Published online by Cambridge University Press: 26 April 2019
The Hindu Kush Himalayan (HKH) region harbours some of the richest and most diverse ecosystems on the planet that are now facing substantial threats through changes in climate, land use and human population growth, with serious consequences for the biodiversity in this mountainous region. In this paper we evaluated the effects of climate change on the distribution of the tripartite epiphytic macrolichen Lobaria pindarensis, considered to be endemic to the Himalayas. To predict the current and future distribution of this species we applied the Random Forest modelling algorithm and climatic variables with a post-processing of projected distributions using a map of habitat types in the study region. We calibrated models based on 1397 species presences within an altitudinal range of 2036–4000 m and extrapolated them according to two IPCC scenarios of climate change (RCP 2·6 and RCP 8·5). Based on the results of ensemble modelling, two new localities where L. pindarensis might potentially occur were predicted. Our simulations predicted a range expansion of this epiphytic lichen to the north-east and to higher altitudes in response to climate change, although the species’ low dispersal abilities and the local availability of trees as a substratum will considerably limit latitudinal and altitudinal shifts. By contrast, assuming the species can migrate to previously unoccupied areas, and depending on different future climate scenarios, our models forecasted a habitat loss of 30–70% for L. pindarensis. The main reason for the simulated habitat loss is the expected increase in mean annual temperature (by 1·5–3·7 °C) and total annual precipitation (by 56–125 mm). Our results contribute further evidence for the high sensitivity of tripartite macrolichens, especially those from mountain areas, to climate change and particularly emphasize the vulnerability of L. pindarensis. Thus, we stress the need to develop and formulate conservation measures and strategies for the protection of this endemic species in the Hindu Kush Himalayan region.