Assessment of the effects of climate change on the future range of Stipa barbata species in the southern Alborz region

Detection of climate parameters indicates that climate change has begun in Iran and it is necessary to identify the potential habitat of the indicator species, present and future years, under climate warning models. In this regard, it should be examined whether the increase in incident temperature in the country, will have a positive effect on the presence of species in the habitats of the distribution site, or a negative effect? For this purpose, the current and future range of Stipa barbata species for the next three decades (year-2050) was predicted under two climate warning models (scenario RCP4.5 and RCP8.5) using the logistic regression model. Output maps, with probability of occurrence between zero and one, to four categories unsuitable habitat (0-0.25), almost suitable habitat (0.25-0.5), habitat with high suitability (0.5-0.75) and habitat with very high suitability (0.75-1), were grouped. Finally, based on the coefficients of the variables in regression relationships, effective variables for the current and future range of S. barbata species were introduced. Based on the results; only temperature-related indices (BIO7 and BIO10) were found to be effective on the distribution of S. barbata species, present and future. The values of the indices increase with increasing climatic conditions. As a result, the range of S. barbata species decreases in response to climate change. This indicates during the next three decades, the presence of S. barbata species will decrease in the habitats of the region and there is a risk of its removal from the ecosystems of the region. In total, climate change and consequently increase in temperature characteristics causing the vertical spresd of S. barbata species, and it will move towards higher latitudes along the altitude gradient of the region.