An unprotected vulnerable relict subtropical conifer-Keteleeria evelyniana: Its forests, populations, growth and endangerment by invasive alien plant species in China

Relict subtropical coniferous forests in China face severe fragmentation,resulting in declining populations,and some are under significant threat from invasive alien species.Despite the crucial importance of understanding forest dynamics,knowledge gaps persist,particularly regarding the impact of invasive plants on vulnerable natives like Keteleeria evelyniana.In this study,we investigated the impact of invasive plants on the regeneration of forests dominated by K.evelyniana,a subtropical relict species in southwestern China.For this purpose,we characterized forest dynamics of 160 forest plots featuring K.evelyniana as the primary dominant species and determined whether the presence of invasive plants was correlated with regeneration of K.evelyniana.We identified four distinct forest types in which K.evelyniana was dominant.We found that radial growth of K.evelyniana trees is faster in younger ageclasses today than it was for older trees at the same age.The population structure of K.evelyniana in each forest type exhibited a multimodal age-class distribution.However,three forest types lacked established saplings younger than 10 years old,a situation attributed to the dense coverage of the invasive alien Ageratina adenophora.This invasive species resulted in a reduction of understory species diversity.Additionally,our analysis uncovered a significant negative correlation in phylogenetic relatedness(net relatedness index)between native and invasive alien plant species in eastern Yunnan.This suggests closely related invasive species face heightened competition,hindering successful invasion.Taken together,our findings indicate that successful establishment and habitat restoration of K.evelyniana seedling/saplings require effective measures to control invasive plants.

A Study on Alien Invasive Plants from the Interactive Mechanism between Species Niche and Material/Energy Flow

[Objective]This study was to reveal the essence of mechanism about how the alien invasive plants spread.[Method]Species niche and material/energy flow were used as basic research indicators to analyze the intrinsic mechanism of alien plants invasion.[Result]Most of the invasive plants have not been explicitly defined and their effective control methods not brought forward.[Conclusion]Overrun of alien invasive plants depends on whether the niche of a species could be continuously met at spatial level.Based on this we put forward corresponding control measures,proposed an assumption to establish a cylinder-network model and discussed the definition of alien invasive plants.

InvasionDB: A genome and gene database of invasive alien species

Invasive alien species(IAS) are species whose introduction to areas outside of their native range cause harm to economics, biodiversity, and the environment. Understanding the genetic basis of invasiveness is critical for preventing invasion by an alien species and managing IAS with eco-friendly control methods. In addition, uncovering the genomic features of IAS is essential for accurately predicting invasiveness. However, even though increasing efforts have been devoted to sequencing the genomes of IAS, there is still not an integrated genome database for the invasive biology community. Here, we first determined a list of invasive plants and animals by mining references and databases. Then, we retrieved the genomic and gene data of these IAS, and constructed a database, Invasion DB. Invasion DB encompasses 131 IAS genomes, 76 annotated IAS assemblies, and links these data to conventional functions such as searching for gene coding sequences and Pfam, KEGG, NR annotations, BLAST server, JBrowse, and downloads services. Next, we analyzed 19 invasivenessrelated gene families which confer invasiveness in insects. To study the roles of noncoding RNA in invasiveness, we also annotated 135 494 mi RNAs, 89 294 r RNAs, and 2 671 941 t RNAs from these IAS. In summary, Invasion DB is useful for studying the invasiveness at the genomic level, and thus helps to develop novel management strategies to control IAS.

Uses of Invasive Alien Plant Species in Rema-Kalenga Wildlife Sanctuary of Bangladesh

An exploratory survey was conducted on the uses and role of invasive alien species(IAS) to local livelihoods in the Rema-Kalenga Wildlife Sanctuary in the northeastern hilly region of Bangladesh.Vegetation was sampled in 50 quadrates,each 10 m×10 m,and 25 line transects,each 50 m×20 m,through a combination of random and systematic sampling.Group discussions were also arranged with fifty local inhabitants(17 % of the total inhabitants) to learn the various uses of IAS.A total of 17 alien plant species belonging to 10 different families,of which Leguminosae constitutes the highest number(5 species),include tree(53%) followed by herb(12%),shrub(12%) and others(weed,climber and palm).The majority of the identified species were found to be used for fuel,followed by timber production,medicinal or curative uses,fodder,and many others.In addition to providing various forest products,alien tree species planted in forest plantation help provide many vital ecosystem services such as soil amelioration through nitrogen fixation.It is true that the alien species have some negative impacts on local ecosystems,and not all of them are harmful.Therefore,a national programme must be initiated to distinguish the harmful from the harmless species and to identify the uses and impacts of the former and latter.

Environmental Impacts of Invasive Alien Plant Species on the Biodiversity of the Nyika National Park, Rumphi District, Malawi

Invasive alien plant species have threatened the integrity of ecosystems and threatened biological integrity throughout the world. In the Nyika National Park, a number of alien invasive plant species have been reported. These invasive alien plants are reported to be very difficult that have caused adverse ecological, economic and social impact. The main objective of this study is to assess the environmental impact of plant invasive alien species in Nyika National Park in order to ascertain means of addressing the possible effects on the biodiversity. This study adopted an exploratory stance in order to answer the hypotheses where purposive and simple random sampling was used. Purposive sampling was only used to the staff of Nyika while simple random sampling was used to collect data from households surrounding Nyika National Park. The results revealed that invasive alien plant species have some ecological impacts of on the biodiversity of the Nyika National Park like change in physical habitats such as loss of native habitats, alteration of ground water regime, drying of rivers, loss of native species and alteration of biomass. The study would therefore be important to policy makers in guiding and development of policies and guidelines governing eradication of invasive alien plant species. The Department of National Parks and Wildlife (DNPW) can form partnership with various stakeholders with a clearly stated intention of developing a relationship, based on collaboration to enhance the control of invading alien plant species and the best management practices.

Detecting the distribution of and public attitudes to charismatic alien species based on media coverage

Charismatic species are often reported by the media,providing information for detecting population status and public perception.To identify the number and distribution of free-living Black Swan(Cygnus atratus),a charismatic alien species in Chinese mainland and to detect the public and the media attitudes to the species,we analyzed the reports and emotional tendency from media coverage in 2000-2022 using manual reading,crawler extraction and latent Dirichlet allocation.A total of 6654 Black Swans were reported at 711 sites,including 147 individuals at 30 nature reserves.Successful breeding was reported at one-fourth of the total sites,including five nature reserves.The proportion of positive emotional tendency to Black Swans was overwhelming in the reports and was higher than that to alien species in general,suggesting that the public and the media are unaware of the risk of biological invasion.Effective management of invasive species requires the media clarifies the invasion risk of charismatic alien species.Promoting the unity between the harmfulness of abstract concept of alien species and the charisma of a specific alien species among the public help effective management.

Bio-Morphological Characters of Alien Legume Species, Influencing Their Invasion in Natural Plant Communities

Five alien legume species, actively invading in natural plant communities in European part of Russia, were studied—Lupinus polyphyllus Lindl., Galega orientalis Lam., Robinia pseudoacacia L., Amorpha fruticosa L. and Caragana arborescens L. Distribution ranges (considering their invasive status) were mapped. Not a single bio-morphological character to forecast invasion success in natural plant communities within secondary distribution range was found. The data of key value/importance for explaining invasive success of the species studied were obtained. Two hypotheses— Propagule Pressure and Evolution of Invasiveness—were critically analyzed in view of the received data.

Invasive Alien Plants of Indian Himalayan Region—Diversity and Implication

The present study deals with comprehensive list of Invasive alien plants of Indian Himalayan Region with background information on family, habit and nativity. A total of 190 invasive alien species under 112 genera, belonging to 47 families have been recorded. Among these, the dicotyledons represent by 40 families, 95 genera and 170 species;monocotyledons represent by 7 families, 17 genera and 20 species. The analysis of invasive species reveals that 18 species have been introduced intentionally, while the remaining species established unintentionally through trade. In terms of nativity, amongst 13 geographic regions, the majority of invasive plants reported from American continent (73%). While in life form analysis, the herbs (148 species) are dominant, followed by shrubs (19 species), Grass (11 species), Trees (4 species), sedges and climber (3 species each). Most of the invasive species are annual habit (63%). Apart from these, 90 species (47%) are being used by locals for medicinal purposes. A better planning is needed for early detection to control and reporting of infestations of spread of new and naturalized weeds to be monitored.

Monitoring River Restoration Efforts: Do Invasive Alien Plants Endanger the Success? A Case Study of the Traisen River

River restoration activities are challenging for the native vegetation and the colonization process. The development of invasive alien plant species (IAS) as well as the development of the pioneer vegetation cover and seed bank were observed in one year prior to construction of a new river bed and within the first two years after construction, along the downstream section of the river Traisen in Austria. One year after completion of the new river channel, the occurrence of IAS above ground decreased while the occurrence of target species increased. Furthermore, no seeds of IAS were detected in the new river bed as a result of proper management of soil movement. Despite the positive impact on the abundance of IAS, the restoration project of the river Traisen shows that the fact that such a restoration activity is a disturbance event must be taken into consideration already during the planning process. Supporting the competitiveness of native plant species is an important tool for reducing the danger of establishment of invasive alien species.

A risk assessment system for alien plant bio-invasion in Xiamen,China

Bio-invasion has caused serious ecosystem damage and enormous economic losses in China,and it has been the greatest factor to island bio-diversity reduction.Xiamen,as an important seaport with a relatively high conservation value,is particularly vulnerable to bio-invasion for its typical island ecosystem as well as frequent human-made disturbance.As a result of field surveys,literature review, and consultation with experts,a list of 67 alien plants identified as major invaders(12 species)and emerging invade...

Genetic structure of the invasive Colorado potato beetle Leptinotarsa decemlineata populations in China

The Colorado potato beetle(CPB),Leptinotarsa decemlineata Say,is an infamous invasive species worldwide.It was first found in Xinjiang Uygur Autonomous Region of China in 1993 and spread to Northeast China in 2013.To better understand the genetic structure and the diffusion path of their populations in China,we used nine polymorphic microsatellite loci to elucidate the genetic diversity,genetic structure and gene flow among nine CPB populations across Xinjiang and Northeast China.The results show that:(1)Two genetically separated clusters were identified by phylogenetic tree,principal coordinate analysis(PCoA)and Bayesian cluster method.Cluster one contained populations from Xinjiang,China.Cluster two contained populations from Northeast China.A genetic differentiation existed between the two clusters.(2)Three populations in Northeast China hold an obvious genetic differentiation according to the phylogenetic tree and PCoA,indicating that multiple introductions may occur in Northeast China.(3)The Altay population in Xinjiang showed a closer genetic relationship with the populations in Northeast China which may be due to the fact that they collectively originated in neighboring Russia.(4)Among all populations,Mulei and Wusu had obvious gene migrations from Tacheng,indicating that the inland populations are most likely to originate from Tacheng,Xinjiang.

Invasive mechanism and management strategy of Bemisia tabaci(Gennadius) biotype B:Progress report of 973 Program on invasive alien species in China

Bemisia tabaci(Gennadius) biotype B,called a "superbug",is one of the most harmful biotypes of this species complex worldwide.In this report,the invasive mechanism and management of B.tabaci biotype B,based on our 5-year studies,are presented.Six B.tabaci biotypes,B,Q,ZHJ1,ZHJ2,ZHJ3 and FJ1,have been identified in China.Biotype B dominates the other biotypes in many regions of the country.Genetic diversity in biotype B might be induced by host plant,geographical conditions,and/or insecticidal application.The activities of CarE(carboxylesterase) and GSTs(glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants,which might have increased its resistance to insecticides.The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants.Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes.The indigenous B.tabaci biotypes were displaced by the biotype B within 225 d.The asymmetric mating interactions and mutualism between biotype B and begomoviruses via its host plants speed up widespread invasion and displacement of other biotypes.B.tabaci biotype B displaced Trialeurodes vaporariorum(Westwood) after 4-7 generations under glasshouse conditions.Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its successful displacement of T.vaporariorum.Greater ability of the biotype B to switch to different host plants may enrich its host plants,which might enable it to better compete with T.vaporariorum.Native predatory natural enemies possess greater ability to suppress B.tabaci under field conditions.The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids.The present results provide useful information in explaining the mechanisms of genetic diversity,evolution and molecular eco-adaptation of biotype B.Furthermore,it provides a base for sustainable management of B.tabaci using biological and ecological measures.

Zoonotic parasites carried by invasive alien species in China

Background:The invasive alien species may lead to great environmental and economic crisis due to its strong capability of occupying the biological niche of native species and altering the ecosystem of the invaded area.However,its potential to serve as the vectors of some specific zoonotic pathogens,especially parasites,has been neglected.Thus,the damage that it may cause has been hugely underestimated in this aspect,which is actually an important public health problem.This paper aims to discuss the current status of zoonotic parasites carried by invasive alien species in China.Main body:This review summarizes the reported zoonotic parasites carried by invasive alien species in China based on the Database of Invasive Alien Species in China.We summarize their prevalence,threat to human health,related reported cases,and the roles of invasive alien species in the life cycle of these parasites,and the invasion history of some invasive alien species.Furthermore,we sum up the current state of prevention and control of invasive alien species in China,and discuss about the urgency and several feasible strategies for the prevention and control of these zoonoses under the background of booming international communications and inevitable globalization.Conclusions:Information of the zoonotic parasites carried by invasive alien species neither in China or worldwide,especially related case reports,is limited due to a long-time neglection and lack of monitoring.The underestimation of their damage requires more attention to the monitoring and control and compulsory measures should be taken to control the invasive alien species carrying zoonotic parasites.

Seed bank dynamics of an invasive alien species, Helianthus annuus L.

Aims The ability to form persistent seed banks is one of the best predictors of species’potential to establish in new ranges.Wild sunflower is native to North America where the formation of persistent seed banks is promoted by disturbance and it plays a key role on the establishment and persistence of native populations.However,the role of the seed banks on the establishment and persistence of invasive populations has not been studied.Here,we evaluated the role of seed bank and disturbance on the establishment and fitness,and seed persistence in the soil in several sunflower biotypes collected in ruderal(wild Helianthus annuus)and agrestal(natural crop–wild hybrid)habitats of Argentina as well as volunteer populations(progeny of commercial cultivars).Methods In a seed-bank experiment,we evaluated emergence,survival to reproduction,survival of emerged seedlings,inflorescences per plant and per plot under disturbed and undisturbed conditions over 2 years;in a seed-burial experiment,we evaluated seed persistence in the soil over four springs(6,18,30 and 42 months).Important Findings Overall,seedling emergence was early in the growing season(during winter),and it was promoted by disturbance,especially in the first year.Despite this,the number of inflorescences per plot was similar under both conditions,especially in ruderals.In the second year,emergence from the seed bank was much lower,but the survival rate was higher.In the seed-burial experiment,genetic differences were observed but seeds of ruderals and agrestals persisted up to 42 months while seeds of the volunteer did not persist longer than 6 months.The agrestal biotype showed an intermediate behavior between ruderals and volunteers in both experiments.Our findings showed that wild and crop–wild sunflower can form persistent seed banks outside its native range and that disturbance may facilitate its establishment in new areas.

Development of a mathematical model to evaluate the rate of aggregate risk of invasive alien plant species： Fuzzy risk assessment approach

This study presents a novel approach to evaluate the rate of aggregate risk of Invasive Alien Plant Species. Using risk values and grade of importance of weights of risk factors which may reflect invasiveness of plant species are considered. We use Linguistic Ordered Weighted Averaging operator to evaluate the grade of important of weights. Since the risk values and important weights are identified from two different linguistic term sets, fuzzy set theory techniques were used to combine the two sets. The rates obtained from the model were compared with NRA risk levels and the model was validated with data from known and non-invasive species. The model is improved by weighting the risk values of risk factors. The improved model produced significant results and resulted a better tracking system for identifying potential invaders than the conventional risk assessment.

Biology,invasion and management of the agricultural invader:Fall armyworm,Spodoptera frugiperda(Lepidoptera:Noctuidae)

The fall armyworm(FAW),Spodoptera frugiperda(J.E.Smith),is native to the Americas.It has rapidly invaded 47 African countries and 18 Asian countries since the first detection of invasion into Nigeria and Ghana in 2016.It is regarded as a super pest based on its host range(at least 353 host plants),its inherent ability to survive in a wide range of habitats,its strong migration ability,high fecundity,rapid development of resistance to insecticides/viruses and its gluttonous characteristics.The inherently superior biological characteristics of FAW contribute to its invasiveness.Integrated pest management(IPM)of FAW has relied on multiple applications of monitoring and scouting,agricultural control,chemical pesticides,viral insecticides,sex attractants,bio-control agents(parasitoids,predators and entomopathogens)and botanicals.Knowledge gaps remain to be filled to:(1)understand the invasive mechanisms of S.frugiperda;(2)understand how to prevent its further spread and(3)provide better management strategies.This review summarizes the biological characters of FAW,their association with its invasiveness and IPM strategies,which may provide further insights for future management.

The origin of invasion of an alien frog species in Tibet, China

Identifying the origins of alien species has important implications for effectively controlling the spread of alien species. The black-spotted frog Pelophylax nigromaculatus, originally from East Asia, has become an alien species on the Tibetan Plateau （TP）. In this study, we collected 300 individuals of P. nigromaculatus from 13 native regions and 2 invasive regions （including Nyingchi and Lhasa） on the TP. To identify the source region of the TP introductions, we sequenced portions of the mitochondrial cyt b gene. We sequenced a -600-bp portion of the mitochondrial cyt b gene to identify 69 haplotypes （124 polymorphic sites） in all sampled populations. According to the network results, we suggest that the P. nigromaculatus found on the TP was most likely originated from Chongqing by human introduction. Furthermore, we found that the genetic diversity was significantly lower for invasive than for native sites due to founder effects. Our study provides genetic evidence that this alien species invaded the cold environment of high elevations and expanded the distribution of P. nigromaculatus in China.

Contrasting responses of native and alien plant species to soil properties shed new light on the invasion of dune systems

Aims Among terrestrial ecosystems,coastal sandy dunes are particularly prone to alien plant invasion.Many studies related the invasion of dune habitats to anthropic causes,but less is known about the role of soil properties and plant traits in plant invasion.In this study,we tested the relationships between soil features and alien plant invasion in dune systems,focusing on the interplay between soil nutrients,soil salinity and plant functional traits.Methods Study sites were sandy barrier islands of the Marano and Grado lagoon(northern Adriatic Sea).One hundred plots(4 m×4 m)were selected within 10 areas according to the main habitats occurring along the ecological gradient of dune system(foredune,backdune and saltmarsh).In each plot,we recorded all plant species occurrence and abundance and we collected a soil core.For each soil sample,soil texture,conductivity(as proxy of soil salinity),organic carbon and nitrogen content were analyzed and related to the species number and cover of native and alien plants.Variation of main reproductive and vegetative functional traits among habitats was also analyzed for both alien and native species.Important Findings Soil properties were strongly related to overall plant diversity,by differently affecting alien and native species pools.In backdune,the most invaded habitat,a high soil conductivity limited the number of alien species,whereas the content of soil organic carbon increased along with alien plant abundance,suggesting also the occurrence of potential feedback processes between plant invasion and soil.We found a significant convergence between native and alien plant functional trait spectra only in backdune habitat,where environmental conditions ameliorate and plant competition increases.Our findings suggest that in harsh conditions only native specialized plants can thrive while at intermediate conditions,soil properties gradient acts in synergy with plant traits to curb/facilitate alien plant richness.

Acacia mearnsii management in a South African National Parks：SWOT analysis using hot topics in biological invasion as a guide

The assessment of the policy framework governing Invasive Alien Species(IAS) control is of critical importance in conservation. The undertaking of a SWOT analysis of such a framework is necessary because it enhances the efficacy of IAS control. The aim of this study is to carry out a SWOT analysis of the policy framework guiding the control of the spreading of Acacia mearnsii and other IAS in the Golden Gate Highlands National Park in South Africa,as well as the implementation of restorative measures in the park and adjacent communities in line with the recommendations of the Convention on Biodiversity. A comparative analysis of this framework and the hierarchical framework that was developed during the European Union Conference on Freshwater Invasives- Networking for Strategy in 2013 is undertaken. The results indicate the need to strengthen parkcommunity relations,upgrade existing legislation,and boost the technical capacity of South African national parks to identify,detect,monitor and predict IAS invasions,both within the parks and their surroundings. This knowledge is important for developing future policies on IAS control in South Africa.

Invasion and Morphological Variation of the Non- Indigenous Barnacle Chthamalus challengeri(Hoek, 1883) in Yangshan Port and its Surrounding Areas

Invasive species generally possess unique characteristics that allow them to survive the invasion process in order to es- tablish and spread in new habitats. Successful invaders must resist both physical and physiological stresses associated with the changing environment. A common littoral barnacle, Chthamalus challengeri Hoek, 1883 （Crustacea, Cirripedia）, which is native to Japan, South Korea and northern China, has become established in the high-littoral zone adjacent to Yangshan Port, Shanghai, China. A comparison of the morphology of Chthamlus species from Zhoushan archipelago with previous description indicates the occur- rence of C. challengeri. The new immigrant becomes a dominant species in certain high-intertidal habitats of the adjacent area to of Yangshan Port. C. challengeri was found in part of sampling sites in Zhoushan in 2010; however, it dispersed to all the eleven sam- piing sites in 2012. Densities of C.challengeri had increased over 10 times in the last 2 years, with the highest mean value reaching 39533 ± 6243 ind. m-2 in the new habitat. The specific ratios of both operculum area （Sa） to base area （SA） and average height of pa- rietal plates （H） to length of base （L） revealed that C. challengeri displays morphological changes to resist stronger currents in the new habitats for invasion.