Elevational shift of endangered European yew under climate change in Hyrcanian mountain forests: Rethinking conservation-restoration strategies and management

Abstract

Prioritizing new areas for conservation in the Hyrcanian mountain forests is important because future climate change is an immediate threat to endangered species in these areas. Taxus baccata L. (European yew) is one of the most important coniferous species of the Hyrcanian forests that is endangered today for various reasons; therefore, the conservation and restoration of this valuable species is essential. The present study was conducted in order to identify areas with high potential for restoration and conservation of yew with consideration of future climate change. Maximum Entropy (MaxEnt) was used to model the current and future distribution of yew in Hyrcanian forests of northern Iran. VIKOR fuzzy model applied to prioritize conservation and restoration areas. The results showed that MaxEnt model has high efficiency in modeling the distribution of yew with area under curve (AUC) = 0.98 in the study area. Importance analysis of explanatory variables showed that distance from rivers, geology, slope, precipitation of warmest quarter (bio18), and annual precipitation (bio12) were more important than other variables in the potential distribution of yew. The results showed that at current condition, suitable areas for yew in the Hyrcanian forests of Iran are distributed along an elevation gradient from sea level to 2600 m, and under the future climate change (2050 and 2070) this species will shift to higher elevations and lose the lower elevation habitats. The findings of this study predict that the desired habitats of yew in Hyrcanian forests will be severely affected by climate change. Given these cases, it is necessary to make management and conservation decisions in relation to this species, taking into account the effects of climate change and adaptation in the Hyrcanian forests.