بررسي ترسيب كربن پوشش درختي و خاك در دو پارك شهري كوهدشت

Study of Carbon sequestration in trees and soil in two urban parks of Kohdasht City

زﻣﯿﻨﻪ و ﻫﺪف: اﻓﺰاﯾﺶ دياﮐﺴﯿﺪﮐﺮﺑﻦ اﺗﻤﺴﻔﺮي در ﺳﺎلﻫﺎي اﺧﯿﺮ ﻣﻨﺠﺮ ﺑﻪ اﻓﺰاﯾﺶ ﮔﺮﻣﺎﯾﺶ ﺟﻬﺎﻧﯽ و ﺗﻐﯿﯿﺮات اﻗﻠﯿﻤﯽ ﺷﺪه اﺳﺖ. ﺗﺮﺳﯿﺐ ﮐﺮﺑﻦ در ﭘﻮﺷﺶ درﺧﺘﯽ، ﮔﯿﺎﻫﯽ و ﺧﺎكﻫﺎي ﺗﺤﺖ آن ﺳﺎدهﺗﺮﯾﻦ و از ﻟﺤﺎظ اﻗﺘﺼﺎدي ﻋﻤﻠﯽﺗﺮﯾﻦ راهﮐﺎر ﻣﻤﮑﻦ ﺟﻬﺖ ﮐﺎﻫﺶ ﮐﺮﺑﻦ اﺗﻤﺴﻔﺮي ﻣﺤﺴﻮب ﻣﯽﺷﻮد. ﻟﺬا اﯾﻦ ﭘﮋوﻫﺶ ﺑﻪ ﻣﻨﻈﻮر ارزﯾﺎﺑﯽ ﻣﯿﺰان ﺗﺮﺳﯿﺐ ﮐﺮﺑﻦ ﭘﻮﺷﺶ درﺧﺘﯽ و ﺧﺎك در دو ﭘﺎرك ﺷﻬﺮي ﮐﻮﻫﺪﺷﺖ ﭘﺎرك ﺷﻘﺎﯾﻖ و ﺷﻬﯿﺪ ﺑﻬﺸﺘﯽ( اﻧﺠﺎم ﺷﺪ. روش ﺑﺮرﺳﯽ: ﺟﻬﺖ دﺳﺖﯾﺎﺑﯽ ﺑﻪ ﻫﺪف ﻣﻮرد ﻧﻈﺮ، درﺧﺘﺎن ﻫﺮ دو ﭘﺎرك ﻣﻮرد آﻣﺎرﺑﺮداري ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﻫﻢﭼﻨﯿﻦ ﻧﻤﻮﻧﻪﻫﺎي ﺧﺎﮐﯽ در دو ﻋﻤﻖ 0 ﺗﺎ 15 و 15 ﺗﺎ 30 ﺳﺎﻧﺘﯽﻣﺘﺮي از داﺧﻞ ﭘﺎرك و زﻣﯿﻦ ﻋﺎري از ﭘﻮﺷﺶ ﮔﯿﺎﻫﯽ ﻣﺠﺎور ﭘﺎرك )ﺑﻪ ﻋﻨﻮان ﺷﺎﻫﺪ( ﺟﻤﻊآوري و ﺑﺮاي اﻧﺠﺎم آﻧﺎﻟﯿﺰﻫﺎي ﻣﺮﺑﻮﻃﻪ آﻣﺎده ﺷﺪﻧﺪ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪﮔﯿﺮي: ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﻣﻘﺪار ﺗﺮﺳﯿﺐ ﮐﺮﺑﻦ ﺧﺎك در اﻋﻤﺎق 0 ﺗﺎ 15 و 15 ﺗﺎ 30 ﺳﺎﻧﺘﯽﻣﺘﺮي در ﭘﺎرك ﺷﻘﺎﯾﻖ و ﻣﻨﻄﻘﻪ ﺷﺎﻫﺪ آن ﺑﻪ ﺗﺮﺗﯿﺐ 23/52 ،251/65 ،106/7 و 45/48 ﺗﻦ در ﻫﮑﺘﺎر از ﭘﺎرك ﺷﻬﯿﺪ ﺑﻬﺸﺘﯽ و ﻣﻨﻄﻘﻪ ﺷﺎﻫﺪ آن ﺑﻪ ﺗﺮﺗﯿﺐ 20/83 ،11/93، 32/05 و 53/13 ﺗﻦ در ﻫﮑﺘﺎر ﺑﻪ ﻃﻮر ﻣﻌﻨﯽداري )P< 0.01( ﺑﯿﺶﺗﺮ ﺑﻮد. ﺗﺮاﮐﻢ و ﺗﻨﻮع در آﻣﯿﺨﺘﮕﯽ ﭘﻮﺷﺶ درﺧﺘﯽ ﻧﯿﺰ ﺗﺎﺛﯿﺮ ﭼﺸﻢﮔﯿﺮي در ﻣﻘﺪار ﮐﺮﺑﻦ ﺗﺮﺳﯿﺐ داﺷﺘﻪ اﺳﺖ )ﭼﻨﺎر53/13، ﮐﺎج ﻣﺸﻬﺪ 31/32، ﮐﺎج ﺗﻬﺮان 32/05 و اﻗﺎﻗﯿﺎي ﺗﻮﭘﯽ 12/81 ﺗﻦ در ﻫﮑﺘﺎر(. ﺑﻪ ﻃﻮرﮐﻠﯽ، ﺗﺮﺳﯿﺐ ﮐﺮﺑﻦ ﭘﺎرك ﺷﻘﺎﯾﻖ از ﭘﺎرك ﺷﻬﯿﺪ ﺑﻬﺸﺘﯽ ﺑﯿﺶﺗﺮ ﺑﻮده و از ﺟﻤﻠﻪ دﻻﯾﻞ اﺻﻠﯽ آن ﻣﯽﺗﻮان ﺑﻪ ﺑﺎﻓﺖ ﺧﺎك )رﺳﯽ(، ﺗﺮاﮐﻢ و ﺗﻨﻮع ﺑﺎﻻي ﭘﻮﺷﺶ درﺧﺘﯽ و ﻫﻢﭼﻨﯿﻦ ﻧﺰدﯾﮑﯽ ﺑﻪ ﺟﺎده دﺳﺘﺮﺳﯽ آﺳﻔﺎﻟﺘﻪ اﺷﺎره ﮐﺮد.

Background and objectives: The increase in atmospheric carbon dioxide in recent years has led to increased global warming and climate change. Carbon sequestration in tree, vegetation and subsoil cover is the simplest and most economically viable way to reduce atmospheric carbon. Therefore, this study was conducted to evaluate the amount of carbon sequestration of tree cover and soil in two urban parks of Kuhdasht (Shaghayegh and Shahid Beheshti parks). Methods: In order to achieve the desired goal, the trees of both parks were surveyed. Also, soil samples were collected at two depths of 0 to 15 and 15 to 30 cm from inside the park and land free of vegetation adjacent to the park (as a control) and prepared for relevant analyzes. Discussion and Conclusion: The results showed that the amount of soil carbon sequestration at depths of 0 to 15 and 15 to 30 cm in Shaghayegh Park and its control area were 107.7, 251.65, 23.52 and 45.48 tons, respectively. In hectares of Shahid Beheshti Park and its control area, 11.93, 20.83, 32.05 and 53.13 tons per hectare were significantly higher (P <0.01), respectively. Density and variability in tree cover mixing also had a significant effect on the amount of sediment carbon (sycamore 53.13, Mashhad pine 31.32, Tehran pine 32.05 and ball acacia 12.81 tons per hectare). In general, the carbon sequestration of Shaghayegh Park is more than Shahid Beheshti Park, and among the main reasons are soil texture (clay), high density and variety of tree cover, as well as proximity to the asphalt access road.