Stakeholders' perceptions towards non-native acacias and implications for their management in Portugal

Humans act as drivers for the introduction of non-native trees. Some non-native species may become invasive and cause undesirable impacts, thereby motivating targeted decision-making and management actions. Australian acacias (or wattles; genus Acacia subgenus Phyllodineae) have been introduced worldwide, offering both opportunities and risks for local communities. Understanding how stakeholders perceive invasive acacias is paramount to assist effective decision-making. We assessed stakeholders' perceptions about these non-native acacias, their invasion process, social-ecological impacts and management. We conducted a questionnaire-based survey with experienced managers and decision-makers in Northern Portugal, where acacia invasions are widespread. We found that most stakeholders are not able to recognize non-native species, failing to identify the introduction period, drivers of dispersion and appropriate management methods of Australian acacias. We could also identify different stakeholder perceptions on the benefits and negative impacts provided by these species. We call for the implementation of technical training and information outreach strategies to address stakeholders' lack of knowledge (and experience) on the recognition and identification of non-native trees, as well as on their introduction and invasion history, drivers of dispersion, costs and benefits, and effective management actions. Stakeholders' engagement should be promoted in the design and implementation of biosecurity efforts to control (and/or adapt to) invasive acacias at relevant scales of invasion management.