Modelling the vulnerability of Taxus wallichiana to climate change scenarios in South East Asia

Abstract

Taxus wallichiana (Himalayan yew) has been subjected to over-exploitation for its anti-cancer ingredient Taxol. As a consequence, the species has already become endangered, facing enhanced threats of regional extinction. To compound this, the species shows high vulnerability to climate change impacts that may significantly reduce its present climatic niche. In spite of the ecological and enormous commercial importance of the species, the direct or indirect impacts of climate change on the species are not yet well-researched and well-documented. To develop sustainable adaptation pathways to conserve the surviving populations of the species, it is important to have precise assessments of the future distribution ranges of the species. The present study models the potential current and future distribution ranges of Taxus wallichiana based on its suitable climatic envelop developed under a baseline scenario (1960–1990) and climate change scenarios centred on representative concentration pathways (RCPs) for the year 2070, as provided in the Fifth Assessment Report (AR5) of the UNO’s Intergovernmental Panel on Climate Change (IPCC). The projected shrink in climatic niche of Taxus wallichiana by 28% (RCP 4.5) and 31% (RCP 8.5) highlights the vulnerability of the endangered species to climate change impacts and the perturbations on the structure of mountain ecosystem. It raises an alarm for immediate conservation of geographic areas that can provide potential refuge to the species under the adverse climate change impacts.