Influence of Terminalia arjuna on the riparian landscapes of the River Cauvery of South India

Mature and large isolated trees act as keystone structures in various ecosystems by supporting the populations of dependent organisms. Terminalia arjuna is one such species that is dominant in the riparian landscapes along the River Cauvery in Cauvery Wildlife Sanctuary. We tested the hypothesis that T. arjuna influences plant community composition in riparian landscapes and supports a distinct local riparian community. We showed plant species richness, diversity, similarity in community composition, and soil quality varied between riparian landscapes under canopy of T. arjuna and areas devoid of T. arjuna. Higher species richness, diversity, dominance, and evenness were noted in areas under canopy of T. arjuna. The non-metric multi-dimensional scaling ordination space analysis identifies the native riparian species assemblages in areas under canopy of T. arjuna with improved soil nutrient conditions. Overall, the study concludes T. arjuna has potential positive effects on riparian landscapes by showing the remarkable differences in biological diversity and it can be considered as keystone species in riparian ecosystems of South India