Clarifying values, risk perceptions, and attitudes to resolve or avoid social conflicts in invasive species management

Multiple invasion routes have led to the pervasive introduction of earthworms in North America

Soil-dwelling organisms play a key role in ecosystem functioning and the delivery of ecosystem services. As a consequence, soil taxa such as earthworms are iconic in good land management practices. However, their introduction in places where species did not co-evolve with them can trigger catastrophic changes. This issue has been largely ignored so far in nature management policies because of the positive image of soil taxa and the lack of knowledge of the magnitude of soil fauna introductions outside their native range. Here we address this gap with a large spatio-temporal database of introduced alien earthworms. We show that 70 alien earthworm species have colonized the North American continent. They have larger geographical ranges than native species and novel ecological functions, representing a serious threat to the biodiversity and functioning of native ecosystems. The probably continuous introduction of alien earthworms, from a variety of sources and introduction pathways, into many distant and often empty niches, contrasts with the classical patterns of invasions in most aboveground taxa. This suggests that earthworms, and probably other soil organisms, constitute a major but overlooked pool of invasive species that are not adequately managed by existing control and mitigation strategies.

Understanding behavioral intention of landowners to promote wildlife richness and biodiversity in the Southern Great Plains

Ranchers have been conducting traditional management practices such as mono-species grazing and limited burning that focus on stocking rate maximization. This has resulted in negative environmental consequences such as woody plant encroachment, land use change, and species diversity loss. Recently, there has been a growing appreciation for alternative range management that simultaneously promotes biodiversity and agricultural productivity through fire and grazing interactions. The purpose of the study was to investigate the influence of landowner values, attitudes, and norms on their behavioral intention to adopt best management practices (BMPs) that enhance wildlife abundance in the southern Great Plains. The required data was generated through a mail survey following the Tailored Design method. We utilized the structural equation path model to construct two latent variables for norms and attitudes and analyzed the relationship of the latent variables with value orientations and behavioral intentions. The study results indicated that the attitudes had a significant positive relationship with biocentric (β = 0.15, p-value<0.05) and a negative relationship with anthropocentric (β = -0.259, p-value<0.05) value orientations, however, the relationship of value orientations was statistically insignificant with norms. Further, the results indicated that both norms (β = 0.404, p-value<0.05) and attitudes (β = 0.508, p-value<0.05) had a positive and statistically significant relation with ranchers' intentions to increase wildlife abundance on their land. Study results emphasize the need for innovative communication and non-traditional outreach methods to educate rangeland owners on the importance of patch-burn grazing and other best management practices.

Public tolerance of lethal wildlife management in Japan: A best-worst scaling questionnaire analysis

Human-wildlife conflict is a major problem for sustainable development worldwide. Lethal management options play an essential role in wildlife management. However, assessing public tolerance of lethal options is crucial. While this has been studied for specific targets, variations in public tolerance by wildlife characteristics such as biological class and nativeness remain unexplored. Accordingly, we administered a questionnaire survey (n = 1000) using best-worst scaling to reveal the comparative tolerance of lethal wildlife management for 10 wildlife species (including mammals, birds, fish, and plants) in Japan. We found that public tolerance of lethal wildlife management differed by species rather than biological class and nativeness. We then used cluster analysis to group respondents with similar lethal wildlife management tolerances and found commonalities based on age, sex, and beliefs. This study offers theoretical insights for understanding public tolerance of lethal wildlife management as well as practical recommendations for wildlife managers.

Eurasian beavers in Central Italy: perceptions in the local community

According to the IUCN guidelines, wildlife reintroduction should consider any impacts on humans within feasibility assessments. Eurasian beavers Castor fiber are recovering across their native range, due to protection laws and reintroductions. In Central Italy, a self-sustaining, naturalised population of Eurasian beavers has been identified in the last five years. A questionnaire to measure whether and how citizens in the local area perceive the presence of the beaver was administered to 1114 respondents. We observed a comprehensive awareness of the presence of the beaver in Italy and a high ability to distinguish it from non-native coypus Myocastor coypus (92.3%). We also recorded a general high knowledge of issues related to the presence of the beaver (i.e., potential effects on indigenous biodiversity). The majority (65.5%) of the surveyed population was in favour of reintroducing the beaver in Central Italy, and only 1.2% was firmly against it. The majority of interviewed people was against the removal of beavers from Central Italy (65.8%), whereas only 3.7% was in favor, citing fears of perceived impacts on the river, crops, and fish populations.

Underexplored and growing economic costs of invasive alien trees

The high ecological impacts of many invasive alien trees have been well documented. However, to date, we lacked synthesis of their economic impacts, hampering management actions. Here, we summarize the cost records of invasive trees to (I) identify invasive trees with cost information and their geographic locations, (II) investigate the types of costs recorded and sectors impacted by invasive trees and (III) analyze the relationships between categories of uses of invasive trees and the invasion costs attributed to these uses. We found reliable cost records only for 72 invasive trees, accumulating a reported total cost of $19.2 billion between 1960 and 2020. Agriculture was the sector with the highest cost records due to invasive trees. Most costs were incurred as resource damages and losses ($3.5 billion). Close attention to the ornamental sector is important for reducing the economic impact of invasive trees, since most invasive trees with cost records were introduced for that use. Despite massive reported costs of invasive trees, there remain large knowledge gaps on most invasive trees, sectors, and geographic scales, indicating that the real cost is severely underestimated. This highlights the need for further concerted and widely-distributed research efforts regarding the economic impact of invasive trees.

Lack of accessibility and clarity in regulations concerning dog access to protected areas lowers public awareness

While natural protected areas are conceived for nature conservation, humans and their activities must also be considered. Conflict between the public and managers of protected areas can be minimized by regulations that clearly communicate which activities are allowed. Domestic dogs (Canis lupus familiaris) affect threatened species and impact numerous protected areas. In this study we evaluate: (1) the accessibility and clarity of regulations regarding dog access to protected areas in Argentina, (2) the public's knowledge of these regulations, (3) the public's expectations of the regulations (4) which institutions people consider should act when dog aggression occurs, and (5) measures suggested by people when dog aggression occurs. Poor accessibility and clarity of regulations were associated with poor public knowledge of them; there was also an association between visited protected areas that did not mention regulations and respondents who reported not knowing whether dogs were allowed or thinking dogs were allowed. In general, the respondents supported measures to regulate dog access to protected areas and the control of problematic dogs. We discuss several aspects that lead to a lack of clarity on dog regulations in protected areas and suggest approaches that could be used to overcome this conservation problem.

Science for social licence to arrest an ecosystem-transforming invasion

The primary role for scientific information in addressing complex environmental problems, such as biological invasions, is generally assumed to be as a guide for management decisions. However, scientific information often plays a minor role in decision-making, with practitioners instead relying on professional experience and local knowledge. We explore alternative pathways by which scientific information could help reduce the spread and impacts of invasive species. Our study centred on attempts to understand the main motivations and constraints of three local governance bodies responsible for the management of invasive (wilding) conifer species in the southern South Island of New Zealand in achieving strategic and operational goals. We used a combination of workshop discussions, questionnaire responses and visits to field sites to elicit feedback from study participants. We applied a mixed inductive-deductive thematic analysis approach to derive themes from the feedback received. The three main themes identified were: (1) impacts of wilding conifers and goals for wilding conifer control, (2) barriers to achieving medium- and long-term goals, and (3) science needed to support wilding conifer control. Participants identified reversal and prevention of both instrumental (e.g. reduced water availability for agriculture) and intrinsic (e.g. loss of biodiversity and landscape values) impacts of wilding conifer invasions as primary motivators behind wilding conifer control. Barriers to achieving goals were overwhelmingly social, relating either to unwillingness of landowners to participate or poorly designed regulatory frameworks. Consequently, science needs related primarily to gaining social licence to remove wilding conifers from private land and for more appropriate regulations. Scientific information provided via spread and impacts forecasting models was viewed as a key source of scientific information in gaining social licence. International experience suggests that invasive species control programmes often face significant external social barriers. Thus, for many biological invasions, the primary role of science might be to achieve social licence and regulatory support for the long-term goals of invasive species control programmes and the management interventions required to achieve those goals.

Valuing the contributions of non-native species to people and nature

While decision-making can benefit from considering positive and negative outcomes of change, over the past half-century, research on non-native species has focused predominately on their negative impacts. Here we provide a framework for considering the positive consequences of non-native species relative to relational, instrumental, and intrinsic values. We demonstrate that their beneficial outcomes are common and profoundly important for human well-being. Identified benefits include social cohesion, cultural identity, mental health, food and fuel production, regulation of clean waters, and attenuation of climate change. We argue that long-standing biases against non-native species within the literature have clouded the scientific process and hampered policy advances and sound public understanding. Future research should consider both costs and benefits of non-native species.

Scaling up qualitative research to harness the capacity of lay people in invasive plant management

Successful management of invasive plants (IPs) requires the active participation of diverse communities across land tenures. This can be challenging because communities do not always share the views of scientists and managers. They may directly disagree, have alternative views, or be unwilling to manage IPs. Reviews of IP social science identify opportunities to better understand the role of cultural processes and everyday practices to address these challenges. To scale up and leverage the insights of existing qualitative social science IP research, we used meta-ethnography to unlock accounts and interpretations of lay perspectives. Meta-ethnography is a form of qualitative research synthesis increasingly used beyond its origins in health and education to produce interpretive syntheses of an area of research. In the 7 phases of meta-ethnography, we systematically identified and synthesized 19 qualitative articles pertinent to lay experience and knowledge of IPs in diverse settings. Action and meaning regarding IPs were influenced by 6 meta-themes in personal and social life: dissonance, priorities, difference, agency, responsibility, and future orientations. Through descriptions and examples of each meta-theme, we demonstrated how the meta-themes are higher level structuring concepts across the qualitative research that we analyzed and we retained grounding in the in-depth qualitative research. We characterized the meta-themes as leverage points and tensions by which we reframed lay people in terms of capacity for reflective IP management rather than as obstacles. The meta-ethnography synthesis shows how leverage points and tensions emerge from everyday life and can frame alternative and meaningful starting points for both research and public engagement and deliberation regarding IP management. These insights are not a panacea, but open up new space for reflective and mutual consideration of how to effectively navigate often complex IP problems and address conservation and social and livelihood issues in dynamic social and physical environments.

Public's perceptions of marine bioinvasive risks and responsible parties - Implications for social acceptability and better-informed communication in the marine biosecurity context

Using the survey data on a representative sample of the New Zealand population, our study presents a process of understanding citizens' perceptions, identifying patterns in the perceptions, and recognising the knowledge gaps existing in the citizenry in the marine biosecurity context. While our findings show a healthy sign of the public accepting their own responsibility and the devolved responsibility of business/industry, there are considerable gaps between the general public's perceptions and (marine) biosecurity current practices and expectations. There is a moderately strong signal from survey respondents that suggest the need of significantly more effort and improved transparency in marine biosecurity communication. Our outcomes indicate an anthropocentric tendency, with influences of gender, age, education, income, frequency of beach visitation upon societal perceptions in terms of awareness, concern, perceived non-indigenous marine species impacts, and accountability in marine biosecurity management. The recognised socio-demographic patterns in societal perceptions would inform marine biosecurity communication strategies.

The EICAT+ framework enables classification of positive impacts of alien taxa on native biodiversity

Species introduced through human-related activities beyond their native range, termed alien species, have various impacts worldwide. The IUCN Environmental Impact Classification for Alien Taxa (EICAT) is a global standard to assess negative impacts of alien species on native biodiversity. Alien species can also positively affect biodiversity (for instance, through food and habitat provisioning or dispersal facilitation) but there is currently no standardized and evidence-based system to classify positive impacts. We fill this gap by proposing EICAT+, which uses 5 semiquantitative scenarios to categorize the magnitude of positive impacts, and describes underlying mechanisms. EICAT+ can be applied to all alien taxa at different spatial and organizational scales. The application of EICAT+ expands our understanding of the consequences of biological invasions and can inform conservation decisions.

An impact assessment of alien invasive plants in South Africa generally dispersed by native avian species

Invasive alien plant species have been identified as a major threat to biodiversity and the relationship with native avian dispersers may increase their invasion potential. The impact of invasive plant species needs to be quantified using comparable assessment tools across different habitats and species to allocate limited resources to high-priority species. Here, we used the Generic Impact Scoring System (GISS) to assess the impacts of 16 fleshy-fruited alien invasive plant species in South Africa generally dispersed by native avian species. The results showed that fleshy-fruited invasive species have both environmental and socio-economic impacts. The cumulated impact scores for lantana (Lantana camara) and the tree of heaven (Ailanthus altissima) were the highest, with scores of 42 and 32, respectively. Some species, such as white mulberry (Morus alba), camphor tree (Cinnamomum camphora), American bramble (Rubus cuneifolius) and Brazilian pepper tree (Schinus terebinthifolius), had low overall impact scores of 8, 18, 14 and 16, respectively, but scored the maximum impact of 5 for certain mechanisms. Environmental impacts of fleshy-fruited invasive plant species had a high impact magnitude through effects on the ecosystem and vegetation. Socio-economic impacts were mainly through effects on forest production, agriculture and human health. Species with large crop sizes, small seeds and fruit sizes had higher environmental and socio-economic impact magnitude. The information generated in this study is important for guiding resource allocation and preventing the uncontrolled introduction of invasive species in South Africa. The impact of the fleshy-fruited invasive species transcended sectors and, therefore, effective management of invasive species will require the collaboration of multiple and inter-sectoral stakeholders in South Africa.

Review and synthesis of the global literature on domestic cat impacts on wildlife

A vast global literature documents that free-roaming domestic cats (Felis catus) have substantial negative effects on wildlife, including through predation, fear, disease, and competition-related impacts that have contributed to numerous wildlife extinctions and population declines worldwide. However, no study has synthesized this literature on cat impacts on wildlife to evaluate its overarching biases and major gaps. To direct future research and conservation related to cat impacts on wildlife, we conducted a global literature review that entailed evaluation and synthesis of patterns and gaps in the literature related to the geographic context, methods, and types of impacts studied. Our systematic literature search compiled 2,245 publications. We extracted information from 332 of these meeting inclusion criteria designed to ensure the relevance of studies analyzed. This synthesis of research on cat impacts on wildlife highlights a focus on oceanic islands, Australia, Europe, and North America, and on rural areas, predation, impacts of unowned cats, and impacts at population and species levels. Key research advances needed to better understand and manage cat impacts include more studies in underrepresented, highly biodiverse regions (Africa, Asia, South America), on cat impacts other than predation, and on methods designed to reduce impacts on wildlife. The identified areas of needed research into cat impacts on wildlife will be critical to further clarifying the role of cats in global wildlife declines and to implementing science-driven policy and management that benefit conservation efforts.

Identifying Priorities, Targets, and Actions for the Long-term Social and Ecological Management of Invasive Non-Native Species

Formulating effective management plans for addressing the impacts of invasive non-native species (INNS) requires the definition of clear priorities and tangible targets, and the recognition of the plurality of societal values assigned to these species. These tasks require a multi-disciplinary approach and the involvement of stakeholders. Here, we describe procedures to integrate multiple sources of information to formulate management priorities, targets, and high-level actions for the management of INNS. We follow five good-practice criteria: justified, evidence-informed, actionable, quantifiable, and flexible. We used expert knowledge methods to compile 17 lists of ecological, social, and economic impacts of lodgepole pines (Pinus contorta) and American mink (Neovison vison) in Chile and Argentina, the privet (Ligustrum lucidum) in Argentina, the yellow-jacket wasp (Vespula germanica) in Chile, and grasses (Urochloa brizantha and Urochloa decumbens) in Brazil. INNS plants caused a greater number of impacts than INNS animals, although more socio-economic impacts were listed for INNS animals than for plants. These impacts were ranked according to their magnitude and level of confidence on the information used for the ranking to prioritise impacts and assign them one of four high-level actions-do nothing, monitor, research, and immediate active management. We showed that it is possible to formulate management priorities, targets, and high-level actions for a variety of INNS and with variable levels of available information. This is vital in a world where the problems caused by INNS continue to increase, and there is a parallel growth in the implementation of management plans to deal with them.

Restricted access to private properties limits management of invasive alien species: A literature review and case studies

Biological invasions are one of the major drivers of global environmental change and there is a need to develop integrated strategies to counteract this phenomenon. Eradication is an effective management option to mitigate the deleterious impacts of invasive alien species (IAS). Eradication can be achieved if all reproductive individuals are removed and population recovery is prevented. However, individuals may survive removal operations in private areas if interventions are not allowed. Here, we present 1) three case studies in which restricted private property access prevented the local eradication of invasive alien populations, and 2) a list of reasons for denying access to private properties and a list of actions implemented or suggested by managers to facilitate access and reported in 29 reviewed papers. The restricted access affected the local eradication of three Eastern grey squirrel (Sciurus carolinensis) populations in Italy. In Lombardy region, in one area a planned eradication did not start and in another area the implemented eradication failed due to the refusal from the owner of a large private property to grant access to managers. In Umbria region, the lack of collaboration from an Italian financial institution produced a delay of 15 months in the removal. In our case studies, therefore, a single person or institution denied access for a personal gain or presumed internal security. The reasons behind landowner opposition may be diverse and individual attitudes towards IAS management will depend on interactions with owners. According to our review, in many cases the denial of access takes place in a general perception of mistrust or opposition to the project as the results of a limited engagement of local people. Such opposition often jeopardizes control activities, with profound negative consequences on eradication, expecially at landscape scale. Bottom-up approaches aiming at involving stakeholders can increase the possibility to achieve IAS eradication, however appropriate legislation remains pivotal to enforce eradication in case of non-cooperative behaviour.

Developing a conceptual influence diagram for socio-eco-technical systems analysis of biofouling management in shipping - A Baltic Sea case study

Ship hulls create a vector for the transportation of harmful non-indigenous species (NIS) all over the world. To sustainably prevent NIS introductions, the joint consideration of environmental, economic and social aspects in the search of optimal biofouling management strategies is needed. This article presents a multi-perspective soft systems analysis of the biofouling management problem, based on an extensive literature review and expert knowledge collected in the Baltic Sea area during 2018-2020. The resulting conceptual influence diagram (CID) reveals the multidimensionality of the problem by visualizing the causal relations between the key elements and demonstrating the entanglement of social, ecological and technical aspects. Seen as a boundary object, we suggest the CID can support open dialogue and better risk communication among stakeholders by providing an illustrative and directly applicable starting point for the discussions. It also provides a basis for quantitative management optimization in the future.

Educational Approaches Help Bridge Perception Gaps of Invasive Alien Species (Mikania micrantha) between Managers and Non-managers

Invasive alien species (IAS) significantly impact biodiversity, human health, and economies, and considerable resources are often used to manage their spread. Few studies have focused on the human perception of IAS management, and little is known about approaches to improve stakeholder perception. This study examined perception gaps between managers and non-managers of a notorious weed Mikania micrantha and the preference for educational approaches to bridge those gaps. Household questionnaires and key informant interviews were conducted in the China-Myanmar Border Region (China), and ordinal logistic regressions and Wilcoxon rank sum tests were used in statistical analyses. We found a high level of perception of M. micrantha among stakeholders, and a significant influence of socio-demographic factors including gender, educational level, ethnic group, and geographical location. Scores of the identification, damage, control measure, and manual treatment of M. micrantha were significantly higher for managers than those for non-managers, indicating that there were certain perception gaps between two stakeholder groups. Nine educational approaches were identified as being effective in improving stakeholder perception of IAS, of which training workshops were mostly preferred, followed by brochures (or leaflets) and other promotional materials. Additionally, we propose that well-designed and well-conducted educational approaches would benefit stakeholder perception of IAS, and that integration of IAS management into a comprehensive rural development scheme would improve its long-term performance in marginalized rural communities.

The economic costs of biological invasions in Africa: a growing but neglected threat?

Biological invasions can dramatically impact natural ecosystems and human societies. However, although knowledge of the economic impacts of biological invasions provides crucial insights for efficient management and policy, reliable syntheses are still lacking. This is particularly true for low income countries where economic resources are insufficient to control the effects of invasions. In this study, we relied on the recently developed "InvaCost" database – the most comprehensive repository on the monetised impacts of invasive alien species worldwide – to produce the first synthesis of economic costs of biological invasions on the African continent. We found that the reported costs of invasions ranged between US$ 18.2 billion and US$ 78.9 billion between 1970 and 2020. This represents a massive, yet highly underestimated economic burden for African countries. More alarmingly, these costs are exponentially increasing over time, without any signs of abatement in the near future. The reported costs were mostly driven by damage caused by invaders rather than expenses incurred for management. This trend was highly skewed towards a few regions (i.e. Southern and Eastern Africa) and activity sectors (i.e. agriculture) and incurred by a small number of invasive taxa (i.e. mainly three insect pests: Chilo partellus, Tuta absoluta, Spodoptera frugiperda). We also highlight crucial, large gaps in current knowledge on the economic costs of invasions that still need to be bridged with more widespread research effort and management actions across the continent. Finally, our study provides support for developing and implementing preventive measures as well as integrated post-invasion management actions at both national and regional levels. Considering the complex societal and economic realities in African countries, the currently neglected problem of biological invasions should become a priority for sustainable development.

Citizens, Scientists, and Enablers: A Tripartite Model for Citizen Science Projects

In this paper, we focus on different roles in citizen science projects, and their respective relationships. We propose a tripartite model that recognises not only citizens and scientists, but also an important third role, which we call the ‘enabler’. In doing so, we acknowledge that additional expertise and skillsets are often present in citizen science projects, but are frequently overlooked in associated literature. We interrogate this model by applying it to three case studies and explore how the success and sustainability of a citizen science project requires all roles to be acknowledged and interacting appropriately. In this era of ‘wicked problems’, the nature of science and science communication has become more complex. In order to address critical emerging issues, a greater number of stakeholders are engaging in multi-party partnerships and research is becoming increasingly interdisciplinary. Within this context, explicitly acknowledging the role and motivations of everyone involved can provide a framework for enhanced project transparency, delivery, evaluation and impact. By adapting our understanding of citizen science to better recognise the complexity of the organisational systems within which they operate, we propose an opportunity to strengthen the collaborative delivery of both valuable scientific research and public engagement.

Between approval and disapproval: Citizens’ views on the invasive tree Ailanthus altissima and its management

While cities are invasion hotspots, the view of urban residents on non-native species is critically understudied – an important knowledge gap since strategies on biological invasions could gain power by integrating human values, attitudes and perceptions. How citizens perceive the non-native tree Ailanthus altissima (tree of heaven) is unknown despite its abundance in many cities globally and its classification as invasive in many countries. In a quantitative survey with closed questions, we analysed (i) whether residents of Berlin, Germany knew the widespread species, (ii) how they perceived it in different urban situations, (iii) how they accepted different management strategies of it, and (iv) how the sociodemographic background of respondents predicted their preference and acceptability ratings.

In total, we surveyed 196 respondents. Most respondents recognized the tree in a photograph, but few provided its correct name. Citizens’ preferences differed significantly among four urban contexts in which the species was shown, with prevailing approval for trees as a component of designed green spaces and less pronounced preferences for wild-grown trees in other urban spaces. When respondents were asked to indicate how the tree should be managed (three options), we found the most support for removal in problematic cases (‘adaptive on-site’ strategy); some support was found for the ‘leave alone’ strategy and least support for the ‘complete removal’ management strategy. Practitioners with expertise in urban landscaping were more critical of Ailanthus than laypeople. Ordinal logistic regression analyses showed that respondents with a ‘close to nature’ behaviour and attitude had a more positive view on Ailanthus and expressed more support for ‘leave alone’ management. Results demonstrate the importance of citizens’ context dependent views about a widespread invasive species, spanning from approval to disapproval in different situations. We conclude that urban management strategies concerning Ailanthus would gain support from citizens when combining multiple approaches: (i) to control the species in case of realized negative impacts; (ii) to prevent the invasion of the species in areas of conservation concern; and (iii) to develop novel approaches of integrating wild Ailanthus trees into urban green spaces. These insights could support management measures that need to be established due to the EU-Regulation on Invasive Alien Species.

Factors Influencing Family Forest Owners' Interest in Community-led Collective Invasive Plant Management

Effective invasive plant management requires collective action. However, little is known about what motivates individuals to work collectively. We conducted a mail survey of 2,600 randomly selected family forest owners in Indiana, USA to examine factors associated with community-led collective action. Specifically, we examined the role of perceived self-efficacy, perceived collective efficacy, concerns about invasive plants, and social norms associated with invasive plant management in shaping family forest owners' self-reported likelihood to work with their neighbors to remove invasive plants. We found that past experience talking to others or working with neighbors to remove invasive plants were important predictors of landowners' intention to work collectively, as were perceived self-efficacy in their own ability to manage invasive plants, perceived need for collective action, social norms, and concerns about invasive plants on neighboring or nearby properties. However, most socio-demographic characteristics (e.g., age, gender, education level, income) and land ownership characteristics (e.g., residence status, having a written forest management plan) were not statisically significant predictors of family forest owners' likelihood to work with their neighbors. Our findings suggest that building individual sense of competence, facilitating neighbor interactions, and strengthening shared concerns may facilitate community-led collective action to manage invasive plants.

Adapting participatory processes to fine-tune conservation approaches in multiactor decision settings

Conservation decisions are typically made in complex, dynamic, and uncertain settings, where multiple actors raise diverse and potentially conflicting claims, champion different and sometimes contradictory values, and enjoy varying degrees of freedom and power to act and influence collective decisions. Therefore, effective conservation actions require conservation scientists and practitioners to take into account the complexity of multiactor settings. We devised a framework to help conservation biologists and practitioners in this task. Institutional economic theories, which are insufficiently cited in the conservation literature, contain useful insights for conservation. Among these theories, the economies of worth can significantly contribute to conservation because it can be used to classify the types of values peoples or groups refer to when they interact during the elaboration and implementation of conservation projects. Refining this approach, we designed a framework to help conservation professionals grasp the relevant differences among settings in which decisions related to conservation actions are to be made, so that they can adapt their approaches to the features of the settings they encounter. This framework distinguishes 6 types of agreements and disagreements that can occur between actors involved in a conservation project (harmony, stricto sensu arrangement, deliberated arrangement, unilateral and reciprocal compromise, and locked-in), depending on whether they disagree on values or on their applications and on whether they can converge toward common values by working together. We identified key questions that conservationists should answer to adapt their strategy to the disagreements they encounter and identified relevant participatory processes to complete the adaptation.

Understanding invasive plant management on family forestlands: An application of protection motivation theory

Invasive forest plants are a growing concern because of their perceived and actual negative ecological, economic, and social impacts. To effectively manage invasive plants in forest ecosystems, it is paramount to understand the management decisions made by family forest owners (FFOs), who collectively own 36% of forestlands in the United States. We contribute to the growing literature on invasive plant management and the factors that influence FFOs' likelihood to manage invasive plants on their property by incorporating protection motivation theory (PMT; Rogers 1975). Protection Motivation Theory argues that the degree to which individuals protect themselves from a perceived threat varies as a function of the perceived severity of the threat, their vulnerability to the threat, their perceptions of self-efficacy to effectively mitigate the threat, and the degree to which they believe they have access to the resources needed to effectively respond to the threat. We surveyed a random sample of 2,600 FFOs in Indiana about their knowledge, perceptions, experience, and plans regarding invasive plants on their wooded lands. Consistent with PMT, we constructed a hierarchical binary logistic model and found that FFOs reported greater intentions to manage invasive plants when they perceived the problem to be more severe and also when they felt a stronger sense of self-efficacy to address the problem. Although perceived vulnerability was not significant in our final model, our results also show that FFOs who had previous invasive plant management experience, had a Bachelor's degree or higher level of education, owned woodlands for recreational purposes, and were more subject to normative social influence also tended to report greater intentions to manage invasive plants. Together, these results suggest that components of PMT (perceived severity and self-efficacy) may be used to inform potential strategies, programs, and outreach for engaging family forest owners in invasive plant management.

Recreationist willingness to pay for aquatic invasive species management

We estimated willingness to pay for local aquatic invasive species lake management in the form of a daily lake access fee by conducting summer lake surveys in Minnesota, USA. Similar pairs of lakes with differing infestations of zebra mussels, Dreissena polymorpha, and starry stonewort, Nitellopsis obtuse, were used as study sites to infer how being at an infested lake vs. being at an uninfested lake and different local species would impact responses. We also examined recreationists’ visit motivation, and aquatic invasive species perceived risk, knowledge, and awareness of problem. We estimated mean willingness to pay about nine to ten dollars per day, which did not differ significantly by lake. Additionally, perceived risk, awareness of problem, and visit motivation were significant in predicting willingness to pay, which could have important ramifications for aquatic invasive species management.

Effects of knowledge and emotion on support for novel synthetic biology applications

There is sometimes an inherent assumption that the logical head will overrule the emotional heart in matters of science and technology. However, the literature on decision making under risk and uncertainty suggests that emotional responses may be more potent. A representative sample of Australians participated in a large, national, online survey (n = 8037), in which we measured the influence of knowledge and emotion in predicting support for possible synthetic biology (synbio) solutions to conservation, environmental, and industrial problems. A hierarchical regression model was used to examine the relative influence of affect- and emotion-related factors beyond the influence of knowledge factors in predicting support for synbio solutions. Subsequently, interaction analyses were conducted to examine the potentially moderating role of emotions in the knowledge-support relationship. There was 64% variance in overall support for synbio solutions (R² = 0.64, p < 0.001). The most influential predictor of support in the model was positive emotion. Feeling hopeful, excited, and curious toward a synbio technology was related to greater overall support for the development of that technology. The second strongest set of predictors was affect-related measures that evaluate the technology as bad or good, harmful or beneficial, and risky or safe. Positive emotion and an assessment that the technology was good significantly moderated the effect of knowledge on support. These findings suggest that, at least initially, people are more likely to be guided by their emotions when considering support for synbio technologies, which has implications for how researchers design and implement engagement and communication strategies more broadly.

The role of citizen science in management of invasive avian species: What people think, know, and do

In North America, nest site competition from invasive cavity-nesting birds can limit the opportunities for successful nesting by native birds. Managing invasive species is costly and complex, requiring input from biologists, decision makers, and the public. An informed and engaged public can play an important role in mitigating the negative effects of invasive avian species. However, little is known regarding the publics' knowledge, attitudes, and behaviors toward non-native bird species. We examined the association between participating in a citizen science project and enjoyment, knowledge, and management of two non-native avian species in North America: European starlings (Sturnus vulgaris) and house sparrows (Passer domesticus). We administered a pre and post survey to 947 people who monitor nest boxes in the United States and Canada, 30% of whom were also reporting their observations to NestWatch, a citizen science project focused on nesting birds. We found that NestWatch participants were more likely to have negative views of non-native species, score higher on bird identification tasks, and manage for invasive species than non-participants. The most important predictor for undertaking management activities was respondents' perceptions of whether they believed non-native birds to be a problem at the continental scale, underscoring the important role of individual factors such as perception. Our study also highlights the important role citizen science may play in shaping attitudes and behaviors and increasing knowledge. We propose a conceptual model describing the mechanisms by which citizen science can be leveraged for management of invasive species.

Stakeholder perspectives towards the use of toxicants for managing wild pigs

Wild pigs (Sus scrofa) are one of the most detrimental invasive mammals in the US. Lack of adequate population control has allowed pigs to become established across the landscape, causing significant ecological and economic damage. Given the need for additional tools for reducing wild pig populations, two toxicants, warfarin and sodium nitrite, are at the forefront of the discussion regarding future wild pig management. However, no research has examined stakeholders' perspectives towards the use of toxicants in wild pig management. Given the lack of knowledge, our goal was to determine stakeholders' perspectives towards the legal use of toxicants for managing wild pigs. We surveyed 1822 individuals from three stakeholder groups (hunters, farmers, and forestland owners) across Alabama during February 2018 using an online survey following the Tailored Design Method. All three stakeholder groups were generally supportive of toxicant use, though their views differed slightly by group. Furthermore, all stakeholder groups were supportive of toxicant purchasing and use regulations, while accidental water contamination, human health impact, and incorrect usage of a toxicant were stakeholders' greatest concerns. These results indicate that these groups would likely be in support of using toxicants for wild pig management in Alabama and could be a model for other states or locations. Consequently, these results have direct implications for shaping policy and possible use of toxicants as a future wild pig management tool.

The economic impact of Drosophila suzukii: perceived costs and revenue losses of Swiss cherry, plum and grape growers

BACKGROUND

Drosophila suzukii can lead to substantial damages in horticultural production. In this article we analyze revenue losses and cost increases due to D. suzukii as perceived of Swiss cherry, plum and grape growers. Moreover, we investigate associations between farm and grower characteristics and revenue losses and perceived costs increases. We surveyed Swiss growers of cherries, plums and grapes repeatedly in the period 2016-2018 (N = 1572).

RESULTS

We find that 76% of cherry, plum and grape growers faced additional costs due to D. suzukii. In contrast, yield losses due to D. suzukii infestation were small on average, but nevertheless high for some growers. We find substantial heterogeneity in perceived costs and revenue losses across crops, years and farms. Larger farms are found to face lower perceived additional costs, suggesting scale effects in prevention and control of D. suzukii. Growers with a higher inter-varietal diversity perceived additional costs to be higher. Furthermore, organic farming was negatively associated with expected additional costs.

CONCLUSION

Our results suggest that the economic impact of invasive species such as D. suzukii goes far beyond reductions in yield quantity and quality, but rather stems from higher costs due to the need to establish preventive and control measures. Heterogeneity in costs and revenue losses suggests that policy measures to support growers need to be tailored to crops and farm types. Policies supporting improvements of measures against D. suzukii and other newly occurring alien pests and reduce additional costs such as more efficient preventive and control measures merit further encouragement.

What drives private landowner decisions? Exploring non-native grass management in the eastern Great Plains

Non-native grasses used as forage for domestic livestock can negatively impact ecosystem services provided by grasslands. In the U.S., most grazed grasslands are privately owned so the introduction and reduction of non-native grasses are both driven by landowner behavior. Yet, the social factors that shape non-native grass management are rarely explored. To address this knowledge gap, we evaluated how decisions to reduce these grasses through practices such as herbicide application, prescribed fire, and physical removal are influenced by attitudes, norms, and perceived ability. We administered a mixed mode (mailback and online) survey in 2017 to landowners in the eastern Great Plains of the U.S., in a region where cattle production remains the predominant land-use. Using structural equation modeling with parceling, we tested hypotheses related to management decisions derived from a model integrating two theories - the Theory of Planned Behavior and the Norm Activation Model. In this analysis, we identified perceived ability (i.e., access to time, skills, or other necessary resources) as a barrier to adoption for landowners who were already willing to manage non-native grasses. Positive attitudes toward management and increased social norm pressures were both associated with increased sentiments of moral responsibility to reduce non-native grasses. These personal norms, together with attitudes, positively influenced willingness to control non-native grasses. Further, we observed that social norms related to expectations of neighbors had more influence on personal norms than the social norms from natural resource agencies. The power of norms to explain individual management decisions suggests that landowners could be engaged in landscape-scale initiatives by leveraging moral responsibility and influential social groups.

Invasive raccoon management systems and challenges in regions with active control

BACKGROUND

The raccoon (Procyon lotor) is an invasive, non-native species in Japan. Throughout the country, it causes significant agricultural damage and negatively affects native biodiversity. Most of the responsibility for raccoon management lies with local government, and there are still many challenges to be overcome. Although raccoon populations have not been eradicated, intensive control campaigns such as focus on the early stages of invasion have controlled raccoons in some regions. To improve the national management of raccoons, we conducted a survey on raccoon management systems in local government departments considered to solve the challenges recognized in many areas. During 2014 and 2015, we surveyed three different municipal departments about raccoon management measures. The semi-structured interview survey covered two topics: (1) the situation leading up to the current management system; (2) the current management system.

RESULTS

Our results describe the scope and methods used in raccoon management. The government staff managed raccoons using monitoring, employing a variety of methods, a range of budgets, and various role divisions. The management practices are similar in that they share a sense of taking precautions, collaborating with stakeholders, understanding that adequate methods must be used, and obtaining support from experts.

CONCLUSIONS

Our case studies reveal the challenges in raccoon management faced by local government officers in regions with active control. The management systems and methods that we surveyed seemed to be effective in solving problems in both developed and undeveloped areas.

Management Policies for Invasive Alien Species: Addressing the Impacts Rather than the Species

Effective long-term management is needed to address the impacts of invasive alien species (IAS) that cannot be eradicated. We describe the fundamental characteristics of long-term management policies for IAS, diagnose a major shortcoming, and outline how to produce effective IAS management. Key international and transnational management policies conflate addressing IAS impacts with controlling IAS populations. This serious purpose–implementation gap can preclude the development of broader portfolios of interventions to tackle IAS impacts. We posit that IAS management strategies should directly address impacts via impact-based interventions, and we propose six criteria to inform the choice of these interventions. We review examples of interventions focused on tackling IAS impacts, including IAS control, which reveal the range of interventions available and their varying effectiveness in counteracting IAS impacts. As the impacts caused by IAS increase globally, stakeholders need to have access to a broader and more effective set of tools to respond.

People's Knowledge and Risk Perceptions of Invasive Plants in Metro Vancouver, British Columbia, Canada

Effective management of invasive plants conserves biodiversity values, reduces economic costs, and minimizes negative impacts on human health. Fostering people's awareness of invasive plants is one of the most cost-effective approaches in preventing the spread and introduction of invasive plants. Therefore, this study aims to understand (1) people's knowledge and risk perceptions, (2) associations between risk perceptions and demographics, and (3) people's willingness to support current management strategies in the Metro Vancouver region, British Columbia, Canada. An online survey was carried out and received 356 responses across the region. We found that people's knowledge and risk perceptions of invasive plants were ecologically oriented. Older respondents perceived higher risks of invasive plants. Among respondents of the same age, annual income higher than $50,000 was associated with higher levels of risk perception. Respondents who had professional and/or recreational group memberships perceived higher economic risks. Respondents highly supported activities that they could take part in directly, such as community invasive pulls and native species planting. Overall, our findings aid managers in allocating appropriate funding or tailoring outreach efforts to different aspects of invasive plants as well as groups/communities where people's knowledge and risk perceptions of invasive plants are low.

Perception and Conflict in Conservation: The Rashomon Effect

Conflict is a common feature in conservation and resource management. Environmental conflicts are frequently attributed to differences in values; however, variability in the perception of facts, rooted in social and cultural differences also underlies conflicts. Such differences in perception have been termed the Rashomon effect after the Kurosawa film. In the present article, we explore a conservation Rashomon effect—a phenomenon that results from a combination of differences in perspective, plausible alternative perspectives of a conservation issue, and the absence of evidence to elevate one perspective above others. As a remedy to the Rashomon effect, policy-makers have turned to scientists as honest brokers who share a common environmental reality. We evaluate this supposition and suggest that scientists, themselves, display Rashomon effects. We suggest that Rashomon effects can be reduced by acknowledging the plurality of reality, embracing epistemic pluralism, and prioritizing an inclusive process of resource management.

The importance of assessing positive and beneficial impacts of alien species

Extensive literature is available on the diversity and magnitude of impacts that alien species cause on recipient systems. Alien species may decrease or increase attributes of ecosystems (e.g. total biomass or species diversity), thus causing negative and positive environmental impacts. Alien species may also negatively or positively impact attributes linked to local human communities (e.g. the number of people involved in a given activity). Ethical and societal values contribute to define these environmental and socio-economic impacts as deleterious or beneficial. Whilst most of the literature focuses on the deleterious effects of alien taxa, some recognise their beneficial impacts on ecosystems and human activities. Impact assessment frameworks show a similar tendency to evaluate mainly deleterious impacts: only relatively few, and not widely applied, frameworks incorporate the beneficial impacts of alien species. Here, we provide a summary of the frameworks assessing beneficial impacts and briefly discuss why they might have been less frequently cited and applied than frameworks assessing exclusively deleterious impacts. Then, we review arguments that invoke a greater consideration of positive and beneficial impacts caused by alien species across the invasion science literature. We collate and describe arguments from a set of 47 papers, grouping them in two categories (value-free and value-laden), which span from a theoretical, basic science perspective to an applied science perspective. We also provide example cases associated with each argument. We advocate that the development of transparent and evidence-based frameworks assessing positive and beneficial impacts might advance our scientific understanding of impact dynamics and better inform management and prioritisation decisions. We also advise that this development should be achieved by recognising the underlying ethical and societal values of the frameworks and their intrinsic limitations. The evaluation of positive and beneficial impacts through impact assessment frameworks should not be seen as an attempt to outweigh or to discount deleterious impacts of alien taxa but rather as an opportunity to provide additional information for scientists, managers and policymakers.