Research Projects

The west Himalayan treeline is dominated by Himalayan Silver Birch (Betula utilis) which is recognised as an ecosystem sensitive to climate change. We propose mechanistic studies on birch survival and reproduction at treelines in two locations i.e., Manali Wildlife Sanctuary and Sural valley in Himachal Pradesh. These locations differ greatly in climate with the former being affected by summer monsoon whereas later is situated in a rain shadow region and faces comparatively dry summers. We will use climatic, taxonomic, phenological, productivity and genetic variation in space and time to infer responses of the birch and other associated taxa at different tropic levels to the climate change. In addition, we will collect data in such a way that the treeline ecosystem can be monitored over at least the next three decades. The overall study design includes establishment of two sites for long-term monitoring of climate, biodiversity and soil composition at lower, middle, and upper range limit of birch. In addition, phenological changes in relation to climatic conditions, impact of herbivory on birch leaves, abundance and morpho-diversity of insects and diversity of insectivorous birds will be recorded and monitored in future for understanding the synchrony and interdependence of different trophic levels in the birch forests of west Himalaya. Circular polycarbonate greenhouses will be established around selected trees at three elevational zones to assess impact of increased soil temperature on phenology of the birch trees. Further, using tree core rings and plant transpiration measurements at the lower and upper elevational range limits, past climate will be reconstructed, and patterns of biomass accumulation will be calculated to infer historical trends and adaptation of the birch towards warmer and colder range limits of the species. Tree community sampling will be conducted and species specific allometric equations will be utilized for understanding the biomass and carbon stock in relation to age derived from tree ring cores to infer growth and adaptation of individuals at contrasting climatic conditions. Finally, Genotyping-by-Sequencing (GBS) will be conducted for birch population to assess the population structure and gene flow patterns and possibly to reveal how birch trees acclimate and adapt to different stress factors, such as herbivory, nutrient economy, photosynthetic efficiency, phenological changes etc. The saplings of birch at lower and upper elevational range will be transplanted at the other extreme range limits to assess their adaptive plasticity towards climate change. The generated data will help in prediction of climate induced asynchrony between different trophic levels. Past climate, plant productivity, gene flow and adaptive plasticity in birch will help in inferring the history to predict the future impacts of climate change on the treeline ecosystem of the west Himalaya.