Climate change alters future distribution of mountain plants, a case study of Astragalus adscendens in Iran.

Climate is one of the most important elements affecting the distribution of species, and it is expected that the distribution of species will be widely influenced by climate change. In plants, edaphic factors also play a special role along with climate in determining the distribution range. The current study aimed to predict the future distribution of the Persian manna (Astragalus adscendens), an endemic perennial shrub in Zagros Mountains of Western Iran. For this purpose, two sets of static (i.e. edaphic and physiographic) and dynamic (i.e. climatic) data and an ensemble approach were used to develop two edaphic-physiographic and climatic models. Current and future suitability maps are representative of the climatic and the edaphic-physiographic niches of A. Adscendens that were obtained based on climatic suitable areas filtered by edaphic-physiographic model. The filtered map has less suitable habitats compared to the climatic model. Three dynamic variables (mean temperature of wettest quarter, temperature seasonality, temperature annual range) and two static variables (altitude and volumetric fraction of coarse fragments) were identified as the most important factors in determining the habitat of A. Adscendens. The importance of altitude was greater than latitude in maintaining or losing suitable habitats under different climate change scenarios, suggesting that the species will not have range expansion or northward shift due to no significant shift in latitude and longitude. Results revealed a sharp decline in the suitable habitats in such that 67% and 91% of the current habitat may be lost by the year 2050 and 2070, respectively. Area reduction was more extreme in future scenarios with the higher level of CO₂ emission. Range contraction of A. Adscendens will increases the risk of extinction. This study provides insights into the response of mountain plants, especially range restricted species, to climate change, revealing major dimensions of plant niche. Therefore, developing habitat management and conservation plans to preserve the predicted habitats of such species are required to preserve the predicted sustainable habitats. [ABSTRACT FROM AUTHOR]