مروري بر تاثيرات تغييرات اقليم بر بوم‌سازگان‌هاي مانگرو

A Review of the Impacts of Climate Change on Mangrove Ecosystems

ﺗﻐﻴﻴﺮات اﻗﻠﻴﻤﻲ و اﺟﺰا ﻣﺨﺘﻠﻒ آن ﻣﺎﻧﻨﺪ اﻓﺰاﻳﺶ ﺳﻄﺢ آب درﻳﺎﻫﺎ، اﻓﺰاﻳﺶ دﻣﺎ، ﺗﻐﻴﻴﺮات ﻏﻠﻈﺖ دي اﻛﺴﻴﺪﻛﺮﺑﻦ ﺟﻮ، ﺗﻐﻴﻴﺮ اﻟﮕﻮﻫﺎي ﭼﺮﺧﻪ ﻫﺎي اﻗﻴﺎﻧﻮﺳﻲ، ﺗﻐﻴﻴﺮات روﻧﺪ ﺑﺎرﻧﺪﮔﻲﻫﺎ و وﻗﻮع ﻃﻮﻓﺎن ﻫﺎ، ﺑﺮ ﺳﻼﻣﺖ ﺑﻮم ﺳﺎزﮔﺎن ﻣﺎﻧﮕﺮوﻫﺎ ﺗﺎﺛﻴﺮ ﻣﻲ ﮔﺬارﻧﺪ اﻳﻦ ﺗﻬﺪﻳﺪات ﻫﻤﭽﻨﻴﻦ ﺷﺎﻣﻞ ﻓﺮﺳﺎﻳﺶ، ﺟﺎري ﺷﺪن ﺳﻴﻞ، اﻣﻮاج ﺳﻬﻤﮕﻴﻦ و در ﺑﺮﺧﻲ ﻣﻨﺎﻃﻖ ﺳﻮﻧﺎﻣﻲ اﺳﺖ. از ﺑﻴﻦ ﺗﻤﺎم اﻳﻦ ﻋﻮاﻣﻞ، اﻓﺰاﻳﺶ ﻧﺴﺒﻲ ﺳﻄﺢ آب درﻳﺎ ﺑﺰرﮔﺘﺮﻳﻦ ﺗﻬﺪﻳﺪ ﺑﺮاي ﺑﻮم ﺳﺎزﮔﺎن ﻣﺎﻧﮕﺮو ﺑﻪ ﺷﻤﺎر ﻣﻲ آﻳﻨﺪ. اﮔﺮﭼﻪ ﺗﺎ ﺑﻪ اﻣﺮوز اﺛﺮات اﻳﻦ ﺗﻬﺪﻳﺪ ﻧﺴﺒﺖ ﺑﻪ ﺗﺎﺛﻴﺮات ﻧﺎﺷﻲ از دﺧﺎﻟﺖ اﻧﺴﺎن ﻣﺎﻧﻨﺪ آﻟﻮدﮔﻲ و ﺗﺨﺮﻳﺐ ﺟﻨﮕﻞﻫﺎ ﻧﺎﭼﻴﺰ اﺳﺖ. ارزش اﻗﺘﺼﺎدي ﺳﺎﻻﻧﻪ ﻣﺎﻧﮕﺮوﻫﺎ ﺑﺮ اﺳﺎس ارزش ﻣﺤﺼﻮﻻت و ﺧﺪﻣﺎﺗﻲ ﻛﻪ اراﺋﻪ ﻣﻲ دﻫﻨﺪ، ﺑﻴﻦ 200 ﻫﺰار ﺗﺎ 900 ﻫﺰار دﻻر در ﻫﺮ ﻫﻜﺘﺎر ﺗﺨﻤﻴﻦ زده ﺷﺪه اﺳﺖ ﻣﺎﻧﮕﺮوﻫﺎ داراي ﻋﻤﻠﻜﺮدﻫﺎي ﻣﻨﺤﺼﺮﺑﻪ ﻓﺮدي ﻫﺴﺘﻨﺪ ﻛﻪ ﻛﺎﻫﺶ ﺳﻄﺢ ﭘﻮﺷﺶ آن ﻫﺎ و ﻳﺎ اﺧﺘﻼل در ﺳﻼﻣﺖ آن ﻫﺎ ﺗﻬﺪﻳﺪ ﺑﺰرﮔﻲ ﺑﺮاي ﺑﻮمﺳﺎزﮔﺎن ﻫﺎي ﺳﺎﺣﻠﻲ ﺑﻪ ﺷﻤﺎر ﻣﻲآﻳﺪ. از ﺑﻴﻦ رﻓﺘﻦ ﻣﺎﻧﮕﺮوﻫﺎ ﻣﻮﺟﺐ ﻛﺎﻫﺶ ﻛﻴﻔﻴﺖ آب، ﻛﺎﻫﺶ ﺗﻨﻮع زﻳﺴﺘﻲ، از ﺑﻴﻦ رﻓﺘﻦ ﻣﻜﺎنﻫﺎي ﺗﺨﻢ رﻳﺰي و ﻧﻮزادﮔﺎﻫﻲ آﺑﺰﻳﺎن و ﺣﺬف ﻣﺤﺼﻮﻻت و ﺧﺪﻣﺎﺗﻲ ﻣﻲﺷﻮد ﻛﻪ ﺑﻪ اﻧﺴﺎن اراﺋﻪ ﻣﻲ دﻫﻨﺪ. ﺗﺨﺮﻳﺐ ﺟﻨﮕﻞ ﻫﺎي ﻣﺎﻧﮕﺮو ﻫﻤﭽﻨﻴﻦ ﻣﻲ ﺗﻮاﻧﺪ ﻣﻘﺎدﻳﺮ زﻳﺎدي ﻛﺮﺑﻦ ذﺧﻴﺮه ﺷﺪه در رﺳﻮﺑﺎت آﻧﻬﺎ را آزاد ﻛﻨﺪ و در ﻧﺘﻴﺠﻪ ﺑﺎ اﻓﺰاﻳﺶ دي اﻛﺴﻴﺪ ﻛﺮﺑﻦ ﺟﻮ ﮔﺮﻣﺎﻳﺶ ﺟﻬﺎﻧﻲ و ﺳﺎﻳﺮ روﻧﺪﻫﺎي ﺗﻐﻴﻴﺮات اﻗﻠﻴﻤﻲ را ﺗﺸﺪﻳﺪ ﻛﻨﺪ.

Climate change components such as sea-level rise, high water events, changes in precipitation regime, temperature fluctuation and altered ocean circulation patterns, affect the health andfunctionally of mangrove ecosystems. Among these disturbances, the sea-level rise has been found to be the most significant threat to mangrove ecosystems. To date, the sea level rise represents the smaller threat than anthropogenic activities such as conversion for aquaculture and deforestation. The estimated annual economic value of mangrove forests is in the range of $200–$900 per hectare. The disappearance of mangroves could have devastating effects on ecosystems and impair the services that they provide. Consequently, the water quality decreases, breeding and nursery ground of fishes are destroyed and species diversity decline under land use changes. Mangrove destruction can also release large quantities of stored carbon in sediments and exacerbate global warming and other climate change trends.