Ecological Drivers of Cogon Grass (Imperata Cylindrica) Invasion: A Global Assessment of Range Expansion under Wildfire and Climate Change

Assessing habitat suitability and potential spread of invasive species is vital for identifying vulnerable regions and guiding management actions to protect biodiversity and ecosystem services. We evaluated the global habitat suitability of cogon grass ( Imperata cylindrica ), one of the world’s 100 worst invasive species, using species distribution modeling with five machine learning algorithms. Shared Socioeconomic Pathway (SSP) scenarios integrating climate, soil, wildfire regimes, and human population dynamics were used to determine ecological drivers and invasion risks. Wildfire emerged as a key factor promoting cogon grass expansion. Globally, suitable habitat is projected to increase by 20.3%, 40.3%, 42.8%, and 44.4% under SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5, respectively. Currently, 41 tropical and subtropical countries already exhibit high habitat suitability, with cogon grass established across grasslands, savannas, steppes, and alpine meadows. Under SSP5-8.5, 70 countries—particularly in Africa and South America (e.g., Angola, Congo, Haiti, Trinidad and Tobago)—are projected to shift to highly suitable conditions by 2061–2080. The Asian alpine and subtropical regions, along with African and South American savannas, are especially vulnerable. These findings reveal significant global invasion risks under future environmental change and provide essential insights for strengthening biosecurity, early detection, and sustainable management strategies.