Invasive Alien Species Management Research Articles

Distribution pattern and management of invasive alien plant species in Sikkim Himalaya, India

An assessment of the distribution pattern of Invasive Alien Plant species in the Sikkim Himalayas was conducted at different elevation gradients and accordingly, management strategies were recommended to combat the ever-increasing condition of invasive plant species threatening the sensitive ecoregions. Among the most relevant factors supporting the present study were changes in the importance value index (IVI), variety, and evenness. There is a greater percentage of domination of invasion at lower elevations than at higher elevations. Species diversity, dominance, and evenness values decreased significantly at higher elevations; interestingly, the fraction of invaded regions is lower at higher elevations. Several factors may contribute to the large cover of invasive plants at lower elevations, including the enabling climate and anthropogenic activities. As a result of invasive alien plant species, such as Ageratum conyzoides, Ageratina adenophora, Bidens pilosa, Chromolaena odorata, Lantana camara, Mikania micrantha and Parthenium hysterophorus, native vegetation, and fauna may suffer adverse consequences, as well as socioeconomic conditions and health issues. This study determined that the invasion of these invasive alien plants in different elevations in the Sikkim Himalaya impacts ecosystem services and depletes several species of commercial importance. The current study recommends quick action to control harmful invasive alien plant species in the Sikkim Himalaya

Habitat Preference of Lesser Whistling Ducks (Dendrocygna javanica) in Selected Wetlands within Colombo Ramsar Wetland City

Lesser Whistling Ducks (LWD) (Dendrocygna javanica) mostly occur in flocks and inhabit lakes, ponds and marshes within freshwater wetlands. They feed mainly on plants taken from water (seed, shoots, tuber and leaves), vertebrates (fishes) and invertebrates (mollusks and worms). In this study, habitat preference of LWD in five selected wetlands in Colombo Ramsar Wetland City (CRWC); Beddagana Wetland Park (BWP), Diyasaru Park (DP), Heen Ela Marsh (HEM), Thalangama Marsh (TM) and Kimbulawala Wetland (KW) was studied from May 2021 to April 2022 as wetlands in urban areas act as the last resort for many resident and migratory bird species and play a major role in the assemblage and conservation of water birds. Habitats present in the selected wetlands were categorized as open water body, floating vegetation, trees, grassland, paddy field, shrubs, bare land. Percentage cover of each habitat type at each sampling site were estimated using quadrat method. LWD were surveyed using line transects of 100m in length, laid in each selected study site to cover representative habitats and observations were made up to 30m towards either side of each transect. Sampling was done in three time slots of the day, morning, mid-day and evening. Floating vegetation, open water body and grassland were the preferred habitat types of D. javanica in BWP, DP, HEM and TM. LWD were not recorded in KW. Floating vegetation (54.97%) was the most preferred habitat by LWD in each study site followed by open water body (24.70%) and grassland (15.82%) habitat types. Eicchornia crassipes (Common water hyacinth) and Salvinia molesta (Giant salvinia) were their most preferred floating vegetation type. Higher abundance of LWD was recorded in TM (83.22%) followed by DP (9.17%), BWP (4.16%) and HEM (3.45%). TM which had higher abundance of LWD had higher floating vegetation coverage (28%) and was rich with E. crassipes and S. molesta. Present study revealed that, LWD mostly used E. crassipes and S. molesta as their main foraging and resting sites. Management of invasive alien species have been undertaken in Colombo wetlands and as E. crassipes and S. molesta are alien species they are currently being removed. Therefore, outright removal of E. crassipes and S. molesta may not be suitable and a monitored removal program that will conserve this habitat type should be implemented in order to conserve the habitats preferred by LWD in CRWC. 
 Keywords: Lesser whistling ducks, Wetlands, Habitat preference

Archetypal representations of dilemmas concerning invasive alien species management—A case of invasive Lantana camara in the protected areas of Nilgiri Biosphere Reserve, India

AbstractThis multi‐site case study on the invasive alien plant Lantana camara in protected areas of Nilgiri Biosphere Reserve, India, addresses the reasons for inadequate institutional responses from stakeholders in managing the species despite the seriousness. The study uses thematic analysis and qualitative systems approach. The themes are converted into a qualitative‐system‐dynamics model and are then abstracted into system archetypes. The study identified three major themes: the dilemma involving stakeholders, the dilemma of alternative and commercial use of Lantana, and the Lantana management conundrum. The study translated these dilemmas into four generalisable archetypes: ‘drifting goals’, ‘modified‐shifting‐the‐burden’, ‘fixes‐that‐fail’ and ‘substitution rebound’. The latest is a novel contribution to the systems literature. Practically, the study helps understand the recurring undesired behavioural patterns in invasive species management and suggests policy and governance changes to tackle them. The study also points towards building stakeholder relationship protocols, focussing on fundamental solutions and having clear Lantana management targets.

Perceptions of Acacia dealbata invasion and clearing in Upper Tsitsana villages in the Eastern Cape Province of South Africa

ABSTRACT Tree holdings provide important socio-economic and environmental benefits, but invasive alien trees can constrain these benefits. However, some invasive alien plants provide both costs and benefits, making management complex due to varied stakeholder perceptions. Using household surveys, the study explored local people’s perceptions of Acacia dealbata invasion and clearing in six villages located in upper Tsitsana communal areas, Eastern Cape Province of South Africa. The results suggest that most respondents are aware of A. dealbata invasion but not its invasion status. The respondents valued A. dealbata for its service provision including firewood, construction poles and shade but also cited negative impacts such as loss of grazing land and water. The respondents were aware of the Working for Water clearing programme and reported employment, income, and are awareness of restored grazing land and increased water availability as key clearing benefits. Although some respondents cleared A. dealbata in their homesteads, a small percentage were opposed to clearing due to the perceived loss of benefits. Overall, the study shows conflicting perceptions on the impacts of A. dealbata invasion and clearing, highlighting the value of considering the social dimensions of invasive alien plant species management to avoid conflict generation.

Remote sensing enabled essential biodiversity variables for invasive alien species management: towards the development of spatial decision support system

Remote sensing enabled essential biodiversity variables for invasive alien species management: towards the development of spatial decision support system

Germany’s first Action plan on the pathways of invasive alien species to prevent their unintentional introduction and spread

The increase in global trade and traffic networks contributes to the introduction and spread of invasive alien species, posing a threat to biodiversity. EU Regulation 1143/2014 addresses the prevention and management of invasive alien species and requires an action plan on the priority pathways of unintentional introduction and spread of invasive alien species by each member state. To this end, the first German action plan was developed for the German government in cooperation with relevant Ministries and authorities, scientists, administrative experts, stakeholder working groups and political as well as public deliberation processes. As a result, 14 priority pathways of unintentional introduction, escape or release and spread were identified, resulting in 24 targeted measures. Nineteen sectors will be involved in the implementation of these measures. Here we describe the development process and outcome of Germany’s first action plan. By this, we aim making the process public and transparent, which can facilitate a revision of the action plan required at least every six years, and trigger broader European as well as national cooperation in the future.

Spatial scale matters for predicting plant invasions along roads

Abstract Biological invasions threaten global biodiversity and can have severe economic and social impacts. The complexity of this problem challenges effective management of invasive alien species as the contribution of many factors involved in the invasion processes across different spatial scales is not well understood. Here, we identify the most important determinants associated with the occurrence of two invasive alien plants, the North American goldenrods (Solidago canadensis and S. gigantea), commonly found in agricultural landscapes of Europe. We used Google Street View images to perform a remote, large‐scale inventory of goldenrods along 1347 roadside transects across Poland. Using open access geospatial data and machine learning techniques, we investigated the relative role of nearly 50 variables potentially affecting the distribution of studied species at five spatial scales (from within 0.25 to 5 km of the studied locations). We found that the occurrence of goldenrods along roadsides was simultaneously associated with multiple drivers among which those related to human impacts, climate, soil properties and landscape structure were the most important, while local characteristics, such as road parameters or the presence of other alien plants were less influential. However, the relative contribution of different variables in predicting goldenrod distribution changed across spatial scales. Synthesis: Mechanisms underlying plant invasions are highly complex and a number of factors can jointly influence the outcomes of this process. However, since different invasion drivers operate at different spatial scales, some important associations may be overlooked when focusing on a single spatial context. Although associations were consistent in direction (positive or negative) across scales, their relative influence on goldenrod occurrence often changed. Socio‐economic factors were largely important at local scales, while the effect of landscape factors broadly increased with increasing spatial scale. We highlight that using multi‐scale approaches involving a wide range of variables may enable setting priorities for the management of invasive alien plants.

Perspectives of invasive alien species management in China.

Perspectives of invasive alien species management in China.

Invasive Alien Species (IAS) spread, impact and management

Invasive Alien Species (IAS) have been an increasing subject of concern with their growing speed of spread and increasing impacts on the invaded areas. The sustainability of IAS control, that is, how to make managing IAS most economical, human, and environmentally efficient is currently an issue under discussion. This review catalogs the general aspects of invasive species, from their natural spread to human-induced causes such as how it is spread through cross-sea and cross-border trades, affected by artificial constructions such as dams and reservoirs, agriculture, climate change, and deliberate introduction. The review also analyzed how IAS causes harm to the ecosystem and human community, what harm it causes, and how humans manage these invaders. Thus, providing a foundation for future research regarding the sustainability of the management of invasive alien species.

Towards Improved Data Flows for the Management of Invasive Alien Species and Wildlife: A LIFE RIPARIAS use case

Invasive alien species (IAS) are recognised as a major threat to biodiversity. To prevent the introduction and spread of IAS, the European Union Regulation (EU) 1143/2014 imposes an obligation on Member States to both develop management strategies for IAS of Union Concern and report on those interventions. For this, we need to collect and combine management data and streamline management actions. This is still a major challenge: the landscape of IAS management is diverse and includes different authorities, managers, businesses and non-governmental organizations. Some organizations have developed their own specific software applications for recording management actions. For other organizations, such a software system is lacking. Their management data are scattered, not harmonized, and often not openly available. For EU reporting, a workflow is needed to centralize all information about the applied management method, management effort, cost, effectiveness and impact of the performed actions on other biota or the environment. At this moment, such a workflow is lacking in Belgium. One of the aims of the LIFE RIPARIAS project is to set up a workflow for harmonizing IAS management data in Belgium. Based on the input from the IAS management community in Belgium, we were able to: draft a community-driven data model and exchange format called manIAS (MANagement of Invasive Alien Species, Reyserhove et al. 2022), and identify the minimal requirements a software application should have for being successfully used in the field (Hillaert et al. 2022). draft a community-driven data model and exchange format called manIAS (MANagement of Invasive Alien Species, Reyserhove et al. 2022), and identify the minimal requirements a software application should have for being successfully used in the field (Hillaert et al. 2022). In this presentation, we will explore both outputs, the lessons learned and the way forward. With our work, we aim to facilitate coordination and transfer of information between the different actors involved in IAS and wildlife management, not only on a Belgian scale, but also within an international context.

Futures for invasive alien species management: using bottom-up innovations to envision positive systemic change

AbstractInvasive alien species (IAS) pose a key threat to biodiversity, the economy and human well-being, and continue to increase in abundance and impact worldwide. Legislation and policy currently dominate the global agenda for IAS, although translation to localised success may be limited. This calls for a wider range of responses to transform IAS management. An under-appreciated strategy to achieve success may come from bottom-up, experimental innovations (so-called “seeds”), which offer alternative visions of what may be possible for IAS management in the future. We present an application of a participatory process that builds on such innovations to create alternative visions of the future, with actionable pathways to guide change. Through a series of workshops with practitioners and academics, we used this process to explore alternative positive futures for IAS management in South Africa. We then identified a set of domains of change, that could enable these visions to be actioned by appropriate stakeholders. The domains of change highlight the social–ecological nature of the IAS sector, with interconnected actions needed in financial, cultural, social, technological and governance spheres. Key domains identified were the need to shift mindsets and values of society regarding IAS, as well as the need for appropriate and functional financing. This participatory futuring process offers a way to interrogate and scale bottom-up innovations, thereby creating optimism and allowing stakeholders to engage constructively with the future. This represents an important step in fostering the potential of bottom-up innovations to transform IAS management.

Decision support tools for invasive alien species management should better consider principles of robust decision making

Invasive alien species (IAS) pose global threat to economies and biodiversity. With rising number of species and limited resources, IAS management must be prioritised; yet agreed tools to assist decision–making and their application are currently inadequate. There is need for simple decision support tools (DST) that guide stakeholders to optimise investment based on objective and quantifiable criteria. This paper reviews DSTs for IAS management to assess their availability and application of principles of robust decision–making. The aim is to provide guidance towards adopting the principles of robust decision–making to improve applicability and practical use of DST. A literature search conducted to identify relevant studies that report on DST in biological invasion. Results indicate an increase in availability of DST; however, available studies are largely biased in geographical, habitat and taxonomic focus. The results also show challenges in practical use of existing tools as most of them do not apply principles of robust decision–making. Application of these principles has the potential to overcome weakness of the current decision–making process and as such, enable decision–makers to efficiently allocate resources towards IAS management. A call is made for more consideration and adoption of principles of robust decision–making when developing DST for IAS invasions.

Contribution of Indigenous Peoples' understandings and relational frameworks to invasive alien species management

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

Green Synthesis of Gold and Silver Nanoparticles Using Invasive Alien Plant Parthenium hysterophorus and Their Antimicrobial and Antioxidant Activities

Due to the high energy demands and environmental hazards of physical and chemical methods, it is now essential to produce nanoparticles using plant sources as reducing and stabilizing agents. In this study, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were biosynthesized using an aqueous extract of Parthenium hysterophorus aerials as a reducing and stabilizing agent. The synthesized nanoparticles were characterized using UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and transmission electron Microscopy (TEM). UV–Vis spectroscopy indicates that the peaks of AgNPs and AuNPs are at 422 and 538 nm, respectively. The results of the DLS analysis showed that both Au and AgNPs are monodispersed and stable and have mean hydrodynamic sizes of 53.55 nm and 68.12 nm, respectively. According to an XRD analysis, the generated AgNPs and AuNPs are face-centered cubic crystals with average crystalline diameters of 33.4 nm and 30.5 nm, respectively. TEM image depicted that the synthesized NPs mainly have spherical shapes with particle size in the range of 3.41–14.5 nm for AuNPs and 5.57–26.3 nm for AgNPs. These biologically produced AuNPs and AgNPs were investigated for their antibacterial, antifungal, and antioxidant effects. Both AuNPs and AgNPs were found to strongly influence the growth of bacterial pathogens, with a maximum zone of 22.3 and 19.7 mm in Escherichia coli and a minimum zone of 11.7 and 10.3 mm in Salmonella enterica, respectively. The synthesized AuNPs and AgNPs reduce the numbers of viable fungi by 51.06% and 47.87%, respectively. The DPPH (2,2-diphenyl-1-picrylhydrazyl) assay revealed that the synthesized AuNPs and AgNPs have significant radical scavenging ability with 88.75% and 86.25% inhibition and 33.62 μg/mL and 42.86 μg/mL of IC50, respectively. Therefore, an aqueous extract of aerial parts of P. hysterophorus can be a suitable precursor for synthesizing AuNPs and AgNPs, with numerous applications. Due to their smaller size, AuNPs have better antimicrobial and antioxidant activities than AgNPs. This study supports the conservation by a utilization strategy of invasive alien plant species control and management (such as P. hysterophorus) for biodiversity conservation and environmental sustainability.

Robinia pseudoacacia L. — an important introduced tree species in protective stands of forest-agrarian landscapes of Ukraine

The article analyzes the importance of black locust (Robinia pseudoacacia L.) in forest-agricultural landscapes of Ukraine. As a result of cultivation and invasion black locust became part of the landscape of a number of European countries, in particular Ukraine, as well as a component of culture and economy, including cultural and historical heritage. In some European countries, this tree species is economically important and is used to obtain commercial wood and firewood, biomass for energy needs, honey, also used to prevent erosion, in greening of populated areas, phytoremediation of contaminated soils, etc. In Ukraine black locust occupies about 5% of the total forest area and is widely used in the planting of protective forest stands (anti-erosion, runoff-controlling, field protection forest belts) and in beekeeping (production of honey). At the same time, this invasive plant poses a threat to the preservation of native species and natural habitats. However, the possibility of uncontrolled spread of the black locust in the agricultural landscapes of Ukraine beyond the boundaries of protective stands is significantly limited by intensively cultivated agricultural land (arable land). In forests, the spread of black locust is controlled by appropriate cutting. The ban on the use of black locust in reforestation will lead to a problem in the restoration of protective forest stands, in particular anti-erosion and field protection forest belts, in which it was the main species. Therefore, we offer a balanced approach, which involves the controlled use of black locust in forest melioration, forestry and agriculture (as a source of wood, honey, forage) and bioenergy (biomass), while simultaneously preventing its invasion into the ecosystems of the nature protection fund. This approach is consistent with the State Forest Management Strategy of Ukraine until 2035 and the environmental policy of the European Union in the field of management of invasive alien plant species.

Effective communications on invasive alien species: Identifying communication needs of Swedish domestic garden owners

Invasive alien species threaten biodiversity with domestic gardens acting as a major pathway for the introduction of alien species. Even though the Nordic region is not currently a hotspot for biological invasions, the number of invasions in the Nordic area has been predicted to increase due to climate change. Given a time lag between introduction and invasion, many non-invasive horticultural alien species already introduced into gardens may become invasive in the future. This study aimed to identify the communication needs of Swedish garden owners regarding their management of invasive alien species. A survey among domestic garden owners, informed by topic specialists and local area experts, and interviews with garden owners were conducted in three different bio-climatic areas in a latitudinal gradient across Sweden. The questions targeted invasive alien species and their relations to biodiversity loss and climate change, as well as measures taken to control these species. Analysing the survey data collected in relation to measures taken to control invasive species, Bayesian Additive Regression Tree (BART) modelling was used to identify geographically varying communication needs of the domestic garden owners. In all study areas, the garden owners' measures taken to control invasive alien species were correlated with their strength of beliefs in having experienced local biodiversity loss. A majority of the garden owners were, moreover, uncertain about the impact of climate change on the invasiveness of alien species. In addition, the garden owners' capacity for identifying invasive alien species was often in need of improvement, in particular with respect to the species Impatiens glandulifera, Reynoutria japonica and Rosa rugosa. The results suggest that the evidence-based guidelines for effective communications we developed, have the potential to help communicators meet the local communication needs of garden owners across Sweden, in relation to the management of invasive alien garden species.

Prioritizing Management of Invasive Alien Species of EU Concern—A Northern Perspective

Invasive alien species (IAS) represent one of the major threats to biodiversity globally. Each member state in the EU is required to compile a management plan for IAS of Union concern. This requires risk assessments to prioritize management measures consistent with the requirements of each EU member state. Here, we review the management priorities for the 88 IAS of Union concern based on the risk assessment scheme developed for Finland. Of 88 species, 52 had not been detected in Finland and 51 species were categorized as species that fail to succeed in Finland. Climatic conditions can be regarded as a major factor limiting the success of those species. Five primary management categories were recognized. Monitoring was deemed the primary management option for 30 species, prevention of entry into Finland for 30 species, prevention of escape into nature for 17 species, prevention of further spread and/or the management of areas with high biodiversity value for 4 species and eradication for 7 species. It is concluded that national management plans should consider local environmental conditions and adjust management options according to national risk assessments.

Spatial priorities for invasive alien species control in protected areas

Given the limited funds available for the management of invasive alien species (IASs), there is a need to design cost-effective strategies to prioritize their control. In this paper, we propose a cost-benefit optimization framework that incorporates the spatially explicit costs and benefits of invasion control, as well as the spatial invasion dynamics. Our framework offers a simple yet operational priority-setting criterion for the spatially explicit management of IASs under budget constraints. We applied this criterion to the control of the invasion of primrose willow (genus Ludwigia) in a protected area in France. Using a unique geographic information system panel dataset on control costs and invasion levels through space for a 20-year period, we estimated the costs of invasion control and a spatial econometric model of primrose willow invasion dynamics. Next, we used a field choice experiment to estimate the spatially explicit benefits of invasion control. Applying our priority criterion, we show that, unlike the current management strategy that controls the invasion in a spatially homogeneous manner, the criterion recommends targeted control on heavily invaded areas that are highly valued by users. We also show that the returns on investment are high, justifying the need to increase the allocated budgets and to treat the invasion more drastically. We conclude with policy recommendations and possible extensions, including the development of operational cost-benefit decision-support tools to assist local decision-makers in setting management priorities.

Educators’ and Visitors’ Perceptions of Invasive Species Education in Zoos

Management of invasive alien species (IAS) depends on public awareness and cooperation, which may be increased by effective IAS education by zoos. We administered a questionnaire to visitors (n = 221) and educators (n = 44) at three Association of Zoos and Aquariums facilities in Florida to explore their perceptions of the content and effectiveness of IAS education at these facilities. Most visitors recalled seeing IAS on display, with 80% of visitors stating that they considered zoos to be a place to learn about IAS. Both visitors and educators agreed that minimal information on how IAS are introduced to Florida was presented. They also agreed that greater implementation of shows and presentations pertaining to IAS would be highly effective in educating the public about IAS and the need for actions to mitigate species invasions. Zoos may improve their educational effectiveness by making visitors aware of IAS citizen science programs and implementing interactive educational methods.

State-of-the-art approach on the management of invasive faunistic aquatic alien species: The American bullfrog in Belgium

Invasive alien species are worldwide one of the main reasons for the decline of species in native communities and hence biodiversity. Control or eradication programs are often fragmented leading to cost-inefficient and inadequate results. This paper addresses a state-of-the-art framework of an integrated management approach based on the case study on the control of the American bullfrog in the Flemish region in Belgium. This approach is based on the close cooperation of scientists, policymakers, field managers and conservationists to create a science-based policy in the management of invasive alien species. Innovative applied research poses an important foundation in the steering process to establish efficient control measures. These are integrated in the management process that is coincided with raising awareness and dissemination of information throughout the whole plan. The results are based on 10 years of experience and cooperation in the management of the American bullfrog in Flanders, Belgium. The several stages of which this framework is built are crucial in the strategy to tackle the invasion in the most integrated way and can be transposed to control other invasive aquatic alien animals.