Predicting Shifts in Bioclimatic envelopes of Indian Biomes for 2050 and 2080 under A2 and B2A climate scenarios
National Center For Biological SciencesAuthors
Dina Rasquinha1, Mahesh Sankaran1 1 National Centre For Biological Sciences, Tifr, Bangalore Email:Dina.Rasquinha@Gmail.Com
The fate of terrestrial biological systems and the communities directly and indirectly dependent on them is uncertain in the light of global change. Climate wields a dominant control over the natural distribution of species. These dynamics provide a way to understand how communities and biomes will respond to global change. An attempt is made to understand the redistribution of biomes under future climate scenarios using a bioclimatic modelling approach.
The biome map of Olson et al. 2001 was used as the base layer for biomes and a total of 10 predictor variables (WorldClim) at 5arc-minutes were selected based on limiting conditions, annual and seasonal trends of temperature and precipitation. A linear discriminant analysis (LDA) was performed by training the model with variables under current climate and prediction of the model with future scenarios (A2 & B2A) to predict changes in the distribution of biomes.
The projected changes for B2A scenario was much more benign than those observed for A2 scenario. Under the A2 scenario by 2050; most of the Moist forests were projected to be replaced by Dry forests (45%) and almost completely by Tropical savannas (99%) by 2080 .A decrease in the Desert, Temperate broadleaf, Flooded grasslands & Tropical Coniferous biome were observed across both the scenarios for 2050 and 2080
By 2080, 91% of all grids will be Tropical Savannas implying loss of many biomes and the accompanying biodiversity and dependent livelihoods. Conservation strategies thus need to incorporate a cost-benefit framework involving communities using incentive based mechanisms like PES, REDD+ etc. Afforestation programmes should be administered considering the consequences of changed conditions (Planting drought resistance species in areas likely to become drier).