Abstract In 2010, the invasive pathogen Austropuccinia psidii was detected in Australia, posing a threat to vegetation communities containing susceptible Myrtaceae species. A large-scale field experiment tested the direct and indirect effects resulting from the infection of two highly susceptible rainforest species, Rhodamnia rubescens and Rhodomyrtus psidioides. Community-level impacts were assessed

Abstract Biodiversity is severely declining worldwide and one of its main threats is invasion by exotic species. Successful management of these species requires citizens to be aware and engaged to prevent new introductions and support control interventions. We used questionnaires to investigate the knowledge and perceptions of Portuguese citizens aware of environmental issues, regarding invasive alien

Abstract Insect pest invasions pose a major threat to agriculture, forestry and many natural ecosystems. Thaumastocoris peregrinus is an invasive sap-sucking pest of significant economic importance to Eucalyptus forestry that has recently invaded several countries worldwide. In this study we identify the origin and retrace the invasion history of T. peregrinus. We analysed samples from six locations

Abstract Worldwide, the spread of alien species in marine ecosystems has increased, with mussels frequently being involved. In South Africa, 91 alien and 39 cryptic marine and estuarine species, from 17 taxonomic groups, are known. Of these, three are associated with major invasions, including the Pacific mussel, Semimytilus algosus, which has rapidly spread and colonised the lower portions of rocky

Abstract Pomacea canaliculata and P. maculata are freshwater apple snails considered two of the most invasive alien species worldwide. They are expanding their ranges in Asia, Europe and North America, damaging crops, wetland ecosystems and endangering human health. Despite having different invasive potential, they have systematically been misidentified because of their morphological plasticity with

Abstract Understanding the causes of spatial variation in the distribution and richness of alien species is a key goal of invasion biology. Thanks to the increasing availability of geographical compendia of alien species it is also the subject of a burgeoning scientific literature. Here, we review elements of this literature to argue that understanding the causes of variation in alien species richness

Abstract The enemy release hypothesis postulates that non-native species establish and become abundant because coevolved enemies from the native range are missing or greatly reduced in the introduced range. We assessed whether the invasive New Zealand mud snail, Potamopyrgus antipodarum, is released from castrating trematode parasites by comparing prevalence and diversity of trematode parasites in

Abstract Aquatic invaders often cause severe declines of native amphibian populations, either through competition, predation and/or alterations of the habitat. Such situation has raised additional concerns for the persistence of endemic species exhibiting rare and alternative phenotypes. Here, we experimentally assessed the impact of the invasive mosquitofish (Gambusia holbrooki) on adult newts (Lissotriton

Abstract Non-native plants can have strong effects on the structure and functioning of ecosystems. Recently, the American pokeweed (Phytolacca americana), indigenous to east United States, has expanded its range in many regions all over the world. The species combines several traits that facilitate its invasiveness and its impact on ecosystems in its introduced range. The aim of this study was to analyse

Abstract Alpine areas will likely experience an increase in non-native plant species invasions. Increased human activity and environmental changes are expected to lower the environmental constraints for their establishment and spread. To understand and prepare for high elevation plant invasions it is necessary to evaluate the changes in environmental factors that make alpine regions susceptible to

Abstract Two contradictory hypotheses have been put forth to forecast alien invasiveness: being either functionally similar, or dissimilar, to resident natives along environmental gradients. The ‘try-harder’ hypothesis predicts that alien plants will be functionally dissimilar to natives and should thus exhibit exaggerated trait values when compared to natives in respect to resource extraction or stress

Abstract In European rivers, one of the most invasive of terrestrial plant species, Reynoutria japonica Houtt. (Polygonaceae), is frequently found at the water-land interface. In this study, ecological effects of native species replacement by this invasive species was explored. In particular, we examined changes in leaf litter composition, and the subsequent impacts of their decomposition on riparian

Abstract Non-native plant invasions are often catalyzed by wildfires and may alter the structure, function, and composition of ecosystems. Of particular concern are non-native annual grasses that promote increased fire frequency and compete with native vegetation for early season moisture. While these effects are well studied in non-forested ecosystems, relatively few studies document invasions of

Abstract Studies of elusive carnivores often rely on passive sampling when investigating either spatial or temporal interactions. However, inference on behavioral mechanisms are usually lacking. We present an analysis that combines previously published spatial co-occurrence estimates and temporal kernel density estimates to explore spatiotemporal interspecific interactions. We do so by deriving a spatiotemporal

Abstract Invasive plants can have significant negative interactions with native flora and fauna, often decreasing the abundance and diversity of native plants and invertebrate and vertebrate herbivores. Less is known, however, about how invasive plants influence higher-order consumers, such as carnivores. Arundo donax is a globally distributed invasive grass that forms dense monotypic stands in the

Abstract Our ability to predict invasions has been hindered by the seemingly idiosyncratic context-dependency of individual invasions. However, we argue that robust and useful generalisations in invasion science can be made by considering “invasion syndromes” which we define as “a combination of pathways, alien species traits, and characteristics of the recipient ecosystem which collectively result

Abstract Potentilla anserina is a common invasive species of Patagonian wetlands. Although this species is commonly found in temporary habitats, where it establishes during the dry phase, the littoral zones of lakes are also susceptible, as water fluctuations make this habitat extremely variable in terms of water availability. Decay rates and nutrient release of P. anserina were compared with two native

Abstract Lianas (woody vines) are a leading concern in urban forest management given their ability to reduce the growth rate and survival of trees. Efforts to control invasive lianas are widespread, yet forests are often reinvaded following management. Changes in soil nutrient availability could help explain why some forests are susceptible to reinvasion. Specifically, invasive lianas could be “drivers”

Abstract The success of invasion by non-native species can be influenced by positive interactions established in the area of introduction. For instance, seed dispersal by birds can increase seed rain, seed germination, and, as a consequence, the probability of establishment of new invasion foci. Schefflera arboricola, an ornamental shrub with fruits largely consumed by birds, is invasive in several

Abstract Invasive alien species (IAS) have become an important driver of biodiversity change and exert severe pressure on natural ecosystems. The development of modelling approaches to assess and predict their distributions and impacts, and evaluate management options has increased substantially. We reviewed these modelling approaches, applied in aquatic ecosystems, using a systematic review approach

Abstract Alien birds are widely distributed across the globe, but information on their environmental impacts is available for less than a quarter of the regions in which they are located. We test a series of hypotheses better to understand why impact data are available for some regions but not others. Information on factors hypothesised to influence spatial variation in the availability of impact data were

Abstract Roadsides are major pathways of plant invasions in mountain regions. However, the increasing importance of tourism may also turn hiking trails into conduits of non-native plant spread to remote mountain landscapes. Here, we evaluated the importance of such trails for plant invasion in five protected mountain areas of southern central Chile. We therefore sampled native and non-native species

Abstract Assessing global variation in phenotypic traits and linking that variation to colonization and range expansion is notably rare in invasion biology. Here, we studied variation in seed size in Centaurea solstitialis, a weed with worldwide distribution. Additionally, we explored how seed size variation affects seedling survival of C. solstitialis under favorable precipitation conditions in Anatolia

Abstract Invasion by exotic plant species can profoundly affect native plant species performance and the inferred proximate cause is typically competition. We used invaded grasslands in the semi-arid Western USA to separate resource competition from structural interference of an exotic grass on native forb performance, specifically evaluating the role of competition from living vegetation versus litter

Abstract Decisions regarding invasive risk of exotic species are often based on species distribution models projected onto the recipient region of interest. Such projections are essentially a measure of prior belief in the ability of an organism to invade. Whilst many decisions are made on the basis of such projections, it is less clear how such prior belief may be empirically modified on the basis

Abstract Species that are introduced into novel habitats have potentially devasting effects on ecosystem services and functions. Predicting which species and introduction events represent the largest threats are important scientific and management goals. It has been suggested that propagule pressure, the sum of individuals introduced, can be used to predict the probability of establishment success

Abstract Feral cats are known to drive numerous extinctions of endemic species on islands. Predation by feral cats also currently threatens many species listed as critically endangered. Island faunas that have evolved in the absence of mammalian predators are particularly susceptible to cat predation. Dirk Hartog Island is no exception as cats have caused the local extinction of its once high vertebrate

Abstract Introduced forest tree species are frequently attacked by insects in their new range; however, it has been seldom investigated whether the presence of such tree species increases the risk of range expansion of native insect herbivores in the introduced range. European Scots pine has been introduced to North America including within a portion of the range of the mountain pine beetle (MPB).

Abstract Invasive species on islands rarely occur in isolation, and their removal will affect other species, both natives and invasives. Hence, conservation interventions must proceed carefully to avoid unintended consequences. A common invaded ecosystem motif consists of an invasive apex predator, an invasive mesopredator, and a native prey species—for example feral cats, rats and native seabirds

Abstract The global ornamental fish trade enables translocation of exotic aquatic pathogens. In many countries, health certification and visual inspection of imported fish are key components of biosecurity to prevent the introduction of aquatic diseases. However, infected fish do not always exhibit clinical or behavioural signs of disease, and alternatives to visual inspection must be validated. This

Abstract Development of a biological control program for invasive Phagmites australis australis in North America required 20 years of careful research, and consideration of management alternatives. A recent paper by Kiviat et al. (Biol Invasions 21:2529–2541, 2019. https://doi.org/10.1007/s10530-019-02014-9) articulates opposition to this biocontrol program and questions the ethics and thoroughness

Abstract Several European and Mediterranean species of pine bark beetles (Coleoptera: Curculionidae: Scolytinae) have become established in North America and the southern hemisphere, posing a novel threat to planted and naturally-occurring pine forests. Our objectives were to investigate (1) the occurrence and relative abundance of pine bark beetles in these regions, and (2) the trapping performance

Abstract Globally, various avian species have been introduced accidentally and deliberately by humans through different pathways. Some of these species were able to establish, multiply, and become invasive. In this study, we identified areas that are climatically suitable for seven introduced invasive bird species and assessed the environmental and socio-economic impacts associated with the selected

Abstract In the context of evolutionary theory, invasion biology provides a fantastic enigma: how does a species with limited standing genetic variation survive and adapt to a novel environment? Reduced genetic diversity is typically associated with low fitness and evolutionary potential, yet some introduced species have proven to be successful invaders despite undergoing a genetic bottleneck during

Abstract The invasive European earthworm, Lumbricus terrestris, is now widely distributed in North America. This success may result from high genetic diversity derived from multiple introductions from founder sources across Europe. Using a mitochondrial gene (COI) and microsatellite markers, L. terrestris from seven sites in the Champlain Valley of Vermont USA were scored for genetic diversity and

Abstract When a species moves into a new area, direct contests with functionally similar residents may determine whether they can establish themselves. In recent years, the web-building cellar spider, Pholcus manueli, has largely displaced its larger well-established congener, Pholcus phalangioides, in SW Ohio. The relationship between these two species is interesting both because they are congeners

Abstract Although the European Water Framework Directive (WFD) does not refer explicitly to alien species (AS), it is clear that invasive AS (IAS) are considered a pressure on WFD water bodies. This article discusses the results of a questionnaire sent to all EU Member States, demonstrating considerable variability in the way that AS data are used in implementing the WFD. Responses were received from

Abstract The reproductive systems of invasive species play a key role in determining their geographical distributions. Oxalis pes-caprae is a clonal, polyploid, heterostylous, plant native to South Africa, but now invasive in all major Mediterranean climatic regions. Here, we extend earlier surveys in the Western Mediterranean basin of floral morph ratios, reproductive traits and ploidy level to include

The article Incorporating climate change into invasive species management: insights from managers, written by Evelyn M. Beaury

Abstract The Allee threshold, the critical population density separating growth from decline in populations experiencing strong Allee effects, can vary over space and time but few empirical studies have examined this variation. A lack of geographically extensive, long-term studies on low density population dynamics makes studying variability in Allee effects difficult. We used North American gypsy

Abstract Genomic tools like RAD-sequencing can provide the resolution to understand the complex genetic patterns underlying cryptic biological invasions. Here we use this method to clarify the genetic consequences of a rampant invasion by the Italian pool frog (Pelophylax bergeri) north of the Alps, threatening the native P. lessonae and its hybridogenetic hybrid P. esculentus. Patterns of genetic

Abstract The impacts of invasive predators can be amplified by high densities of invasive prey species. In Australia, hyper abundant rabbit populations lead to high densities of feral cats and correspondingly high impact of cats on native species, especially small mammals. Therefore, it would be expected reducing rabbits could also reduce abundance of cats, and thereby alleviate predation on native

Abstract Predicting shifts in the distribution and abundance of pest organisms relies on an accurate forecasting of their response to climate change. The oak processionary moth (OPM) Thaumetopoea processionea causes serious damages to oak trees in forest, urban and other landscapes as well as severe allergic reactions to humans and animals. In the 1990’s and 2000’s, the OPM extended its range from

Abstract Exotic species can cause ecosystem and landscape-level changes in their novel ranges, but factors associated with novel ranges can also change the invaders. By tracking trait changes over space and time, we can learn about the future ecological and economic implications of invasive species’ dispersal. Here, we investigated body size changes of two invasive mole cricket species, Neoscapteriscus

Abstract The Novel Weapons Hypothesis postulates that the release of allelochemicals by alien plants can inhibit the growth of evolutionary naïve native plants. On the other hand, when species share a recent evolutionary history, recognition of phytochemicals from neighboring plants can have adaptive value by providing cues to signal suitable conditions conducive to establishment. This has been termed

Abstract Eradication of invasive alien species is a form of pest control linked to biodiversity conservation, which usually involves animal killing. Squirrels are prominent among invasive alien species in Italy, with four species introduced. Three of them are included within the list of alien species of European concern, and their eradication and control is recommended. However, their local control

Abstract Despite advances in understanding the ecology and consequences of pine invasions, information on the patterns of structure, dynamics, and growth needed to manage these invasive populations are still poorly known. Here we used tree ring analysis to elucidate growth dynamics, age distribution and fire effects, by sampling three populations of slash pine invading Cerrado vegetation in southeastern

Abstract Biological invasions are one of the most important challenges for protected areas around the world, both because of the seriousness of their effects and because of the costs and difficulties associated with their control. Some features of the biology of invasive species, such as growth rate and reproduction, can be particularly important when organizing control actions. Moreover, the control

Abstract Invasive alien species are likely to interact with climate change, thus necessitating management that proactively addresses both global changes. However, invasive species managers’ concerns about the effects of climate change, the degree to which they incorporate climate change into their management, and what stops them from doing so remain unknown. Therefore, we surveyed natural resource

Abstract Hybridisation between invasive and native species represents a significant threat to biodiversity. The Mallard Duck (Anas platyrhynchos) is known to hybridise with numerous closely related Anas species in regions where they have been introduced, threatening the genetic integrity of native ducks and in some instances contributing to their extinction risk. Mallard Ducks were introduced into

Abstract The Chinese mitten crab (Eriocheir sinensis) is a damaging invader which is designated as a species of Union Concern within the European Union. A negative impact of the crabs on macrophyte vegetation in lowland rivers is suspected but not yet proven or quantified. We have performed a mesocosm study that combines a density gradient of Chinese mitten crabs (0, 0.3, 1.0 and 2.5 ind. m−2) with

Abstract Invasive gobies can have severe detrimental effects on local fish communities, however, direct methods for population control are often insufficient (i.e. fishing) or not feasible (i.e. poisoning). Indirect methods, such as habitat modifications in the course of restoration programs, appear promising but are poorly studied. In this study, we investigate the effects of different restoration

Abstract The South African scale insect Pulvinariella mesembryanthemi was introduced worldwide in several coastal areas with Mediterranean climate, probably through infested plants of Carpobrotus sp. Its high host specificity and its capacity to produce severe damages in the invasive Carpobrotus sp. plants makes this insect a potential biocontrol agent. To test the efficiency and host range of insects

Abstract How an invader responds to the novel biotic elements of a new community will affect its ability to invade. Species that are able to cope well with novel competitors might be expected to achieve greater establishment success. We compared the population-level responses of two mosquitofish species, the widespread invader Gambusia affinis and non-invasive G. geiseri to competition from each other

Abstract A monogenean flatworm Gyrodactylus jennyae Paetow, Cone, Huyse, McLaughlin & Marcogliese, 2009 was previously described as a pathogen on bullfrog Lithobates catesbeianus Shaw, 1802, in a Canadian captive population originating in Missouri, U.S.A. The ITS barcoding of G. jennyae showed relatedness to Asian Gyrodactylus macracanthus Hukuda 1940, a parasite of the Asian loach Misgurnus anguillicaudatus

Abstract Plants that become invasive outside their native range often benefit from the absence of their native-range herbivores. Ficus microcarpa is a widely-planted Asian–Australasian species of fig tree that has become invasive in parts of its introduced range. As in most places where it is planted, the pollinator of F. microcarpa has been introduced to Cyprus, together with at least six other Asian

Abstract A common complication in invasive pest management is that the infectious state of the host can be wrongly assessed, leading to biases in the estimation of the prevalence of the pest and on the efficacy of mitigation actions. We designed a multievent model that accommodates uncertainty on host state to investigate the dynamics of the infestation of Phoenix canariensis by the invasive Rhynchophorus

Abstract Invasion by exotic woody species is a major concern in grasslands worldwide. Woody invasions pose a particularly serious threat to forest–grassland mosaics globally, but the factors influencing the success of woody species in these systems, including the role of disturbances such as fire, are not well understood. In this study, we evaluated the role of fire in influencing mortality and regeneration

Abstract Over 90% of global commercial trade occurs between seaports, which are initial points-of-entry for nonnative, potentially invasive propagules. As such, there is a need to develop means to both rapidly intercept and identify propagules as they arrive. Here, we focus on plant propagules that are assumed to be non-native, in seed form. Because standard morphological techniques alone are laborious

Abstract Himalayan balsam (Impatiens glandulifera) is a highly invasive annual herb that has become extremely prevalent in riparian zones across the UK. The competitive ability of I. glandulifera, both in terms of resource exploitation and allelopathy (i.e., the release of biochemicals that may be toxic to neighbouring plants), is considered a key determinant of its success. Little is known, however