Invasive alien species are considered a major threat to biodiversity and seriously impact the economy and public health of recipient regions. Identifying the determinants of protected areas’ vulnerability to the establishment of invasive alien species (IAS) may improve management, prevention and early warning systems of biological invasions. We elicited the perceptions of 106 experts working in 56 protected areas located in 6 European countries, to gather insights on the determinants of ecosystem vulnerability to IAS. We implemented an online questionnaire to understand the following: i) the expectations and perceived drivers of the future entry of IAS to protected areas, ii) the most common policy frameworks and management options used, and iii) the main challenges encountered when managing or preventing biological invasions. Experts project an increased entrance of IAS in protected areas located in Corsica, Portugal, and Spain. Areas where the entry of IAS is expected to increase comprise i) low to average anthropogenic disturbance, ii) average biodiversity richness, with endemic/threatened/protected species, iii) current presence of IAS, and iv) anthropogenic activities in surrounding regions. Respondents expecting increased entrance of IAS in protected areas also consider corridors as the main pathway of their entry, whereas those expecting IAS entrance to decrease believe IAS enter protected areas mainly through intentional introductions. Our results also underline the complexity of IAS management, which is often hampered by the lack of clear policies, shortage of economic resources and specialised staff, and poor awareness of biological invasions. Future research should further strive to understand which areas are more vulnerable to IAS, especially in regions with free trade and movement agreements, such as the EU. Meanwhile, vulnerability to IAS can be minimized through a stricter management of both protected areas and surrounding anthropogenic activities, and by raising manager and citizen awareness of the ecological and economic problems caused by IAS.

外来入侵物种被认为是对生物多样性的主要威胁，并严重影响了受援地区的经济和公共卫生。确定保护区是否容易建立外来入侵物种（IAS）的决定因素，可能会改善生物入侵的管理，预防和预警系统。我们得出了在6个欧洲国家的56个保护区工作的106位专家的看法，以收集有关生态系统对IAS脆弱性决定因素的见解。我们实施了在线问卷调查，以了解以下内容：i）IAS将来进入保护区的期望和驱动因素； ii）使用的最常见的政策框架和管理选项； iii）在管理或预防方面遇到的主要挑战生物入侵。专家预计，IAS在科西嘉岛，葡萄牙和西班牙的保护区内的入口将增加。预计IAS进入的地区将增加：i）人为干扰低至平均水平； ii）具有地方性/受威胁/受保护物种的平均生物多样性丰富度； iii）IAS当前的存在；以及iv）周边地区的人为活动。预期IAS进入保护区的人数增加的受访者也将走廊作为其进入的主要途径，而那些预期IAS进入次数减少的受访者则认为，IAS的进入主要是通过有意引入。我们的结果还强调了国际会计准则管理的复杂性，通常由于缺乏明确的政策，缺乏经济资源和专业工作人员以及对生物入侵的意识不足而受到阻碍。未来的研究应进一步努力了解哪些地区更容易受到IAS的影响，尤其是在具有自由贸易和流动协议的地区，例如欧盟。同时，可以通过对保护区和周围人为活动进行更严格的管理，并提高管理者和公民对由IAS引起的生态和经济问题的认识，将对IAS的脆弱性降至最低。