Sustainability-Oriented Management of Invasive Alien Species Risk in Infrastructure Projects with Significant Environmental Impact: A Case Study from Poland

Invasive alien species (IAS) are an important but insufficiently integrated risk in sustainable infrastructure development, particularly in projects involving earthworks, soil movement, habitat disturbance and prolonged construction. Their spread may cause biodiversity loss, ecosystem degradation, higher maintenance costs, project delays and long-term deterioration of land-use sustainability. This study identifies critical stages of infrastructure project implementation associated with elevated IAS risk and proposes management measures supporting prevention, early detection, rapid response and post-intervention monitoring. The research used a comparative multiple-case study of three large infrastructure projects in Poland implemented under FIDIC conditions: flood embankment reconstruction, railway line modernisation and express road construction. A Before–After approach combined analysis of pre-construction environmental documentation, baseline ecological inventories, field verification after IAS detection, control measures and monitoring outcomes. Japanese knotweed (Reynoutria japonica Houtt.) was analysed as a model species because of its high regeneration potential and relevance to soil management. The analysed cases indicate that elevated IAS risk may occur during site preparation, earthworks, topsoil stripping and storage, soil reuse, finishing, landscaping and utility relocation. The study proposes a practical IAS risk classification framework to support risk identification, preventive action and monitoring intensity with the potential to support sustainability performance and reduce ecological and economic impacts.