Search

Aim: Reducing the rate of alien species introductions is a major conservation aim. However, accurately quantifying the rate at which species are introduced into new regions remains a challenge due to the confounding effect of observation efforts on discovery records. Despite the recognition of this issue, most analyses are still based on raw discovery records, leading to biased inferences. In this study, we evaluate different models for estimating introduction rates, including new models that use auxiliary data on observation effort, and identify their strengths and weaknesses. Innovation: We compare four models: (1) a naïve model which assumes perfect detection; (2) a model proposed by Solow and Costello (the S&C model); (3) constant detection model: a modified version of the S&C model with constant detection probabilities and (4) a novel sampling proxy model: a model that uses external data on observation effort. We simulate discovery records of varying lengths, introduction rates and temporal patterns of detection probabilities to explore scenarios under which these models accurately estimate underlying introduction rates. (5) We also include code to perform a model based on Belmaker using independent data on the number of native species. Main conclusion: We found that the length of the discovery records and the annual number of recorded species play a crucial role in the performance of all models. Under simulated scenarios of high detection, the naïve model is usually the best‐performing model, but it falls short when detection is low. Moreover, we find that in simulations which most likely mimic most real‐world cases (i.e. non‐monotonic probability of detection), incorporating external data on observation effort using the sampling proxy model, substantially improve estimates. This highlights the importance of considering observation effort when estimating introduction rates of alien species. To facilitate the use of these models, we provide a decision workflow and a dedicated R package ('alien'). [ABSTRACT FROM AUTHOR]

Ailanthus altissima is one of the major invasive trees at a global scale. Despite numerous reports about its invasiveness in different habitats, so far it was not observed on harsh ultramafic soils and to colonize the vegetation of these outcrops. In this paper we show that the species can also spread in these habitats in the Mediterranean region and is able to cope with the severe anomalies of ultramafic soils. We sampled A. altissima in four ultramafic outcrops of central Italy and in control sites to unravel the behavior of this species toward the typically high soil concentrations of trace metals, such as Ni, Cr and Co, as well the imbalance of the Ca:Mg quotient. A similar sampling was performed for the native Fraxinus ornus that occurs naturally on a broad range of soils, including those from ultramafic rocks. Trace metal concentrations in leaves of both species were below toxicity thresholds, but A. altissima showed lower translocation and bioaccumulation factors (TF and BF, respectively) for Ni. Compared with F. ornus, the invasive species displayed higher leaf concentrations of Mg, thus suggesting a higher tolerance of potentially toxic levels of this element. Moreover, the higher TF and BF values for Ca in both control and serpentine populations suggested that A. altissima was more able to extract and accumulate this macronutrient in leaves in respect to F. ornus. Given the inherent deficiency of this element in ultramafic soils, efficient use of Ca could be a key trait contributing to the invasiveness of A. altissima on these soils. [ABSTRACT FROM AUTHOR]

Fisheries-dependent data and information gathered through fisheries-related scientific surveys can significantly contribute to research on the patterns and processes underlying marine biological invasions and their interactions with fisheries. This study presents an overview of the presence of non-native fish species in the North Aegean Sea, offering insights into their distributions and impact on fisheries. The findings are based on a comprehensive compilation of commercial fisheries-dependent and scientific survey data collected in Greece from 2016 to 2023, along with a systematic review of the international scientific literature. The study resulted in the documentation of the presence of 37 nonnative fish species, including several recorded for the first time in the area. The results suggest that non-native fish species invasions in the North Aegean Sea are dynamic. Although most species were classified as casual, and the frequencies of occurrence as well as the quantities in commercial fisheries catches of established species are smaller than in the South Aegean Sea, species introductions and the extent of occurrence and area of occupancy of several species have been increasing since the 2000s. The significance of non-native fish species is becoming increasingly relevant to commercial fisheries in the study area. This is particularly evident in the Northeastern Aegean Sea, where catches of non-native species are on the rise, and new species with potential commercial value have emerged in recent years. [ABSTRACT FROM AUTHOR]

Allometric data of marine fish species from Rhodes, southeastern Aegean Sea are scarce. Their collection is crucial as they provide important information on the ongoing changes of small-scale fisheries in Rhodian coastal marine waters, a highly affected region of the Eastern Mediterranean by biological invasions. Monthly experimental trials and random samplings with static nets were conducted from April 2021 to March 2022 in the coastal marine waters of eastern Rhodes, Levantine Sea. Experimental boat seining was deployed in November 2022 in the coastal waters of northwest Rhodes, Aegean Sea. Total length and total weight of several individuals of 21 fish species were measured and the length-weight relationships of 12 indigenous and nine nonindigenous fish species were examined. The allometric coefficient (b) did not differ significantly from 3.00 for most of the species (70%), demonstrating isometric growth. Positive and negative allometry were found for three indigenous and three non-indigenous species. The largest and heaviest species were the bluespotted cornetfish (Fistularia commersonii), with a maximum TL of 117.60 cm and the silver-cheeked toadfish (Lagocephlaus sceleratus), with a maximum weight of 4640.90 g. Statistically significant positive allometric relationships were found for three non-indigenous fish, namely the bluespotted cornetfish, the devil firefish (Pterois miles) and the dusky spinefoot (Siganus luridus), suggesting that these species are thriving in the under-study area. [ABSTRACT FROM AUTHOR]

The presence of alien species represents a major cause of habitat degradation and biodiversity loss worldwide, constituting a critical environmental challenge of our time. Despite sometimes experiencing reduced propagule pressure, leading to a reduced genetic diversity and an increased chance of inbreeding depression, alien invaders are often able to thrive in the habitats of introduction, giving rise to the so‐called "genetic paradox" of biological invasions. The adaptation of alien species to the new habitats is therefore a complex aspect of biological invasions, encompassing genetic, epigenetic, and ecological processes. Albeit numerous studies and reviews investigated the mechanistic foundation of the invaders' success, and aimed to solve the genetic paradox, still remains a crucial oversight regarding the temporal context in which adaptation takes place. Given the profound knowledge and management implications, this neglected aspect of invasion biology should receive more attention when examining invaders' ability to thrive in the habitats of introduction. Here, we discuss the adaptation mechanisms exhibited by alien species with the purpose of highlighting the timing of their occurrence during the invasion process. We analyze each stage of the invasion separately, providing evidence that adaptation mechanisms play a role in all of them. However, these mechanisms vary across the different stages of invasion, and are also influenced by other factors, such as the transport speed, the reproduction type of the invader, and the presence of human interventions. Finally, we provide insights into the implications for management, and identify knowledge gaps, suggesting avenues for future research that can shed light on species adaptability. This, in turn, will contribute to a more comprehensive understanding of biological invasions. [ABSTRACT FROM AUTHOR]

The Atlantic croaker Micropogonias undulatus, a sciaenid fish native to the North Atlantic American coast, holds importance in recreational and commercial fisheries. Moreover, its potential as an invasive species should be noted, given its expansion and establishment in Atlantic European waters. This study reports its southernmost occurrence in Europe, in the Gulf of Cadiz. Morphological and molecular analysis confirmed its identity, revealing genetic similarities to US sequences. A comprehensive review of historical non-native distribution records underscored the species' expansion throughout European waters, suggesting human-mediated introduction. The escalating frequency of such arrivals emphasises the critical need for effective monitoring and management efforts in order to control non-native species in this region. [ABSTRACT FROM AUTHOR]

Simple Summary: The Atlantic blue crab Callinectes sapidus, which is native to the western Atlantic coast and listed among the 100 most invasive alien species in the Mediterranean Sea, is attracting a great deal of interest because of its rapid colonisation of new areas, the significant increase in its population, and the impacts it may have on ecosystems. Outside its natural distribution range, the species was first found on the European coasts of the Atlantic in the early 1900s, and a few decades later, it was introduced into the Mediterranean Sea, probably through maritime traffic. Currently, it is found in almost the entire Mediterranean Basin and is also expanding into the Black Sea and along the north African and Iberian Atlantic coasts. This study describes the distribution of the Atlantic blue crab in Northwest Europe, in the Mediterranean Sea, and in adjacent waters through a series of ecological indicators elaborated using spatial–temporal statistics. The main results highlight that the species is expanding in the Mediterranean and adjacent waters, while in northern Europe, the population remains confined in some areas. The main species detection methods are analysed, finding that traps and nets are the most used methods, and management suggestions are provided. The Atlantic blue crab Callinectes sapidus, which is native to the western Atlantic coast and listed among the 100 most invasive alien species in the Mediterranean Sea, is attracting a great deal of interest because of its rapid colonisation of new areas, the significant increase in its population, and the impacts it may have on ecosystems and ecosystem services. Outside its natural distribution range, the species was first found on European Atlantic coasts in the early 1900s and was introduced into the Mediterranean Sea a few decades later, probably through ballast water. Currently, it is found in almost the entire Mediterranean Basin and is also expanding into the Black Sea and along the north African and Iberian Atlantic coasts. Based on a systematic review of C. sapidus occurrences, this study describes its distribution, aggregation patterns, and spatial structure in Northwest Europe, the Mediterranean Sea, and adjacent waters through a series of ecological indicators elaborated using GIS spatial–temporal statistics. The main results highlight that the species is expanding in the Mediterranean and adjacent waters, while in northern Europe, the population remains confined in some areas. Furthermore, the main species detection methods are analysed, finding that traps and nets are the most frequently used methods, and management suggestions are provided. [ABSTRACT FROM AUTHOR]

Several Oriental and Australian species of Ficus have been introduced outside their native range and planted as ornamentals in urban habitats throughout the Mediterranean. This translocation of plant species has led to the introduction of host-specific insects such as their pollinating fig wasps (Hymenoptera: Agaonidae). Here, the Australian fig wasp Pleistodontes imperialis Saunders, 1882 is reported for the first time from Greece. Partial COI genes were sequenced for specimens sampled in Greece and Cyprus, and they appear to share identical haplotypes. Interestingly, this species-specific wasp not only develops in figs of its usual host, Ficus rubiginosa, but also in figs of Ficus watkinsiana, another Australian species introduced in Greece, which is pollinated by a second agaonid species (Pleistodontes nigriventris Girault, 1915) in its native range. Although no negative economic or environmental impacts have been observed yet, monitoring of alien Ficus spp. in the region is encouraged to prevent their possible establishment in natural habitats. [ABSTRACT FROM AUTHOR]

Freshwater megafish species, such as sturgeons, salmonids, carps, and catfishes, have a maximum reported weight ≥30 kg. Due to their charisma and economic value, they have been widely introduced outside of their native ranges. Here, we provide a comprehensive overview of the introduction of freshwater megafish and an assessment of their environmental impacts. Of the 134 extant freshwater megafish species, 46% have been introduced to new environments, and of these, 69% have established self‐sustaining alien populations. These introductions affect 59% of the world's main basins, with the USA and western Europe being particular hotspots of megafish introductions. The common carp (Cyprinus carpio) is the most widely introduced species. Using the Environmental Impact Classification for Alien Taxa (EICAT and EICAT+) frameworks, we assessed the severity and type of negative and positive impacts posed by alien megafish on native species. Alien megafish caused negative impacts through nine different mechanisms, with predation being the most frequently reported mechanism, followed by herbivory and competition. Moreover, 58% of the alien megafish species with sufficient data to evaluate the severity of their impacts caused declining populations of native species, or worse, extirpations of native species populations. The positive environmental impacts of alien megafish were far less frequently documented. They include biotic interactions that benefit native species, and the provision of trophic resources or habitats. Widely introduced or extensively studied species are more likely to have documented severe impacts on native species. There is a clear trade‐off between the economic benefits associated with megafish introductions and the severe adverse impacts they have on native biodiversity. Our study highlights the need for comprehensive risk assessments to evaluate the potential environmental impacts of megafish. More research and long‐term monitoring schemes are required to inform management actions to protect biodiversity, particularly in the Global South. [ABSTRACT FROM AUTHOR]

A "blacklist" of the flora of Orenburg oblast, including 63 species of invasive plants, was compiled. According to the recommendations for the maintenance of regional black books, the blacklist species are divided into four groups according to their invasive status. Ten key species (status 1) are able to change the structure and composition of plant communities, 12 species of invasive status 2 are actively naturalizing in natural and seminatural habitats, 23 species of invasive status 3 have dispersed in anthropogenic habitats. Eighteen species are potentially invasive (status 4). The article is a phase of preparation of the regional Black Book of Flora of Orenburg Oblast and contributes to the study of invasion processes in the Southern Urals and in the Russian Federation in general. The information can be used for taking measures of verification of the number of dangerous invasive species in order to reduce ecological and economic damage due to their invasions. [ABSTRACT FROM AUTHOR]

Microclimates of large cities and global warming favor the range expansion of the Far-Eastern invasive fish Perccottus glenii in northern regions of Europe where this invader becomes a component of local ecosystems and participates in transmission of parasites and pollutants along food chains. We have assessed contents of seven trace elements in muscle tissues of this invasive fish in 16 water bodies within the city of Moscow. In all water bodies studied, quantities of all studied elements did not exceed the maximum concentrations permitted in national and international guidelines. Therefore, the screened water bodies of Moscow may be assessed as unpolluted. The fish P. glenii is a convenient object for assessing pollution levels of city ponds, since this fish species is now widespread, reaches a high population densities in shallow aquatic sites, may be caught easily, no permit is required for its capture because the species is recognized as invasive, and its partial elimination does not damage native freshwater ecosystems. [ABSTRACT FROM AUTHOR]

Forests support a variety of functions essential for the provisioning of ecosystem services. However, invasive plants can disrupt forest functioning, particularly in temperate forest understories that commonly experience invasive plant encroachment, by altering community-level trait distributions. Invasive plants, frequently characterized by acquisitive traits such as higher specific leaf area and nitrogen content, may either outcompete native species with different trait values (displacement), or add trait values to the existing community (complementarity). Therefore, complementarity may still allow restoration of the original community function by removing invasive species, and consequently the added provision of function when compared to the natives, but displacement may not. While understanding which process occurs is critical in managing ecosystem functionality, little is known about the impact of invasion on the co-occurring native community trait distributions. To address this knowledge gap, we leveraged survey data on temperate forest understories that varied in their degree of invasion (i.e., gradient of invasion). We calculated the community- weighted mean of three leaf traits: leaf nitrogen, specific leaf area, and leaf dry matter content -- traits strongly linked to invasion, sensitive to environmental changes, and that affect ecosystem functions. Our findings show that increasing invasion had a significant positive effect on total (native and invasive) community leaf nitrogen, but did not alter native community trait distributions. This suggests that potential impacts on ecosystem functions, such as increased primary productivity and nitrogen cycling, would be primarily driven by trait complementarity and not displacement. We did not find any significant differences in the total or native communities with respect to specific leaf area or leaf dry matter content. Differentiating trait displacement from trait complementarity contributes to our understanding of how invasion affects functionality of understory plant communities in forests. Additionally, it provides a valuable framework to facilitate evidence-based decisions for the management of ecosystem functionality. [ABSTRACT FROM AUTHOR]

Aim: Anticipating the ultimate fraction of a landscape that might be susceptible to invasion is challenging as several species are able to expand the range of environmental conditions used over invasion. Despite its relevance, the more proximate processes underlying observed shifts are not sufficiently understood. Habitat selection theory predicts that as population density increases, individuals start using sub‐optimal resources to compensate for the limitation of the preferred ones. However, niche shifts might also occur as result of changes in habitat preferences over time. Here, we tested these alternative hypotheses by investigating nesting resource use and selection over a biological invasion and the relative effect of density‐dependence on such patterns. Location: Barcelona, Spain. Methods: We take advantage of a large dataset recording the occurrence of the invasive monk Parakeet, Myiopsitta monachus in Barcelona in the period 1975–2015. We apply generalized linear models to analyse changes in nesting habitat preferences and its interactive effect with conspecific presence. Results: Temporal changes in nesting habitat use occurred. Palm species were the most commonly used nesting substrate since the beginning of the invasion but the diversity and frequency of use of other nesting substrates increased over time. Changes in nesting substrate use were consistent with a change in habitat selection, when accounting for habitat availability. Although a general role of conspecific aggregation on occupation patterns was found, it was mostly additive. That is, shifts in nesting substrate did not structure in relation to conspecific distribution. Conclusions: Shifts in nesting resource selection can occur during the spread stage of biological invasions, probably related to innovation and learning, rather than to optimal habitat selection. These shifts present a significant challenge for forecasting efforts and management. However, changes do not happen rapidly over time, highlighting that there is a management opportunity window before significant shifts occur. [ABSTRACT FROM AUTHOR]

Species richness is a fundamental property of biodiversity patterns and is properly expressed by the species–area relationship (SAR), namely the increase in the number of species with the area. Here, we studied and explored the species–area relationship with respect to vascular plant species in Italy and compared vascular plant richness among Italian administrative regions. Concerning the entire vascular flora (native and alien), the best-performing formula is the Arrhenius' Power function: S = c Az. The constants of this function are c = 241.2 and z = 0.281. The best-performing formula concerning just native (c = 245.2 and z = 0.263) and alien (c = 10.1 and z = 0.404) richness is the Power function as well. The floristically richest Italian regions considering the entire flora are Liguria, Friuli Venezia Giulia, and Trentino-Alto Adige, which are also the regions that are richest in alien flora unfortunately. Regions of particular naturalistic interest are Abruzzo, Valle d'Aosta, and Molise, because only these three regions exhibit native floristic richness that is higher than expected, and this is coupled with an alien floristic richness that is lower than expected. On the contrary, four regions (Lombardia, Veneto, Toscana, and Emilia-Romagna) show potentially severe conservation problems due to biological invasions since they experience native floristic richness that is lower than expected, with an alien floristic richness that is higher than expected. This study offers for the first time the 'c' and 'z' constants specifically calibrated at the national level for Italian vascular flora. The availability of such constants allows the calculation of the number of expected species for a given area to be investigated, providing a robust starting hypothesis for floristic studies. [ABSTRACT FROM AUTHOR]

Fisheries-dependent data and information gathered through fisheries-related scientific surveys can significantly contribute to research on the patterns and processes underlying marine biological invasions and their interactions with fisheries. This study presents an overview of the presence of non-native fish species in the North Aegean Sea, offering insights into their distributions and impact on fisheries. The findings are based on a comprehensive compilation of commercial fisheries-dependent and scientific survey data collected in Greece from 2016 to 2023, along with a systematic review of the international scientific literature. The study resulted in the documentation of the presence of 37 non-native fish species, including several recorded for the first time in the area. The results suggest that non-native fish species invasions in the North Aegean Sea are dynamic. Although most species were classified as casual, and the frequencies of occurrence as well as the quantities in commercial fisheries catches of established species are smaller than in the South Aegean Sea, species introductions and the extent of occurrence and area of occupancy of several species have been increasing since the 2000s. The significance of non-native fish species is becoming increasingly relevant to commercial fisheries in the study area. This is particularly evident in the Northeastern Aegean Sea, where catches of non-native species are on the rise, and new species with potential commercial value have emerged in recent years.

Solidago × niederederi (Asteraceae) is a natural hybrid of the native S. virgaurea and the alien invasive S. canadensis, originated in Europe. Its naturalisation potential is still questionable. One of the largest (more than 20 ramet clusters, treated as individuals) known population of this nothospecies, is located in the «Aleksin Bor» Natural Monument (Aleksin town, Tula Region, Russia) in the floodplain of the River Oka. We studied its genetic structure with the help of chloroplast and nuclear markers. Analysis of sequence of nuclear ribosomal internal transcribed spacer ITS 1–2 showed that all individuals with intermediate morphology are actually hybrids. Data on the intergenic chloroplast non-coding spacer rpl32–trnL showed that S. canadensis is the maternal species in 60% of the studied individuals. It was shown that even closely located individuals were not clones; therefore, they were results of sexual, rather than vegetative reproduction. Analysis of ISSR markers showed that the studied individuals of S. × niederederi in this population are not only F1 hybrids, but also their descendants (F2 hybrids and/or backcrosses, mostly with S. canadensis). We conclude that S. × niederederi has successfully been naturalised in the studied community and, possibly, is outcompeting its native parental species, S. virgaurea, through introgression.

Abstract Alien species can be damaging to native biodiversity, human well‐being and the economy. Identifying the complete range of impacts they cause, and the ways that these impacts are connected, may inform the prioritisation of management actions to mitigate impacts. Using datasets on the biodiversity impacts and monetary costs (damage and management costs) of alien birds, we aimed to establish whether species with the most severe biodiversity impacts also had the highest costs; whether types of biodiversity impact were associated with high costs; and whether specific factors associated with alien species are linked to both damaging biodiversity impacts and high costs. We identified a positive relationship between a specific type of biodiversity impact (predation) and costs, possibly because predation by alien birds can be severely damaging to native species and therefore attracts management actions. However, predation impacts are likely to occur more frequently and to be easier to identify than some other impact mechanisms such as hybridisation and transmission of diseases, and they are therefore likely to be more frequently managed and hence to have costs. We identified a specific species characteristic (generalism) to be associated with severe biodiversity impacts and high costs, probably because generalist species have greater opportunity to cause impacts, whether they be on biodiversity or the economy, or both. We also found widely distributed alien birds to be associated with high costs, probably because these species also have greater opportunity to cause impacts. Management interventions that prevent the introduction of both predatory and generalist alien bird species, or that reduce their geographic distribution at early stages of invasions, may have significant biodiversity and economic benefits. Read the free Plain Language Summary for this article on the Journal blog.

Ponto–Caspian gobies are among Europe's most invasive freshwater fish species. These small freshwater and brackish water fish have spread rapidly since the end of the last century, invading the major European river systems, including the Rivers Danube, Rhine, Moselle, Meuse, Vistula, Elbe, Nemunas, Neva, Volga, while also establishing in streams, dam reservoirs, lakes, and artificial canals in 17 European countries. Two species have also successfully established in North America. The contribution of Ponto–Caspian gobies to local fish assemblages varies, but locally they are abundant or dominant components of fish assemblages in invaded ecosystems. We have considered their invasive distribution, range of occupied aquatic environments, abundance, and frequency of occurrence, and summarised their role and position in the trophic webs of invaded ecosystems. We focused on four goby species: western tubenose goby Proterorhinus semilunaris, bighead goby Ponticola kessleri, racer goby Babka gymnotrachelus and monkey goby Neogobius fluviatilis. Based on our own research and other published studies, we described the habitat preferences of these species and assessed their ecological impact on co-occurring species, both native and non-native, as predators, prey, competitors, and as hosts and vectors of parasites. [ABSTRACT FROM AUTHOR]

Globalization, the expansion of trade relations, inter- and intracontinental movements of population, the development of transport networks between the countries led to an active settlement of many plant species outside their natural areas. Among such plants, a group of invasive species (those whose distribution has serious environmental, economic, and social consequences) is distinguished. The article contains information about the results of the inventory of invasive species of vascular plants growing in the Russian Federation, as well as an overview of the actions taken in the country to manage the invasive plant species. At present, there are 584 invasive species of vascular plants in Russia; out of them, Acer negundo, Echinocystis lobata, and Erigeron canadensis are the most common. It has to be stated, that until now, both legislative acts regulating the policy in the field of invasive species (legal regulation of phytoquarantine is an exception) and a national strategy for alien species in Russia are absent. The efficient management of biological invasions can work in the case where the general public is aware of the adverse consequences of the invasion of invasive species. [ABSTRACT FROM AUTHOR]

Rising temperatures due to climate change are expected to interplay with biological invasions, and may enhance the spread and growth of some alien species upon arrival in new areas. To successfully invade, a plant species needs to overcome multiple biological barriers. Among the crucial life stages, seed germination greatly contributes to the final species assembly of a plant community. Several studies have suggested that alien plant success is related to their high seed germination and longevity in the soil. Hence, our aim is to test if the germination potential of alien seeds present in the seed bank will be further enhanced by future warming in temperate dry grasslands, an ecosystem that is among those most prone to biological invasions. We designed a laboratory germination experiment at two temperatures (20 and 28 °C), to simulate an early or late heat wave in the growing season, using seeds from nine common grassland Asteraceae species, including native, archaeophyte and neophyte species. The test was performed on both single and mixed pools of these categories of species, using a full-factorial orthogonal design. The warmer germination temperature promoted neophyte success by increasing germination probability and germination speed, while negatively impacting these parameters in seeds of native species. The co-occurrence of native and archaeophyte seeds at the lower temperature limited the invasiveness of neophytes. These results provide important information on future management actions aimed at containing alien plant invasions, by improving our knowledge on the possible seed-bank response and interaction mechanisms of common species occurring in disturbed natural areas or restored sites. Summary of the experimental results. The colour of the flowers represent the status, divided as native (blue), neophyte (red) and archaeophyte (green). Each flower symbol represents the species pool for each plant category (i.e. NA = Buphthalmum salicifolium, Carlina vulgaris, Centaurea scabiosa; NE = Artemisia annua, Symphyotrichum novi-belgii, Senecio inaequidens; AR = Centaurea cyanus, Cichorium intybus, Tripleurospermum inodorum). The number of flowers represent the germination percentage of the various category assembly. In the columns are divided the various combination. From up to bottom the trend of germination percentage at 20 and 28 °C are shown. [ABSTRACT FROM AUTHOR]

Biological invasions are among the main threats to the diversity of freshwater ecosystems, particularly invasions of freshwater crayfishes, which have negatively impacted native populations and ecosystem functions. Various invasions of freshwater crayfishes have been relatively well documented, allowing the use of Ecological Niche Modeling (ENM) techniques to forecast their potential invasive distribution. Modeling the most environmentally suitable areas for exotic species can provide guidelines to allocate resources, thus contributing to the control and management of invasions. We modelled the potential distribution of Cherax quadricarinatus (von Martens, 1868) and Procambarus clarkii Girard, 1852 in Mesoamerica and the Caribbean using global occurrence data and ten environmental variables to ensemble a model using nine different algorithms. Our models showed that C. quadricarinatus has a high probability of invasion in tropical lowland areas, with the presence of exotic populations of this species already reported. Our results support that P. clarkii has a higher probability of invasion in some of the mountain ranges and plateaus of the study region, where this species has already established non-native populations. These models visualize the high-risk areas of invasion of these two non-native crayfish species in Mesoamerica and the Caribbean. A regional approach for monitoring and control of the invasive populations is encouraged as well as regulations for trade and aquaculture of freshwater crayfishes. [ABSTRACT FROM AUTHOR]

Biological invasions are one of the major constraints worldwide because of the economic and environmental consequences they may pose. Root mealybugs (Hemiptera: Coccomorpha: Rhizoecidae) are continuously transported worldwide with plant soil because of their cryptic behavior. In this study it was reported the presence of Ripersiella multiporifera Jansen in Sicily for the first time and discussed the presence of R. maasbachi (Jansen) and R. hibisci (Kawai & Takagi) in Italy. A key is provided to identify the species of Rhizoecidae currently known in Italy. The species were identified by morphological features and characterized molecularly by using a partial COI mitochondrial gene. Our report alerts the presence of alien root mealybugs in Italy. R. hibisci is a quarantine species listed in Annex IIA of EU Regulation 2019/2072. [ABSTRACT FROM AUTHOR]

Invasive alien species (IAS), including aquatic invasive alien rodents (AIAR), cause extensive damage to ecosystems with significant economic, human health, and environmental concerns. In France, AIAR populations are well established, and a permanent control programme has been set up in several areas to reduce their impact. While some studies have reported the results of AIAR control activities, detailed information on current management strategies and how control activities are implemented in the field is lacking. This study evaluates the implementation of the management plan and control activities of AIAR in France regarding (i) problem definition, feasibility and objectives, (ii) planning from action plan, organization, funding and methods, (iii) field implementation from spatial prioritisation and personnel and (iv) monitoring and evaluation. Our study reveals that in France, (i) local and regional institutions mainly manage control activities primarily through volunteers and (ii) national and regional management plans on AIAR controls are missing. We elaborate on several actions that can help local and regional entities in improving their control programme, including zonation for priority actions, development of performance indicators of control activities, engagement of volunteers, and scientific monitoring of AIAR populations. [ABSTRACT FROM AUTHOR]

Aquatic ecosystems are particularly vulnerable to the introduction of non-indigenous species (NIS), leading to multi-faceted ecological, economic and health impacts worldwide. The Iberian Peninsula comprises an exceptionally biodiverse Mediterranean region with a high number of threatened and endemic aquatic species, most of them strongly impacted by biological invasions. Following a structured approach that combines a systematic review of available information and expert opinion, we provide a comprehensive and updated multi-taxa inventory of aquatic NIS (fungi, macroalgae, vascular plants, invertebrates and vertebrates) in Iberian inland waters. Moreover, we assess overall patterns in the establishment status, introduction pathways, native range and temporal introduction trends of listed NIS. In addition, we discuss the legal coverage provided by both national (Spanish and Portuguese) and European NIS regulations. We inventoried 326 aquatic NIS in Iberian inland waters, including 215 established, 96 with uncertain establishment status and 15 cryptogenic taxa. Invertebrates (54.6%) and vertebrates (24.5%) were the groups with the highest number of NIS, with Arthropoda, Mollusca, and Chordata being the most represented phyla. Recorded NIS originated from diverse geographic regions, with North and South America being the most frequent. Vertebrates and vascular plants were mostly introduced through intentional pathways (i.e. release and escape), whereas invertebrates and macroalgae arrived mostly through unintentional ways (i.e. contaminant or stowaway). Most of the recorded NIS were introduced in Iberian inland waters over the second half of the 20th century, with a high number of NIS introductions being reported in the 2000s. While only 8% of the recorded NIS appear in the European Union list of Invasive Alien Species of Union concern, around 25% are listed in the Spanish and Portuguese NIS regulations. This study provides the most updated checklist of Iberian aquatic NIS, meeting the requirements set by the EU regulation and providing a baseline for the evaluation of its application. We point out the need for coordinated transnational strategies to properly tackle aquatic invasions across borders of the EU members. [ABSTRACT FROM AUTHOR]

Citizen science initiatives have been increasingly used by researchers as a source of occurrence data to model the distribution of alien species. Since citizen science presence‐only data suffer from some fundamental issues, efforts have been made to combine these data with those provided by scientifically structured surveys. Surprisingly, only a few studies proposing data integration evaluated the contribution of this process to the effective sampling of species' environmental niches and, consequently, its effect on model predictions on new time intervals. We relied on niche overlap analyses, machine learning classification algorithms and ecological niche models to compare the ability of data from citizen science and scientific surveys, along with their integration, in capturing the realized niche of 13 invasive alien species in Italy. Moreover, we assessed differences in current and future invasion risk predicted by each data set under multiple global change scenarios. We showed that data from citizen science and scientific surveys captured similar species niches though highlighting exclusive portions associated with clearly identifiable environmental conditions. In terrestrial species, citizen science data granted the highest gain in environmental space to the pooled niches, determining an increased future biological invasion risk. A few aquatic species modelled at the regional scale reported a net loss in the pooled niches compared to their scientific survey niches, suggesting that citizen science data may also lead to contraction in pooled niches. For these species, models predicted a lower future biological invasion risk. These findings indicate that citizen science data may represent a valuable contribution to predicting future spread of invasive alien species, especially within national‐scale programmes. At the same time, citizen science data collected on species poorly known to citizen scientists, or in strictly local contexts, may strongly affect the niche quantification of these taxa and the prediction of their future biological invasion risk. [ABSTRACT FROM AUTHOR]

Copyright of People & Nature is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Atlantic blue crab Callinectes sapidus, which is native to the western Atlantic coast and listed among the 100 most invasive alien species in the Mediterranean Sea, is attracting a great deal of interest because of its rapid colonisation of new areas, the significant increase in its population, and the impacts it may have on ecosystems and ecosystem services. Outside its natural distribution range, the species was first found on European Atlantic coasts in the early 1900s and was introduced into the Mediterranean Sea a few decades later, probably through ballast water. Currently, it is found in almost the entire Mediterranean Basin and is also expanding into the Black Sea and along the north African and Iberian Atlantic coasts. Based on a systematic review of C. sapidus occurrences, this study describes its distribution, aggregation patterns, and spatial structure in Northwest Europe, the Mediterranean Sea, and adjacent waters through a series of ecological indicators elaborated using GIS spatial–temporal statistics. The main results highlight that the species is expanding in the Mediterranean and adjacent waters, while in northern Europe, the population remains confined in some areas. Furthermore, the main species detection methods are analysed, finding that traps and nets are the most frequently used methods, and management suggestions are provided.

Thaumastocoris peregrinus Carpintero and Dellapé, 2006, originally from Australia, has become a cosmopolitan alien species associated with Eucalyptus spp. (Myrtaceae). In this study, the species is recorded for the first time in Cyprus from the Limassol district and the Akrotiri UK Sovereign Base Area. The adverse socioeconomic impacts of the species on the island are briefly discussed.

Simple Summary: When species from one place invade and settle in another, it can cause serious problems for the local environment. These invasions, known as bio-invasions, disrupt natural ecosystems and can lead to major changes. The Mediterranean Sea is especially at risk because the water conditions are changing rapidly due to climate change, which, coupled with the opening of the Suez Canal, creates an appropriate environment for species from the Red Sea to move in. In May 2023, divers found a type of soft coral called Dendronephthya, that is new to the Mediterranean Sea near Israel. This coral is normally found in the Indo-Pacific region and is common in the Red Sea. Using molecular and morphological analysis, we confirmed the identity of the coral. Because this coral can attach swiftly to surfaces and grow quickly, it is expected to spread rapidly and become more common throughout the Mediterranean Sea. Bio-invasions have the potential to provoke cascade effects that can disrupt natural ecosystems and cause ecological regime shifts. The Mediterranean Sea is particularly prone to bio-invasions as the changing water conditions, evoked by climate change, are creating advantageous conditions for Lessepsian migrants from the Red Sea. Recently, in May 2023, a new alien species was documented in the Mediterranean Sea—a soft coral of the genus Dendronephthya. This discovery was made by divers conducting 'Long-Term Ecological Research' surveys, along the coast of Israel, at a depth of 42 m. Genetic and morphological testing suggest that the species identity may be Dendronepthya hemprichi, an Indo-Pacific coral, common in the Red Sea. According to life history traits of this species, such as accelerated attachment to available surfaces and fast growth, we expect it to rapidly expand its distribution and abundance across the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Shifts between native and alien climatic niches pose a major challenge for predicting biological invasions. This is particularly true for insular species because geophysical barriers could constrain the realization of their fundamental niches, which may lead to underestimates of their invasion potential. To investigate this idea, we estimated the frequency of shifts between native and alien climatic niches and the magnitude of climatic mismatches using 80,148 alien occurrences of 46 endemic insular amphibian, reptile, and bird species. Then, we assessed the influence of nine potential predictors on climatic mismatches across taxa, based on species' characteristics, native range physical characteristics, and alien range properties. We found that climatic mismatch is common during invasions of endemic insular birds and reptiles: 78.3% and 55.1% of their respective alien records occurred outside of the environmental space of species' native climatic niche. In comparison, climatic mismatch was evident for only 16.2% of the amphibian invasions analyzed. Several predictors significantly explained climatic mismatch, and these varied among taxonomic groups. For amphibians, only native range size was associated with climatic mismatch. For reptiles, the magnitude of climatic mismatch was higher for species with narrow native altitudinal ranges, occurring in topographically complex or less remote islands, as well as for species with larger distances between their native and alien ranges. For birds, climatic mismatch was significantly larger for invasions on continents with higher phylogenetic diversity of the recipient community, and when the invader was more evolutionarily distinct. Our findings highlight that apparently common niche shifts of insular species may jeopardize our ability to forecast their potential invasions using correlative methods based on climatic variables. Also, we show which factors provide additional insights on the actual invasion potential of insular endemic amphibians, reptiles, and birds. [ABSTRACT FROM AUTHOR]

Predicting the likelihood that non-native species will be introduced into new areas remains one of conservation's greatest challenges and, consequently, it is necessary to adopt adequate management measures to mitigate the effects of future biological invasions. At present, not much information is available on the areas in which non-native aquatic plant species could establish themselves in the Iberian Peninsula. Species distribution models were used to predict the potential invasion risk of (1) non-native aquatic plant species already established in the peninsula (32 species) and (2) those with the potential to invade the peninsula (40 species). The results revealed that the Iberian Peninsula contains a number of areas capable of hosting non-native aquatic plant species. Areas under anthropogenic pressure are at the greatest risk of invasion, and the variable most related to invasion risk is temperature. The results of this work were used to create the Invasion Risk Atlas for Alien Aquatic Plants in the Iberian Peninsula, a novel online resource that provides information about the potential distribution of non-native aquatic plant species. The atlas and this article are intended to serve as reference tools for the development of public policies, management regimes, and control strategies aimed at the prevention, mitigation, and eradication of non-native aquatic plant species. [ABSTRACT FROM AUTHOR]

This article provides information on the modern distribution of an alien species in the ichthyofauna of the Republic of Dagestan, the topmouth gudgeon Pseudorasbora parva (Temminck et Schlegel, 1846) (Cyprinidae). This species is found practically in all studied water bodies—the Manasozen, Gamriozen, Ulluchai, Rubas, and Avarskoe Koisu (a tributary of the Sulak River, in the area of the Gotsatlinskaya HPP) rivers—and in Lake Mochokh. Apparently, the wide distribution of P. parva is associated with its ecological plasticity, migratory activity, high growth rate, accelerated puberty, and high level of survival of the offspring. [ABSTRACT FROM AUTHOR]

Biological invasions, resulting from human activities, exert substantial impacts on ecosystems worldwide. This review focuses on marine invasive alien species (IAS) in Europe, examining the current state, proposing strategies to address the problem, and offering recommendations for enhanced management. Effective management of biological invasions relies on accessible, accurate data to inform decision-making. Information systems such as the European Alien Species Information Network (EASIN), Aquatic Non-Indigenous and Cryptogenic Species (AquaNIS), and World Register of Introduced Marine Species (WriMS) provide comprehensive databases on IAS, but their sustainability requires long-term maintenance, continuous updates, and support. Most countries lack specific monitoring programs for marine IAS, and standardization and improvement of monitoring methods are needed. Port monitoring plays a vital role in the early detection of new arrivals, and recent advancements in molecular techniques show promise for effective IAS monitoring. Risk screening tools are commonly employed to rank taxa based on their invasiveness potential in European regions, but variations in protocols can yield inconsistent results. European impact assessments highlight resource competition, novel habitat creation, and predation as primary mechanisms for negative impacts on biodiversity, while the creation of novel habitats represents a key mechanism for positive impacts. Preventing IAS introductions is critical, and measures such as ballast water treatment systems are implemented to reduce the likelihood of marine introductions. However, understanding introduction pathways remains uncertain for many IAS. Eradication and control efforts for marine IAS have limited success, emphasizing the need for enhanced biosecurity measures. Climate change, especially ocean warming, can intensify IAS impacts on native species and ecosystems. In climate change hotspots, some tropical aliens may, however, compensate for the loss of thermally sensitive natives with similar traits. Therefore, it is imperative to consider the interactions between climate change and IAS in developing effective management and conservation strategies. Enhancing IAS management in Europe entails i) securing adequate funding, ii) expanding the list of IAS of Union Concern to adequately cover marine invasions, iii) learning from countries with successful biosecurity practices, iv) sustaining information systems, v) improving monitoring and early warning systems with innovative technologies, vi) enhancing prediction models, vii) conducting integrated impact assessments and mapping cumulative IAS impacts, and vii) considering the potential benefits of IAS in ecosystem functioning and services.

We report the occurrence of Kallstroemia tribuloides (Mart.) Steud. in Rio de Janeiro, Brazil after 136 years. Kallstroemia tribuloides is adapted to open, sunny environments with a preference for sandy soils, which are typical drylands (e.g., the Caatinga biome) and Restingas. This species has attributes that may favor its expansion into newly environments, and its bioinvasive potential should not be overlooked. Thus, we strongly recommend that further studies monitor the spread of K. tribuloides on the Brazilian southeast coast, which can help in its control. [ABSTRACT FROM AUTHOR]

Biological invasions represent one of the main drivers of biodiversity loss with adverse impacts on human societies, economies and public health. More than 500 ant species have been transported outside their native range with the help of humans, while the majority of them have managed to establish viable populations in the wild. Nevertheless, data from the Mediterranean region suggest that most alien ants occupy anthropogenic habitats with little spread in semi-natural and natural habitats. Research on biological invasions of ants in Greece had previously identified a total of 15 alien ant species. In this article, an extensive literature investigation and material examination provide a revised checklist of the alien myrmecofauna of Greece. Although the number of alien ant species remains the same, the checklist's composition is largely altered to provide an up-to-date overview of the country's alien myrmecofauna in order to enhance management decisions and future research. The presence and distribution of alien ants within Greek administrative divisions, NATURA 2000 sites and Corine Land Cover types are analysed and presented. In particular, the species richness of alien ants seems to be highest in the Aegean Archipelago (Crete and Southern Aegean Islands) probably due to uneven collecting efforts and increased climatic suitability. Alien ant species are mostly associated with anthropogenic habitats including urban and agricultural areas, although a significant percentage has managed to spread into forest and semi-natural areas, including protected NATURA 2000 sites. Future research directions enhancing the monitoring of alien ants and their impacts are indicated to safeguard native ant biodiversity and conservation efforts of rare and endemic taxa. [ABSTRACT FROM AUTHOR]

Biological invasions remain one of the most pressing threats to biodiversity globally, with unprecedented rates of establishment that are unlikely to abate in the future. As such the occurrence of multiple interacting invasive non‐native species (INNS) is becoming more common. Despite this, much of the research on the interaction of multiple INNS is conducted within laboratory settings, with field studies remaining rare or being conducted as one‐off sampling. There is therefore a deficit of knowledge pertaining to the natural population trajectories of multiple INNS and the wider ecological implications for the structure and function of the native communities. Here we present multiple years of data collected from a reservoir in the United Kingdom, which has undergone invasion by three congener non‐native amphipods. We initially observed the coexistence of Dikerogammarus haemobaphes with Crangonyx pseudogracilis under habitat segregation in the reservoir. However, the following year saw complete displacement of C. pseudogracilis and reduced abundances of D. haemobaphes once the more competitive Dikerogammarus villosus established abundant populations in the reservoir. D. villosus exhibited strong effects for the structure and function of the wider macroinvertebrate community composition in addition to driving reductions in taxa and functional richness. Gastropoda taxa appeared to be unaffected by the invasion dynamics. Significant increases in functional divergence (and less so functional dispersion) values were also observed following D. villosus establishment, with this response metric possibly representing an important tool in detecting stress from biological invasions that we urge scientists to test more extensively. In contrast to D. villosus, D. haemobaphes implications for the wider ecological community appeared to be limited. Importantly, we observed evidence to suggest the presence of boom–bust cycles with the explosion of D. villosus leading to a dramatic drop in their abundances the following year. We believe that the wider ecological implications of their abundant populations were so great that resources were not sufficient within the reservoir to support their abundant populations, leading to the observed population collapses. We call for further studies that investigate the population trajectories and wider ecological implications of multiple non‐native species in field settings to further our limited knowledge base. [ABSTRACT FROM AUTHOR]

A dead individual of Metamasius hemipterus (Linnaeus, 1758) was collected by a citizen scientist in Athens, Greece from a hand of imported bananas. The equatorial origin of the fruit as well as the extensive growth of a fungus on the specimen, both suggest an unintentional introduction as a contaminant. Nevertheless, this record highlights the valu-able contribution of citizen scientists in the study of alien species. Although the species is not presently considered as established in the country, citizen-science initiatives in order to raise awareness and monitor its presence are ongoing.

Recent synthesis studies have shown inconsistent responses of crop pests to landscape composition, imposing a fundamental limit to our capacity to design sustainable crop protection strategies to reduce yield losses caused by insect pests. Using a global dataset composed of 5242 observations encompassing 48 agricultural pest species and 26 crop species, we tested the role of pest traits (exotic status, host breadth and habitat breadth) and environmental context (crop type, range in landscape gradient and climate) in modifying the pest response to increasing semi-natural habitats in the surrounding landscape. For natives, increasing semi-natural habitats decreased the abundance of pests that exploit only crop habitats or that are highly polyphagous. On the contrary, populations of exotic pests increased with an increasing cover of semi-natural habitats. These effects might be related to changes in host plants and other resources across the landscapes and/or to modified top-down control by natural enemies. The range of the landscape gradient explored and climate did not affect pests, while crop type modified the response of pests to landscape composition. Although species traits and environmental context helped in explaining some of the variability in pest response to landscape composition, the observed large interspecific differences suggest that a portfolio of strategies must be considered and implemented for the effective control of rapidly changing communities of crop pests in agroecosystems.

Aim of study: Pallas´s squirrel (Callosciurus erythraeus) is a harmful and generalist invasive mammal species that causes different problems in the forestry sector. The aim of this study was to evaluate the damage on the wood in three commercial tree species in Argentina, Eucalyptus dunnii, Populus deltoides and Pinus elliottii, due to debarking caused by this squirrel species. Area of study: ¨Liebres Fue¨ forest plantation, located in Luján District (Province of Buenos Aires, Argentina). Material and methods: We analyzed affected tissues and internal defects of wood associated with debarking signs. We randomly collected 74 stems of the three forest species with (N=62) and without debarking (N=12) between October 2016 and December 2017. Transversal cuttings (N=37) and longitudinal cuttings (N=37) of the stems were analyzed. Main results: The defects inside the wood related to the damage due to the debarking caused by Pallas´s squirrels are described. All the damaged samples presented affected wood tissues, with unfavorable healing forming ribbed cracks and ram`s horn scars and/or presence of some internal defect (crack, crack with abnormal coloration, crack with kino/resin or crack with bark included). None of the damaged pieces, according to the rules of visual classification of sawn woods, showed the highest quality grade (Premium). Research highlight: Pallas´s squirrel action causes wounds on the trees, leading to different responses by the trees that are transferred internally, showing abnormalities in the wood which diminish its value from a commercial point of view.

Simple Summary: Monitoring non-native species is important to assess their invasion risk. Here, we carried out a literature review on roadkill studies to investigate geographical patterns of biological invasions. We believe that roadkill data from published literature can be a valuable resource for people dealing with biological invasions, especially when field surveys cannot be performed. We retrieved 2314 studies published until January 2022, but only 40 of them (in addition to our own unpublished field data) included a full list of road-killed species (with a number of affected individuals for each species), so we were able to include them in our analyses. We classified all road-killed species from retrieved studies as native or introduced (domestic, introduced in historical times or recently released). We found that a higher number of introduced species would be recorded among roadkill in Mediterranean and Temperate regions with respect to Tropical and Desert areas. This result is in line with the current knowledge on non-native species distribution at the global scale, thus confirming that roadkill datasets can be used beyond the study of road impacts, such as for an assessment of different levels of biological invasions among different countries. Monitoring the presence and distribution of alien species is pivotal to assessing the risk of biological invasion. In our study, we carried out a worldwide review of roadkill data to investigate geographical patterns of biological invasions. We hypothesise that roadkill data from published literature can turn out to be a valuable resource for researchers and wildlife managers, especially when more focused surveys cannot be performed. We retrieved a total of 2314 works published until January 2022. Among those, only 41 (including our original data) fitted our requirements (i.e., including a total list of roadkilled terrestrial vertebrates, with a number of affected individuals for each species) and were included in our analysis. All roadkilled species from retrieved studies were classified as native or introduced (domestic, paleo-introduced, or recently released). We found that a higher number of introduced species would be recorded among roadkill in Mediterranean and Temperate areas with respect to Tropical and Desert biomes. This is definitely in line with the current knowledge on alien species distribution at the global scale, thus confirming that roadkill datasets can be used beyond the study of road impacts, such as for an assessment of different levels of biological invasions among different countries. [ABSTRACT FROM AUTHOR]

The Emergency Recovery Plan for freshwater biodiversity recognizes that addressing nonnative species is one of six principal actions needed to bend the curve in freshwater biodiversity loss. This is because introduction rates of nonnative species continue to accelerate globally and where these species develop invasive populations, they can have severe impacts on freshwater biodiversity. The most effective management measure to protect freshwater biodiversity is to prevent introductions of nonnative species. Should a nonnative species be introduced, however, then its early detection and the implementation of rapid reaction measures can avoid it establishing and dispersing. If these measures are unsuccessful and the species becomes invasive, then control and containment measures can minimize its further spread and impact. Minimizing further spread and impact includes control methods to reduce invader abundance and containment methods such as screening of invaded sites and strict biosecurity to avoid the invader dispersing to neighbouring basins. These management actions have benefitted from developments in invasion risk assessment that can prioritize species according to their invasion risk and, for species already invasive, ensure that management actions are commensurate with assessed risk. The successful management of freshwater nonnative species still requires the overcoming of some implementation challenges, including nonnative species often being a symptom of degraded habitats rather than the main driver of ecological change, and eradication methods often being nonspecies specific. Given the multiple anthropogenic stressors in freshwaters, nonnative species management must work with other restoration strategies if it is to deliver the Emergency Recovery Plan for freshwater biodiversity. [ABSTRACT FROM AUTHOR]

The Chinese banyan (Ficus microcarpa) is an Australasian fig tree commonly planted in urban and semi-urban sites throughout the warmer parts of the world. Assisted by its host-specific mutualist pollinator Eupristina verticillata (Agaonidae), F. microcarpa often manages to colonise urban areas outside its native range and can invade natural habitats. In Cyprus, the species is widely planted in city centres, town squares and parks, where seedlings have been observed. Increasing numbers of fig wasp species of Asian origin are being recorded from the Mediterranean and it appears that the pace of colonisation of F. microcarpa is increasing. Fig surveys in Cyprus during the last seven years have uncovered a total of 11 fig wasp species associated with F. microcarpa. The composition of the fig wasp fauna is described here. It includes two species previously unknown from the Western Palearctic: Sycophila petiolata Chen (Eurytomidae) and an undescribed species of uncertain generic affinity (Pteromalidae, Epichrysomallinae) that we refer to as "Eufroggattisca sp. indesc.". The distribution, ecology and relationships of the Cypriot fig wasps associated with the Chinese banyan are discussed, together with their potential impacts on the spread of their host plant. [ABSTRACT FROM AUTHOR]

The Chinese banyan, Ficus microcarpa is an ornamental fig tree, widely planted throughout Southern Greece. Native to Asian - Australasian regions, it can be found in plazas, parks, roadsides as well as private gardens. Along with its host, various insect species have managed to follow and establish themselves outside of their native range. In Rhodes, the mass defoliation of an emblematic fig tree, led to the subsequent finding of Josephiella microcarpae infestation. Repetitive samplings in the following years confirmed the establishment of the species on the island, which constitutes the first record of this species in Greece. Collected specimens from Rhodes and Cyprus were sequenced for the COI DNA barcoding region. Further investigation of fig trees throughout various locations in Southern Greece, proved fruitless. Based on our findings, the distribution of J. microcarpae in Greece seems restricted in the city of Rhodes. [ABSTRACT FROM AUTHOR]

Human‐mediated changes in island vegetation are, among others, largely caused by the introduction and establishment of non‐native species. However, data on past changes in non‐native plant species abundance that predate historical documentation and censuses are scarce. Islands are among the few places where we can track human arrival in natural systems allowing us to reveal changes in vegetation dynamics with the arrival of non‐native species. We matched fossil pollen data with botanical status information (native, non‐native), and quantified the timing, trajectories and magnitude of non‐native plant vegetational change on 29 islands over the past 5000 years. We recorded a proportional increase in pollen of non‐native plant taxa within the last 1000 years. Individual island trajectories are context‐dependent and linked to island settlement histories. Our data show that non‐native plant introductions have a longer and more dynamic history than is generally recognized, with critical implications for biodiversity baselines and invasion biology. [ABSTRACT FROM AUTHOR]

A growing body of evidence has shown that biological invasions cause shifts in species composition of communities in space and time. Although biological invasions are considered a major driver of biotic homogenisation worldwide, most previous studies were conducted at small spatial scales and over short time periods, which may have underestimated the impacts of exotic species on native communities.Using a unique dataset of aquatic plants sampled in 235 sites over 12 years (2007–2010 and 2015–2019) in a large reservoir (Itaipu Reservoir; 1350 km2), we analysed how the invasion of a non‐native grass Urochloa arrecta affects the species richness, ecological uniqueness (i.e. local contribution to beta diversity—LCBD) and temporal β–diversity of native plant communities.From 3934 surveyed plant communities, U. arrecta was recorded in 2888 samples and it was absent from 1046 samples. Overall, species richness and ecological uniqueness of native plant communities were markedly lower in sites invaded than non‐invaded by U. arrecta. From 2007 to 2019, the ecological uniqueness of native plants was 60% lower in the invaded than non‐invaded sites. Whereas in invaded sites species loss was the dominant process driving native communities over time, in non‐invaded sites gain of new native species was the primary process underlying community trajectories. Moreover, comparing native plant communities before and after the invasion of U. arrecta, species richness, ecological uniqueness and species gains of native plant communities decreased, whereas species losses increased after the invasion of U. arrecta. Finally, the positive relationship between native biodiversity and precipitation was stronger in non‐invaded than invaded sites.Synthesis. Our findings provide comprehensive evidence that an invasive plant is decreasing the spatial and temporal β–diversity of native plant communities through declining species richness, rather than simply correlating with them. This suggests that U. arrecta is driving native plants to become less diverse and homogeneous after the invasion, both spatially and temporally. Our findings illustrate that at broad scales, aquatic plant communities may become increasingly homogeneous with the increasing number of biological invasion events taking place worldwide. [ABSTRACT FROM AUTHOR]

Invasive "game-changer" species cause severe ecological impacts such as "phase shifts" in recipient ecosystems all over the world. Since the early 1990s, the ongoing global spread of the small but highly invasive Ponto-Caspian round goby Neogobius melanostomus into diverse freshwater and marine ecosystems has been observed. We postulate that this species is an ideal model to better understand and mitigate aquatic invasions. Its wide invaded range, as well as its diverse impacts on native species, have triggered a large body of research worldwide concerning its spread, ecology, and traits facilitating invasion. Several hypotheses related to invasiveness have been tested for the round goby, which are also applicable to other invasive species and for understanding general principles in invasion biology. However, a common theory explaining invasion success, especially in round goby, is still lacking. Many case studies do not consider time since invasion and use different sampling protocols and methodologies, hampering the comparability of results and conclusions. We thus propose strengthening the network of goby researchers and establishing long-term databases based on continuous and harmonized monitoring covering all stages of the invasion process as crucial requirements to better understand and manage aquatic invasions. In many cases, such monitoring can easily be integrated into existing survey schemes. [ABSTRACT FROM AUTHOR]

A central focus of invasive species research has been on human efforts to eradicate invaders or reduce their abundance to mitigate the worst of their impacts. In some cases, however, populations of invasive species decline without human intervention, which may inform management responses to these invaders. Such is the case of the invasive rusty crayfish (Faxonius rusticus) in northern Wisconsin, USA, where systematic population monitoring since 1975 has revealed population declines in approximately half of the lakes surveyed. Population declines of invasive species without human intervention remain understudied, but there is even less research on how communities respond following such declines. Using 10 lakes in Vilas County, Wisconsin, we investigated community recovery of habitat (macrophytes) and prey (freshwater snails) of F. rusticus following up to 33 years of declines of this invader in some lakes using a dataset with a rare, long‐term span over which consistent data were collected (1987, 2002, 2011, and 2020). We compared community responses in lakes where F. rusticus populations reached a peak and subsequently declined (boom‐bust lakes) and lakes where our dataset only captured the decline of F. rusticus (bust lakes) to reference lakes with consistently high or low crayfish abundance over time. We found partial recovery of macrophytes and snails in the bust and boom‐bust lakes where F. rusticus has declined, with recovery of macrophyte abundance and richness in the boom‐bust lakes achieving levels observed in the low‐crayfish reference lakes. Snail abundance and richness increased after declines of F. rusticus, though not to the level of the low‐crayfish reference lakes, suggesting that snail recovery may lag macrophyte recovery because snails are dependent on macrophytes and associated periphyton for habitat. The recovery we document potentially represents long‐term ecosystem resilience of lakes to biological invasions. Our results suggest that lake communities may recover without active restoration interventions after invasive crayfish population declines, although identifying which lakes experience these natural declines remains a priority for future research and management. [ABSTRACT FROM AUTHOR]

Our knowledge of how niche dynamic patterns respond to invasion trajectories and influence invasion risk prediction is elusive for the majority of notorious invaders, hindering scientific understanding, biosecurity planning and practice, and management implementation of biological invasions. We used Mikania micrantha, one of the world's worst invasive alien species (IAS), to test the hypothesis that multiple invasion trajectories could induce niche dynamics inconsistency and increase risk uncertainty of IAS. We compiled a robust database of M. micrantha occurrence across its native range in Central and South America and invaded range in China. This database was used to clarify different invaded ranges and invasion trajectories of M. micrantha in China. Principal components analysis of climatic variables associated with the database was used to explore the niche dynamic patterns associated with multiple invasion trajectories of M. micrantha. Maximum entropy algorithm was used to predict the high‐risk area of M. micrantha invasion using occurrence datasets for invaded ranges where niches remained conservative, and to detect area changes with the inclusion of occurrence datasets for invaded ranges where niche shifts occurred. M. micrantha invasion occurred in three geographically distinct regions, with conservative climate niches in southern and southeastern China and climatic niche shifts in southwestern China. A high‐risk area for M. micrantha invasion spanned multiple provinces and cities and expanded considerably with the inclusion of the occurrence dataset for southwestern China. Our findings contribute to the theoretical understanding of invasion mechanisms and the practical optimization of biosecurity planning and implementation. [ABSTRACT FROM AUTHOR]

The diversity of biota in different parts of the planet has demonstrated dramatic changes within the last several decades due to the extinction of native taxa and the appearance of invasive taxa. The correct taxonomic identification of non-native species is important for understanding their dispersal abilities, especially when potential invaders may be of closely related species. Information on the species identity of ricefish (Oryzias spp.), which have formed self-sustainable populations in some parts of Eurasia, is contradictory. In this paper, we studied samples from non-native populations of Oryzias from several Eurasian regions. The results of our mtDNA COI partial sequence study confirm that the individuals we studied belong to the species Chinese ricefish, O. sinensis. Analyses of the literature and our own data suggest that all known alien populations of Oryzias in continental Eurasia belong to the same species, O. sinensis. A recent finding of O. sinensis in the Don delta suggests that one of the species' secondary dispersal pathways could run from the Kuban region through the lower part of the Don basin to the Cis-Azov area. [ABSTRACT FROM AUTHOR]