اثرات پيش بيني شده احتمالي تغيير اقليم بر اكوسيستم هاي ساحلي مانگرو خليج فارس با تاكيد بر متغييرهاي دما و بارش

Potential Expected Climate Change Impact on Persian Gulf Coastal Mangrove Ecosystems Based on Temperature and Precipitation Variables

زﻣﯿﻨﻪ و ﻫﺪف : ﺗﻐﯿﯿﺮ اﻗﻠﯿﻢ و ﮔﺮﻣﺎﯾﺶ ﺟﻬﺎﻧﯽ ﯾﮑﯽ از ﮔﺴﺘﺮدهﺗﺮﯾﻦ و ﻣﻬﻢ ﺗﺮﯾﻦ ﻣﺨﺎﻃﺮات زﯾﺴﺖ ﻣﺤﯿﻄﯽ اﺳﺖ. ﻫﺪف اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮرﺳﯽ روﻧﺪ دﻣﺎي ﺣﺪاﻗﻞ، ﺣﺪاﮐﺜﺮ و ﺑﺎرﻧﺪﮔﯽ در دوره ﮔﺬﺷﺘﻪ ﺑﻮﺷﻬﺮ ﺑﻪ ﻋﻨﻮان اﺳﺘﺎن ﺳﺎﺣﻠﯽ ﺧﻠﯿﺞ ﻓﺎرس و ﭘﯿﺶﺑﯿﻨﯽ آﯾﻨﺪه اﻗﻠﯿﻤﯽ آن ﺗﺎ اﻧﺘﻬﺎي ﺳﺎل 2100 ﻣﯿﻼدي و ﻫﻤﭽﻨﯿﻦ اﺛﺮات اﺣﺘﻤﺎﻟﯽ ﭘﯿﺶﺑﯿﻨﯽ ﺷﺪه ﺑﺮ اﮐﻮﺳﯿﺴﺘﻢ ﻫﺎي ﺟﻨﮕﻠﯽ ﻣﺎﻧﮕﺮو ﺧﻠﯿﺞ ﻓﺎرس ﻣﯽ ﺑﺎﺷﺪ. روش ﺑﺮرﺳﯽ: در اﯾﻦ ﻣﻄﺎﻟﻌﻪ از روش رﯾﺰﻣﻘﯿﺎس رﮔﺮﺳﯿﻮﻧﯽ SDSM3 و از ﻣﺪل GCM4 ﮐﺎﻧﺎداﯾﯽ CanESM2 در ﺳﻪ ﺳﻨﺎرﯾﻮ RCP4.5 ،RCP2.6 و RCP8.5 و ﻣﺪل HadCM3 در ﺳﻨﺎرﯾﻮ A2 ﺑﺮاي ﺷﺒﯿﻪﺳﺎزي دادهﻫﺎي اﻗﻠﯿﻤﯽ اﯾﺴﺘﮕﺎه ﺳﯿﻨﻮﭘﺘﯿﮏ ﺑﻮﺷﻬﺮ در دورهﻫﺎي ﭘﺎﯾﻪ، ﻣﺸﺎﻫﺪاﺗﯽ و آﺗﯽ )2010-2100( اﺳﺘﻔﺎده ﺷﺪ. ﻫﻤﭽﻨﯿﻦ اﻋﺘﺒﺎرﺳﻨﺠﯽ ﻣﺪل ﺑﺎ ﭘﻨﺞ ﺷﺎﺧﺺ آﻣﺎري و ﻋﺪم ﻗﻄﻌﯿﺖ ﻣﺪل ﺑﺎ روش ﺑﻮت اﺳﺘﺮپ ﻣﺤﺎﺳﺒﻪ ﺷﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﻣﯿﺰان اﻓﺰاﯾﺶ دﻣﺎي ﻣﯿﺎﻧﮕﯿﻦ ﻓﺼﻞ زﻣﺴﺘﺎن و ﺗﺎﺑﺴﺘﺎن در ﻃﻮل دوره 47 ﺳﺎﻟﻪ ﺑﻪ ﺗﺮﺗﯿﺐ 1/8 و 1/7 درﺟﻪ ﺳﺎﻧﺘﯽﮔﺮاد ﺑﻮده اﺳﺖ. ﭘﯿﺶﺑﯿﻨﯽ آﯾﻨﺪه اﻗﻠﯿﻤﯽ دﻣﺎي ﺑﯿﺸﯿﻨﻪ و ﮐﻤﯿﻨﻪ در ﻣﺪل CanESM25 و HadCM36 ﺑﯿﺶ ﺗﺮﯾﻦ اﻓﺰاﯾﺶ را در ﻣﺎهﻫﺎي ﺳﺮد ﺳﺎل ﻧﺸﺎن دادﻧﺪ. ﻫﻤﭽﻨﯿﻦ دﻣﺎي ﭘﯿﺶﺑﯿﻨﯽ ﺷﺪه ﻣﺪل CanESM2 در ﻣﺎه ﻫﺎي ﮔﺮم از دﻣﺎي ﮐﻨﻮﻧﯽ ﮐﻢﺗﺮ ﺧﻮاﻫﺪ ﺑﻮد. ﺷﺒﯿﻪﺳﺎزي ﻣﺘﻐﯿﯿﺮ اﻗﻠﯿﻤﯽ ﺑﺎرش در ﻣﺪل HadCM3 اﻓﺰاﯾﺶ ﺑﺎرش را در ﻓﺼﻞ ﺗﺎﺑﺴﺘﺎن و ﭘﺎﯾﯿﺰ و ﻣﺪل CanESM2 اﻓﺰاﯾﺶ ﺑﺎرش را ﺑﺮاي ﻫﻤﻪ ﻓﺼﻮل ﺳﺎل ﻧﺸﺎن دادﻧﺪ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪ ﮔﯿﺮي : ﻫﺮ دو ﻣﺪل زﻣﺴﺘﺎنﻫﺎي ﮔﺮمﺗﺮي را در دﻫﻪﻫﺎي آﺗﯽ ﺑﺮاي اﺳﺘﺎن ﺑﻮﺷﻬﺮ ﭘﯿﺶﺑﯿﻨﯽ ﮐﺮدﻧﺪ. ﺑﺎ ﭘﯿﺶﺑﯿﻨﯽ ﻃﻮﻻﻧﯽ ﺷﺪن ﻓﺼﻞ ﮔﺮم در ﻣﺪل CanESM2 ﻣﻤﮑﻦ اﺳﺖ زﻣﺎن ﺟﻮاﻧﻪزﻧﯽ و ﮔﻞدﻫﯽ ﻣﺎﻧﮕﺮوﻫﺎ ﻃﻮﻻﻧﯽﺗﺮ و از ﺳﻪ ﻣﺎه ﺑﻪ ﺷﺶ ﻣﺎه ﺗﻐﯿﯿﺮ ﯾﺎﺑﺪ. در ﺻﻮرﺗﯽ ﮐﻪ اﻓﺰاﯾﺶ ﺑﺎرش ﻫﺎي ﭘﯿﺶﺑﯿﻨﯽ ﺷﺪه ﺑﻪ ﺻﻮرت رﯾﺰشﻫﺎي ﺣﺪي ﻧﺒﺎﺷﻨﺪ ﻣﯽﺗﻮاﻧﻨﺪ ﻫﻤﺮاه ﺑﺎ اﻓﺰاﯾﺶ دﻣﺎ ﺑﺎﻋﺚ رﺷﺪ و ﺗﻮﺳﻌﻪ ﺑﯿﺶ ﺗﺮ ﻣﺎﻧﮕﺮوﻫﺎ ﺷﻮﻧﺪ.

Background and Objective: Climate change and global warming are one of the most widespread and important environmental hazards. The purpose of this study is to investigate the trend of minimum, maximum and rainfall temperatures in the past period of Bushehr as a coastal province of the Persian Gulf and predict its climatic future by the end of 2100 AD, as well as the possible effects on the mangrove forest ecosystems of the Persian Gulf. Method: In this research, the statistical down scaling model (SDSM) along with two different GCMs entitle CanESM2 in three RCP2.6, RCP4.5 RCP8.5 scenarios and HadCM3 in A2 scenario, were used to simulate climatic variables during base (1961-2005), current and future (2010–2099) periods in Bushehr synoptic station. Furthermore, model evaluation and uncertainty assessment performed by five different statistical criteria and a non-parametric bootstrapping technique, respectively. Findings: The linear regression of the observed winter and summer mean temperature showed that mean temperature has increased +1.8 and +1.7°C over the past 47 years, respectively. Both, CanESM2 and HadCM3 model simulation results demonstrated that the most raise of minimum and maximum temperatures will occur in the future cold seasons. But, CanESM2 simulation analysis revealed that a decrease trend will occur in the minimum and maximum temperatures through future warm months. Also, HadCM3 simulation results showed that precipitation will rise in summer and fall seasons, while CanESM2 results presented an increase in rainfall variable throughout the year. Discussion and Conclusion: Both of models have predicted warmer winter in the next several decades. Based on CanESM2 model results that we will have longer warmer seasons, there is a possibility of prolonging reproduction (germination and flowering) season in Persian Gulf mangroves from 3 to 6 months. Based on our results, future rainfall is more likely to become more frequent and intense. If those precipitations do not occur in extreme events, accompany with high temperature can cause more mangrove expansion and growth in future decades.