اثر تغيير كاربري جنگل به باغ چاي بر خصوصيات شيميايي خاك و جمعيت قارچ ميكوريز آربوسكولار (مطالعه موردي: لاهيجان)

The Influence of Forest Land Use Changing into Tea Garden on Soil Chemical Properties and Arbuscular Mycorrhizal Fungi Population (Case Study: Lahijan)

ﭼﮑﯿﺪه ﺗﻐﯿﯿﺮ ﮐﺎرﺑﺮي اراﺿﯽ ﺗﻐﯿﯿﺮاﺗﯽ را در ﺧﺎك اﯾﺠﺎد ﻣﯽﮐﻨﺪ ﮐﻪ ﺑﻪ دﻧﺒﺎل آن ﻣﺎده آﻟﯽ، ﻣﻮاد ﻣﻐﺬي، ﻣﻮﺟﻮدات ﺧﺎﮐﺰي از ﺟﻤﻠﻪ ﻗﺎرچﻫﺎ را ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﻗﺮار ﻣﯽدﻫﺪ. ﻗﺎرچﻫﺎي ﻣﯿﮑﻮرﯾﺰ آرﺑﻮﺳﮑﻮﻻر )AMF( از ﺟﻤﻠﻪ رﯾﺰﺟﺎﻧﺪاران ﺧﺎﮐﺰي ﻣﯽﺑﺎﺷﻨﺪ ﮐﻪ ﺑﺎ رﯾﺸﻪ ﻃﯿﻒ ﮔﺴﺘﺮدهاي از ﮔﯿﺎﻫﺎن ﺟﻨﮕﻠﯽ و ﻏﯿﺮﺟﻨﮕﻠﯽ، ﻫﻤﺰﯾﺴﺖ ﻣﯽﺷﻮﻧﺪ. ﺗﻨﻮع و ﭘﺮاﮐﻨﺪﮔﯽ اﯾﻦ ﻗﺎرچ ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﺗﺮﮐﯿﺐ ﮔﻮﻧﻪﻫﺎي ﮔﯿﺎﻫﯽ، ﻣﺸﺨﺼﻪﻫﺎي ﺧﺎك، ﺷﺮاﯾﻂ ﻣﺤﯿﻄﯽ و رﯾﺰﺟﺎﻧﺪاران ﺧﺎك ﻗﺮار دارد. ﻫﺪف از اﻧﺠﺎم اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮرﺳﯽ ﺗﺎﺛﯿﺮ ﺗﻐﯿﯿﺮ ﮐﺎرﺑﺮي اراﺿﯽ از ﺟﻨﮕﻞ ﺑﻪ ﺑﺎغ ﭼﺎي ﺑﺮ وﯾﮋﮔﯽﻫﺎي ﺷﯿﻤﯿﺎﯾﯽ ﺧﺎك و ﻣﯿﺰان ﻫﻤﺰﯾﺴﺘﯽ ﻗﺎرچ ﻣﯿﮑﻮرﯾﺰ آرﺑﻮﺳﮑﻮﻻر اﺳﺖ. ﻧﻤﻮﻧﻪﺑﺮداري از ﺧﺎك ﻣﻨﺎﻃﻖ ﺟﻨﮕﻠﯽ و ﭼﺎيﮐﺎريﻫﺎي ﻣﺠﺎور ارﺗﻔﺎﻋﺎت ﺷﻬﺮﺳﺘﺎن ﻻﻫﯿﺠﺎن ﺑﻪﺻﻮرت ﺗﺼﺎدﻓﯽ و ﺑﻪ ﺗﻌﺪاد 20 ﻋﺪد از ﻫﺮﮐﺪام از ﮐﺎرﺑﺮيﻫﺎ در ﻋﻤﻖ 0-30 ﺳﺎﻧﺘﯽﻣﺘﺮ اﻃﺮاف رﯾﺸﻪ و در ﻓﺼﻞ ﭘﺎﯾﯿﺰ اﻧﺠﺎم ﮔﺮﻓﺖ. ﻫﻤﺰﻣﺎن ﻧﻤﻮﻧﻪﻫﺎي رﯾﺰ رﯾﺸﻪﻫﺎ از رﯾﺰوﺳﻔﺮ درﺧﺘﺎن و ﺑﻮﺗﻪﻫﺎي ﭼﺎي ﺗﻬﯿﻪ ﺷﺪ. درﺻﺪ ﮐﻠﻮﻧﯿﺰاﺳﯿﻮن و ﺗﻌﺪاد اﺳﭙﻮرﻫﺎي ﻗﺎرچ ﻣﯿﮑﻮرﯾﺰ، ﮐﺮﺑﻦ آﻟﯽ، pH، ﻓﺴﻔﺮ و ﭘﺘﺎﺳﯿﻢ ﻗﺎﺑﻞ ﺟﺬب ﺧﺎك اﻧﺪازهﮔﯿﺮي ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻣﯿﺎﻧﮕﯿﻦ درﺻﺪ ﮐﻠﻮﻧﯿﺰاﺳﯿﻮن و ﺗﻌﺪاد اﺳﭙﻮرﻫﺎ در ﺧﺎك ﺟﻨﮕﻞ ﺑﯿﺸﺘﺮ از ﺧﺎك ﺑﺎغ ﭼﺎي ﺑﻮد. ﺑﯿﻦ pH و ﮐﺮﺑﻦ آﻟﯽ و ﭘﺘﺎﺳﯿﻢ ﻗﺎﺑﻞ ﺟﺬب در ﺧﺎك دو ﮐﺎرﺑﺮي اﺧﺘﻼف ﻣﻌﻨﯽداري دﯾﺪه ﺷﺪ. ﻫﻤﺒﺴﺘﮕﯽ ﻣﻨﻔﯽ ﺑﯿﻦ ﺗﻌﺪاد اﺳﭙﻮرﻫﺎي ﻗﺎرچ ﻣﯿﮑﻮرﯾﺰا ﺑﺎ ﭘﺘﺎﺳﯿﻢ ﻗﺎﺑﻞ ﺟﺬب ﺧﺎك )0/418- =r( و pH ﺧﺎك )0/571- =r( و ﻫﻤﺒﺴﺘﮕﯽ ﻣﺜﺒﺖ ﺑﯿﻦ درﺻﺪ ﮐﻠﻮﻧﯿﺰاﺳﯿﻮن رﯾﺸﻪ و r=0/453**) pH( دﯾﺪه ﺷﺪ. در ﻧﻬﺎﯾﺖ ﺗﻐﯿﯿﺮ ﮐﺎرﺑﺮي و ﭘﻮﺷﺶ ﮔﯿﺎﻫﯽ ﺑﺎ ﺗﻐﯿﯿﺮ ﺧﺼﻮﺻﯿﺎت ﺷﯿﻤﯿﺎﯾﯽ ﺧﺎك ﻣﻮﺟﺐ ﮐﺎﻫﺶ ﻣﯿﺰان ﻫﻤﺰﯾﺴﺘﯽ و ﺗﻌﺪاد اﺳﭙﻮرﻫﺎي ﻗﺎرچ ﻣﯿﮑﻮرﯾﺰ در ﺧﺎك ﺷﺪ.

Changing land use causes changes in the soil, which in turn affect the organic matter, nutrients, and soil organisms including fungi. Arbuscular mycorrhizal fungi (AMF) are terrestrial microorganisms that coexist with the roots of a wide range of forest and non-forest plants. The diversity and distribution of this fungus are affected by the composition of plant species, soil characteristics, environmental conditions, and soil microorganisms. The present study aimed to investigate the effect of changing land use from forest to tea garden on soil chemical properties and the coexistence of arbuscular mycorrhizal fungi. The samples were randomly collected from forest and tea plantation areas near to the heights of Lahijan and 20 samples were collected from each area at a depth of 0-30 cm around the roots in the autumn. At the same time, fine root samples were obtained from the rhizosphere of the trees and tea bushes. The colonization percentage and the number of spores of mycorrhizal fungi, organic carbon, pH, phosphorus, and soil absorbable potassium were measured. The results indicated that the average percentage of colonization and the number of spores in the forest soil was higher than in the tea garden soil. There was a significant difference between pH and organic carbon and absorbable potassium in the soil. There was a negative correlation between the number of mycorrhiza spores and the soil absorbable potassium (r = -0.418) and soil pH (r = -0.571). There was a positive correlation between the percentage of root colonization and pH (r = 0.453 **). Finally, changing of land use and vegetation following by soil chemical properties changing, resulted in decreasing the coexistence and number of mycorrhizal fungi spores in the soil.