Riparian Zones and Pollination Service: A Case Study from Coffee-Agrosystem Along River Cauvery, South India

摘要

The study aims to understand the influence of pollinator visitation rate to coffee plantations located along the riparian zones of river Cauvery in Karnataka, using distance as a criterion. Plots were fixed at 10 m, 30 m and 60 m points from the edge of riparian zone towards the coffee plantations. In each of these three points, five plants were selected. In each plant, four branches with approximately six inflorescences per branch were observed for 15 minutes and the visitation rate of selected floral visitors to Coffea canephora was recorded. To understand if a riparian zone was a suitable pollinator habitat, bee colonies in the riparian zone were identified through a transect of approximately 500 m adjacent to the study plot. The total number of bee visits for Apis dorsata, Apis cerana, Tetragonula iridipennis and Apis florea was 18,100 for an observation time of 9540 minutes. A. dorsata and A. cerana were the main contributors to the total number of visits. The visitation rate of pollinators, A. cerana and A. dorsata decreased with increase in distance from the riparian zone. Additionally, colonies of A. cerana and A. dorsata were found in the riparian zones indicating riparian zones as potential pollinator habitats. A negative relationship has been observed between total species visits and distance indicating a reduction in species visits with increased distance from the riparian zone. Conservation of riparian zones increases pollination service to adjacent coffee plantations along with a multitude of other ecosystem services.