تحليل و پيش‌بيني اقليم استان گيلان با استفاده از سري زماني گاهشناسي درختي در مخاطرات توليد بذر گياهان

Climate forecast in Guilan province using tree chronology and time series analysis at risks of plant seed production

آﮔﺎﻫﯽ از ﭼﮕﻮﻧﮕﯽ روﻧﺪ ﺗﻐﯿﯿﺮ اﻗﻠﯿﻢ، ﮔﺮﻣﺎﯾﺶ ﺟﻬﺎن و ﭘﯿﺶﺑﯿﻨﯽ اﯾﻦ ﺗﻐﯿﯿﺮات در ﻣﻘﯿﺎسﻫﺎي ﻣﺨﺘﻠﻒ، از ﻣﺴﺎﺋﻞ ﺑﺴﯿﺎر ﻣﻬﻤﯽ اﺳﺖ ﮐﻪ ﻣﻮرد ﺗﻮﺟﻪ داﻧﺸﻤﻨﺪان ﺣﻮزهﻫﺎي ﻣﺨﺘﻠﻒ ﻋﻠﻮم ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. اﺳﺘﺎن ﮔﯿﻼن ﺑﺎ ﺷﺮاﯾﻂ اﻗﻠﯿﻤﯽ و ﺣﺎﺻﻠﺨﯿﺰي ﺧﻮب اراﺿﯽ از ﺗﻮﻟﯿﺪﮐﻨﻨﺪهﻫﺎي ﻣﻬﻢ ﻣﺤﺼﻮﻻت ﮐﺸﺎورزي اﺳﺖ. اﻗﻠﯿﻢﺷﻨﺎﺳﯽ درﺧﺘﯽ ﻣﯽﺗﻮاﻧﺪ وﻗﺎﯾﻊ و روﯾﺪادﻫﺎي ﮔﺬﺷﺘﻪ آب ﻫﻮاﯾﯽ را ﻧﺸﺎن دﻫﺪ. اﻧﺪازه ﻗﻄﺮي ﺣﻠﻘﻪﻫﺎي رﺷﺪ ﺳﺎﻻﻧﻪ درﺧﺘﺎن ﺳﺮي زﻣﺎﻧﯽ را ﺗﺸﮑﯿﻞ ﻣﯽدﻫﻨﺪ. ﺳﺮي زﻣﺎﻧﯽ 202 )1396- 1195( ﺳﺎﻟﻪ از ﮔﺎﻫﺸﻨﺎﺳﯽ درﺧﺘﺎن راش ﺗﻬﯿﻪ ﺷﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ از ﺳﺮيﻫﺎي زﻣﺎﻧﯽ و ﺑﻬﺮهﮔﯿﺮي از ﻣﺪلﺳﺎزي ﺑﻪ روش ﺑﺎﮐﺲ ﺟﻨﮑﯿﻨﺰ ﺑﺎ ﺗﺎﮐﯿﺪ ﺑﺮ ﻣﺪلﻫﺎي ARIMA اﺳﺘﻔﺎده ﮔﺮدﯾﺪ. ﺑﺮاي اﻧﺘﺨﺎب ﺑﻬﺘﺮﯾﻦ ﻣﺪل ﭘﯿﺶﺑﯿﻨﯽ از ﻣﻌﯿﺎر آزﻣﻮن ﺧﻄﺎي ﺑﺎﻗﯿﻤﺎﻧﺪه اﺳﺘﻔﺎده ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ، ﺳﺮي زﻣﺎﻧﯽ ﺑﺎ ﻣﺪل 1,1,1( ARIMA ﺑﻬﺘﺮﯾﻦ ﺑﺮازش را داﺷﺘﻪ و ﺑﻪﻋﻨﻮان ﻣﺪﻟﯽ ﻣﻨﺎﺳﺐ ﺑﺮاي ﭘﯿﺶﺑﯿﻨﯽ ﺗﻌﯿﯿﻦ و ﺑﺮاي ﭘﯿﺶﺑﯿﻨﯽ 10 ﺳﺎل آﯾﻨﺪه اﺳﺘﻔﺎده ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎندﻫﻨﺪه ﮐﺎﻫﺶ روﻧﺪ رﺷﺪ ﺣﻠﻘﻪﻫﺎي ﺳﺎﻻﻧﻪ ﺑﺮاي 10 ﺳﺎل آﯾﻨﺪه ﻣﯽﺑﺎﺷﺪ. ﻋﻨﺼﺮ اﻗﻠﯿﻤﯽ ﺑﺎرش ﺳﺎﻻﻧﻪ در اﯾﺴﺘﮕﺎه ﻣﻨﻄﻘﻪ ﻣﻄﺎﻟﻌﺎﺗﯽ و اﯾﺴﺘﮕﺎهﻫﺎي ﻫﻤﺠﻮار داراي روﻧﺪي ﮐﺎﻫﺸﯽ و ﻣﻨﻔﯽ، ﻣﯿﺎﻧﮕﯿﻦ دﻣﺎﻫﺎي ﮐﻤﯿﻨﻪ، ﻣﺘﻮﺳﻂ و ﺑﯿﺸﯿﻨﻪ اﻓﺰاﯾﺸﯽ و ﺑﺮاي ﻓﺼﻞ روﯾﺶ ﮔﯿﺎﻫﺎن ﻣﻌﻨﯽدار ﺑﻮدﻧﺪ. ﺗﻐﯿﯿﺮات در ﻋﻮاﻣﻞ اﻗﻠﯿﻤﯽ ﻣﯽﺗﻮاﻧﺪ ﻋﻠﺖ ﮐﺎﻫﺶ رﺷﺪ دواﯾﺮ ﺑﺎﺷﺪ و در ﺻﻮرت ﺗﺪاوم ﺗﻬﺪﯾﺪي ﺑﺮاي ﺟﻨﮕﻞﻫﺎي ﻫﯿﺮﮐﺎﻧﯽ ﺑﻮده و ﻫﻤﭽﻨﯿﻦ ﻣﯽﺗﻮاﻧﻨﺪ ﻣﺤﺼﻮﻻت ﺑﺎﻏﯽ زراﻋﯽ اﺳﺘﺎن و اﻣﻨﯿﺖ ﻏﺬاﯾﯽ را ﻧﯿﺰ ﺗﺤﺖاﻟﺸﻌﺎع ﻗﺮار داده و ﮔﻮاﻫﯽ ﺑﺮ ﺑﺮوز ﺗﻐﯿﯿﺮ اﻗﻠﯿﻢ در اﺳﺘﺎن ﮔﯿﻼن ﺑﺎﺷﺪ.

Global warming and climate change are very important issues of the last century, which have been considered by scientists in various fields of science. The Hyrcanian forest is one of the oldest and most historic habitats of the world's deciduous trees. Beech trees are one of the valuable industrial species with a lifespan of 200 to 300 years. The science of tree chronology can show past weather events. The diameter of the annual growth rings of the trees forms a time series. With this method, a time series of 202 (1816-2017) years was obtained from the diameter of the growth rings of beech trees.Researchers are always thinking about the future. This study uses time series of growth rings of forest beech trees and analyzes it.And the use of modeling based on the Box-Jenkins method with emphasis on ARIMA models were examined. The results showed, Time series with ARIMA model (1,1,1) had the best fit, at the 95% level, it is significant and the trend forecast has a negative and decreasing slope. Climatic factor of annual precipitation in the regional station and neighboring stations with a decreasing and negative trend The average minimum, middle and maximum average temperatures are increasing. Climate change is reducing growth for Hyrcanian forest trees. It was registered as the second natural heritage of Iran in UNESCO. It will pose a threat to plant and animal communities.