ﻣﺤﻘﻘﺎن ﻣﺮﮐﺰ ﺗﺤﻘﯿﻘﺎت ﻣﺸﺘﺮك ﮐﻤﯿﺴﯿﻮن اروﭘﺎ (JRC) ﺑﺮاي ﺗﻌﯿﯿﻦ اﺛﺮات ﺗﻐﯿﯿﺮات اﻗﻠﯿﻤﯽ و ﭘﺪﯾﺪه ﻫﺎي آب و ﻫﻮاﯾﯽ ﺷﺪﯾﺪ ﺑﺮ روي ﻧﻮﺳﺎﻧﺎت ﻣﻨﻄﻘﻪ اي و ﺟﻬﺎﻧﯽ ﺗﻮﻟﯿﺪ ﮔﻨﺪم روﯾﮑﺮد ﺟﺪﯾﺪي را اراﺋﻪ ﮐﺮده اﻧﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ اﺛﺮ اﺧﺘﻼﻻت ﺣﺮارﺗﯽ و آﺑﯽ در ﮐﺎﻫﺶ ﻣﺤﺼﻮل در ﻃﯽ ﯾﮏ دوره 30 ﺳﺎﻟﻪ ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. اﯾﻦ ﻣﺤﻘﻘﺎن اﻫﻤﯿﺖ ﻧﺴﺒﯽ ﺗﻨﺶ ﮔﺮﻣﺎﯾﯽ و ﺧﺸﮑﺴﺎﻟﯽ را ﺑﺮ روي ﻋﻤﻠﮑﺮد ﮔﻨﺪم در ﻓﺎﺻﻠﻪ ﺳﺎل ﻫﺎي 1980 ﺗﺎ 2010 ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻗﺮار داده اﻧﺪ.آﻧﻬﺎ ﺑﺮاي ﺷﻨﺎﺧﺖ ﺑﻬﺘﺮ اﺛﺮات ﻫﻤﺰﻣﺎن اﺳﺘﺮس ﻫﺎي آب و ﮔﺮﻣﺎ، ﺷﺎﺧﺺ ﺗﺮﮐﯿﺒﯽ ﺟﺪﯾﺪي ﺑﺮاي ﺗﻨﺶ ﺗﻮﺳﻌﻪ داده اﻧﺪ. اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺼﻮرت ﻣﻘﺎﻟﻪ اي در ﺗﺤﺖ ﻋﻨﻮان ﺗﻌﯿﯿﻦ ﻣﯿﺰان ﮐﺎﻫﺶ ﻋﻤﻠﮑﺮد ﮔﻨﺪم در ﺑﺮاﺑﺮ ﻣﻮج ﻫﻮاي ﮔﺮم،ﺧﺸﮑﺴﺎﻟﯽ، آب زﯾﺎد در ﻣﻘﯿﺎس ﺟﻬﺎﻧﯽ، ﻣﻨﻄﻘﻪ اي و ﻓﺮاﻣﻠﯽ Environmental Research Letters ﻣﻨﺘﺸﺮ در ﻣﺠﻠﻪ ﺷﺪه اﺳﺖ. در اﯾﻦ ﻣﻘﺎﻟﻪ ﺗﻮﺿﯿﺢ داده ﺷﺪه اﺳﺖ ﮐﻪ ﻫﻤﺰﻣﺎﻧﯽ ﺗﻨﺶ ﮔﺮﻣﺎ ﺑﺎ ﺧﺸﮑﺴﺎﻟﯽ و اﻓﺰاﯾﺶ آب ﻣﯽ ﺗﻮاﻧﺪ ﻣﻨﺠﺮ ﺑﻪ ﺗﻐﯿﯿﺮات 40 درﺻﺪي در ﻋﻤﻠﮑﺮد ﮔﻨﺪم از ﺳﺎﻟﯽ ﺑﻪ ﺳﺎل دﯾﮕﺮ ﺷﻮد. ﯾﮑﯽ دﯾﮕﺮ از ﯾﺎﻓﺘﻪ اﯾﻦ ﺗﺤﻘﯿﻖ در ﻣﻘﺎﯾﺴﻪ ﺑﺎ ﭘﯿﺶ ﺑﯿﻨﯽ ﻫﺎي ﺳﺎﺑﻖ اﯾﻦ اﺳﺖ ﮐﻪ اﺛﺮات آب ﺑﯿﺶ از ﺣﺪ ﺑﺮ روي ﺗﻮﻟﯿﺪ ﮔﻨﺪم در ﺑﺴﯿﺎري از ﮐﺸﻮرﻫﺎ ﺑﯿﺸﺘﺮ از ﺧﺸﮑﺴﺎﻟﯽ اﺳﺖ. ﺑﺎرش ﻫﺎي ﺑﯿﺶ از ﺣﺪ و ﭘﻮﺷﺶ اﺑﺮ زﯾﺎد ﺑﻮﯾﮋه در ﻣﺮﺣﻠﻪ ﺣﺴﺎس رﺷﺪ ﮔﯿﺎه از ﻓﺎﮐﺘﻮرﻫﺎي ﻋﻤﺪه در ﮐﺎﻫﺶ ﻋﻤﻠﮑﺮد ﻫﺴﺘﻨﺪ زﯾﺮا اﯾﻦ ﺷﺮاﯾﻂ ﺑﻪ ﺗﮑﺜﯿﺮ آﻓﺎت و ﺑﯿﻤﺎري ﻫﺎ ﮐﻤﮏ ﮐﺮده و درﯾﺎﻓﺖ اﮐﺴﯿﮋن و ﻧﻮر ﻣﻮردﻧﯿﺎز ﮔﯿﺎه را ﻣﺸﮑﻞ ﻣﯽ ﺳﺎزﻧﺪ.
خبر:https://ec.europa.eu/jrc/en/news/extreme-weather-conditions-and-climate-change-account-40-global-wheat-production-variability
JRC scientists have proposed a new approach for identifying the impacts of climate change and extreme weather on the variability of global and regional wheat production. The study analysed the effect of heat and water anomalies on crop losses over a 30-year period. JRC scientists studied the relative importance of heat stress and drought on wheat yields between 1980 and 2010. They developed a new Combined Stress Index in order to better understand the effects of concurrent heat and water stress events. The study ‘Wheat yield loss attributable to heat waves, drought and water excess at the global, national and subnational scales’ was published in Environmental Research Letters earlier this month. It finds that heat stress concurrent with drought or water excess can explain about 40% of the changes in wheat yields from one year to another. One finding is that in contrast to the common perception, water excess affects wheat production more than drought in several countries. Excessive precipitation and greater cloud cover, especially during sensitive development stages of the crop, are major contributors to reduced yields, as they help pests and disease proliferate and make it harder for the plants to get the oxygen and light they need.
