Understanding the invasion potential of Chromolaena odorata and Lantana camara in the Western Ghats, India: An ecological niche modelling approach under current and future climatic scenarios

Invasive species are the major cause of native biodiversity loss and species extinction, which have predominantly affected one of the world's 'hottest hotspots' of biodiversity located in the Western Ghats, India with varied intensity. Therefore, in the present study, an investigation has been undertaken to model the potential habitat of dominant invasive plant species (IPSs) viz., Chromolaena odorata (L.) R.M.King & H.Rob. and Lantana camara L. in the Western Ghats, in the current and future climate change scenarios by evaluating the influence of the bioclimatic and topographical variables using species distribution modelling (SDM). The study exhibited the large invasion and proliferation of C. odorata (33.01%) and L. camara (30.33%) in the Western Ghats, especially the Nilgiri Biosphere Reserve (NBR) under the current scenario. The future projections derived using Shared Socioeconomic Pathways of Climate Scenarios datasets (SSPs 126, 245, 370, and 585) demonstrated a significant reduction in the invasion of C. odorata (>5.48% of WG), while a surge in the invasion of L. camara (>5.83% of WG) barring a few exceptions. However, the study highlighted the major future invasion of L. camara (45,262 sq. km; 31.33% under SSP 126 (2021-40)) and C. odorata (33,844 sq. km; 23.43% under SSP 245 (2021-40)) in the Western Ghats, of which large concentrations were observed in the NBR (L. camara: 5711 sq. km; 12.6%; C. odorata: 5090 sq. km; 15.04%) and the southern coasts. The study introduces a comprehensive and novel method leveraging SSPs of climate scenarios to identify the hotspots of major plant invasions in the Indian tropical forests using an ecological niche modelling. These findings hold significant relevance for prompt actions for invasion management in both current major hotspots and the regions susceptible to future invasions.