Native vegetation pattern and the spread of three invasive species in Palani Hill National Park, Western Ghats of India

Invasions by exotic plants threaten the biodiversity and integrity of Protected Areas (PAs) by manipulating the species composition, the nutrient cycling and the hydrology prevailing in the specific habitat. Invasion of plant species in the natural ecosystem especially in the precincts of Western Ghats is due to rampant anthropogenic pressures. Complete assessment of the vegetation, richness distribution of Invasive Alien Species (IAS) and their association with the environmental drivers is essential to manage the PAs effectively. The present study analyses the richness of native vegetation with a comparative view on the distribution of Lantana camara, Chromolena odorata and Pteridium aquilinum in proposed Palani Hill National Park (PHNP), Western Ghats of Tamil Nadu. Secondly prepare models of the distribution of the target invasive species in the region. The biotic and abiotic data along with the vegetation type were generated and overlaid on IAS distribution to model the spread of target plant species. The study revealed that the distribution of invasive species negative relationship between the native species richness and positive relationship between the species dominance. Among the forest types dry evergreen, moist deciduous and tree savanna were found to be more vulnerable to invasion of Lantana camara and Chromolena odorata, wherein tree savanna and plantation were more vulnerable to invasion of Pteridium aquilinum. The information will strongly support effective management of Protected Areas.