Invasive alien species are considered a major contributor to biodiversity loss. Yet many are favoured for particular ecosystem services that they provide. This is often so in urban environments experiencing rapid environmental and social change and land transformation. Public support is viewed as critical for invasive alien species prevention and management. Furthermore, it is assumed that local citizens are more likely to be willing and ready to engage if they are informed about the costs and benefits associated with invasive alien species. However, the use of, and attitudes towards, invasive alien species in urban areas is poorly understood, especially regarding urban gardens under private ownership and control. This lack of understanding is likely to compromise potential management interventions.

Here we report on a survey of 240 people across 12 small towns in the Eastern Cape province of South Africa to determine their knowledge and perceptions regarding woody invasive alien plants (IAPs), their willingness to engage in control, and how these vary in relation to respondent attributes.

The findings indicated that respondents have low levels of knowledge about woody IAPs despite 84 % of them having at least one woody IAP species in their garden. Nineteen different woody IAPs were noted across the sample of 240 households. A wide range of ecosystem services and disservices from woody IAPs were mentioned. Because of the benefits provided, or the effort required to remove them, only 56 % of respondents were willing to have the woody IAPs removed from their gardens, with most considering it the responsibility of government agencies to do so. There was a positive association between the levels of education, income, and the impression that woody IAPs pose a problem and being aware of the term, but not willingness to remove them. 

Synthesis & implications:

These results reveal the complex relationship that urban citizens have with IAPs in gardens settings, and for authorities to consider appropriate and targeted awareness campaigns if control strategies are to be successful.

In each of the 12 study towns, 20 residential households were randomly selected using Google Earth. To randomly select households in each town, each household was identified on Google Earth, assigned a unique number, and then a random sample drawn, using Microsoft Excel. Randomly selected households were then approached for face-to-face  interviewers and in situations where there was nobody available or willing in a randomly selected household, the next available household was sampled. Permission was asked from the owner to survey their garden and list any woody Invasive Alien Plants (IAP) present. Within the selected households, a willing adult respondent was interviewed to gather information on knowledge, perceptions and willingness to control woody IAPs. The interviews were conducted either in IsiXhosa, English, Afrikaans, or according to the respondent’s preference. If the preference was another language, then a translator was hired to assist and recorded the responses which were later translated. The interviews were conducted between 10 am and 5 pm on weekdays and weekends, during February 2021 and March 2021.

The structured questionnaire was divided into three sections and took approximately 30-40 minutes to complete. The first section covered topics on knowledge and perceptions of woody IAPs. Participants were also asked to rate their knowledge of woody IAPs on a five-point scale (1 having no knowledge and 5 being highly knowledgeable). The second section of the questionnaire captured information about the willingness to have IAPs removed from their garden. The demographic profile of respondents was recorded in the last section, including age, gender, and level of education (see Appendix 1). The research protocol and questionnaire were approved by the Rhodes University Ethics Committee (reference number 2020-1638-4758). A copy of the questionnaire is provided as supplementary materials to the published paper. 

The data from the interviews were analysed in Statistica Version 13, after classifying nominal answers into numerical codes. The potential relationships were assessed using Principal Component Analysis (PCA) with variables scaled between zero and one against the highest value, mainly demographics and knowledge of IAP, the identification of IAP, willingness to remove IAP from garden and willingness to participate in an environmental initiative. Particular associations of interest were tested via correlation analysis. We used a Chi-squared test to examine if there was any association between the proportion of respondents mentioning particular IAPs and their corresponding proportional contribution to the total number of IAP individuals reported by Seboko et al. (2024).