Category: Neobiota

Beetles in a bottle: a message from aliens to schools

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.

Cnestus mutilatus. Photo by Durham Field Office – Forest Health Protection under a CC BY-NC-SA 2.0 license.

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

Fighting off pests with deep learning and drones

In a new study, researchers tested different deep learning methods to detect the nests made by pine processionary moth larvae on pine and cedar trees.

The nest of a pine processionary moth.

Early detection of pest infestation is an important first step in the adoption of control measures that can be tailored to specific local conditions. Remote sensing technology can be a helpful tool, allowing the quick scanning of large areas, but it’s not universally applicable as sometimes items can be hard to detect. Unmanned aerial vehicles (UAVs), or drones, on the other hand, can help by getting closer to individual trees and detecting smaller atypical signals.

The pine processionary moth is an insect infesting trees in gardens and parks, threatening public health because of the hairs released by its larvae, which can cause a stinging or itching sensation. The pest is rapidly growing in numbers and conquering new territories, which makes it a species of concern.

In a new study, researchers tested different deep learning methods to detect the nests made by pine processionary moth larvae on pine and cedar trees. Drones flying over the trees took images, which were then analysed with the help of artificial intelligence (AI) to identify and localise the nests.

Drone images from Portugal.

The use of AI on drone images proved effective to detect pine processing moth nests on trees of different species and sizes, even under variable densities. The method can be successfully used in both forest and urban settings to help detect moth nests. That way, tree health managers can be informed about where the nests are and take appropriate measures to contain the damage and the public health risks.

“The study proved the advantage of using UAVs to document the presence of at least one nest per tree,” the researchers write in their study, which was published in a special issue of the journal NeoBiota dedicated to forest pests in Europe. “It therefore represents a substantial step forward in the integration of the UAV survey with ground observations in the monitoring of the colonies of an important forest defoliating insect in the Mediterranean area.”

image from the ground in daylight
image from the ground in infrared light
image from drone

Furthermore, they suggest that the method can be extended to other pests.

“This technique can pave new avenues in the surveillance and management of emerging and non-native pests of trees, where early detection and early action should go together to achieve a satisfactory level of protection,” the study authors write in conclusion.

Research article:

Garcia A, Samalens J-C, Grillet A, Soares P, Branco M, van Halder I, Jactel H, Battisti A (2023) Testing early detection of pine processionary moth Thaumetopoea pityocampa nests using UAV-based methods. 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: 267-279. https://doi.org/10.3897/neobiota.84.95692

New NeoBiota special issue: tackling invasive alien forest pests in Europe

The issue comprises 16 articles on various aspects of the ecology and management of invasive alien insects and fungal pathogens in Europe’s forests.

Every year, new alien species of insects and fungi invade European forests. Some of them are exotic pests and diseases that can affect the survival and growth of trees.

To help develop strategies for monitoring and managing these non-native forest pests, a consortium of over 50 scientists representing 23 research institutions and 15 countries from across the globe joined their skills in the Horizon 2020 project HOMED “Holistic management of emerging forest pests and diseases.”

Alex Stemmelen during his presentation at the XXVI ICE Congress 2022. He is the first author of a paper on the pests of Douglas fir in NeoBiota‘s special issue.

Between 2018 and 2022, the HOMED consortium developed a full panel of scientific knowledge and practical solutions to better deal with emerging native and alien invasive pests and diseases.

Fruiting bodies of Austropuccinia psidii on Myrtus communis (symptoms of myrtle rust). Photo by Alberto Santini

This includes targeting the successive phases of invasion, and developing innovative methods for each phase: risk analysis, prevention/detection, surveillance, eradication/containment, and control.

To share the results of this cooperation and help researchers further improve the management of emerging forest pests and pathogens, HOMED has made the main outcomes of its research publically available.

They are now published in a special issue in the open-access journal NeoBiota, called “Conceptual and technical innovations to better manage invasions of alien pests and pathogens in forests”. The issue comprises 16 articles on various aspects of the ecology and management of invasive alien insects and fungal pathogens in Europe’s forests.

The cover of NeoBiota’s new special issue.

“Because forests provide irreplaceable goods and materials for people and the European economy, because maintaining healthy forests is essential for their contribution to climate change mitigation through sequestration and storage of atmospheric carbon, it is urgent to develop more effective protective measures against the ever-increasing threat of invasive forest pests,” the editors of the special issue write in an editorial.

More tools are needed that can help identify, prevent and monitor invasive alien species and improve early warning methods, which makes the research in this issue so crucial and timely.

“The role of researchers is to develop, test and promote the most relevant methods and tools at each stage of the invasion framework, i.e., for the early detection of these invasive alien organisms, for the identification of the species and for the monitoring of their damage and spread, but also for new eradication and control solutions,” the editors continue.

Hervé Jactel, Lukas Seehausen and Martin Gossner at HOMED’s and Pensoft’s stand during the XXVI ICE Congress 2022.

One highlight in the published research is a study exploring how using the methods of citizen science at schools can increase invasive species awareness. Another explores the efficiency of artificial intelligence in pest detection.

“The publications collected in this special issue demonstrate that current conceptual, methodological, and technological advances allow a great progress in the anticipation, monitoring and management of invasive pest species in forests,” the editors conclude.

Follow HOMED on Twitter. Follow NeoBiota on Twitter and Facebook. See the latest tweets on the special issue using the hashtag #HOMED_SI.

Comprehensive review of Burmese python science released

A USGS-led publication offers a new look at the constrictor that has invaded southern Florida.

The U.S. Geological Survey has released a comprehensive synthesis of Burmese python science, showcasing results from decades of USGS-funded research on python biology and potential control tools. The giant constrictor now represents one of the most challenging invasive species management issues worldwide.

Occurrence records were obtained from a large geospatial database of invasive species reports (Early Detection & Distribution Mapping System) submitted by both researchers and the public. The map illustrates the chronology of python removals across southern Florida and represents the best professional estimate of the invasion front, which is not exact and will change over time.

“For the first time, all the science on python ecology and potential control tools has been consolidated into one document, allowing us to identify knowledge gaps and important research areas to help inform future python management strategies. This synthesis is a major milestone for Burmese python research; six years in the making, it represents the consensus of the scientific community on the python invasion,” said USGS Ecologist Jacquelyn Guzy, lead author for the publication.

Burmese pythons were confirmed to have an established breeding population in Everglades National Park in 2000. The population has since expanded and now occupies much of southern Florida. They consume a wide range of animals and have altered the food web and ecosystems across the Greater Everglades.

Photo by U.S. Geological Survey.
Photo by Conservancy of Southwest Florida.
Photo by U.S. Geological Survey.
Burmese pythons.

The synthesis, which pulled together the expertise of scientists and managers nationwide, provides a breakdown of 76 prey species found in python digestive tracts, which primarily included mammals and birds, as well as two reptile species, American alligator and Green iguana. However, as the scientists noted, the number of animals may increase as the python population expands to new areas.

It also reports new findings including a summary of body sizes of pythons measured by state and federal agencies between 1995 and 2022, as well as descriptions of length-mass relationships, the estimated geographic spread of pythons over time, and a comprehensive assessment of all control tools explored to date.

Illustration by Natalie Claunch demonstrates typical features of the Burmese python.

One of the hallmark issues of the Burmese python invasion has been the difficulty of visually detecting or trapping pythons in an immense natural landscape, Guzy said. Pythons do not readily enter any type of trap, occupy vast stretches of inaccessible habitat, and camouflage extremely well within the subtropical Florida environment.

Examples of cryptic coloration contributing to low detection probability in representative habitat where Burmese pythons have been captured. White circles indicate pythons. Photos by

“Extremely low individual python detection rates hamper our ability to both estimate python abundance and expand control tools across the extensive natural landscape” says USGS Research Ecologist Kristen Hart, an author of the publication.

Because the Burmese python has spread throughout southern Florida, eradication of the population across the landscape is not possible with existing tools, the publication states. However, researchers at USGS and partner institutions are exploring potential novel techniques such as genetic biocontrol, that may one day provide an avenue towards larger-scale population suppression.

In the meantime, important areas of research according to the publication include reproductive life history and estimation of demographic vital rates such as survival, to help managers evaluate and refine existing control tools. With improved control tools managers may be able to reduce population expansion and minimize the future impact of pythons on the environment.

The USGS python research over the past decades has been largely supported by the USGS Greater Everglades Priority Ecosystem Sciences (GEPES) Program with additional support from the USGS Biothreats and Invasive Species program.

Research article:

Guzy JC, Falk BG, Smith BJ, Willson JD, Reed RN, Aumen NG, Avery ML, Bartoszek IA, Campbell E, Cherkiss MS, Claunch NM, Currylow AF, Dean T, Dixon J, Engeman R, Funck S, Gibble R, Hengstebeck KC, Humphrey JS, Hunter ME, Josimovich JM, Ketterlin J, Kirkland M, Mazzotti FJ, McCleery R, Miller MA, McCollister M, Parker MR, Pittman SE, Rochford M, Romagosa C, Roybal A, Snow RW, Spencer MM, Waddle JH, Yackel Adams AA, Hart KM (2023) Burmese pythons in Florida: A synthesis of biology, impacts, and management tools. NeoBiota 80: 1-119. https://doi.org/10.3897/neobiota.80.90439

Story originally published by the USGS. Republished with permission.

North American turtles establish succcessful populations in Germany, possibly threathening ecosystems

For the first time, self-sustaining populations of three non-native species of turtles were identified in south-western Germany by researchers at the University of Freiburg

For the first time, self-sustaining populations of three non-native species of turtles were identified in south-western Germany by researchers at the University of Freiburg

Original text published by the University of Freiburg

Three species of turtles native to North America have been successfully reproducing in the wild in Germany, report for the first time environmental researcher Benno Tietz and biologist Dr. Johannes Penner of the University of Freiburg, along with Dr. Melita Vamberger of the Senckenberg Natural History Collection in Dresden.

Their results were published in the open-access scientific journal NeoBiota.

The scientists examined a total of nearly 200 animals living in the wild in lakes in Freiburg and Kehl. Their findings suggest that the turtles have established themselves in a new habitat, where they could become a threat to the local ecosystem.

For two species, this is the first evidence of independent reproduction outside of their natural reproductive range. For the third species, this is the northernmost evidence of its presence up to now,

says Penner.
The false map turtle (Graptemys pseudogeographica) enjoys the sun’s warmth. Photo: Johannes Penner.

Turtles released into the wild

Invasive species do a great deal of economic damage world-wide. They also contribute to advancing global species extinctions.

Alien reptiles regularly make their way into the wild in Germany. Most often, this is because they have been released by pet owners.

Large numbers of North American pond sliders (Trachemys scripta) were imported into the European Union (EU) in the 1980s and 1990s as house pets. In 1997, their import into the EU was banned. By 2016, the sale of specimens born here was also made illegal.  Since then, pet shops have replaced them with other freshwater turtles, such as the river cooter (Pseudemys concinna) and the false map turtle (Graptemys pseudogeographica).

Genetic analyses of specimens of all three species in a range of ages have now demonstrated that they are reproducing independently in local waters. 

What’s surprising is that the invasive species have established themselves so far north. In Europe, successful reproduction and self-maintaining populations of Trachemys scripta were only known in the Mediterranean regions and the continental climate zone of Slovenia,

explains Benno Tietz.

Until recently, it had been assumed the turtles being examined couldn’t reproduce in Central Europe due to the colder climate. Especially the false map turtle is actually quite sensitive to the cold,

he says.
A North American pond slider (Trachemys scripta) resting on a lily pad. Photo: Johannes Penner.

Consequences for local species unclear

The invasive turtles could become a problem for indigenous species.

The European pond turtle (Emys orbicularis), for example, is now only present in Germany in parts of Brandenburg.

In an experimental setup, the European pond turtle showed weight loss and an increased death rate when being kept together with Trachemys scripta,

reports Penner.

Penner says that could be caused by the larger, alien species forcing the smaller local turtles from places where they sun themselves, leading the local turtles to have  problems with thermoregulation. Or perhaps the competition led to them having greater challenges when seeking food. 

Beyond that, aquatic turtles could be hosts for viruses and parasites, leading them to play a role in the spread of diseases. This could potentially have a damaging influence on other parts of the ecosystem, including amphibians, fish, or aquatic plants.

On the other hand, in their study, the researchers consider the alien species could assume functions in damaged ecosystems that would otherwise go unreplaced.

Vamberger says these questions urgently need to be explored further.

We need to raise public awareness that people should not release – no matter what kind of species – any animals into the wild in future.”

she insists.
A river cooter (Pseudemys concinna) lets itself drift in the water. Photo: Johannes Penner.
Meet the research team:

Dr. Johannes Penner was the scientific coordinator of the research training group “Conservation of Forest Biodiversity in Multiple-Use Landscapes of Central Europe” (ConFoBi) and a lecturer for the Chair of Wildlife Ecology and Management of the University of Freiburg. Currently, he is a curator at the NGO “Frogs and Friends” and a guest researcher in wild animal ecology.

Benno Tietz has completed a Master’s degree in Environmental Sciences at the University of Freiburg. His thesis – finished in the Winter Semester of 2020/2021 – investigated alien turtles. Currently, he is a research assistant at the Freiburg Institute of Applied Animal Ecology.

Dr. Melita Vamberger is a researcher at the Senckenberg Natural History Collection in Dresden.

***

The study was supported by the Hans Schimenz Fund of the German Society for Herpetology and Terrarium Science (DGHT) as well as the Academic Society of Freiburg.

***

Research paper:

Tietz B, Penner J, Vamberger M (2023) Chelonian challenge: three alien species from North America are moving their reproductive boundaries in Central Europe. NeoBiota 82: 1-21. https://doi.org/10.3897/neobiota.82.87264

Follow NeoBiota on Twitter and Facebook.

Interoperable biodiversity data extracted from literature through open-ended queries

OpenBiodiv is a biodiversity database containing knowledge extracted from scientific literature, built as an Open Biodiversity Knowledge Management System. 

The OpenBiodiv contribution to BiCIKL

Apart from coordinating the Horizon 2020-funded project BiCIKL, scholarly publisher and technology provider Pensoft has been the engine behind what is likely to be the first production-stage semantic system to run on top of a reasonably-sized biodiversity knowledge graph.

OpenBiodiv is a biodiversity database containing knowledge extracted from scientific literature, built as an Open Biodiversity Knowledge Management System. 

As of February 2023, OpenBiodiv contains 36,308 processed articles; 69,596 taxon treatments; 1,131 institutions; 460,475 taxon names; 87,876 sequences; 247,023 bibliographic references; 341,594 author names; and 2,770,357 article sections and subsections.

In fact, OpenBiodiv is a whole ecosystem comprising tools and services that enable biodiversity data to be extracted from the text of biodiversity articles published in data-minable XML format, as in the journals published by Pensoft (e.g. ZooKeys, PhytoKeys, MycoKeys, Biodiversity Data Journal), and other taxonomic treatments – available from Plazi and Plazi’s specialised extraction workflow – into Linked Open Data.

“I believe that OpenBiodiv is a good real-life example of how the outputs and efforts of a research project may and should outlive the duration of the project itself. Something that is – of course – central to our mission at BiCIKL.”

explains Prof Lyubomir Penev, BiCIKL’s Project Coordinator and founder and CEO of Pensoft.

“The basics of what was to become the OpenBiodiv database began to come together back in 2015 within the EU-funded BIG4 PhD project of Victor Senderov, later succeeded by another PhD project by Mariya Dimitrova within IGNITE. It was during those two projects that the backend Ontology-O, the first versions of RDF converters and the basic website functionalities were created,”

he adds.

At the time OpenBiodiv became one of the nine research infrastructures within BiCIKL tasked with the provision of virtual access to open FAIR data, tools and services, it had already evolved into a RDF-based biodiversity knowledge graph, equipped with a fully automated extraction and indexing workflow and user apps.

Currently, Pensoft is working at full speed on new user apps in OpenBiodiv, as the team is continuously bringing into play invaluable feedback and recommendation from end-users and partners at BiCIKL. 

As a result, OpenBiodiv is already capable of answering open-ended queries based on the available data. To do this, OpenBiodiv discovers ‘hidden’ links between data classes, i.e. taxon names, taxon treatments, specimens, sequences, persons/authors and collections/institutions. 

Thus, the system generates new knowledge about taxa, scientific articles and their subsections, the examined materials and their metadata, localities and sequences, amongst others. Additionally, it is able to return information with a relevant visual representation about any one or a combination of those major data classes within a certain scope and semantic context.

Users can explore the database by either typing in any term (even if misspelt!) in the search engine available from the OpenBiodiv homepage; or integrating an Application Programming Interface (API); as well as by using SPARQL queries.

On the OpenBiodiv website, there is also a list of predefined SPARQL queries, which is continuously being expanded.

Sample of predefined SPARQL queries at OpenBiodiv.

“OpenBiodiv is an ambitious project of ours, and it’s surely one close to Pensoft’s heart, given our decades-long dedication to biodiversity science and knowledge sharing. Our previous fruitful partnerships with Plazi, BIG4 and IGNITE, as well as the current exciting and inspirational network of BiCIKL are wonderful examples of how far we can go with the right collaborators,”

concludes Prof Lyubomir Penev.

***

Follow BiCIKL on Twitter and Facebook. Join the conversation on Twitter at #BiCIKL_H2020.

You can also follow Pensoft on Twitter, Facebook and Linkedin and use #OpenBiodiv on Twitter.

Where did all those insects come from? Tracking the history of insect invasion in Chile

Going through centuries-old literature, researchers compiled a database of the exotic insects established in the country.

Guest blog post by Daniela N. López, Eduardo Fuentes-Contreras, Cecilia Ruiz, Sandra Ide, Sergio A. Estay

Understanding the history of non-native species arrivals to a country can shed light on the origins, pathways of introduction, and the current and future impacts of these species in a new territory. In this sense, collecting this information is important, and sometimes essential, for researchers and decision makers. However, in most cases, reconstructing this history takes a lot of work. Finding antique references is hard work. To add more complexities, changes in the taxonomy of species or groups could be frustrating as we try to track the moment when a species was referenced in the country for the first time, sometimes centuries ago. Of course, we only learned about these issues when, almost seven years ago, we thought that compiling a database for the exotic insects established in Chile would be interesting to people working on invasive species in the country.

Tremex fuscicornis caught in Chile. Photo by Sergio Estay

First, we collected information from physical and electronic books and journals available in our institutional libraries, but soon we noticed that we needed a more significant effort. In Chile, the National Library and The National Congress library allowed us to review and collect information from texts, in many cases, over a hundred years old. We also had to request information from foreign specialized libraries and bookstores. Sometimes, we had to negotiate with private collectors to buy antique books or documents. When we figured the first version of the database was ready, we began a second step for detecting errors, correcting the taxonomy, and completing the information about the reported species.

Ctenarytaina eucalypti individuals and damage in Chile. Photo by Sergio Estay

The analysis began when we finally completed the database. What types of questions could we answer using this data? Was the database complete enough to detect historical, biogeographic, and ecological patterns? Two competing hypotheses were the starting point for the study at this stage. On the one hand, the species that dominated the non-native insect assemblage could have come from original environmental conditions that matched Chile’s. Or, the pool of non-native insects arrived using pathways associated with the country’s economic activities, regardless of their origin.

We found records of almost 600 non-native insect species established in continental Chile. Most species corresponded to Hemiptera (true bugs and scales, among others) from Palaearctic origin and were linked to agriculture and forestry, as we initially hypothesized. These characteristics point to the central role of intercontinental human-mediated transport in structuring non-native insect assemblages in Chile. Non-native insect introductions began immediately after the arrival of Europeans to the central valley of Chile and have shown an enormous acceleration since 1950. Using data on the economic history of Chile, we can preliminary link this acceleration with the strong development in agriculture and forestry in Chile after World War II and the increase in intercontinental air traffic.

Exotic aphids in garden in Chile. Photo by Sergio Estay

The development and analysis of this database gave us some preliminary answers about the ecology of invasive insect species and opened the door to new questions. Also, this is a work in progress. We need the scientific community’s support to improve and correct the records, provide new reports and collect further references to support the database. Our data and analysis may be representative of other countries in South America. Similarities between our countries can facilitate using this information to manage recent introductions and prevent significant economic, social, or environmental damage.

Reference

López DN, Fuentes-Contreras E, Ruiz C, Ide S, Estay SA (2023) A bug’s tale: revealing the history, biogeography and ecological patterns of 500 years of insect invasions. NeoBiota 81: 183-197. https://doi.org/10.3897/neobiota.81.87362

How non-native tree species affect biodiversity

Non-native forest tree species can reduce native species diversity if they are planted in uniform stands, finds an international review study.

Non-native forest tree species can reduce native species diversity if they are planted in uniform stands. In contrast, the effects of introduced species on soil properties are small. This was found by an international review study with the participation of the Swiss Federal Institute for Forest, Snow and Landscape Research WSL.

Curse or blessing? Opinions are divided on non-native tree species. In addition to native species, many foresters also plant non-native species that can withstand the increasing summer drought. In various parts of Europe, the latter are already important suppliers of timber. However, conservationists fear ecological damage, for example if native species are displaced or tree pathogens and insect pests are introduced.

In Switzerland, Douglas fir is partly used for afforestation. However, large pure stands, such as those found in Germany, are prohibited there. Photo by Thomas Reich

Now a team of European researchers, led by Thomas Wohlgemuth of WSL, has looked at the state of knowledge on the ecological consequences of alien tree species in Europe. They analysed the results of 103 studies on seven such species. All of these studies had investigated how stands dominated by non-native tree species affected biodiversity or soil condition under the trees compared to stands of native tree species. The organisms studied included plants, mosses, microorganisms and insects from the forest floor to the treetops.

Of the seven alien species studied, only the Douglas fir is currently planted in larger numbers in the Swiss forests. While foresters used to value its fast, straight growth and its versatile wood, today they appreciate its higher drought tolerance compared to spruce. Other species are problematic because they can spread uncontrollably. The North American Robinia, for example, is invasive and can displace native species. It was already introduced in Europe 400 years ago and used in Switzerland, among other things, to stabilise soils.

Robinia can spread rapidly and form stands as here in Valais. Photo by Thomas Reich

Negative effects on biodiversity predominate

Across the 103 studies, the consequences of non-native species for biodiversity were negative. Comparisons from 20 studies show, for example, that on average fewer insect species live on and in Douglas fir than in spruce or beech stands. Robinia also reduces the diversity of insects, eucalyptus that of birds. This is hardly surprising, says Wohlgemuth, head of the WSL Forest Dynamics Research Unit. Because: “These results apply to comparisons between pure stands.” In continuous, uniform plantations, many alien species clearly have worse impacts than native species.

Proportion of cases with increasing (green), decreasing (red) or non-significant (grey) effects of tree species non-native to Europe on diversity attributes (abundance, species richness or diversity) of different taxonomic groups in comparison to native vegetation. Numbers of cases are shown next to the NNTs names, below the diversity attributes and above the bars.

But alien species do not only have negative impacts. Most of them do not affect soil properties. The easily degradable needles of Douglas firs can even make more nutrients available than the poorly degradable spruce needles. “When it comes only to soil properties, the Douglas fir has no negative impact,” Wohlgemuth says. In general, an equal number of studies found positive and negative effects of the seven non-native species on the soil.

Douglas firs are attractive for forestry because of their fast growth, good wood properties and – in regard to climate change – their drought resistance. Photo by Thomas Reich

Furthermore, it makes a difference whether the alien species are more closely or more distantly related to European tree species. “Tree species without closer relatives, such as eucalyptus and acacia from Australia, reduce species diversity more strongly across all studies than closely related species, such as Douglas fir and wild black cherry from North America,” adds Martin Gossner, head of the WSL Forest Entomology Group and second author of the study.

A Douglas fir. Photo by Neptuul under a CC BY-SA 4.0 license

It all depends on the management

Management has a significant influence on whether Douglas fir or other tree species are good or bad for a forest overall. Uniform and dense Douglas fir stands are unsuitable habitats for many organisms. However, the same is true for spruces, which have been planted extensively for timber production in lowland areas of Central Europe over the last 100 years. On the other hand, Douglas firs in stands of native forest trees, individually or in small groups, would hardly disturb the ecosystem, Wohlgemuth says: “We conclude that the impact on native biodiversity is low with mixed-in Douglas firs.”

Should foresters plant non-native tree species or not? Despite certain negative aspects, Wohlgemuth does not recommend total renunciation. “Particularly in the case of Douglas fir, the facts show that moderate admixture in stands has little impact on native biodiversity, while at the same time preserving ecosystem services such as the production of construction timber. This is especially true when other, less drought-resistant conifers are increasingly lacking with regard to unchecked climate change.”

Research article:

Wohlgemuth T, Gossner MM, Campagnaro T, Marchante H, van Loo M, Vacchiano G, Castro-Díez P, Dobrowolska D, Gazda A, Keren S, Keserű Z, Koprowski M, La Porta N, Marozas V, Nygaard PH, Podrázský V, Puchałka R, Reisman-Berman O, Straigytė L, Ylioja T, Pötzelsberger E, Silva JS (2022) Impact of non-native tree species in Europe on soil properties and biodiversity: a review. NeoBiota 78: 45-69. https://doi.org/10.3897/neobiota.78.87022

Web news piece originally published by the Swiss Federal Institute for Forest, Snow and Landscape Research WSL. Republished with permission.

Follow NeoBiota on Twitter and Facebook.

Alien land snail species are increasing exponentially

A new study compiles an overview of the exponential increase and dynamic spread of land snail species introduced to Europe and the Mediterranean.

Invasive land snail species can displace native species and harm human health. A recent study by the Leibniz Institute for Biodiversity Change Analysis (LIB) compiles an overview of the exponential increase and dynamic spread of land snail species introduced to Europe and the Mediterranean from other continents.

Laevicaulis alte, an invasive species from tropical Africa that was introduced into Egypt in 2018. © Reham F. Ali

To date, there is a lack of information for the spread of alien species, especially invertebrates such as snails. “Despite efforts to compile lists of alien species, there is not even a well-documented inventory of alien invertebrate species for Europe,” emphasizes Prof. Dr. Bernhard Hausdorf, section leader Mollusca at LIB. His study, just published in the journal NeoBiota, provides a basis for decisions on further measures to control or eradicate introduced populations.

Alien land snail species in the Western Palaearctic Region: Zonitoides arboreus, Hawaiia minuscula, Guppya gundlachii, Polygyra cereolus

Land snails play a supporting role in ecosystems. They decompose decaying plants and thus play an important role in nutrient cycling and soil formation. However, more and more species are being spread beyond their native range, usually by humans, sometimes intentionally, but often unintentionally by goods or travellers.

The study examines 22 land snail species introduced to Europe and the Mediterranean from other continents. Most of them are small, live on decaying plant parts and apparently cause few problems. In contrast, carnivorous species can threaten native species; and species that feed on living plants can cause damage to agriculture. Some even serve as hosts and vectors of parasites that can cause brain encephalitis, for example, and thus can indirectly harm human health.

Alien land snail species in the Western Palaearctic Region: Paralaoma servilis and Helicodiscus parallelus.

Harmful species include the Laevicaulis species recently introduced to the Mediterranean from tropical Africa and the African giant snail Lissachatina fulica. They can cause economic damage on irrigated farmland or in greenhouses by destroying or contaminating crops, making them unsaleable.

Hausdorf’s study compiles records of land snail species introduced to the Western Palearctic region, Europe and the Mediterranean, from other regions after 1492 and established in the wild. In doing so, he observes that the number of alien species has increased steadily since the 19th century, even exponentially from the 1970s onward, and that the introduced species have become more widespread.

Within Europe, alien species generally spread from south to north and from west to east. Thirteen of the 22 species studied were from North America, three from sub-Saharan Africa, two from the Australian region, three probably from the Oriental region, and one from South America.

Alien land snail species in the Western Palaearctic Region: llopeas clavulinum, Allopeas gracile, Lissachatina fulica, Paropeas achatinaceum, and Discocharopa aperta.

Even if trade relations and the spread of species can be correlated, Hausdorf believes that the prevailing climate is primarily decisive: “The spread of many of the introduced species, especially the tropical species dispersing in Mediterranean, is probably favored by climate change.”

Bernhard Hausdorf, “Distribution patterns of established alien land snail species in the Western Palaearctic Region”, NeoBiota, Pensoft
https://doi.org/10.3897/neobiota.81.96360

Press release originally published by Leibniz Institute for the Analysis of Biodiversity Change. Republished with permission.

Follow NeoBiota on Facebook and Twitter.

Pensoft among the first 27 publishers to share prices & services via the Journal Comparison Service by Plan S

All journals published by Pensoft – each using the publisher’s self-developed ARPHA Platform – provide extensive and transparent information about their costs and services in line with the Plan S principles.

In support of transparency and openness in scholarly publishing and academia, the scientific publisher and technology provider Pensoft joined the Journal Comparison Service (JCS) initiative by cOAlition S, an alliance of national funders and charitable bodies working to increase the volume of free-to-read research. 

As a result, all journals published by Pensoft – each using the publisher’s self-developed ARPHA Platform – provide extensive and transparent information about their costs and services in line with the Plan S principles.

The JCS was launched to aid libraries and library consortia – the ones negotiating and participating in Open Access agreements with publishers – by providing them with everything they need to know in order to determine whether the prices charged by a certain journal are fair and corresponding to the quality of the service. 

According to cOAlition S, an increasing number of libraries and library consortia from Europe, Africa, North America, and Australia have registered with the JCS over the past year since the launch of the portal in September 2021.

While access to the JCS is only open to librarians, individual researchers may also make use of the data provided by the participating publishers and their journals. 

This is possible through an integration with the Journal Checker Tool, where researchers can simply enter the name of the journal of interest, their funder and affiliation (if applicable) to check whether the scholarly outlet complies with the Open Access policy of the author’s funder. A full list of all academic titles that provide data to the JCS is also publicly available. By being on the list means a journal and its publisher do not only support cOAlition S, but they also demonstrate that they stand for openness and transparency in scholarly publishing.

“We are delighted that Pensoft, along with a number of other publishers, have shared their price and service data through the Journal Comparison Service. Not only are such publishers demonstrating their commitment to open business models and cultures but are also helping to build understanding and trust within the research community.”

said Robert Kiley, Head of Strategy at cOAlition S. 

***

About cOAlition S:

On 4 September 2018, a group of national research funding organisations, with the support of the European Commission and the European Research Council (ERC), announced the launch of cOAlition S, an initiative to make full and immediate Open Access to research publications a reality. It is built around Plan S, which consists of one target and 10 principles. Read more on the cOAlition S website.

About Plan S:

Plan S is an initiative for Open Access publishing that was launched in September 2018. The plan is supported by cOAlition S, an international consortium of research funding and performing organisations. Plan S requires that, from 2021, scientific publications that result from research funded by public grants must be published in compliant Open Access journals or platforms. Read more on the cOAlition S website.