Perception of Stakeholder Groups on Ailanthus altissima in Hungary

In order to tackle the problems caused by invasive alien plant species, it is important to know what the main groups that have the largest influence on the spreading of the species, know and think about them. Nation-wide questionnaire surveys were carried out in Hungary between 2016 and 2019 among three important stakeholder groups (local governments, national park directorates (NPDs), and state forestry units (SFUs)) of tree of heaven (Ailanthus altissima). The aim of the surveys was to reveal the perception of the three groups about Ailanthus altissima, their experiences with eradication, and other needs for its successful management of the species. Besides basic statistical methods, the chi² test, Fisher’s exact test, Cramer’s V value, and Mann–Whitney U test were conducted to compare groups and reveal relationships between different variables. 221 local governments, 10 NPDs, and 110 SFUs filled in the questionnaire. The response rate was quite low for local governments (8,8%) and high for NPDs (100%) and SFUs (97.5%). Our findings show that the species was recognised by only 59% of respondents representing local governments. Further results are presented regardingthis subsample.The negative impacts of Ailanthus altissima were perceived in all three groups at a higher rate (over 95% in all three groups) than positive impacts (local governments: 63%, NPDs: 10%, SFUs: 35%). The two groups managing forest areas (NPDs and SFUs) ranked the problems caused by the species high (the median was −4 for both groups on a −5–+5 scale). Ailanthus altissima was present in the areas of at least 80 percent in each examined group. In areas where the species was present, eradication was applied in a significantly higher percent of NPDs (86%) and SFUs (88%) than regarding local governments (36%), and the same tendency was found for using mechanical and chemical methods (p < 0.05). The two groups managing forest areas also applied biological methods, although at a lower rate (NPDs: 10%, SFUs: 14%). The unit costs and area of eradication varied between NPDs and SFUs, but the difference was not significant between the two groups (p = 0.073 and 0.213, respectively). NPDs used more external funding for eradication than local governments and state forestry units, mostly co-financed by European Union funds (e.g., LIFE and European Regional Development Fund). Information was required by a large percentage of respondents from local governments (75% of those who recognised the species). The need for cooperation between stakeholder groups was indicated by 78% of local governments recognising the species, and was ranked high by the two expert groups as well (medians were 4 for NPDs and 5 for SFUs on a 0–5 scale). Sharing knowledge about and experience with eradication among the two expert groups and transferring knowledge to the local governments are recommended for the successful management of the species. Further research is needed regarding the effectiveness, the environmental impacts, and the costs of eradication, as well as influencing factors.