Ms Aashna Sharma1, Dr Vineet Dubey1, Dr Jeyaraj Johnson1, Dr Kuppusamy Sivakumar1
1Wildlife Institute Of India, Dehradun, India
Macroinvertebrates are brilliant study organisms to understand climate change (CC) effects on the high-altitude lotic systems owing to low dispersal abilities and high environmental specificity. This study aimed at delineating Climate Sensitive Zones (CSZs) zones in Himalayan streams based on macroinvertebrate community thresholds.
The CSZ concept has been used for CC studies in central Himalayan streams. The present study aims at testing the concept on north-west Himalayan streams in India (total streams n=25, stream stretch =168km). The study sites fall within the drainage network of Tirthan, one of the last undammed rivers of India, protected by the boundaries of Great Himalayan National Park.
Kick and drag netting techniques were used with extensive sampling approach for field data collections of macroinvertebrates. A total of 37 physico-chemical and habitat covariates were recorded at all sampling points including bioclimatic variables (n=178 points, elevational range=989-4569msl). Identifications were made to family level. Predictor variables were determined by fitting environmental data to Classification and Regression Trees (CART) and Generalised Additive Models (GAM). Threshold Indicator Taxa analysis (TITAN) run with 500 bootstrap cycles to determine the CSZ. Analyses were performed using R ver.3.4.1.
Macroinvertebrates sampled (n=2204) revealed a total of 59 families. Model fitting revealed altitude as the best predictor variable (p<0.01). A total of 11 indicator families (z-=9, z+=2) and CSZ delineation from 1593 to 2383 masl resulted from community change score values of TITAN.
Demarcated CSZs through this study would help developing nations to track CC effectively by narrow band monitoring.
Ms Aashna Sharma is a Senior Research Fellow pursuing her doctoral work on native-exotic trout interactions in the Himalayan Rivers. She has done extensive surveys on the aquatic fauna of high altitude Himalayan Regions including trans Himalaya. She has particular interest on macroinvertebrates of cold water streams. She loves singing, poetry and trekking to unexplored lands.
Dr Vineet Dubey is a research associate from Wildlife Institute of India and is studying the freshwater ecology and species associations in the Indian Himalayan Region. His doctoral work comprised comparisons of pre and post river interlinking scenarios. He has experiences on wildlife surveys in National Parks and Tiger Reserves of India, a major one being all India Tiger estimation. He loves traveling, photography and wildlife exploration, all time favorite being in Himalaya.