Research Article |
Corresponding author: Franz Essl ( franz.essl@univie.ac.at ) Academic editor: Llewellyn Foxcroft
© 2020 Raphael Höbart, Stefan Schindler, Franz Essl.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Höbart R, Schindler S, Essl F (2020) Perceptions of alien plants and animals and acceptance of control methods among different societal groups. NeoBiota 58: 33-54. https://doi.org/10.3897/neobiota.58.51522
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Biological invasions are a widespread phenomenon and cause substantial impacts on the natural environment and human livelihoods. Thus, the European Union (EU) recently adopted Regulation No 1143/2014 to limit the negative impacts of invasive alien species (IAS). For implementing IAS management and policies, public support is highly and increasingly important, especially when it comes to charismatic species and lethal methods. Recognising the importance of the interaction of public perception with acceptance of IAS management methods, we used an online survey targeting three different stakeholder groups in Austria to evaluate potential differences in perception of IAS and management methods.
In total, we received 239 completed responses: 20 nature users (farmers, hunters), 91 nature experts (conservationists, biologists) and 128 from the general public. Participants were more likely to accept lethal management methods when it was an IAS. Nature experts’ acceptance of IAS management methods was rather similar to those of nature users, while the general public preferred non-lethal methods. Chemical lethal methods (herbicides, poison pellets) received low rates of acceptance throughout all stakeholder groups, although nature users were more open to accept such methods for plants. Most respondents (> 50%) were not aware of the role of the EU in IAS topics nor did they know of the existence of the EU IAS regulation 1143/2014. However, more than 75% of respondents agreed that IAS measures and regulations should be implemented at EU level.
This study shows that knowledge about native versus invasive alien status has an influence on the acceptance of management methods. Nature users may have higher levels of acceptance of lethal methods because they are economically dependent on extracting resources from nature. Invasive alien species regulations on EU level are generally acceptable, but there is low awareness for actions already undertaken EU.
EU Regulation 1143/2014, IAS control, management methods acceptance, nature conservation, perception, survey, values
Biological invasions are a widespread phenomenon and cause substantial impacts on the natural environment and human livelihoods (Pejchar and Mooney 2009;
According to this regulation, “alien species” are defined as any live specimen of a species, subspecies or lower taxon of animals, plants, fungi or micro-organisms introduced outside its natural range; it includes any part, gametes, seeds, eggs or propagules of such species, as well as any hybrids, varieties or breeds that might survive and subsequently reproduce. “Invasive alien species” are those alien species whose introduction or spread threatens or adversely impacts upon biodiversity and related ecosystem services (
One key component of the EU regulation is the “List of Invasive Alien Species of Union Concern” (
Therefore, the question arises if killing a charismatic animal for conservation purposes is justified and appropriate (Jaric et al. 2020). Scientific and general public opinions can differ tremendously (
Aesthetic and charismatic species are often used as flagship species for engaging stakeholders, increasing acceptance and promoting conservation programmes (
Here, we used an online survey targeted at three stakeholder groups. Participants assessed pairs of IAS included in the EU IAS regulation and native species. By doing so, we addressed the following questions: 1) What are the differences in perceptions of invasive alien plant and animal species and similar native species? 2) What is the level of knowledge in identifying invasive alien and native species? 3) What are the differences in acceptance of different management measures? 4) Which institutions should play stronger roles in IAS management?
For this research, the non-probability method of self-selective convenience sampling was chosen, i.e. there are no rules for selecting the potential participants (
An additional advantage of convenience sampling is that it facilitates reaching out to participants from stakeholder groups that are otherwise difficult to reach (
We designed an online survey (in German; see Suppl. material
Photos of the four pairs of native versus invasive alien study species used in the online survey. All photos are from Wikimedia Commons a Аимаина хикари b H. Zell c Donald Hobern d Malte e I. Pkuczynski f http://www.nps.gov/acad/photos/redfox.htm [Public domain] g Bastique h Zefram.
A total of four species pairs (thus eight species in total) consisting of a native and an invasive alien species were selected. We used two mammal species pairs and two vascular plant species pairs. The four invasive alien species are included in the “EU List of IAS of Union Concern” (
Overview of the distribution, region of origin, first records and habitat affiliation of the invasive alien species of the survey (
Common Milkweed (Asclepias syriaca) | Himalayan Balsam (Impatiens glandulifera) | Raccoon Dog (Nyctereutes procyonoides) | Raccoon (Procyon lotor) | |
---|---|---|---|---|
Origin | North America | India, Himalaya | Siberia, Ussuri, Manchuria, Korea, Japan | North and Central America |
Habitat | ruderal slopes, roadsides, fallows | riversides, floodplains, ruderal plains, wet fallows | broadleaf and mixed forests, near waterbodies | wet broadleaf forests, near waterbodies, near settlements |
Distribution in Austria | Vienna, Lower Austria, Upper Austria, Styria, Burgenland, Carinthia | All of Austria | Lower Austria, Upper Austria, Styria, Burgenland, Salzburg | Vienna, Lower Austria, Upper Austria, Styria, Carinthia, Vorarlberg, Salzburg |
Ecological impacts | displacement of native plants; overgrowing of large areas; high spreading | displacement of native plants (riverside vegetation); overgrowing of large areas; high spreading | predation of molluscs, insects and amphibians; transmitter of diseases | no detailed data, predation of bird nests, amphibians, reptilians and fish; transmitter of diseases |
First record in Austria | unknown | 1898 | 1963 | 1974 |
Overview of the distribution and habitat affiliation of the native species of the survey (
White Swallow-Wort (Vincetoxicum hirundinaria) | Touch-me-not-Balsam (Impatiens noli-tangere) | Red fox (Vulpes vulpes) | Beech Marten (Martes foina) | |
---|---|---|---|---|
Habitat | dry grasslands, open forests | riversides, floodplains, tall herb vegetation, broadleaf and mixed forests | cultural landscapes, settlements | parks, gardens, settlements, cultural landscapes |
Distribution in Austria | widespread | widespread | widespread | widespread |
Perception of species
For every study species pair, the species photos were shown together with six questions which referred to the attitude of the survey participant towards the species.
For each study species, a list of different management methods was presented. The participants were asked to assess the acceptance of these management methods and if there is a need to reduce or halt the spread of the species. The questions and the answer options were identical for mammal and vascular plant species.
The management methods presented were chosen according to Article 19 of Regulation (EU) no.1143/2014. As stated in the Regulation, the management option selection consists of “lethal and non-lethal physical, chemical and biological actions aimed at the eradication, population control or containment of a population of an invasive alien species” (
The eight study species were shown and the participants were asked to specify for each species if it was native or invasive alien.
First, the participants were asked to give an assessment of the relevance of alien species in general and their management for Austria. Subsequently, the contribution of different stakeholders (EU, national and regional governments, NGOs, farmers, foresters, hunters, gardeners, landscape architects) to IAS management was asked (five-point verbal unipolar scale, ranging from no agreement to strong agreement (
As Regulation (EU) no. 1143/2014 is the cornerstone of European IAS policies, participants were asked about their awareness of this Regulation and if they believed that IAS policies indeed required an EU regulation. For these purposes, participants were asked to assess statements on the usefulness of the EU IAS legislation. Participants had the choice between “agree”, “no answer” and “disagree”.
The following personal data of the participant was recorded: gender, age, size of municipality of residence, home country and highest completed level of education. These personal data were used to assess the characteristics of the sample of survey participants. These questions were presented with single-choice options.
We selected participants from three pre-defined stakeholder groups. To do so, participants were asked to characterise themselves at the beginning of the survey as members of one of the following three stakeholder groups: i) Nature-Users (farmers, hunters, gardeners, landscape architects, foresters), b) Nature-Experts (biologists, environmental-NGO-staff, nature-conservationists) and c) General public (participants who do not belong to the above-mentioned groups). The same set of questions was used for all three groups of participants.
For the online survey, the software Limesurvey 3.15 (https://www.limesurvey.org/) was used. It was installed on a server provided by the University of Vienna. The survey was conducted in German, because the main target groups were people living in Austria. The survey was open from 5 November to 25 December 2018. The following media outlets were used for distributing the survey: Facebook (https://www.facebook.com/), WhatsApp and E-mail. As the convenience sampling method was used, it was considered acceptable to choose specific media channels to reach potential participants of the different stakeholder groups. On Facebook, for example, the link to the survey was posted in different “groups” for Austrian biologists. A reminder was sent via E-mail and posted on the used social media two weeks after the first call. Several participants were contacted directly via E-mail or chat message.
In total, 967 participants started the survey, of which 239 (24.8%) fully completed it. Non-completed surveys (n = 728) were excluded from the analysis. For analyses, we pooled the responses per person (by calculating the arithmetic mean) across the two study species in each of the four focal groups “native plant species”, “native mammal species”, “invasive alien plant species” and “invasive alien mammal species”.
We used the Kruskal-Wallis-Test (
We used Wilcoxon-Tests (
Of the 239 respondents who had provided full replies, 128 participants (53.5%) were members of the “general public” (GP), 20 (8.4%) “nature users” (NU) and 91 (38.1%) “nature experts” (NE). Unless otherwise noted, these are the sample sizes used in the analyses. The majority (72%) of the participants were younger than 30 years, 63% were female and 45% lived in a large city with more than 100,000 inhabitants. This was particularly the case for the “general public” stakeholder group. Other studies on the perception of IAS have shown similar demographic patterns (
Knowledge of native/invasive alien status
The assignment of the species, i.e. whether they are native or invasive alien species, was similar among the stakeholder groups (Figure
The response on the perceived importance of the native species for ecosystem functioning in Austria was similar across all stakeholder groups. Interestingly, native mammals were rated to be more important for ecosystem functioning than any other species group (Figure
A The perceived importance of native and invasive alien plant and mammal species for ecosystem functioning in Austria rated by the three stakeholder groups. Scale: -2 (very unimportant) to 2 (very important) B The physical appearance of native and invasive alien plant and mammal species rated by the three stakeholder groups. Scale: -2 (not aesthetic) to 2 (very aesthetic) C Does the species belonging to Austrian ecosystems as rated by the three stakeholder groups. Scale: -2 (No) to 2 (Yes) D Assessment of the acceptance of the management method “clearing (plants)/shooting (mammals)”. Scale: -2 (not acceptable) to 2 (very acceptable) E Assessment of the acceptance of the management method “killing by chemical agents”. Scale: -2 (not acceptable) to 2 (very acceptable) F Assessment of the acceptance of the management method “legal measures” (e.g. prohibition of keeping, trading and releasing, import bans). Scale: -2 (not acceptable) to 2 (very acceptable). For significance tests, see main text.
The majority of the participants across the stakeholder groups rated all species in the study as aesthetic or very aesthetic. Mammal species’ aesthetics were rated higher than plant species, but this difference was not significant (Figure
The question of whether the study species belongs to Austrian ecosystems was similar among all stakeholder groups. Furthermore, native species were more frequently assigned to Austrian ecosystems than alien species (Figure
The comparison across stakeholder groups showed that nature users had a significantly higher acceptance of clearing/shooting than the general public (Dunn-Bonferroni: IAS plants: F = 2.55; p = 0.032; native mammals: F = 3.79; p = < 0.001; IAS mammals: F = 4.95; p = < 0.001), except for native plants. The acceptance of shooting management of alien mammals varied among stakeholder groups (Kruskal-Wallis: F = 29.94; p = < 0.001) (Figure
Nature experts’ assessment of the study species belonging to Austrian landscapes (Figure
Most of the participants assessed killing by chemical agents as ‘rather not’ to ‘not acceptable’ (Figure
Legal measures (e.g. prevention of introduction, prohibition of keeping, trading and releasing, import bans) for IAS were highly acceptable as a management method among all stakeholder groups (Figure
Generally, the three stakeholder groups had similar perceptions in their assessment of different stakeholders’ contribution to IAS management (Figure
Assessment of the stakeholder groups opinion of the contribution to IAS management by different stakeholders. Differences were tested for significance by X²-test and Fisher’s exact tests – no differences detected. Significant differences between NU and NE were found in the “Farmers and Foresters” group (Kruskal-Wallis: F = 2.01; p = < 0.001). Abbreviations: GU = general public; NU = nature users; NE = nature experts.
More than 75% of all participants replied that IAS and their management are ‘a rather’ to ‘very relevant’ topic for Austria and that it is “rather to very important” to manage them at EU level (Figure
Relevance and awareness of the IAS topic and the EU regulation. Abbreviations: GP = general public; NU = nature users; NE = nature experts.
The results regarding the specific statements on EU IAS actions show that an overwhelming majority of participants agreed that IAS affect biodiversity in Europe (Figure
Since perceptions of IAS are diverse (
The participants of this survey had a distinct knowledge about the origin of the species and the assessments of their ecological function and their belonging to Austrian ecosystems followed this pattern. Native species were more positively connoted than invasive alien ones across all three stakeholder groups. The physical appearance assessment showed that all species were rated as “aesthetic” (German: “optisch ansprechend bzw. schön”) or “very aesthetic” (German: “optisch sehr ansprechend bzw. sehr schön”) by the majority of the participants. In this context, we were particularly interested to test if there is a significant relationship between the aesthetic appearance of species and the acceptance of different management methods. Previous studies have shown that acceptability of management measures often reflect aesthetic motivations (
We found a significant correlation between the assessment of study species as belonging to Austrian ecosystems and the acceptance of lethal management. When a species was considered to be an invasive alien species, acceptance of lethal methods was significantly higher. This result confirms other studies that had found similar results for the acceptance of eradication measures for IAS with negative impacts on the environment (
The overall rejection of chemicals (herbicides, poison pellets) as a method for killing invasive alien species was already shown in other studies (
Since approximately 86% of the territory of Austria is used for agriculture or forestry (
In the disputed cases of failed grey squirrel eradication in Italy (
Across stakeholder groups, the participants’ knowledge whether survey species were native or invasive alien species was very high. The majority of the participants assigned the species to the correct category. As the level of knowledge affects understanding and behaviour of people (
Although the contribution of the EU to IAS management is rated low (nearly 50% responded that there is currently little or no contribution by the EU) among all stakeholder groups, there is overwhelming support for more ambitious measures to be implemented at EU-level. The majority of the participants agreed with the advantages of IAS management organised and regulated by the EU. Thus, there is a high awareness of IAS and the survey participants are aware of the advantages of tackling this problem on a European level. For comparison, in a Swiss study only 40% of the participants belonging to the general public-stakeholder group were aware of the term invasive alien species (
This online survey used the convenience sampling method, i.e. the survey was open to everyone interested as long as (s)he lives in Austria. This approach is useful and widely used in cases when the basic sample size is unknown or very large, as is the case for the three stakeholder groups in this survey (
When distributing the survey, we used a broad set of communication channels for spreading the survey widely and thus reaching out to diverse audiences. In addition, the personal information of participants revealed that while some social strata (e.g. young urban populations) are somewhat over-represented, the distribution among basic demographic and personal parameters is relatively closely reflecting the Austrian population composition (Suppl. material
Since the majority of the participants agreed that IAS concern Austria and that there is a need to regulate them on a European level, this study indicates substantial awareness of the topic. The high level of knowledge, whether it is a native or an invasive alien species, as well as the perception parameters in the survey, emphasise this finding. As other studies have shown, one key to success for raising the general public’s awareness and support for IAS control measures is education and knowledge transfer (
We are highly grateful for all participants of the survey. FE appreciates funding by the Austrian Science Foundation FWF (grant I 3757-B29). We are grateful for helpful suggestions by Giuseppe Brundu and Ross Shackleton and the Handling Editor, Llewellyn Foxcroft.
Text S1, S2
Data type: text documents
Explanation note: Text S1. Original (German) version of the survey text. Text S2. Translated English version of the survey text.
Table S1. Overview on demographic data of survey respondents
Data type: statistical data