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Summary Darwin's two opposing hypotheses, proposing that non‐native species closely or distantly related to native species are more likely to succeed, are known as ‘Darwin's Naturalization Conundrum’. Recently, invasion ecologists have sought to unravel these hypotheses. Studies that incorporate rich observational data in disturbed ecosystems that integrate phylogenetic and functional perspectives have potential to shed light on the conundrum. Using 313 invaded plant communities including 46 invasive plant species and 531 native plant species across the Three Gorges Reservoir Area in China, we aim to evaluate the coexistence mechanisms of invasive and native plants by integrating phylogenetic and functional dimensions at spatial and temporal scales. Our findings revealed that invasive plants tended to co‐occur more frequently with native plant species that were phylogenetically distant but functionally similar in the reservoir riparian zone. Furthermore, our study demonstrated that the filtering of flood‐dry‐flood cycles played a significant role in deepening functional similarities of native communities and invasive‐native species over time. Our study highlights the contrasting effects of phylogenetic relatedness and functional similarity between invasive and native species in highly flood‐disturbed habitats, providing new sights into Darwin's Naturalization Conundrum. [ABSTRACT FROM AUTHOR]

In 2023, two bark beetle species were recorded in Russia for the first time based on findings in Sochi: the cypress bark beetle, Phloeosinus armatus, on Mediterranean cypress (Cupressus sempervirens) and the black twig borer, Xylosandrus compactus, on southern magnolia (Magnolia grandiflora), noble laurel (Laurus nobilis), and cherry laurel (Prunus laurocerasus). P. armatus is a Mediterranean pest attacking exclusively Cupressaceae. In Sochi, it was recorded on cypress trees in several locations, including on plants for planting imported from Italy. X. compactus is a highly polyphagous pest from East Asia. In Sochi, it has established populations in ornamental planted areas. The paper provides species descriptions with identification keys. One specimen of X. compactus from Sochi was DNA‐barcoded and compared with 31 specimens deposited in the BOLD and GenBank under the name of X. compactus. High genetic variability (>7%) was detected highlighting the difficulty of identifying 'true' X. compactus using DNA data. Genetically, the specimen of X. compactus from Sochi was identical to those from Italy, Spain and France. An accidental introduction with ornamental plants for planting from Italy is considered the most probable pathway of invasion of both bark beetle species into the Russian Black Sea coast of the Caucasus. [ABSTRACT FROM AUTHOR]

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]

A large number of non‐native trees (NNTs) have been introduced globally and widely planted, contributing significantly to the world's economy. Although some of these species present a limited risk of spreading beyond their planting sites, a growing number of NNTs are spreading and becoming invasive leading to diverse negative impacts on biodiversity, ecosystem functions and human well‐being. To help minimize the negative impacts and maximize the economic benefits of NNTs, Brundu et al. developed eight guidelines for the sustainable use of NNTs globally—the Global Guidelines for the Use of NNTs (GG‐NNTs).Here, we used an online survey to assess perceptions of key stakeholders towards NNTs, and explore their knowledge of and compliance with the GG‐NNTs.Our results show that stakeholders are generally aware that NNTs can provide benefits and cause negative impacts, often simultaneously and they consider that their organization complies with existing regulations and voluntary agreements concerning NNTs. However, they are not aware of or do not apply most of the eight recommendations included in the GG‐NNTs.We conclude that effectively managing invasions linked to NNTs requires both more communication efforts using an array of channels for improving stakeholder awareness and implementation of simple measures to reduce NNT impacts (e.g. via GG‐NNTs), and a deeper understanding of the barriers and reluctance of stakeholders to manage NNT invasions. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [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]

Marine protected areas (MPAs) can protect and restore marine biodiversity and fisheries, but there are concerns that they may also benefit invasive species. The spatial and temporal colonization of invasive lionfish (Pterois miles) in the eastern Mediterranean was compared across zones with varying fishing restrictions (no fishing, recreational and commercial fishing, and commercial fishing only), and stations where targeted removal events were conducted by volunteer SCUBA divers. Lionfish density in no fishing areas was nearly double that of areas with commercial fishing only, and over four times greater than in areas where both commercial and recreational fishing were allowed. Lionfish density increased with depth, possibly due to easier human exploitation in shallow waters (0–10 m) that are accessible to recreational spearfishers. Targeted removals by volunteer divers decreased lionfish densities by over 60%, while areas without removals had a 200%–400% increase. Along with management actions, natural and ecological processes might drive lionfish densities within MPAs, and the speed with which lionfish colonized fishery‐restricted zones, emphasized the need for a more sophisticated MPA management strategy that considers invasive species impacts and dynamics in an ecosystem‐based approach. [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]

Invasive alien species are a major driver of biodiversity loss. Currently, the process of biological invasions is experiencing a constant acceleration, foreshadowing a future increase in the threat posed by invasive alien species to global biodiversity. Therefore, it is necessary to assess the impact risks of invasive alien species and related factors. Here, we constructed a dataset of negative environmental impact events to evaluate the impact risks of alien species. We collected information on 1071 established alien terrestrial vertebrates and then gathered negative environmental impacts for 108 of those species. Generalized linear mixed‐effects model and phylogenetic generalized least‐squares regression model were used to examine the characteristic (including life‐history traits, characteristics related to distribution, and introduction event characteristics) correlates of species’ impact risks at the global scale for 108 established alien terrestrial vertebrates (mammals, birds, reptiles and amphibians). Our results showed that a total of 3158 negative environmental impacts were reported for 108 harmful species across 71 countries worldwide. Factors associated with impact risks varied slightly among taxa, but alien range size, habitat breadth, origin location, and domestication were significantly correlated with impact risks. Our study aims to identify the characteristics of alien species with high‐impact risks to facilitate urgent assessment of alien species and to protect the local ecological environment and biodiversity. [ABSTRACT FROM AUTHOR]

Macrophytes, comprising aquatic vascular plants, bryophytes, and macroalgae, including charophytes, are crucial components of lake ecosystems. Their diversity affects ecosystem functions and services, and they are sensitive to environmental changes, making them effective indicators of lake health. Historical records of macrophyte species composition are essential for evaluating environmental changes and conservation goals. In this study, we compiled a comprehensive database of macrophytes, along with lake and survey information from the literature, providing a historical record of macrophyte biodiversity for lakes in Japan. This database enables the analysis of changes in the flora of Japanese lakes and fluctuations in species distribution, facilitating future monitoring. The complete dataset for this abstract published in the Data Article section of the journal is available in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2024-02.1/jalter-en. [ABSTRACT FROM AUTHOR]

The extreme low humidity and temperatures in Antarctica make it one of the harsher areas for life on our planet. In a global change context, environmental barriers that prevented the arrival of alien species in Antarctica are weakening. Deception Island, one of the four active volcanoes of Antarctica, is especially vulnerable to the impacts of alien species. Geothermal areas (GA) in this Island offer unique microclimatic conditions that could differentially affect native and alien soil arthropods. Here we explore the desiccation tolerance of a native (Cryptopygus antarcticus) and an alien (Proisotoma minuta) springtail (Collembola) species to these extreme environmental conditions. GA and non‐geothermal areas (NGA) were selected to evaluate intra‐ and interspecific variation in desiccation tolerance. Populations of P. minuta from GA had greater desiccation tolerance than populations from NGA. However, desiccation tolerance of C. antarcticus did not differ between GA and NGA. This native species had greater desiccation tolerance than the alien P. minuta, but also greater body size. Our findings show that the alien P. minuta responds differently to environmental conditions than the native C. antarcticus. Furthermore, body size may influence desiccation tolerance in these two springtail species. Research highlights: Populations of the alien species from geothermal areas in Antarctica had greater desiccation tolerance than populations from non‐geothermal areas.The native species had greater desiccation tolerance than the alien species, but also greater body size. [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]

Micromorphological visualization of plant surface peculiarities provides valuable characters for the precise identification of plant species. Invasive alien species, introduced outside their native range, pose significant ecological, and health challenges. This study focuses on micromorphological investigations of selected invasive plant species belonging to the families Amaranthaceae, Asteraceae, Moraceae, Crassulaceae, Cannabaceae, Fabaceae, Commelinaceae, and Oxalidaceae. The study employs scanning electron microscopy (SEM) to analyze the species micromorphology of pollen structure in depth to characterize the sculpturing patterns. Additionally, the study examines the pollen characteristics of these invasive plants, including shape, size, and fertility, along with exine sculpturing. The maximum polar diameter was observed for Senna tora (41.2 μm). The spines in Achillea fragrantissima were measured to have dimensions of approximately 1.91 μm in length and 2.11 μm in width. The findings shed light on the allergy‐causing potential of these invasive species, providing crucial information for accurate identification and effective management strategies to safeguard the indigenous flora of the region. The study contributes to the knowledge base for botanists, taxonomists, policy makers, climate experts, and biodiversity specialists. Research Highlights: Integrating SEM to analyze the pollen of invasive species.Unveiling pollen micromorphology of invasive species.Exploring the microscopic realm of invasive pollen to accurately identify the species. [ABSTRACT FROM AUTHOR]

Aim: Worldwide, floras are becoming homogenized at global scales, but regional patterns vary. Here, we present the first assessment for the Malesian phytogeographical region in terms of the timing of introductions, direction, magnitude and drivers of floristic change due to alien plant naturalizations. Location: Malesian phytogeographic region, including Southeast Asia and the Pacific. Taxon: Tracheophyta (vascular plants). Methods: We compiled data on first records of naturalized plants in Malesia to investigate temporal trends in the rate and origin of introductions. We then calculated β‐diversity (including turnover and nestedness) for the native, naturalized and Anthropocene (native + naturalized) floras for each pair of island groups (36 pairs), and a homogenization index for the native and Anthropocene floras, using presence/absence data for 31,580 plant species. Mantel tests were used to investigate the geographic, climatic and anthropogenic correlates of dissimilarity and homogenization. Results: Around 75% of all naturalized species documented to date were already reported for the first time within Malesia prior to 1950. This has led to homogenization between the historic (native) and contemporary (Anthropocene) floras for all island group pairs. Turnover was the most important process for driving compositional dissimilarity between island groups in Malesia in the native and Anthropocene floras, but homogenization resulted from decreases in nestedness and turnover. Differences in average taxonomic homogenization for island groups were associated with differences in their level of anthropogenic modification. Main Conclusions: This study improves current understanding of the direction and drivers of floristic homogenization in one of the world's most diverse tropical regions. Alien plant introductions carry a long historical legacy in Malesia, and naturalizations of these plants have led to overall taxonomic homogenization of the region's flora. Expected increases in the magnitude of human modification, without appropriate policy, will likely lead to further reductions in the floristic uniqueness of island groups. [ABSTRACT FROM AUTHOR]

Aim: Biodiversity on islands is commonly explained by a set of natural drivers such as area, isolation and habitat heterogeneity. However, constant human impact has led to considerable changes in island floras worldwide. This is reflected, among others, in increased numbers of non‐native species. Barrier islands are discrete land units, strongly influenced by humans and not displaying significant evolutionary dynamics. This makes them highly suitable for studying contemporary patterns of species richness and underlying processes. We aim to disentangle the effects of established natural and anthropogenic drivers on native and non‐native plant species richness at the example of 31 European barrier islands. Location: 31 North Sea barrier islands located off the Dutch, German and Danish coast. Taxon: Native and non‐native plant species (spermatophytes and ferns). Methods: Individual relationships of natural and anthropogenic drivers with native and non‐native plant species richness are analysed with generalised linear models (GLMs). We use structural equation models (SEMs) to additionally account for interrelations between drivers. Results: Island area was the strongest predictor of native and non‐native plant species richness but affected richness mostly indirectly through habitat heterogeneity (non‐native species) and island inhabitants (native species). Isolation had a slight negative effect on native and non‐native plant species numbers on islands. Main Conclusions: The richness of native and non‐native plant species on islands is associated with different drivers, that is, habitat heterogeneity and island inhabitants respectively. This might be caused by distinct underlying processes forming native and non‐native richness patterns. Area was confirmed to be the most important driver of species richness but acting primarily through other natural and anthropogenic drivers of plant species richness. We encourage considering both natural and anthropogenic drivers and their interrelatedness to explain contemporary biogeographic patterns of species richness. [ABSTRACT FROM AUTHOR]

Ecological Niche Models (ENMs) are often used to project species distributions within alien ranges and in future climatic scenarios. However, ENMs depend on species‐environment equilibrium, which may be absent for actively expanding species. We present a novel framework to estimate whether species have reached environmental equilibrium in their native and alien ranges. The method is based on the estimation of niche breadth with the accumulation of species occurrences. An asymptote will indicate exhaustive knowledge of the realised niches. We demonstrate the CNA framework for 26 species of mammals, amphibians, and birds. Possible outcomes of the framework include: (1) There is enough data to quantify the native and alien realised niches, allowing us to calculate niche expansion between the native and alien ranges, also indicating that ENMs can be reliably projected to new environmental conditions. (2) The data in the native range is not adequate but an asymptote is reached in the alien realised niche, indicating low confidence in our ability to evaluate niche expansion in the alien range but high confidence in model projections to new environmental conditions within the alien range. (3) There is enough data to quantify the native realised niche, but not enough knowledge about the alien realised niche, hindering the reliability of projections beyond sampled conditions. (4) Both the native and alien ranges do not reach an asymptote, and thus few robust conclusions about the species' niche or future projections can be made. Our framework can be used to detect species' environmental equilibrium in both the native and alien ranges, to quantify changes in the realised niche during the invasion processes, and to estimate the likely accuracy of model projections to new environmental conditions. [ABSTRACT FROM AUTHOR]

Invasive alien species are among the most pervasive threats to biodiversity. Invasive species can cause catastrophic reductions in populations of native and endemic species and the collapse of ecosystem function. A second major global conservation concern is the extirpation of large‐bodied mobile animals, including long‐distance migrants, which often have keystone ecological roles over extensive spatial extents. Here, we report on a potentially catastrophic synergy between these phenomena that threatens the endemic biota of the Galapagos Archipelago. We used GPS telemetry to track 140 migratory journeys by 25 Western Santa Cruz Island Galapagos tortoises. We plotted the spatial interaction between tortoise migrations and recently established non‐native forest dominated by the invasive tree Cedrela odorata (Cedrela forest). We qualified (a) the proportion of migratory journeys that traversed Cedrela forest, and (b) the probability that this observed pattern occurred by chance. Tortoise migrations were overwhelmingly restricted to small corridors between Cedrela forest blocks, indicating clear avoidance of those blocks. Just eight of 140 migrations traversed extensive Cedrela stands. Tortoises avoid Cedrela forest during their migrations. Further expansion of Cedrela forest threatens long‐distance migration and population viability of critically endangered Galapagos tortoises. Applied research to determine effective management solutions to mitigate Cedrela invasion is a high priority. [ABSTRACT FROM AUTHOR]

Differences in the number of alien plant species in different locations may reflect climatic and other controls that similarly affect native species and/or propagule pressure accompanied with delayed spread from the point of introduction. We set out to examine these alternatives for Himalayan plants, in a phylogenetic framework. We build a database of alien plant distributions for the Himalaya. Focusing on the well‐documented regions of Jammu & Kashmir (west) and Bhutan (east) we compare alien and native species for (1) richness patterns, (2) degree of phylogenetic clustering, (3) the extent to which species‐poor regions are subsets of species‐rich regions and (4) continental and climatic affinities/source. We document 1470 alien species (at least 600 naturalised), which comprise ~14% of the vascular plants known from the Himalaya. Alien plant species with tropical affinities decline in richness with elevation and species at high elevations form a subset of those at lower elevations, supporting location of introduction as an important driver of alien plant richness patterns. Separately, elevations which are especially rich in native plant species are also rich in alien plant species, suggesting an important role for climate (high productivity) in determining both native and alien richness. We find no support for the proposition that variance in human disturbance or numbers of native species correlate with alien distributions. Results imply an ongoing expansion of alien species from low elevation sources, some of which are highly invasive. Several reasons have been proposed for why alien species richness patterns vary across the globe, but they are rarely compared in a comprehensive test. Here we build a complete database of Himalayan alien plant species and show that both location of introduction and climate per se are likely important in explaining elevational and geographical patterns of species diversity. [ABSTRACT FROM AUTHOR]

Range‐expansion and speciation are not new to life on Earth, but they have been scarcely observed contemporarily and, likely, never over several continents simultaneously. Evidence of incipient reproductive isolation between native and non‐native regions of some invasive alien species indicates that invasive speciation is closer than we expected. Some neo‐allopatric populations are likely to qualify as distinguishable subspecies already. Given their trajectory, whether they will become new species is not an if, but a when. I present two decision tables to help to (1) assess the coining of new invasive species or subspecies with the current taxonomical approach or (2), introduce the term "neo" to name invasive neo‐species resulting from synchronous allopatric speciation from a single, known, living ancestor. This latter case can be exemplified with the hypothetical names: "Ginkgo biloba neo americana", "G. biloba neo europea", etc. [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]

Aim: Human activities have introduced numerous non‐native species (NNS) worldwide. Understanding and predicting large‐scale NNS establishment patterns remain fundamental scientific challenges. Here, we evaluate if NNS composition represents a proportional subset of the total species pool available to invade (i.e. total global biodiversity), or, conversely, certain taxa are disproportionately pre‐disposed to establish in non‐native areas. Location: Global. Time period: Present day. Major taxa studied: Global diversity. Methods: We compiled one of the most comprehensive global databases of NNS (36,822 established species) to determine if NNS diversity is a representative proportional subset of global biodiversity. Results: Our study revealed that, while NNS diversity mirrors global biodiversity to a certain extent, due to significant deviance from the null model it is not always a representative proportional subset of global biodiversity. The strength of global biodiversity as a predictor depended on the taxonomic scale, with successive lower taxonomic levels less predictive than the one above it. Consequently, on average, 58%, 42% and 28% of variability in NNS numbers were explained by global biodiversity for phylum, class and family respectively. Moreover, global biodiversity was a similarly strong explanatory variable for NNS diversity among regions, but not habitats (i.e. terrestrial, freshwater and marine), where it better predicted NNS diversity for terrestrial than for freshwater and marine habitats. Freshwater and marine habitats were also greatly understudied relative to invasions in the terrestrial habitats. Over‐represented NNS relative to global biodiversity tended to be those intentionally introduced and/or 'hitchhikers' associated with deliberate introductions. Finally, randomness is likely an important factor in the establishment success of NNS. Main conclusions: Besides global biodiversity, other important explanatory variables for large‐scale patterns of NNS diversity likely include propagule and colonization pressures, environmental similarity between native and non‐native regions, biased selection of intentionally introduced species and disparate research efforts of habitats and taxa. [ABSTRACT FROM AUTHOR]

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The azalea lace bug Stephanitis (Stephanitis) pyrioides (Scott, 1874) (Hemiptera: Heteroptera: Tingidae) originates from the East Palaearctic. In 2020, this alien species was recorded for the first time in the European part of Russia (Krasnodar Territory, Sochi), notably attacking Rhododendron × hybridum hort. It most likely arrived there with plants for planting from Italy. The main morphological characteristics of adults and larvae are described and illustrated. The morphological differences between S. pyrioides and closely related S. pyri (Fabricius, 1775) are highlighted in the key to distinguish these two species, bearing in mind that now both of them can be found in the south of the European part of Russia. Additionally, DNA barcoding data for S. pyrioides from Sochi were analysed against other related species of Stephanitis whose DNA barcodes are available in Barcode of Life Data Systems (BOLD) and GenBank: S. takeyai Drake et Maa, 1955, S. oberti (Kolenati, 1857), S. mendica Horváth, 1912, and S. chinensis Drake, 1948. The bionomics, distribution, damage and impact of S. pyrioides are outlined. [ABSTRACT FROM AUTHOR]

Studies have shown that fruits of plants from the Fabaceae family harbour a diverse community of herbivorous insects and their natural enemies. Despite this observation, we still lack information on the specific interactions within these multi‐trophic communities. Herein, we describe the food web of insects associated with fruits and seeds of Leucaena leucocephala (Fabaceae), an invasive plant in Brazil, and their relationship with plant traits including seed biomass.We found 17 species of insects distributed across three trophic levels. The main herbivore species sampled was Acanthoscelides macrophthalmus (Coleoptera, Chrysomelidae, Bruchinae), which was responsible for most of the seed predation and associated with the highest parasitoid biodiversity (N = 10 species). Four other herbivorous species were lower in abundance, including a previously unreported Lepidopteran species with two parasitoids and one hyperparasitoid associated with it.Seeds with more mass promoted an increase in insect abundance, insect species richness, and the number of links and connectivity. We observed two native parasitoid species, Paracrias pluteus and Stenocorse suldamericanos, shift from herbivores on native plants to herbivores on the invasive L. leucocephala, consistent with a potential host shift. However, more investigation is required to ascertain the effects of recent shifts of native insect communities (on native plants) to non‐native ones and their consequences on plant fitness. Our study contributes to the understanding of the dynamics of communities and food webs in unknown systems, specifically in fruits of an invasive plant, and provides information about the influence of different plant traits on these communities. [ABSTRACT FROM AUTHOR]

Ducks and geese are little studied dispersal vectors for plants lacking a fleshy fruit, and our understanding of the traits associated with these plants is limited. We analyzed 507 faecal samples of mallard (Anas platyrhynchos) and Canada goose (Branta canadensis) from 18 natural and urban wetlands in England, where they are the dominant resident waterfowl. We recovered 930 plant diaspores from 39 taxa representing 18 families, including 28 terrestrial and five aquatic species and four aliens. Mallards had more seeds and seed species per sample than geese, more seeds from barochory and hydrochory syndromes, and seeds that on average were larger and from plants with greater moisture requirements (i.e., more aquatic). Mallards dispersed more plant species than geese in natural habitats. Plant communities and traits dispersed were different between urban (e.g., more achenes) and natural (e.g., more capsules) habitats. Waterfowl can readily spread alien species from urban into natural environments but also allow native terrestrial and aquatic plants to disperse in response to climate heating or other global change. Throughout the temperate regions of the Northern Hemisphere, the mallard is accompanied by a goose (either the Canada goose or the greylag goose) as the most abundant waterfowl in urbanized areas. This combination provides a previously overlooked seed dispersal service for plants with diverse traits. [ABSTRACT FROM AUTHOR]

Aim: If communities have a ceiling determining the number of species that can coexist, then the ability of alien species to establish at any given location should be related to the quantity of vacant niches available. We developed a new approach to estimate the extent to which niches are vacant and then explored the relationship between vacant niches and alien species. Location: Global with focal tests in Europe and North America. Taxon: Birds. Methods: Drawing on a global classification of trophic structures for birds, we calculated a 'vacant niche ratio' metric to quantify the expected level of saturation (i.e. number of vacant niches) for each 1° × 1° grid cell globally, based on the difference between expected and observed numbers of bird species for all trophic guilds. Next, we used random forests to examine if the presence of plant‐invertivore (whose food source represents plants, seeds, fruits and invertebrates) and granivore alien bird species was associated with the vacant niche ratio across well‐sampled regions. Results: In Europe, we found a significant relationship between alien species and vacant niches, with greater numbers of alien species being found in communities that offered greater numbers of vacant niches overall, and across habitat types. In North America, we found no significant relationship between plant‐invertivores and vacant niches, while for granivores, we found that areas with fewer vacant niches had greater numbers of alien species, especially in forests. However, vacant niches alone correctly predict 69% of the presence of alien bird species when combining both regions and trophic guilds. Main Conclusions: Most regions of the world have unsaturated bird communities, with the level of saturation in communities varying within regions and trophic guilds. We found that although often‐neglected, vacant niches are likely to be, at least partially, related with the successful establishment of alien bird species. [ABSTRACT FROM AUTHOR]

Invasive species are the second most important reason for species extinction since 1500 ad. In addition, these invasive species can cause vast economic loss. In marine ecoregions, alien species introductions are increasing, and those that become invasive have caused profound changes in many marine ecoregions. We compiled a database consisting of information about where species are alien, where they are not, and which species are listed as threatened by invasive species. In addition, we developed an interactive Webapp for visualizing and analyzing the results. We used the Ocean Biogeographic Information System (OBIS) for identifying the presence of a species in a marine ecoregion. Information from the World Register of Marine Species (WoRMS), the Global Invasive Species Database (GISD), and the Nature Conservancy database on marine invasive species (NatCon) was used to identify the names and locations of marine alien species. Information from the International Union for Conservation of Nature (IUCN) Red List revealed which species are considered to be threatened by invasive species. Our database lists 112,399 marine species, of which 966 are alien species and 1655 are listed as threatened by invasive species by the IUCN. These are distributed throughout 225 marine ecoregions (97% of marine ecoregions). Our results confirm previous studies about the prevalence of alien and invasive species and provide an up‐to‐date status about known and recorded species and their distribution. This information can be used as a fundament for developing impact assessment models and identifying management strategies to combat marine invasive species. [ABSTRACT FROM AUTHOR]

Heracleum mantegazzianum is an invasive environmental weed that is widely distributed in Europe and whose distribution is continually expanding. Novel management methods are required to address its impacts and spread. We studied the use of pyrolysis liquids (PL) as a component of biodegradable mulch and as biobased herbicide to control H. mantegazzianum. A five‐year field experiment was conducted to compare pyrolysis liquid peat mulch (PLM) with plastic PE–mulch, biobased Ökolys® mulch and glyphosate. Application of PL biobased herbicide after stem cutting was studied in a one‐year field experiment. We established that PLM does not control the growth or reproduction of mature H. mantegazzianum effectively in contrast with the other mulching materials and glyphosate. The coverage of H. mantegazzianum differed only in 1 year between application of PLMs and the control. The number of flower stems increased in PLM treatments and in the control, indicating that PLM failed to control reproduction and spread of H. mantegazzianum. PL treatment of cut H. mantegazzianum stems was more effective than application of acetic acid alone. The results suggest that biobased control methods do not provide as effective control of H. mantegazzianum as widely used current methods (plastic mulches and glyphosate). If biobased methods are to be more widely used for controlling H. mantegazzianum, lower control efficacy must be accepted, and they should be used in an integrated approach with other methods. [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]

Background: Toumeyella parvicornis is an invasive soft scale insect native to North America that is rapidly spreading in Italy and France, provoking severe infestations on Pinus pinea L. To date, the control of this pest is entrusted to three endotherapic techniques whose short‐term efficacy is partially known. No information on long‐term efficacy is currently available, although fundamental. This work aims to report on the long‐term effect that abamectin‐based insecticides, injected with the three different techniques, have on adult female populations. Results: The study was carried out in an infested P. pinea forest in the area of Rome, Italy. Results showed that the tested methods had a similar long‐term effect, and only in one case there were differences with the untreated control. Multiresidue analysis reported a zero level of abamectin in plant tissues 14 months apart from injection, except for one treatment where pesticide concentration was just above the limit of quantification. Conclusions: This study represents the first long‐term evaluation about endotherapic control strategy against T. parvicornis. In fact, the pest may quickly bring the death and fall of the stone pines, representing a concerning risk for citizens, however, control actions to manage it are still partially known and deserve more in‐depth investigations. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Introduced species that spread and become invasive are recognised as a major threat to global biological diversity, ecosystem resilience and economic stability. Eradication is often a default conservation management strategy even when it may not be feasible for a variety of reasons. Assessment of the substantive socioeconomic and ecological impacts of invasive alien species (IAS), both negative and positive, is increasingly viewed as an important step in management.We argue that one solution to IAS management is to align models of alien species management with Indigenous management frameworks that are relational and biocultural. We make the theoretical case that centring Indigenous management frameworks promises to strengthen overall management responses and outcomes because they attend directly to human and environmental justice concerns.We unpack the origins of the 'introduced species paradigm' to understand how binary framing of so‐called 'aliens' and 'natives' recalls harmful histories and alienates Indigenous stewardship. Such a paradigm thereby may limit application of Indigenous frameworks and management, and impede long‐term biodiversity protection solutions.We highlight how biocultural practices applied by Indigenous Peoples to IAS centre protecting relationships, fulfilling responsibilities and realising justice.Finally, we argue for a pluralistic vision that acknowledges multiple alternative Indigenous relationships and responses to introduced and IAS which can contribute to vibrant futures where all elements of society, including kin in the natural world, are able to flourish. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

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Some populations identifiable as Alternanthera flavescens were discovered in the Kerala region (SE‐India), representing the first record of the national Flora. A macro‐ and micro‐morphological description based on the plants found, as well as ecological notes, are given. The phenotypic plasticity observed was also discussed. [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]

Popillia japonica is a quarantine pest of priority interest for the EU, given its potentially important economic, social and environmental impacts. Alternative strategies to chemical methods are essential to limit its spread in newly infested areas with favourable climatic and environmental conditions. Saponins are biologically active molecules widely distributed in plants, displaying a well‐known repellent activity combined with a mortality effect against insects. In this context, saponins were extracted from alfalfa Medicago sativa, where medicagenic and zanhic acid glycosides and Soyasaponin I were the most abundant compounds and used in the laboratory and semi‐field experiments for treating leaves of susceptible host plants for P. japonica. Under laboratory conditions, a food deterrence effect and a significant mortality rate were observed using Corylus avellana leaves treated at increasing saponin concentrations, ranging from 1% to 5% w/v. Semi‐field condition experiment supported the food deterrence effect, as a significant food preference was observed for untreated plants of Vitis vinifera compared to treated plants. The promising results obtained suggest that alfalfa saponins could represent a potential eco‐friendly approach for Japanese beetle control. [ABSTRACT FROM AUTHOR]

Premise: Understanding establishment and spread of non‐native plants is important in the face of a homogenizing global flora. While many studies focus on successful, invasive species, fewer have studied failed plant introductions. Until the early 1900s, large quantities of ship ballast, often containing foreign plant propagules, were deposited in New Jersey (USA). The resulting ballast flora is documented in extensive herbarium records, providing us a unique opportunity to analyze successes and failures of novel plant species introductions. Methods: We used digitized specimens from 75 herbaria to study 264 non‐native species introduced into New Jersey through 19th century ballast deposition. We used spatial (density‐based clustering; HDBSCAN) and temporal analyses of species retention and geographic spread to quantify disappearance rate, survival, and dispersion through time and define trajectory groups. Results: Four distinct trajectory groups were identified: waif (only present during import; 32% of species), short‐term (disappeared quickly; 20%), established–limited spread (survives locally, 30%), and established–widespread (widespread, 18%). Species disappearance rate was highest during ballast deposition and decreased soon after deposition stopped around 1900. Spatial patterns showed a strong association with 19th century railroads for inland dispersal from ports. The disappearance rate and spatial analyses are robust to herbarium collection bias. Conclusions: This study using New Jersey as a model is one of the few documenting multispecies successes and failures in inadvertent plant introductions. Results reveal distinct trends in species establishment and geographic spread and highlight the utility of herbarium specimens in answering questions that span large time scales. [ABSTRACT FROM AUTHOR]

Since Darwin put forward his opposing hypotheses to explain the successful establishment of species in areas outside their native ranges, the preadaptation and competition‐relatedness hypotheses, known as Darwin's naturalization conundrum, numerous studies have sought to understand the relative importance of each. Here, we take advantage of well‐characterized beetle communities across laurel forests of the Canary Islands for a first evaluation of the relative support for Darwin's two hypotheses within arthropods. We generated a mitogenome backbone tree comprising nearly half of the beetle genera recorded within the Canary Islands for the phylogenetic placement of native and introduced species sampled in laurel forests, using cytochrome c oxidase I (COI) sequences. For comparative purposes, we also assembled and phylogenetically placed a data set of COI sequences for introduced beetle species that were not sampled within laurel forests. Our results suggest a stronger effect of species preadaptation over resource competition, while also revealing an underappreciated shortfall in arthropod biodiversity data—knowledge of species as being native or introduced. We name this the Humboldtean shortfall and suggest that similar studies using arthropods should incorporate DNA barcode sequencing to mitigate this problem. [ABSTRACT FROM AUTHOR]

The prevention and control of invasive of alien species is an important work for nature reserves. This study analyzes the development trend of the alien species sika deer in Liancheng National Nature Reserve. From October 2019 to June 2020, 3523 valid photos and videos of terrestrial animals were acquired from 130 camera traps, and sika deer were recorded in 21 photos from 13 traps. The survival of the sika deer population was investigated by means of morphological identification, population structure analysis, species relative abundance indices, and species spatial association analysis. A total of 13 sika deer individuals were identified by camera trapping, including two kids and three subadults representing the reproductive capacity of the population. Spatially, sika deer is not associated with any local species and was outside the spatial association network of terrestrial animals in Liancheng National Nature Reserve, indicating that the sika deer population has not been integrated into the local community and has failed to perform its ecological function. It is worth noting that the reserve provides habitat suitable for sika deer and that the population has adequate reproductive capacity. Due to the lack of large apex predators in the reserve, the population size of ungulates such as sika deer, red deer, and Siberian roe deer may expand and lead to population outbreaks and the associated problems for the ecosystem. To restore large‐ and medium‐sized carnivores and avoid the population outbreak of the species, the present challenges require immediate attention in Liancheng National Nature Reserve. [ABSTRACT FROM AUTHOR]

Plant invasions can lead to homogeneous communities with decreased functional diversity. However, invasive plants, with various morphological and phenological traits, may drive pollinator communities in a less predictable, more complex way. They can promote pollinators compatible with their floral traits, while leaving others without foraging resources. Our observational study on 10 invasive herbaceous species applied a trait‐based approach to investigate plant invasion‐driven changes in floral resources, hoverfly and bee communities. We sampled invaded and non‐invaded (control) sites before and during the flowering of the invasive plants. We analysed the differences in floral traits between invasive and native plants, functional diversity and trait distributions of flower and pollinator communities between the invaded and control sites. Five invasive plant species differed from natives in floral traits. Plant invasion caused species‐specific changes in functional diversity and trait distributions of communities. For instance, invaded sites had a decreased functional diversity of hoverflies before flowering of invasive species, and larger hoverflies during flowering of invasive species compared with control sites. Smaller bees were associated with invasive plants with shallow flowers, while larger and long‐tongued bees were associated with two invasive species with restricted floral access. Similar to previous studies, pollinator traits showed mixed or neutral responses to plant invasion. This is probably due to the high integration capability of invasive plants into plant‐pollinator systems, or limitations in sampling, trait resolution, and unrevealed environmental factors. We provide recommendations for future studies to better understand the trait‐based community composition of flowering plants and pollinators. [ABSTRACT FROM AUTHOR]

Climate change, intensified tourism and trade activity have resulted in several exotic mosquito species invading the temperate zone, with considerable ecological and economic consequences, as well as threats to human health, due to the pathogen‐transmitting role of these organisms. Accordingly, three invasive mosquito species (Aedes albopictus, Ae. japonicus and Ae. koreicus) have been described in the last decade in Hungary, a Central European country. It is crucial to understand how invasive species are introduced and their distribution is expanded at the country‐level, for which intense surveillance programs are needed.We have established a citizen science program, in which we asked the public to submit reports on their observations of invasive mosquitoes. During a 3‐year campaign, we collected and taxonomically validated about 3000 reports that can be arranged along both temporal and spatial scales. We aggregated these observations into 35 km2 quadrats and examined if these can be used for reliable scientific inferences.We first found that the number of validated reports in a quadrat depends on the underlying sampling effort (i.e. number of total reports), but this relationship varies among species and study years. Second, after controlling for study effort, we showed that the prevalence and presence/absence of invasive mosquitoes within quadrats are significantly repeatable among years, but this consistency varies in a species‐specific way. Third, we demonstrated that conclusions about the local presence/absence of focal species based on citizen reports corroborate well the results of direct field sampling with conventional trapping protocols.Synthesis and applications: We suggest that if the reporting intensity is appropriate (i.e. the number of reports reaches a species‐specific threshold), citizen science results can be used to derive biologically meaningful conclusions about the distribution of invasive mosquitoes in a country. Distribution maps of the three invasive species in Hungary can be used to identify ecological predictors that determine such spatial patterns and also to develop a mosquito control program and assess epidemiological risk. [ABSTRACT FROM AUTHOR]

Tropical forest restoration is needed to mitigate the negative consequences of anthropogenic disturbances and climate change. One of the main limitations for the establishment of tropical forests is the competition with invasive species decreasing the survival and growth of native trees. Invasion management should affect soil microorganisms, which play essential roles in nutrient cycling, plant nutrition and on ecosystem functioning. Although chemical and nonchemical methods are applied worldwide to herbaceous invasion management, their impacts on soil microbial biomass, respiration and litter decomposition have yet to be measured over longer timeframes (>3 months) after application. Using a 3‐year‐old tropical forest restoration managed through chemical (herbicide pulverization) or nonchemical (mowing) treatments, and a secondary native forest patch nearby used as reference, we measured (1) soil microbial biomass and (2) basal soil respiration over 6 months, and on (3) litter decomposition over 1 year, after one management. We used mixed models to test whether management affected the response variables and found that chemical management resulted in lower microbial biomass and respiration after 5 months. Similarly, after 1 year, litter decomposition rate under chemical management was lower than that in the nonchemical and in the control. Chemical management effects on soil activity and litter decomposition should be considered when choosing suitable methods and its frequency to manage invasion, targeting the success of native trees and general ecosystem functioning. [ABSTRACT FROM AUTHOR]

BACKGROUND: Classical biological control has been identified as the most promising approach to limit the impact of the invasive pest species Halyomorpha halys (Heteroptera: Pentatomidae). This study investigated the parasitism rate at sites where the biocontrol agent Trissolcus japonicus (Hymenoptera: Scelionidae) was released and where its unintentional introduction took place, in the Trentino–South Tyrol region. The effect of land‐use composition was studied to understand which factors favor the establishment of hosts and parasitoids, including native and exotic species. RESULTS: The released T. japonicus were detected a year after the start of the program, with a significant parasitoid impact and discovery, compared to control sites. Trissolcus japonicus was the most abundant H. halys parasitoid, and Trissolcus mitsukurii and Anastatus bifasciatus were recorded also. The efficacy of T. mitsukurii was lower in sites where T. japonicus was successfully established, suggesting a possible competitive interaction. Parasitism level by T. japonicus at the release sites was 12.5% in 2020 and 16.4% in 2021. The combined effect of predation and parasitization increased H. halys mortality up to 50% at the release sites. Landscape composition analysis showed that both H. halys and T. japonicus were more likely to be found at sites with lower altitude and with permanent crops, whereas other hosts and parasitoids preferred different conditions. CONCLUSION: Trissolcus japonicus showed a promising impact on H. halys, at release and adventive sites, with minor nontarget effects, mediated by landscape heterogeneity. The prevalence of T. japonicus in landscapes with permanent crops could support IPM in the future. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [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]

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]

The buffy‐tufted‐ear marmoset (Callithrix aurita) is a small primate endemic to the Brazilian Atlantic Forest biome, and one of the 25 most endangered primates in the world, due to fragmentation, loss of habitat, and invasion by allochthonous Callithrix species. Using occurrence data for C. aurita from published data papers, we employed model selection using Akaike Information Criterion corrected for small samples and cumulative AICc weight (w+) to evaluate whether fragment size, distance to fragments with allochthonous species, altitude, connectivity, and surrounding matrices influence the occurrence of C. aurita within its distributional range. Distance to fragments with C. jacchus (w+ = 0.94) and nonvegetated areas (w+ = 0.59) correlated negatively with C. aurita occurrence. Conversely, the percentage of agriculture and pasture mosaic (w+ = 0.61) and the percentage of savanna formation (w+ = 0.59) in the surrounding matrix correlated positively with C. aurita occurrence. The findings indicate that C. aurita is isolated in forest fragments surrounded by potentially inhospitable matrices, along with proximity of a more generalist and invasive species, thereby increasing the possibility of introgressive hybridization. The findings also highlighted the importance of landscape elements and allochthonous congeneric species for C. aurita conservation, besides indicating urgency for allochthonous species management. Finally, the approach used here can be applied to improve conservation studies of other endangered species, such as C. flaviceps, which is also endemic to the Brazilian Atlantic Forest and faces the same challenges. [ABSTRACT FROM AUTHOR]

Graphocephala fennahi Young, 1977 (Cicadellidae) was observed for the first time in Russia in 2018 in Moscow City on hedge bindweed, Calystegia sepium (Convolvulaceae) and Rhododendron spp. (Ericaceae). A small population of Pochazia shantungensis (Chou & Lu, 1977) (Ricaniidae) was recorded for the first time in Russia in 2022 in Sochi City, Krasnodar Territory, on the broad‐leaf privet, Ligustrum lucidum (Oleaceae). It is likely that both species of insects were accidentally introduced with ornamental plants for planting. In total, alien Auchenorrhyncha species in Russia now comprise six species, two of which are of Asian origin (Orosanga japonica and P. shantungensis; both Ricaniidae) and four are of Nearctic origin (Stictocephala bisonia [Membracidae], Metcalfa pruinosa [Flatidae], Scaphoideus titanus and G. fennahi [both Cicadellidae]). [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]

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]

Plant species invasion represents one of the major drivers of biodiversity change globally, yet there is confusion about the nature of nonindigenous species (NIS) impact. This confusion stems from differing notions of what constitutes invasive species impact and the scales at which it should be assessed. At local scales, the mechanisms of the impact on local competitors can be classified into four scenarios: (1) minimal impact from NIS inhabiting unique niches; (2) neutral impact spread across the community and proportional to NIS abundance; (3) targeted impact on a small number of competitors with overlapping niches; and (4) pervasive impact that is disproportionate to NIS abundance and caused by modifications that filter out other species. I developed a statistical test to distinguish these four mechanism scenarios based on plant community rank‐abundance curves and then created a scale‐independent standardized impact score. Using an example long‐term dataset with high native plant diversity and an abundance gradient of the invasive vine, Vincetoxicum rossicum, I show that the impact resulted in either targeted or pervasive extirpations. Regardless of whether the NIS impact is neutral, targeted, or pervasive, the net outcome will be the homogenization of ecosystems and reduced biodiversity at larger scales, perhaps reducing ecosystem resilience. The framework and statistical evaluation of impact presented in this paper provide researchers and managers with an objective approach to quantifying NIS impact and prioritizing species for further management actions. [ABSTRACT FROM AUTHOR]

The alien Asian date mussel Arcuatula senhousia inhabits several coastal environments worldwide. This species can form dense mats where individuals attach through byssus threads, thus altering the structure, functioning and biodiversity of the native communities. We investigated the feeding preference of different predators on this alien species in a Mediterranean coastal lagoon. To do this, a mesocosm experiment was conducted using two crab species (the Mediterranean green crab Carcinus aestuarii) and the Say mud crab Dyspanopeus sayi, and one gastropod, the banded dye‐murex Hexaplex trunculus as predators of A. senhousia with or without byssus mats. Our data suggest that C. aestuarii is a more effective predator against A. senhousia than D. sayi, and that H. trunculus is almost ineffective. A possible implication of this result is the potential use of the native crab C. aestuarii for limit the formation of the byssus mats, thus mitigating their potential negative effects on the native communities. [ABSTRACT FROM AUTHOR]