International Science Community Association International Research Journal of Environmental Sciences 2319-1414 10 4 2021 10 22 Impact of flood on biodiversity of Kerala: A case study from Malappuram district of Kerala, India 8 19 EN Vishnu P.S. 1 Soil Science Department, KSCSTE- Kerala Forest Research Institute, Peechi, Kerala, India Sandeep S. 2 Soil Science Department, KSCSTE- Kerala Forest Research Institute, Peechi, Kerala, India N. Aleem Yoosuf 1 Department of Plant Science, Central University of Kerala, Kasaragod India – 671316, Kerala, India T.P. Unaisudheen 2 Department of Botany, Jamal Mohamed College (Autonomous), Thiruchirappally– 620020, Tamilnadu, India > Case Study 2021 4 28 2021 10 22 The Kerala state has witnessed the worst flood of the century during 2018 monsoon, most devastated at Nilambur Taluk of Malappuram district. The present study at this location, precisely Mathilmoola colony and nearby areas of Chaliyar Panchayath assessed the impacts of flood on vegetation with focus on plant species diversity and invasive plant dissemination. Ten 10×10 m quadrants are taken in the study area, 5 represented floods affected and 5 represented non flood affected regions, having same topography. Species density, frequency, abundance and relative density are calculated. The result substantiates that invasive plant dissemination is relatively high in flood affected area. The relative density of invasive species is more (79.07%) in flood affected area compared to that (65.03%) in the non-affected area. This clearly shows that the flood has favored the distribution of diverse exotic alien species and accelerated the growth of invasive plant species already inhabited in the area. Even if relative density of invasive species is high, they are not frequently and uniformly distributed in the flooded quadrants. This gives the clear idea about influence of fury on the carrying and re-distribution of species in its natural habitat during flood. Copyright@ International Science Community Association