ساﺧﺘﺎر ﺗﻮدهﻫﺎي ﻣﺒﺘﻼ ﺑﻪ ﺑﯿﻤﺎري زﻏﺎﻟﯽ ﺑﻠﻮط در ﺟﻨﮕﻞﻫﺎي داﻻب اﯾﻼم

Stands structure under oak charcoal disease in Dalab forests of Ilam, Iran

ﭼﮑﯿﺪه در دو دﻫﻪ اﺧﯿﺮ ﮔﺴﺘﺮه ﻗﺎﺑﻞ ﺗﻮﺟﻬﯽ از ﺟﻨﮕﻞﻫﺎي زاﮔﺮس ﺑﻪ وﯾﮋه در اﺳﺘﺎن اﯾﻼم ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﺑﯿﻤﺎري زﻏﺎﻟﯽ ﺑﻠﻮط ﻗﺮار ﮔﺮﻓﺘﻪ ﮐﻪ ﻣﻨﺠﺮ ﺑﻪ ﺧﺸﮏﺷﺪن ﺳﻄﺢ وﺳﯿﻌﯽ از ﺗﻮدهﻫﺎي ﺑﻠﻮط اﯾﺮاﻧﯽ ﺷﺪه اﺳﺖ. ﻫﺪف اﯾﻦ ﭘﮋوﻫﺶ ﺷﻨﺎﺳﺎﯾﯽ وﺿﻌﯿﺖ ﺳﺎﺧﺘﺎري ﺗﻮدهﻫﺎي ﻣﺒﺘﻼ ﺑﻪ اﯾﻦ ﺑﯿﻤﺎري و ارﺗﺒﺎط ﺑﯿﻦ وﯾﮋﮔﯽﻫﺎي ﺳﺎﺧﺘﺎري ﺟﻨﮕﻞ و ﻣﺸﺨﺼﻪﻫﺎي درﺧﺖ ﺑﺎ ﻣﯿﺰان آﻟﻮدﮔﯽ ﺑﻪ ﻋﻼﯾﻢ ﺑﯿﻤﺎري زﻏﺎﻟﯽ ﺑﻠﻮط ﺑﻮد. ﺑﺪﯾﻦ ﻣﻨﻈﻮر 20 ﻗﻄﻌﻪ ﻧﻤﻮﻧﻪ 20 آري در راﺳﺘﺎي ﺧﻂ ﻧﻤﻮﻧﻪاي ﺑﻪ ﻃﻮل ﺷﺶ ﮐﯿﻠﻮﻣﺘﺮ در ﺟﻨﮕﻞ داﻻب اﯾﻼم ﭘﯿﺎده و ﻣﺸﺨﺼﻪﻫﺎﯾﯽ ﻣﺎﻧﻨﺪ ﻗﻄﺮ ﯾﻘﻪ، ﻗﻄﺮ ﺑﺮاﺑﺮﺳﯿﻨﻪ، ارﺗﻔﺎع درﺧﺖ، ﻣﺴﺎﺣﺖ ﺗﺎج و درﺟﻪ ﺧﺸﮑﯿﺪﮔﯽ درﺧﺘﺎن اﻧﺪازهﮔﯿﺮي و ﺛﺒﺖ ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺗﺮﮐﯿﺐ ﮔﻮﻧﻪاي ﺟﻨﮕﻞ ﺑﺮودار ﺧﺎﻟﺺ ﺑﺎ ﻓﺮم داﻧﻪ و ﺷﺎﺧﻪزاد ﺑﻮد. ﺗﻌﺪاد ﭘﺎﯾﻪﻫﺎي درﺧﺘﯽ 153 اﺻﻠﻪ و روﯾﻪزﻣﯿﻨﯽ 14/6 ﻣﺘﺮﻣﺮﺑﻊ در ﻫﮑﺘﺎر ﻧﺸﺎندﻫﻨﺪه ﺗﺮاﮐﻢ و ﻣﻮﺟﻮدي ﻧﺴﺒﺘﺎ زﯾﺎد ﺟﻨﮕﻞ ﺑﻮد. ﺑﻪﻃﻮر ﮐﻠﯽ 85/5 درﺻﺪ ﭘﺎﯾﻪﻫﺎ ﻧﺸﺎﻧﻪﻫﺎﯾﯽ از ﺑﯿﻤﺎري داﺷﺘﻨﺪ و ﻧﺴﺒﺖ آﻟﻮدﮔﯽ ﭘﺎﯾﻪﻫﺎي داﻧﻪزاد و درﺧﺘﺎن ﻣﯿﺎنﺳﺎل و ﻣﺴﻦ ﻧﺴﺒﺖ ﺑﻪ ﭘﺎﯾﻪﻫﺎي ﺷﺎﺧﻪزاد و ﺟﻮان ﺑﯿﺸﺘﺮ ﺑﻮد. ﺑﺮ ﭘﺎﯾﻪ ﻧﺘﺎﯾﺞ، ﻣﺸﺨﺼﻪﻫﺎي درﺧﺘﺎن ﻣﺎﻧﻨﺪ ﻗﻄﺮ ﯾﻘﻪ، ﻗﻄﺮ ﺑﺮاﺑﺮﺳﯿﻨﻪ، ﺳﻄﺢ ﻣﻘﻄﻊ، ارﺗﻔﺎع ﮐﻞ و ﻣﺴﺎﺣﺖ ﺗﺎج در ﺳﻄﻮح ﻣﺨﺘﻠﻒ ﺑﯿﻤﺎري ﺑﻪﻃﻮر ﻣﻌﻨﯽداري ﺑﺎ ﻫﻢ ﺗﻔﺎوت داﺷﺖ. ﺑﻪﻣﻨﻈﻮر درك ﭘﻮﯾﺎﯾﯽ ﺳﺎﺧﺘﺎر ﺗﻮده ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﺑﯿﻤﺎري زﻏﺎﻟﯽ، ﭘﺎﯾﺶ ﻣﺪاوم اﯾﻦ ﺟﻨﮕﻞﻫﺎ ﺿﺮوري ﺑﻮد. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺷﺪت ﺑﯿﺸﺘﺮ ﺑﯿﻤﺎري در درﺧﺘﺎن ﻣﯿﺎنﺳﺎل و ﻣﺴﻦ، ﻫﺮس و ﮐﻮﭼﮏ ﮐﺮدن ﺗﺎج درﺧﺘﺎن ﺑﯿﻤﺎر ﺑﺮاي ﺗﻨﻈﯿﻢ ﻧﺴﺒﺖ ﺗﺎج ﺑﻪ رﯾﺸﻪ و ﻫﻤﭽﻨﯿﻦ ﻗﻄﻊ و ﺧﺮوج درﺧﺘﺎﻧﯽ ﮐﻪ ﻗﺎﺑﻞ اﺣﯿﺎ ﻧﯿﺴﺘﻨﺪ از ﺟﻤﻠﻪ ﺑﺮﻧﺎﻣﻪﻫﺎي ﻋﻤﻠﯿﺎﺗﯽ ﭘﯿﺸﻨﻬﺎدي اﺳﺖ.

In the last two decades, the vast areas of Zagros forests especially in Ilam province have been infected by charcoal oak disease, which killed many Persian oak trees. This study aimed to recognize the structure of the infected stands and to address the relationships between structural features and the tree characteristics with the infection level to the symptoms of charcoal oak disease. For this purpose, a number of 20 sample plots was established along a 6 km transect in Dalab protected forest to collect data such as collar diameter, diameter at breast height, height, crown area, and tree drying degree were measured and recorded for each tree within the sample plots. The number of tree bases was 153 and the surface area was 14.6 m2/ha, indicating a relatively high density and inventory of forests. In general, 85.5% of the individuals had a sign of the charcoal disease and the rate of infection was higher in seed-originated trees, middle-aged and old trees than branching bases and young ones. Based on the results, tree characteristics including collar diameter, diameter at breast height, basal area, total height, and crown area were significantly different among different infection levels of the disease. To understand the dynamics of stands’ structure under the charcoal disease, continuous monitoring of the forests is necessary. Since the higher severity of the disease outbreak in middle-aged and old trees, pruning and shrinking the infected trees’ crown to adjust the crown to root ratio as well as cutting and removing the trees which are not restorable are among the proposed practical plans.