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The invasive blue crab Callinectes sapidus was monitored in the Moulay Bousselham Lagoon on the Moroccan Atlantic coast, from January to December 2023. This pioneering study on the African Atlantic coast aimed to evaluate the species’ biometric characteristics, reproductive patterns, and spatiotemporal dynamics. Overall, 1932 crabs were collected from which 1806 were investigated. The average carapace width was 83.68 ± 37.88 mm, carapace length was 38.38 ± 15.25 mm, and average weight was 64.43 ± 57.93 g. Significant sexual dimorphism was noted, with females larger than males, having an average carapace width of 89.82 ± 36.72 mm and total weight of 66.82 ± 50.87 g compared to males’ 75.84 ± 37.15 mm and 36.65 ± 16.26 g, respectively. The carapace width at 50% maturity was 90.7 mm overall, with females maturing at a larger size (93.7 mm) compared to males (86.9 mm). The global sex ratio was skewed towards females (0.64:1), deviating significantly from the expected 1:1 ratio. Spatiotemporal variations revealed low abundance in winter, moderate in spring, and high in summer. Reproductive activity showed two peaks: spring (April) and summer (August), with increased gonadosomatic index and higher percentage of ovigerous females during these periods. These results confirm the typical reproductive dynamics of the species and highlight the characteristics of the invasive blue crab population in the Moulay Bousselham Lagoon, including smaller biometric traits and earlier maturity compared to other areas. Moreover, they emphasize the need for management strategies tailored to the local biological cycle and continuous monitoring to adapt to the crab’s reproductive dynamics. [ABSTRACT FROM AUTHOR]

Understanding the underlying temporal dynamics influencing invasive plant control outcomes is essential to achieve restoration and land management goals. Within grasslands, herbicides are commonly used as the main method for invasive plant control, but the efficacy of management may be dependent on seasonal dynamics, as well as the number of applications. Additionally, assessments to quantify invasive plant control are often limited to aboveground plant composition, overlooking the potential repository of propagules stored in the soil seedbank, and additional impacts on nontarget species. To ensure that an herbicide method is effectively controlling invader populations, while limiting impacts on the resident plant communities, both above‐ and belowground species responses must be assessed. We established an herbicide field experiment across different sites and years in Riverside, CA, U.S.A., to assess the control of a global annual invasive forb, Oncosiphon pilulifer. We investigated how seasonal herbicide management (early‐season vs. late‐season) and repeated annual herbicide applications (1 vs. 2 years) influenced cover and seedbank density of our focal invader and the resident plant community 1 year after treatment. We found that although late‐ and early‐season‐applied herbicides reduced invader cover, early‐season applications were the only strategy to reduce invader seedbank density, indicating potential longer term management control. Lastly, native cover was limited in post‐treated areas, suggesting that additional management strategies may be needed to overcome native establishment limitations in invaded grasslands. [ABSTRACT FROM AUTHOR]

Horizon scans have emerged as a valuable tool to anticipate the incoming invasive alien species (IAS) by judging species on their potential impacts. However, little research has been conducted on quantifying actual impacts and assessing causes of species‐specific vulnerabilities to particular IAS due to persistent methodological challenges. The underlying interspecific mechanisms driving species‐specific vulnerabilities therefore remain poorly understood, even though they can substantially improve the accuracy of risk assessments. Given that interspecific interactions underlying ecological impacts of IAS are often shaped by phenological synchrony, we tested the hypothesis that temporal mismatches in breeding phenology between native species and IAS can mitigate their ecological impacts. Focusing on the invasive American bullfrog (Lithobates catesbeianus), we combined an environmental DNA (eDNA) quantitative barcoding and metabarcoding survey in Belgium with a global meta‐analysis, and integrated citizen‐science data on breeding phenology. We examined whether the presence of native amphibian species was negatively related to the presence or abundance of invasive bullfrogs and whether this relationship was affected by their phenological mismatches. The field study revealed a significant negative effect of increasing bullfrog eDNA concentrations on native amphibian species richness and community structure. These observations were shaped by species‐specific vulnerabilities to invasive bullfrogs, with late spring‐ and summer‐breeding species being strongly affected, while winter‐breeding species remained unaffected. This trend was confirmed by the global meta‐analysis. A significant negative relationship was observed between phenological mismatch and the impact of bullfrogs. Specifically, native amphibian species with breeding phenology differing by 6 weeks or less from invasive bullfrogs were more likely to be absent in the presence of bullfrogs than species whose phenology differed by more than 6 weeks with that of bullfrogs. Taken together, we present a novel method based on the combination of aqueous eDNA quantitative barcoding and metabarcoding to quantify the ecological impacts of biological invaders at the community level. We show that phenological mismatches between native and invasive species can be a strong predictor of invasion impact regardless of ecological or methodological context. Therefore, we advocate for the integration of temporal alignment between native and IAS's phenologies into invasion impact frameworks. [ABSTRACT FROM AUTHOR]

Cytisus scoparius (L.) Link, commonly referred to as Scotch broom, is a Mediterranean shrub capable of thriving in a variety of ecosystems that has invaded every habitable continent on Earth. Our research presents a timeline and estimated rate of expansion from 1816 to 2016. We then model its expected range over the next 70 years, highlighting the need for investigation into its expansion mechanisms and the establishment of monitoring programs. [ABSTRACT FROM AUTHOR]

Managing invasive species is essential for achieving mineland rehabilitation goals and ensuring the long‐term provision of critical ecosystem services while preventing new dispersion sources to neighboring areas. Traditional techniques include chemical and manual weeding, but frequent reinvasion limits their long‐term success. Therefore, additional integrated tools, such as stimulating natural competitors, may become necessary, especially where sensitive ecosystems, e.g. the ferruginous savanna ecosystem (cangas) from the Carajás National Forest, Eastern Amazon, Brazil, are found nearby rehabilitation sites. Here, we investigate the influence of different substrates and fertilization levels on the biotic interactions between two native canga grasses (Axonopus longispicus and Paspalum cinerascens) and the invasive molasses grass (Melinis minutiflora), which is frequently found in anthropized and natural ecosystems in Latin America. Nutrient application significantly influenced the growth, resource use strategies, and competitive outcomes of M. minutiflora. Nutrient application has positive effects on the growth of native species when cultivated in isolation but reduces plant development when subjected to competition with molasses grass, potentiating the invader. Although neither of the tested native species exhibited competitive advantages over M. minutiflora, increased nitrogen availability favored the competitive ability of this invasive grass. Thus, eliminating fertilization during mineland rehabilitation may be important for reducing the cover of M. minutiflora in the Carajás region, as sensitive canga ecosystems lack natural barriers against invasion. This strategic approach mitigates the operational risks and costs associated with combating invasive species from rehabilitating minelands, reducing propagule pressure on neighboring canga areas. [ABSTRACT FROM AUTHOR]

Few studies tried to explore the mitigation effect and underlying mechanisms of biochar and their complex for negative allelopathy from invasive plants, which may provide a new way in the invasive plant management. Herein, an invasive plant (Solidago canadensis)‐derived biochar (IBC) and its composite with hydroxyapatite (HAP/IBC) were synthesized by high temperature pyrolysis, and characterized by scanning electron microscopy, energy dispersion spectrometer, X‐ray diffraction, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy. Then, both the batch adsorption and pot experiments were conducted to compare the removal effects of kaempferol‐3‐O‐β‐D‐glucoside (C21H20O11, kaempf), an allelochemical from S. canadensis, on IBC and HAP/IBC, respectively. HAP/IBC showed a stronger affinity for kaempf than IBC due to its higher specific surface area, more functional groups (P‐O, P‐O‐P, PO43−), stronger crystallization [Ca3(PO4)2]. The maximum kaempf adsorption capacity on HAP/IBC was six times higher than on IBC (10.482 mg/g > 1.709 mg/g) via π–π interactions, functional groups, and metal complexation. The kaempf adsorption process could be fitted best by both pseudo‐second‐order kinetic and Langmuir isotherm models. Furthermore, HAP/IBC addition into soils could enhance and even recover the germination rate and/or seedling growth of tomato inhibited by negative allelopathy from the invasive S. canadensis. These results indicate that the composite of HAP/IBC could more effectively mitigate the allelopathy from S. canadensis than IBC, which may be a potential efficient approach to control the invasive plant and improve invaded soils. [ABSTRACT FROM AUTHOR]

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

Plant invasions can change native communities in complex ways. Restoring invasion-altered habitats starts with invader removal, and imposes significant physical and compositional changes. Restoration facilitates desirable plant community development, but arthropod community responses to removal and the timelines required for native vegetation establishment are difficult to predict. We examined initial effects of Elaeagnus angustifolia (Russian olive) removal on arthropod communities during a long-term experiment evaluating the combined consequences of invasive shrub removal and plant community restoration. We sampled E. angustifolia -invaded areas pre-removal (2010) and post-removal (2013) using sweep netting, and identified arthropods to family level. We found greater variation in the arthropod community composition within removal blocks than within invaded blocks after two years. These shifts resulted from changes in the relative abundance of community members (e.g. Dictynidae (Araneae), Culicidae (Diptera), and Cicadellidae (Hemiptera)), rather than overall richness or diversity. This response is likely due to increased plant diversity in E. angustifolia removal sites but also structural differences in vegetation cover after removal. Removing a dominant structural element like E. angustifolia instantly changes the successional stage of the ecosystem. Thus, restoration managers should consider methods that maintain structural continuity during restoration implementation. Arthropods provide important ecosystem services such as nutrient cycling and pollination and serve as a prey base for higher trophic levels. Thus, understanding how arthropod communities change after plant restoration events is vital to assessing future management decisions to limit ecosystem impacts of invasive plants and their management. [ABSTRACT FROM AUTHOR]

Empirical evidence shows that early arrival of native species, which induces the priority effects, can contribute to invasive plant species containment. However, more systematic studies are required to test the applied relevance of the priority effect. This study therefore aimed at testing the priority effects generated by different sowing times of seeds of nine native species on one target invasive plant species, that is, Giant ragweed (Ambrosia trifida). This study hypothesized that, when sown earlier, some native species will be able to substantially contain A. trifida through resource preemption. An additive competition design was used to test the competitive effects of native species on A. trifida. Depending on the sowing times of native and invasive plant species, three priority treatments were conducted: all species sown at the same time (T1); native species sown 3 weeks before A. trifida (T2); and native species sown 6 weeks before A. trifida (T3). Priority effects created by all nine native species significantly affected the invasibility of A. trifida. The average value of the relative competition index (RCIavg) of A. trifida was the highest when native seeds were sown 6 weeks early and decreased with decreasing early sowing time of native plants. The species identity effect was not significant on RCIavg if natives were sown at the same time or 3 weeks earlier than A. trifida invasion, but it was significant (p =.0123) if they were sown 6 weeks earlier than A. trifida. Synthesis and applications. The findings of this study clearly show that native species, when sown early, provide strong competition and resist invasion through prior utilization of resources. The consideration of this knowledge might improve A. trifida invasion management practices. [ABSTRACT FROM AUTHOR]

Sicyos angulatus is a serious threat to riverine ecosystem functions and services worldwide. Here, we studied the effect of species identity and diversity on biotic resistance to S. angulatus under two different soil nutrient levels (unfertilized vs. fertilized). Soil nutrient levels showed no significant effect on invasion by S. angulatus in the control treatment, where intervention by native plants was absent. Species identity of native plants and its interaction with soil nutrient levels had a significant effect on biotic resistance to S. angulatus. For instance, Pennisetum alopecuroides and Lespedeza cuneata best resisted invasion in fertilized soil, whereas Lespedeza bicolor and Lactuca indica best resisted invasion in unfertilized soil. In addition, a mixture of four plant species resisted invasion equally as well as the monoculture of a species in unfertilized soil, whereas the mixed treatment resisted invasion much better in fertilized soil compared with unfertilized soil. Structural equation modeling revealed that species identity and diversity as well as fertilizer application significantly influenced biotic resistance to S. angulatus invasion, while soil nutrients did not influence invasion success directly. Based on these results, we strongly suggest sowing seed mixtures of various species after eradicating S. angulatus plants to prevent re-invasion. Overall, these results demonstrate how native plants rely on resource availability to resist colonization by an invasive plant, such as S. angulatus. This information can be used for the development of improved guidelines for plant restoration and invasive species control. [ABSTRACT FROM AUTHOR]

In the introduced range, the successful establishment of an invasive species may be influenced by positive plant-plant interactions. Pre-existing vegetation, particularly conspecific mature trees, can shape the availability and attributes of microsites, thus potentially creating favorable conditions for the establishment of conspecific seedlings through facilitation. Pines are widely introduced in the Southern Hemisphere primarily as forestry plantations; these pines can become invasive, causing detrimental effects on local ecosystems and economies. In the high-elevation grasslands of the Sierras de Córdoba , Central Argentina, pines have begun to invade the native grassland as a result of improper (or lack of) management of pine plantations. During early pine invasion in this semi-arid grassland, we aimed to quantify the influence of adult live pines and on congeneric pine seedling recruitment and survival. For this, 48,000 seeds of Pinus elliottii and P. taeda were sown in three consecutive field trials, under different tree status treatments: live pines, dead pines, and no pines (i.e., open grassland). Seed were sown with and without irrigation and seeded microsites were oriented to the north and south of the live and dead trees. We also considered the hillslope aspect where the sites were located. Our results show that pine seedling recruitment was 57 % higher under live pines compared to dead pines and no pines treatment, but only in the trials that were not irrigated. Microsites south of the live pine trees, more shaded from direct sunlight in the Southern hemisphere, presented 36 % more pine seed germination than those to the north. In terms of topography, hillslope aspects with lower solar incidence (wetter hillslopes) also showed higher pine seedling recruitment. Our results suggest that moisture availability is a dominant factor driving further invasion, and that adult pines may be facilitating the invasion process by creating moister microsites for germination and pine seedling establishment. Thus, the early removal of adult pines is important to consider in the management of pine invasions. They do not only serve as a source of propagules, but also positively affect the establishment of their congeneric seedlings. [Display omitted] • Recruitment of congeneric seedlings was greater in microsites under live pines. • Recruitment is greater in microsites found to the south of the live pines (more shade). • South-facing hillslopes (wetter) had greater number of microsites with pine seedlings. • Water availability is a main factor influencing pine seedling establishment in the mountain grassland. • Adult pine trees may facilitate seedling establishment by improving moisture availability. [ABSTRACT FROM AUTHOR]

Acquisition of biological information on invasive fishes during the early stages of invasion could be critical in orienting subsequent management strategies. To achieve such a task, biological invasion researchers and practitioners take advantage of numerous technologies (e.g. genomics and acoustic telemetry). Surprisingly, the study of invasive fish ecology by analysis of the chemical composition of calcium carbonate hard parts (e.g. otoliths and scales) remains underutilized, despite some convincing examples of successful applications in the scientific literature. Among its most common applications in invasion biology, otolith chemistry has been used to identify natal origins, reconstruct migratory behaviour and assess mixed-stock structure. In this literature review, we provide a general overview of those previous applications but more importantly identify some gaps and obstacles to applications of otolith chemistry in invasion biology and suggest development for innovative applications, including use in wildlife forensic sciences and reconstruction of the early dynamics of invasions. [ABSTRACT FROM AUTHOR]

Interactions among native and invasive species may affect management outcomes and goals. We implemented different mowing regimes to control the invasive Solidago gigantea and restore natural diversity, and also examined interactions between Solidago and a European native competitor, Tanacetum vulgare in the context of these regimes. Experimentally planted Tanacetum suppressed Solidago by 79% without management, and a suite of mowing management regimes reduced the density of Solidago by 80–98% when Tanacetum was absent. But, when Tanacetum was added, the density of the invader was not reduced by mowing. Put another way, in mowed plots with Tanacetum, Solidago was twofold to over fivefold denser than in mowed plots without Tanacetum. It is not clear why the effect of Tanacetum shifted from competition in the absence of disturbance to facilitation with intense management‐associated disturbance, but other studies suggest that Tanacetum may create plant–soil feedbacks that favor Solidago. Evidence shows similar shifts from competition to facilitation under mowing regimes for other species, but these are not mechanistically clear either. We speculate that mowing reduced competition from Tanacetum while leaving belowground facilitative effects unchanged, shifting the net effect of Tanacetum to facilitation. When single‐year mowed plots were abandoned for just 1 year, Solidago was twofold denser than in the control, thus maintaining treatments over time was important for successful management. Our results indicate that mechanical control may substantially alter biotic resistance gained from native competition. [ABSTRACT FROM AUTHOR]

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

The management of biological invasions is a worldwide conservation priority. Unfortunately, decision‐making on optimal invasion management can be impeded by lack of information about the biological processes that determine invader success (i.e. biological uncertainty) or by uncertainty about the effectiveness of candidate interventions (i.e. operational uncertainty). Concurrent assessment of both sources of uncertainty within the same framework can help to optimize control decisions.Here, we present a Value of Information (VoI) framework to simultaneously analyse the effects of biological and operational uncertainties on management outcomes. We demonstrate this approach with a case study: minimizing the long‐term population growth of musk thistle Carduus nutans, a widespread invasive plant, using several insects as biological control agents, including Trichosirocalus horridus, Rhinocyllus conicus and Urophora solstitialis.The ranking of biocontrol agents was sensitive to differences in the target weed's demography and also to differences in the effectiveness of the different biocontrol agents. This finding suggests that accounting for both biological and operational uncertainties is valuable when making management recommendations for invasion control. Furthermore, our VoI analyses show that reduction of all uncertainties across all combinations of demographic model and biocontrol effectiveness explored in the current study would lead, on average, to a 15.6% reduction in musk thistle population growth rate. The specific growth reduction that would be observed in any instance would depend on how the uncertainties actually resolve. Resolving biological uncertainty (across demographic model combinations) or operational uncertainty (across biocontrol effectiveness combinations) alone would reduce expected population growth rate by 8.5% and 10.5% respectively.Synthesis and applications. Our study demonstrates that intervention rank is determined both by biological processes in the targeted invasive populations and by intervention effectiveness. Ignoring either biological uncertainty or operational uncertainty may result in a suboptimal recommendation. Therefore, it is important to simultaneously acknowledge both sources of uncertainty during the decision‐making process in invasion management. The framework presented here can accommodate diverse data sources and modelling approaches, and has wide applicability to guide invasive species management and conservation efforts. [ABSTRACT FROM AUTHOR]

Biological invasions are one of the leading causes of global environmental change and their impacts can affect biodiversity, ecosystem services, human health and the economy. Yet, the understanding on the impacts of invasive alien species is still limited and mostly related to alien species outbreaks and losses in agricultural yield, followed by the understanding of the ecological impacts on natural systems. Notably, the economic impacts of biological invasions have rarely been quantified. Brazil has at least 1214 known alien species from which 460 are recognized as invasive alien species. Still, there are no comprehensive estimates of the cost of their impact and management. Here, we aimed at filling this gap by providing a comprehensive estimate of the economic cost of biological invasions in Brazil. In order to quantify these costs for species, ecosystems and human well-being we used the InvaCost database which is the first global compilation of the economic costs of biological invasions. We found that Brazil reportedly spent a minimum of USD 105.53 billions over 35 years (1984-2019), with an average spent of USD 3.02 (± 9.8) billions per year. Furthermore, USD 104.33 billion were due to damages and losses caused by invaders, whereas only USD 1.19 billion were invested in their management (prevention, control or eradication). We also found that recorded costs were unevenly distributed across ecosystems, and socio-economic sectors, and were rarely evaluated and published. We found that the economic costs with losses and damages were substantially greater than those used for prevention, control or eradication of IAS. Since our data show costs reported in Brazil for only 16 invasive alien species, our estimates are likely a conservative minimum of the actual economic costs of biological invasions in Brazil. Taken together, they indicate that invasive alien species are an important cause of economic losses and that Brazil has mostly opted for paying for the damage incurred by biological invasions rather than investing in preventing them from happening. [ABSTRACT FROM AUTHOR]

Abstract As a result of biodiversity and ecosystem service losses associated with biological invasions, there has been growing interest in basic and applied research on invasive species aiming to improve management strategies. Tradescantia zebrina is a herbaceous species increasingly reported as invasive in the understory of disturbed forest ecosystems. In this study, we assess the effect of spatial and seasonal variation on biological attributes of this species in the Atlantic Forest. To this end, we measured attributes of T. zebrina associated with plant growth and stress in the four seasons at the forest edge and in the forest interior of invaded sites in the Iguaçu National Park, Southern Brazil. The invasive plant had higher growth at the forest edge than in the forest interior and lower leaf asymmetry and herbivory in the winter than in the summer. Our findings suggest that the forest edge environment favours the growth of T. zebrina. This invasive species is highly competitive in the understory of semi-deciduous seasonal forests all over the year. Our study contributes to the management of T. zebrina by showing that the summer is the best season for controlling this species.

This review summarizes and analyses information on freshwater crayfish introductions in Africa. A total of 136 research papers and reports were found to be relevant. Forty-eight percent reported presence; 21% described negative impacts; 11% referred to potential socio-economic benefits; 9% evaluated control measures; 6% documented co-introduced parasites. Out of nine introduced crayfish species, five species Astacus astacus, Cherax quadricarinatus, Faxonius limosus, Procambarus clarkii, and Procambarus virginalis have established populations in the wild. Astacus astacus and F. limosus are present only in Morocco and P. virginalis is limited to Madagascar. Cherax quadricarinatus and P. clarkii have established populations in five and six countries, respectively. The main driver of crayfish introductions was to provide socio-economic benefits through aquaculture and fisheries development but there is limited evidence of success. Prevailing negative socio-economic impacts are linked to damage to agricultural water infrastructure, damage to fishing gear and declining fisheries performance. Ecological impacts pertain to direct and multi-trophic consumptive effects as well as indirect competitive effects primarily upon macro-invertebrates and potential spillover of parasites to other decapods. Research priorities are determining abundance, distribution and spread of crayfishes and assessing ecological impact to inform management decisions. [ABSTRACT FROM AUTHOR]

Hull fouling is a dominant vector in marine systems, with recreational vessels playing an important role in intra-regional transfer of biota. Encapsulation (i.e. the wrapping of a structure in plastic to deprive biota of oxygen and food, ultimately causing their death), offers promise as a tool for treating vessel fouling in situ. However, there is currently no standardised approach with detailed field application recommendations. In recognition of this gap this study aimed to: 1) use laboratory experiments to establish a timeframe for the effective encapsulation of yachts, 2) test this approach in the field and 3) consider the practicalities associated with implementing an encapsulation program. Laboratory experiments exposed the ascidian Ciona robusta, the mussel Semimytilus algosus and fouling communities to four treatments: aerated control in seawater, encapsulation in seawater, aerated seawater with 4% acetic acid and encapsulation in seawater with 4% acetic acid. All biota in acetic acid died in 24 hours regardless of encapsulation, while in encapsulated seawater mortality of all taxa occurred within three days. In the field four yachts and five pontoons with high (80-100%) and low (30-50%) fouling cover were encapsulated. It took more than three days to achieve mortality on all structures (pontoons high cover 3.7 days (± 0.48 SD); pontoons low cover 3.8 days (± 0.42 SD) and yachts 4.3 days (± 0.5 SD)). The discrepancy between laboratory and field results likely reflects an unavoidably higher water to fouling biomass ratio in field systems. These results suggest that five days may be sufficient for successful encapsulation of yachts. However, in recognition of the limited sample size of yachts in this study, it is recommended that these findings be used as a basis for further developing region specific protocols through adaptive management. Logistical considerations around the implantation of national encapsulation programs are also discussed. [ABSTRACT FROM AUTHOR]

Due to the presence of few dominant predators on South African rocky shores, this coastline could be vulnerable to invasion by predatory crabs. This study applied horizon scanning to create an ordered watch list of alien crab species that could establish along this coastline under present-day and future temperature scenarios. This was done by: (i) identifying the species with both an invasion history and a possible pathway to South Africa; (ii) comparing the temperature ranges of the species' native and introduced distributions to those of each of the four South African ecoregions; and (iii) ranking the species based on their potential ecological impacts. Of the 56 alien predatory crab species known worldwide, 28 species have pathways to South Africa. Incompatible temperature ranges excluded only two species from each ecoregion. Negative ecological impacts in their invaded ranges placed Japanese shore crab Hemigrapsus sanguineus, brush-clawed shore crab H. takanoi and Chinese mitten crab Eriocheir sinensis at the top of the watch list. This study highlights that many alien crab species have the potential to reach South Africa, with most likely to survive. This watch list should be used to support targeted monitoring and so facilitate early detection of these species, should they reach South Africa. [ABSTRACT FROM AUTHOR]

Abstract Tree invasions are increasing globally, causing major problems for biodiversity, ecosystem services and human well-being. In South America, conifer invasions occur across many ecosystems and while numerous studies address the ecological consequences of these invasions, little is known about social perceptions and people's attitudes toward their control. The social perceptions on the effect of invasive conifers can include recreational, cultural and conservation dimensions. This study, conducted in the Malalcahuello National Reserve, aims to assess visitor's perception about invasive pines (Pinus spp.) and their effects on the endangered Araucaria araucana forests and determine their willingness to pay for pine control. We used a questionnaire to survey visitors to the reserve in both winter and summer (n = 138 for each season). When confronted with six images of araucaria and pine forests with and without snow, visitors consistently preferred landscapes without pines and disliked those completely dominated by pines the most. Almost half, 46.5%, of the visitors expressed their willingness to pay (WTP) for pine control and after given a brief explanation about pine impacts, this number rose to 79%. Visitors who said they were unwilling to pay argue ethical, aesthetic and pragmatic considerations relating closely to a number of social value systems and beliefs. Our study shows that there is a high variation in how people assess the threat of invasive pine species in natural areas, but education even in a very brief format can help to increase awareness of the problem and build social and financial support for its control. Highlights • We studied people's perceptions about pine invasions in south-central Chile. • Age, income and education affect how people perceive pine invasions. • Experience in the area and environmental literacy is also relevant. • Environmental education increases willingness to pay for pine invasion control. • People's perceptions should be included in invasive species management. [ABSTRACT FROM AUTHOR]

The development of environmentally safe and cost-effective methods for controlling invasive species Sosnowsky's hogweed (Heracleum sosnowskyi Manden.) is an urgent issue for the European part of Russia. The article presents findings of an experiment on the effect of snow cover removal from the areas occupied by H. sosnowskyi in the early spring period (the beginning of March 2018) in the vicinity of the city of Syktyvkar (Komi Republic, Russia). The snow depth reached 100 cm on the intact plots; the sum of below-zero air temperatures measured at 6 a.m. constituted –448°C, with a minimum of –29.0°C during the experiment. The number of H. sosnowskyi plants of all age groups at the experimental plots (with removed snow cover) was shown to be significantly decreased. The median seedling density (pcs. per square meter) was equal to zero. Most of the surviving plants were located along the sides and in the corners of experimental plots. This can be explained by the higher temperature of soil on the borders of plots with an intact snow cover. The results of the experiment may be used for development of invasive plant eradication technology by removal of the snow cover. This technology can be suitable for kindergartens, schools, hospitals, and water protection zones, where the use of chemical methods of plant control is limited or prohibited. The obtained data set with respect to H. sosnowskyi monitoring is available in the repository of Zenodo. [ABSTRACT FROM AUTHOR]

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

Preventing the arrival of invasive alien species ( IAS) is a major priority in managing biological invasions. However, information on introduction pathways is currently scattered across many data bases that often use different categorisations to describe similar pathways. This hampers the identification and prioritisation of pathways to meet the main targets of recent environmental policies., Therefore, we integrate pathway information from two major IAS data bases, IUCN's Global Invasive Species Database ( GISD) and the DAISIE European Invasive Alien Species Gateway, applying the new standard categorisation scheme recently adopted by the Convention on Biological Diversity ( CBD). We describe the process of mapping pathways from the individual data bases to the CBD scheme and provide, for the first time, detailed descriptions of the standard pathway categories. The combined data set includes pathway information for 8323 species across major taxonomic groups (plants, vertebrates, invertebrates, algae, fungi, other) and environments (terrestrial, freshwater, marine)., We analyse the data for major patterns in the introduction pathways, highlighting that the specific research question and context determines whether the combined or an individual data set is the better information source for such analyses. While the combined data set provides an improved basis for direction-setting in invasion management policies on the global level, individual data sets often better reflect regional idiosyncrasies. The combined data set should thus be considered in addition to, rather than replacing, existing individual data sets., Pathway patterns derived from the combined and individual data sets show that the intentional pathways 'Escape' and 'Release' are most important for plants and vertebrates, while for invertebrates, algae, fungi and micro-organisms unintentional transport pathways prevail. Differences in pathway proportions among marine, freshwater and terrestrial environments are much less pronounced. The results also show that IAS with highest impacts in Europe are on average associated with a greater number of pathways than other alien species and are more frequently introduced both intentionally and unintentionally., Synthesis and applications. Linking data bases on invasive alien species by harmonising and consolidating their pathway information is essential to turn dispersed data into useful knowledge. The standard pathway categorisation scheme recently adopted by the Convention on Biological Diversity may be crucial to facilitate this process. Our study demonstrates the value of integrating major invasion data bases to help managers and policymakers reach robust conclusions about patterns in introduction pathways and thus aid effective prevention and prioritisation in invasion management. [ABSTRACT FROM AUTHOR]

The chief aim of invasive species management is to prevent biological invasions by taking measures for suppressing or eradicating potential invaders. Biological control as a management tool is frequently implemented to reduce the population size, adverse ecological impacts, and dispersal of invasive species. The efficacy of biological control measures in managing the Perccottus glenii population was assessed in four small lakes of Lithuania. The biocontrol was carried out by introducing the native piscivorous fishes Esox lucius and Perca fluviatilis into the invaded water bodies for two successive reproductive seasons. The stocking of these fishes led to an instant reduction in P. glenii abundances, and the outcome of the repeated stocking was complete disappearance of the species from the water bodies investigated. Our study proves that native predator fishes can be successfully used for eradicating well-established P. glenii populations in small eutrophic lakes. We hope the current study results will contribute to developing risk-commensurate methodologies for the control of invasive P. glenii populations in small water bodies.

Considerable resources are spent worldwide to manage invasive plant species and preserve the integrity and diversity of native or restored habitats and communities. Here, we review empirical evidence to identify relevant ecological principles and practices that could guide plant community restoration when the goal is to prevent re-invasion after management of an invasive species. Our focus is on the restoration of North American freshwater or tidal wetland communities after invasion by Phragmites australis , but our findings could apply to the design and restoration of invasion-resistant communities for any plant invader. The ecological principles that emerge from this review are (1) seedling establishment of P. australis provides a critical window for limiting invasion through ecological resistance; (2) abiotic conditions modulate ecological resistance; (3) resident species do best when they have a head start on the invader; (4) competition through limiting similarity can help strengthen ecological resistance; (5) species and functional diversity enhance invasion resistance through complementarity effects; and (6) propagule pressure of the invader and seeding density of the resident species interact to determine invasion success. We propose a conceptual model that synthesizes these ecological principles as well as a decision tree in support of field applications. Finally, we conclude by encouraging experiments that encompass the temporal and spatial variability of restored ecosystems to test the limits of these principles and better support the applications of, and generalization about, ecological resistance. [ABSTRACT FROM AUTHOR]

Management of non-native species aims to prevent biological invasions using actions including control and containment of the potential invader. Biocontrol and biomanipulation strategies are used frequently to reduce population sizes of non-native species and reduce their ecological impacts and dispersal rates., Assessments of the efficacy of biocontrol and biomanipulation actions for managing non-native pest fish, and the ecological mechanisms involved, were studied here using lentic populations of the invasive fish Pseudorasbora parva. Biocontrol was through release of the indigenous piscivorous fish Perca fluviatilis and biomanipulation through intensive fish removals., A combined biocontrol and removal programme was completed in an invaded pond over two reproductive seasons. Almost 10 000 P. parva were removed, with cumulative removal numbers significantly related to their decreased abundance (>60 to <0·1 m−2). Ten adult P. fluviatilis were also released initially and reproduced each season. Analyses revealed P. parva contribution to P. fluviatilis diet was high initially, but decreased as P. parva abundance reduced. Individual contributions of the management actions to declined P. parva abundance were difficult to isolate., The individual effects of biocontrol and removals on P. parva populations were then tested using a field trial in replicated pond mesocosms over three reproductive seasons. Replicates started with 1500 P. parva. The control (no interventions) revealed no significant temporal changes in P. parva abundances. In the removal treatment, where over 17 000 P. parva were removed per replicate over the trial, abundance declined initially, but increased significantly after each reproductive season as remaining fish compensated through increased reproductive output. In the biocontrol, abundance declined and remained low; analyses revealed P. parva were an important dietary component of larger P. fluviatilis, with predation suppressing compensatory responses., Synthesis and applications. Biocontrol and removals can significantly reduce abundances of lentic populations of small invasive fishes. Removals provide short-term population suppression, but high effort is needed to overcome compensatory responses. Biocontrol can provide longer-term suppression but could invoke unintended ecological consequences via 'stocking-up' food webs. Application of these results to decision-making frameworks should enable managers to make more objective decisions on risk-commensurate methodologies for controlling small invasive fishes. [ABSTRACT FROM AUTHOR]

Biological invasions are a prominent factor contributing to global biodiversity loss. As a result, managing invasive species is a priority for many conservation scientists and natural resource managers. Invasive species management requires a multidisciplinary approach and there is increasing recognition that physiology can be used to inform conservation efforts because physiological processes underlie an individual's response to its environment. For example, physiological concepts and tools can be used to assess the impacts of invasive animals on their new ecosystems, to predict which animal species are likely to become invasive, to prevent the introduction of non-native animals, and to control incipient or established invasions. To evaluate whether physiology is integrated within invasion science, the journal Biological Invasions was surveyed for a quantitative literature review. To determine how physiology is used to inform invasion science and which subdisciplines of physiology are particularly relevant to invasive animal management, the broader invasion literature was also reviewed to identify examples where physiology has contributed to studying and managing invasive animals. Only 6 % of articles published in Biological Invasions incorporated physiological knowledge or tools, mostly for the purposes of identifying traits associated with species invasiveness (i.e. prediction). However, the broader literature indicated that successful invasive species research and management can be supported by fundamental and applied physiological research for assessing, predicting, preventing, and controlling invasive animals. Development of new techniques and increased availability of equipment for remote or rapid monitoring of physiology in the field will increase opportunities for integrating physiology within invasion science. [ABSTRACT FROM AUTHOR]

Attempts to investigate the drivers of invasion success are generally limited to the biological and evolutionary traits distinguishing native from introduced species. Although alien species introduced to the same recipient environment differ in their invasion intensity - for example, some are 'strong invaders'; others are 'weak invaders' - the factors underlying the variation in invasion success within alien communities are little explored. In this study, we ask what drives the variation in invasion success of alien mammals in South Africa. First, we tested for taxonomic and phylogenetic signal in invasion intensity. Second, we reconstructed predictive models of the variation in invasion intensity among alien mammals using the generalized linear mixed-effects models. We found that the family Bovidae and the order Artiodactyla contained more 'strong invaders' than expected by chance, and that such taxonomic signal did not translate into phylogenetic selectivity. In addition, our study indicates that latitude, gestation length, social group size, and human population density are only marginal determinant of the variation in invasion success. However, we found that evolutionary distinctiveness - a parameter characterising the uniqueness of each alien species - is the most important predictive variable. Our results indicate that the invasive behavior of alien mammals may have been 'fingerprinted' in their evolutionary past, and that evolutionary history might capture beyond ecological, biological and life-history traits usually prioritized in predictive modeling of invasion success. These findings have applicability to the management of alien mammals in South Africa. [ABSTRACT FROM AUTHOR]

1. Lampricides are commonly used to control invasive sea lampreys ( Petromyzon marinus) in tributaries around the Great Lakes (U.S.A.) by targeting their larvae (ammocoetes). As lampricides have sublethal effects on unionids, this study investigated unionid and ammocoete distribution and habitat use to aid in refining lampricide applications. 2. Habitat and unionid surveys were conducted in the Paw Paw River, in south-west Michigan (U.S.A.). Unionids were predominately present in the upper main stem, while the probability of ammocoete presence was highest in the tributaries and lower main stem. 3. Generalised linear models revealed median particle size and gradient to be effective predictors of unionid distributions, while distance to sea lamprey spawning habitat and bank stability were effective predictors of ammocoete distributions. 4. Minimal overlap of unionid and ammocoete distributions suggests that refinement of lampricide treatment in the Paw Paw River is possible. We propose redefining the extent of the treatment unit so that only areas with a high probability of ammocoete presence and a low probability of unionid presence are treated with lampricide. This could result in reducing treatment costs and minimising threats to unionid conservation, while not jeopardising the success of lampricide treatment programmes. [ABSTRACT FROM AUTHOR]

Finding efficient ways to manage the threat of invasive species helps make the most of limited resources. Different management actions reduce the impact of invasions differently: preventing invasion eliminates impacts entirely, surveillance can facilitate early detection and eradication, and removing individuals can reduce future impact. Few studies have examined the trade-off between all three facets of invasion management. Using a simple model of island invasion, we find how resources should be allocated to each action to minimise the total cost of management and impact. We use a case study of black rat (Rattus rattus) invasion on Barrow Island, Western Australia. The optimal amount to invest in each management action depends on the effectiveness of each action, and the magnitude of impact caused by different stages of invasion. If the pest is currently absent, it is more cost-effective to prevent impacts through prevention or surveillance. If the pest is already widespread, it can sometimes be cost-effective to give up rather than attempting eradication. This model of invasion can provide useful decision support by identifying the trade-offs inherent in each candidate management strategy, the thresholds that alter optimal strategies, and the parameters for which we need more information. [Copyright &y& Elsevier]

Why do some alien plants become naturalized, and some naturalized become invasive? Do different factors determine successful naturalization and invasion? Most, if not all, studies addressing these questions have focused either on the part of the invasion continuum or a specific group of alien species. In this study, we aimed to answer these questions for alien plant invasion in India by considering 13 variables related to biogeography, introduction pathways, uses, functional traits, and distribution for 715 species belonging to three invasion categories. We deciphered the variables' influence on successful naturalization and invasion through a structural equation modeling framework implemented as path analyses and translated the findings to management implications. Our study revealed that the invasive aliens had significantly higher naturalized range size, a greater number of uses, and higher specific leaf area than the naturalized and casual aliens. Path analyses revealed that the native and naturalized range sizes, number of uses, and growth form had a direct influence on naturalization success, whereas longer minimum residence time (MRT) facilitated overcoming of the dispersal barrier for naturalized species. Invasion success was directly influenced by the MRT and number of uses, which were further influenced by the number of native congeners and the naturalized range size, respectively. Plant growth forms indirectly influenced invasion success, whereas the native range sizes had indirect effects on successful naturalization and invasion by strongly influencing the size of the naturalized range. Our findings suggested considering species biogeography in the formulation of quarantine measures, imposing policies to discourage the uses and spread of alien plants within the country, and implementing early control measures, especially for the naturalized aliens. The curated dataset used in this study would also provide a ready reference for future research and decision-making towards the management of alien plant invasion in the country. • First study to reveal factors for successful invasion of Indian alien flora. • Relative influence of 13 variables on the entire invasion continuum was tested. • Geographical range size and plant uses influenced successful naturalization. • Plant uses and residence time directly influenced invasion success. • Study may assist policy makers taking informed decisions for invasion management. [ABSTRACT FROM AUTHOR]

Invasions by invasive alien species (IAS) are recognized as one of the largest threats to earth's ecosystem services and represent rapidly growing economic costs as they damage local ecosystems and force surrounding communities to divert resources towards IAS management and control. The study objectives were to assess the economic impacts of a Prosopis juliflora invasion in Jordan and gauge community preferences for management plans. The study was conducted in Sweimeh, Jordan Valley using a combination of focus groups and randomized interviews with 203 local households. Direct-use values for products derived from P. juliflora and direct costs owing to P. juliflora's presence have been calculated. A binary logistic regression model was then developed to predict the households' preferences between two policy responses: P. juliflora management or complete eradication. The results revealed the dualistic role of P. juliflora in household livelihoods: it was widely used for firewood, fodder, and charcoal offering benefits valued at JOD 2165 per household/year (JOD 1 = USD 0.71). At the same time, the invasion reduced household welfare by taking over arable lands and injuring humans and animals. Consequently, the income lost as a result of the invasion was estimated by JOD 1410.5 per household/year. As a result, two-thirds of respondents choose the option of P.juliflora invasion management. Only respondents' monthly income and perception of P. juliflora's impact on the prevention of soil erosion were significant predictors of respondents' preferences for the management plans. In conclusion, more coordinated responses between policy makers, institutions, and local communities are required to mitigate the negative impact of P. juliflora invasion. [ABSTRACT FROM AUTHOR]

Despite increasing concerns about the global threat of cordgrass (S. alterniflora) expansion and the interest in its invasion mechanisms, there is not yet a general understanding of the mechanistic processes underlying the interaction between cordgrass invasion and geomorphic structures such as tidal channels. This study elucidated the effects of the hydrodynamic disturbance of tidal channels on initial seedling establishment of cordgrass in the margins of two different types of tidal channels (i.e., main tidal channels and secondary tributaries). We performed field experiments that transplanted cordgrass seedlings to above-mentioned tidal channel margins with on-site controlled hydrodynamic conditions. The results showed that high hydrodynamic disturbance intensity (i.e., HDI) on the margin of main tidal channels (i.e., MMC) was not beneficial to cordgrass invasion, whereas low HDI created windows of opportunity for cordgrass invasion to the margin of secondary tributaries (i.e., MST) by facilitating the survival, growth, and stability of cordgrass seedlings. The presence of high HDI predominantly reduced the seedling survival and total biomass of cordgrass, whereas root biomass allocation of cordgrass increased significantly to resist dislodgment and toppling. Moreover, field investigations showed that soil salinity and moisture in the margin of tidal channels were not the limiting factors affecting the establishment of cordgrass seedlings. However, higher propagule pressure combined with suitable soil salinity-moisture conditions (i.e., low salinity and high moisture) laid a firm foundation favoring seedling establishment. Our results highlight the importance of hydrodynamic disturbance as a dominating driver regulating seedling establishment of cordgrass in tidal channel margins and the potential implications for controlling cordgrass landward invasions. Image 1 • Low hydrodynamic disturbance creates cordgrass invasion window to channel margin. • High hydrodynamic disturbance reduces survival and total biomass of seedlings. • High hydrodynamic disturbance increases root biomass allocation of seedlings. • Soil salinity-moisture are not key factors for seedlings to invade at channel margin. • Propagule pressure is higher in margins of secondary tributaries than main channels. [ABSTRACT FROM AUTHOR]

ABSTRACTAlien species have been transported and traded by humans for many centuries. However, with the era of globalization, biological invasions have reached notable magnitudes. Currently, introduction of alien species is one of the major threats to biodiversity and ecosystem functioning. The North American crayfish Procambarus clarkii is one of the most widely introduced freshwater species in the world, especially due to its high economic importance. It is responsible for great modifications in invaded environments causing irreparable ecological and economic damages. Its impressive ability to successfully colonize a wide range of environments is a consequence of its behavioural and biological characteristics that can adapt to features of the invaded location, conferring to this species a notable ecological plasticity. This review summarizes the available information regarding P. clarkii's biology and invasive dynamics around the world in order to contribute to the understanding of the threats posed by its establishment, as well as to support management and impact mitigation efforts.