The effect of climate change on almond phenology in Chaharmahal and Bakhtiari province

The purpose of this study is analyzing the climate changing effects on almond phenology in  a region with severe temperature fluctuation in Chaharahal and Bakhtiari  province. For this purpose in this study, small-scale model SDSM and large-scale data of atmospheric general circulation canESM2 were used. Daily minimum, maximum temperature data, and precipitation in the statistical period of 30 years (1985-2015) for 4 stations were used as a basic data. And with using the SDSM model and general circulation under 2 scenario RCP4.5 and 8.5 from 2020-2050 compared with current amounts and its changes was evaluated. The results showed that the height factor had an important role in changing climatic elements and consequently temporal changes of almond phonological stages in the study region. Analyzing the reviewed scenarios showed that by affecting the climate changing, almond cultural calendar change and dates of crop phonological stages will happen sooner. Also the growth period will decrease; due to warming up of the region and early completion degree of required growth days. Special pattern of phonological stages changing showed that in both scenarios changes rates are more in the southern parts of the province and amounts changes decrease to the north. As regards in the forecasting period, the flowering stage occurs sooner and it coincides with the late spring frost of an almond tree. And because this stage is sensitive to cold, care proceedings should be increased. The results showed that in the regions where phonological stages occur sooner, the Impressionability of almond cultivation phonological stages is more than climate changing. In the province’s southern regions the phonological stages occur sooner than other parts. And these regions have a greater impact from climate change.