Assessment and Management of Invasive Plant Species in Nigerian Protected Area Ecosystems: Challenges and Strategic Responses

Invasive plant species represent one of the most pressing threats to biodiversity conservation in Nigerian protected areas, yet the management frameworks, institutional capacities, and professional practices addressing this threat are poorly evaluated across the national protected area estate. This study assessed the distribution, impact severity, and management effectiveness of invasive plant species in five selected protected areas across Nigeria's geopolitical zones: Okomu National Park (South South), Afi Mountain Wildlife Sanctuary (South East), Kainji Lake National Park (North Central), Gashaka-Gumti National Park (North East), and Kamuku National Park (North West). A professional assessment methodology combining structured stakeholder interviews, management document review, vegetation monitoring data analysis, and field verification was employed across all five sites. A total of 28 invasive plant species were identified as priority management concerns across the sites, with Chromolaena odorata, Mimosa invisa, and Lantana camara consistently ranked as highest impact. Management capacity was assessed as inadequate in four of five protected areas, with invasive species budgets constituting less than 5% of annual operational expenditure. Early detection systems were absent in all five sites. Site-specific management plans addressing invasive species existed in only one protected area (Okomu). The study concludes that invasive plant management in Nigerian protected areas requires urgent institutional strengthening, cross-site coordination, and dedicated invasive species budgets. A national invasive plant management framework with monitoring protocols and rapid response funding is recommended.

Keywords: invasive plants, protected areas, biodiversity management, Chromolaena odorata, Nigeria