Detection of climate change based on cold temperature indices in the forest ecosystem ‎of Central Zagros

One of the assumptions raised about the phenomenon of forest decline is the change of climatic indicators. In this study, in order to detect the occurrence of climate change in the ecosystem of Zagros forests of Chaharmahal and Bakhtiari province, cold temperature indicators indicating climate change have been used. Daily climatic data including precipitation, maximum temperature and minimum temperature for the statistical period 1991-2019 were extracted at the nearest synoptic stations to the Chego, Ghalesama, Rahimaabad, and Gelsefid deterioration monitoring sites. Before calculating the indicators, daily input data were examined for quality and homogeneity and prepared in the desired format to enter ClimPACT software. Among the global standard indicators detecting the occurrence of climate change, cold temperature indicators; Two days and two nights consecutive cold, number of frosty days, number of icy days, percentage of cold nights frequency, percentage of cold days frequency, two-day cold period and 6-day cold period were extracted and analyzed. The results showed that all cold indicators of climate change had a significant and decreasing trend and experienced the largest decrease in the last decade, especially in 2017 and 2018. The percentage of decrease in cold night temperature indices is more than daily cold temperature indices. Some indicators in all deterioration monitoring sites, especially in the last decade, have been severely reduced to some extent and will probably be unrepeatable in the future due to the continued increase in temperature. Awareness and recognition of climate change in the Zagros Forest ecosystem based on standard indicators can help manage forest conservation and restoration through climate change adaptation methods.