was based for lab work in the group of Elizabeta Briski. After some stress over posting delays and an increasingly fraught relationship developing with the GEOMAR receptionist, the snails arrived. Over the next day, watching them go about their lives in our climate chamber in their new tanks became a favourite way to spend working breaks. With obvious dimorphism you could clearly tell males from females, which added to the developing snail soap operas. However, just before packing up to leave the lab, I noticed a huge lump on one snail. What on earth is that? Soon I noticed a second. I called Elizabeta with my suspicions, which she confirmed the next day. Photos were taken, measurements made, and our go-to ecological geneticist Reid Brennan was begged to work his DNA sequencing magic. Before long, it was all confirmed: we had zebra mussels.
Potential implications
The biggest takeaway message here is that even native species in the pet trade can facilitate the spread of non-native hitchhikers. In a parallel universe, those snails did not go to an invasion ecology lab but rather to someone keen to stock their garden pond. Escape from ponds is a major pathway for freshwater species introductions, and even if the impact of a native species escaping might be limited, its potential for the zoochorous dispersal of a non-native should not be ignored.
Zebra mussels, Dreissena polymorpha, found amongst ordered European pond snail, Viviparus viviparus.
Of course, questions surround the conditions under which the pond snails were held before selling. Were they stocked in zebra mussel infested outdoor ponds? Which other species are held in a similar way? How prevalent are these practices within the trade? One way of combating this risk of non-native species spread is via legislation. Calls have been made for white lists of low-risk species that can be sold in the trade in place of risky species, but in our study, the issue stems from the selling of a native species within its native range, which would surely be deemed low-risk.
We propose that should a white-list system be adopted, the potential for a “low-risk” species to transport invasive species must be accounted for. We also call for stricter biosecurity practices to be enforced, including regular checking and disinfecting of outdoor stock ponds where appropriate. Tools such as environmental DNA surveillance could be used to effectively detect the presence of targeted invasive species, as part of biosecurity “audits”. However, for the time being, a desperate, final line of defence is to raise awareness amongst consumers and for them to be wary of unwanted hitchhikers.
References:
Dickey JWE, Brennan RS, Chung SS, Jeschke JM, Steffen GT, Briski E (2023) More than we bargained for: Zebra mussels transported amongst European native freshwater snails. NeoBiota 10: 1–10. https://doi.org/10.3897/neobiota.83.97647
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Lozek F, Patoka J, Bláha M (2021) Another hitchhiker exposed: Diceratocephala boschmai (Platyhelminthes: Temnocephalida) found associated with ornamental crayfish Cherax spp. Knowledge and Management of Aquatic Ecosystems 2020-Janua. https://doi.org/10.1051/kmae/2021023
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A citizen science project in Italy had high school students monitor the activities of ambrosia beetles, catching them with traps made from recycled plastic bottles.
While invasive alien species (IAS) represent a growing threat to global biodiversity and ecosystems, public awareness of them hasn’t seen a significant increase. Many researchers believe informing people about IAS is an essential long-term investment to counter biological invasions; in particular, “learning by doing” is an extremely effective method for involving new audiences, such as students.
Map of the study area (the Veneto Region) indicating the high school locations.
About 500 Italian students aged 11-18 took part in a citizen science project that led to new geographical records of two alien species of ambrosia beetles considered to be quarantine pests by the European Union. Dr. Fernanda Colombari and Prof. Andrea Battisti of the University of Padova have described the results in a paper in the open-access journal NeoBiota.
The project involved schools located in urban areas in north-eastern Italy and aimed to connect environmental education and experiential outdoor learning through lectures, videos, reports, and large-scale surveillance of ambrosia beetles. The students used plastic bottles and hand sanitizer to trap ambrosia beetles in their school grounds. They then assessed their abundance, looking at the different species. Before and after the educational activities, their knowledge and awareness of IAS were tested using simple anonymous questionnaires.
Schematic representation of a plastic bottle trap filled with hand sanitizer as attractant
“Our study aimed to both educate students and collect scientific data at sites such as schools where surveillance for potentially invasive ambrosia beetles is not usually conducted, or where it is sometimes misunderstood,” Dr. Colombari and Prof. Battisti write in their paper.
Identifying the specimens collected by the students, the authors found that IAS amounted to 35% of total catches. Remarkably, two out of the four alien species caught, Cnestus mutilatus and Anisandrus maiche, were recorded for the first time in Europe thanks to this study.
Furthermore, questionnaire results showed that the students acquired greater knowledge and increased their awareness and interest in IAS by more than 50%. After the experiment, most of them were interested in learning more about the negative effects of the introduction of IAS and practices to limit their spread.
This study shows that citizen science can successfully involve school students, giving them an opportunity to contribute in an effective early detection of IAS, as most first records occur in cities or suburban areas. The results also point to the primary role of education, which is as a major driver of change in tackling sustainability challenges. Moreover, as students bring home the message and share it with their relatives, the process supports intergenerational learning and enlarges public collaboration.
A plastic bottle trap filled with hand sanitizer as attractant. Photo by Dr Fernanda Colombari
“People are often unaware of the role they have in the entire invasive process,” the researchers write in their study. Citizen science projects like this one are more than a reliable tool for collecting scientific data; they also help engage the public and spread awareness of biological invasions, eventually contributing to the creation of more efficient management strategies.
The monitoring programme in this study was conducted in the context of the European project HOMED (Holistic management of emerging forest pests and diseases), which has developed a full panel of scientific knowledge and practical solutions for the management of emerging native and non-native pests and pathogens threatening European forests. The main results of HOMED’s research are publically available in a special issue in the open-access scholarly journal NeoBiota.
Original source:
Colombari F, Battisti A (2023) Citizen science at school increases awareness of biological invasions and contributes to the detection of exotic ambrosia beetles. In: Jactel H, Orazio C, Robinet C, Douma JC, Santini A, Battisti A, Branco M, Seehausen L, Kenis M (Eds) Conceptual and technical innovations to better manage invasions of alien pests and pathogens in forests. NeoBiota 84: 211-229. https://doi.org/10.3897/neobiota.84.95177
