Potential effects of climate change on the geographic distribution of the Hordeum bulbosum L. in the central Zagros region

Climate change affects many plants and animals by changing the growing season or temperature patterns that stimulate life cycle changes. Hordeum bulbosum is widely distributed in the Zagros region, especially under the storey of western oak forests in the vegetation zone of the Irano-Turanian region, and is considered as an important species for rangeland restoration and improvement. In this study, the effect of climate change on the geographical distribution of this species was assessed in Chaharmahal and Bakhtiari Province, located in central Zagros region. For this purpose, 73 points of presence were recorded using the global positioning system (GPS). In addition,11 environmental variables including bioclimatic, physiographic and landuse variables were used in the modeling process. Ensemble modeling include artificial neural network model, generalized boosting method, generalized linear model, flexible discriminant analysis, random forest and multivariate adaptive regression. Finally, the most reliable model was determined as the random forest model. The final forecast for 2070 is based on three scenarios of increasing greenhouse gases (SSP126, SSP370, and SSP585) as well as two general circulation models 9GFDL-ESM4 and MRI-ESM2-0). Findings showed that 25% of the study area is currently identified as suitable habitat for Hordeum bulbosum, and the most effective variables in species distribution are the Annual precipitation, mean temperature of the wettest quarter, and Total rainfall is the hottest season of the year. It is also predicted that based on GFDL-ESM4 and MRI-ESM2-0 models, 27.32% (SSP370) - 31.02% (SSP585) and 26.06% (SSP370)-31.68% (SSP585) of the suitable habitats will be reduced, respectively, by 2070 due to climate change. The present and future habitat maps prepared in this study can be used for the development and implementation of the given species’ management and conservation plans.