Research Projects

Assessing the impacts of climate change is a critical challenge in this epoch of rapid environmental change. Most climate change assessment studies focus on species redistribution along the thermal axis to higher latitudes or elevations. Such a shift is important to track the thermal niche of the species. However, the role of physiology and plasticity and other abiotic factors (eg: hypoxia, UV radiation, water balance) in upslope movement is less understood. In the Himalaya, ~3000 m is a transition zone where the high-altitude and foothill species segregate, thereby showing peak diversity in this zone (Acharya & Chhetri, 2011). Conventional assumptions, based on the conical shape of the mountains, hypothesize high-altitude species to be particularly vulnerable to climate change due to limited area for upslope range expansion. Himalaya is described as an hourglass-shaped, potentially constraining species at ~3000 m elevation (Elsen & Tingley, 2015). Foothill species expanding upslope in the Himalaya may therefore face multiple challenges like hypoxia, UV exposure, and extreme direct heat due to limited canopy cover alongside narrowing suitable habitat with spatial constraints. Yet, foothill species remain understudied in climate change studies (reviewed in Dahal et al., 2021). Range shift under climate change involves complex interactions between the environment, genetics, and traits. Adaptation can occur through (i) phenotypic plasticity (environment-induced variability in phenotype without genetic changes; Ho et al., 2020) – a rapid, reversible short-term response, and (ii) genetic adaptation – a long-term adaptive response driven by genetic variation. Rapid environmental change might be initiated by plasticity, but it delays long-term adaptive responses, weakening directional selection (Nunney, 2016). Whether and under what conditions plasticity facilitates or impedes adaptation is central to understanding species’ responses to environmental changes. The overall aim of the project is to understand how populations at elevation range edges, each exposed to distinct long-term selection pressures, optimize their strategies to deal with sudden environmental change. We assess if the response varies between sedentary and altitudinal migrant species. We will use two contrasting foothill species i.e. Plumbeous Water Redstarts (Phoenicurus frontalis; PWR) and White-capped Redstart (P. leucocephalus; WCR), as a model to examine the mechanistic basis of rapid environmental change. Specifically, the objectives are to: (i) characterize phenotypic optima along a fine-grained altitudinal gradient (ii) select discrete high and low-elevation populations (without history of gene flow) (iii) assess genomic selection and their functional attributes (iv) compare phenotypic and gene expression plasticity during reciprocal elevation transplantation.