كمي‌سازي فشار آشيان انتخابي گونه‌هاي چوبي در جنگل‌هاي ميان‌بند شمال ايران (منطقه مورد مطالعه: بخش گرازبن جنگل خيرود)

Quantitative Determination of the Selected Nests Pressure of Wood Species in the Middle Forest of Northern Iran (Case study: Gorazbon section of Kheyroud forest)

زﻣﯿﻨﻪ و ﻫﺪف: ﺷﻨﺎﺧﺖ آﺷﯿﺎن اﮐﻮﻟﻮژﯾﮑﯽ ﮔﻮﻧﻪﻫﺎي ﻣﺨﺘﻠﻒ در ﺑﺴﯿﺎر از ﻣﺴﺎﺋﻞ اﮐﻮﻟﻮژﯾﮑﯽ ﺿﺮوري اﺳﺖ. آﺷﯿﺎن اﮐﻮﻟﻮژﯾﮏ ﮔﻮﻧﻪﻫﺎ ﯾﮑﯽ از ﻓﺎﮐﺘﻮرﻫﺎي ﻣﻬﻢ در ﺗﺸﺨﯿﺺ اﻟﮕﻮي ﭘﺮاﮐﻨﺶ درﺧﺘﺎن ﺑﻮده و ﺑﺮاي ﮐﻞ ﮔﻮﻧﻪﻫﺎ، ﺑﺎ ﺑﺮرﺳﯽ ﺗﻮزﯾﻊ ﭘﺮاﮐﻨﺶ ﮔﻮﻧﻪﻫﺎ ﻗﺎﺑﻞ ﺗﺸﺨﯿﺺ اﺳﺖ. ﻣﺪلﻫﺎي آﺷﯿﺎن اﮐﻮﻟﻮژﯾﮏ اﻏﻠﺐ ﺑﻪ ﻓﻬﻢ ﺑﯿﺸﺘﺮ اﮐﻮﺳﯿﺴﺘﻢ ﮐﻤﮏ ﻣﯽﻧﻤﺎﯾﺪ. اﯾﻦ ﻣﺪلﻫﺎ در ﭘﯿﺶﺑﯿﻨﯽ ﺑﺮآورد ﺗﻐﯿﯿﺮات ﭘﺎﯾﺪاري اﮐﻮﺳﯿﺴﺘﻢ و ﻧﺴﺒﺖ ﭘﺎﯾﺪاري و اﮐﻮﺳﯿﺴﺘﻢﻫﺎ ﮐﺎرﺑﺮدي اﺳﺖ. روش ﺑﺮرﺳﯽ: ﺑﻪ ﻣﻨﻈﻮر ﺗﻌﯿﯿﻦ ﻓﺸﺎر اﻧﺘﺨﺎﺑﯽ ﮔﻮﻧﻪﻫﺎي ﻣﺨﺘﻠﻒ از ﺷﺎﺧﺺﻫﺎي ﺳﻄﺢ ﺗﻌﺎدل آﺷﯿﺎن اﻧﺘﺨﺎﺑﯽ، ﺳﻄﺢ ﻏﺎﻟﺐ آﺷﯿﺎن اﻧﺘﺨﺎﺑﯽ و ﺳﻄﺢ ﺑﺤﺮان آﺷﯿﺎن اﻧﺘﺨﺎﺑﯽ اﺳﺘﻔﺎده و 41/5 ﻫﮑﺘﺎر از ﺟﻨﮕﻞآﻣﻮزﺷﯽ ﭘﮋوﻫﺸﯽ ﺧﯿﺮود ﻣﻮرد آﻣﺎرﺑﺮداري ﮐﺎﻣﻞ )ﺻﺪدرﺻﺪ( ﻗﺮار ﮔﺮﻓﺖ. ﺳﭙﺲ، ﻣﺸﺨﺺﻫﺎي ﻧﻈﯿﺮ ﻗﻄﺮ ﺑﺮاﺑﺮ ﺳﯿﻨﻪ درﺧﺘﺎن اﻧﺪازهﮔﯿﺮي و ﺑﺎ اﺳﺘﻔﺎده از ﺷﺎﺧﺺﻫﺎي آﺷﯿﺎن اﻧﺘﺨﺎﺑﯽ ﺑﻪ اﻧﺪازهﮔﯿﺮي ﻓﺸﺎر اﻧﺘﺨﺎﺑﯽ و ﺳﻄﻮح آﺷﯿﺎن ﮔﻮﻧﻪﻫﺎي راش، ﺑﻠﻮط، ﻣﻤﺮز، ﺗﻮﺳﮑﺎ ﭘﺮداﺧﺘﻪ ﺷﺪ. ﯾﺎﻓﺘﻪﻫﺎ: ﻣﻘﺪار ﺑﺪﺳﺖ آﻣﺪه از ﻓﺸﺎر اﻧﺘﺨﺎﺑﯽ ﺑﺮاي ﮔﻮﻧﻪﻫﺎي راش 66/419 ، ﺑﻠﻮط 28/313، ﻣﻤﺮز 261/3، ﺗﻮﺳﮑﺎ 36/962 و ﻧﻤﺪار 9/39 ﺑﻪ ﺗﺮﺗﯿﺐ ﻣﺤﺎﺳﺒﻪ ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﻬﺎﯾﯽ ﺑﺪﺳﺖ آﻣﺪه ﻧﺸﺎن داد ﮔﻮﻧﻪ ﻣﻤﺮز در ﺳﻄﺢ آﺷﯿﺎن ﻏﺎﻟﺐ، ﮔﻮﻧﻪ راش و ﺗﻮﺳﮑﺎ در ﺳﻄﺢ آﺷﯿﺎن ﺗﻌﺎدل، ﮔﻮﻧﻪ ﺑﻠﻮط در ﺣﺪ واﺳﻂ آﺷﯿﺎن ﺗﻌﺎدل و ﻣﻐﻠﻮب و ﻧﻤﺪار در ﺳﻄﺢ آﺷﯿﺎن ﻣﻐﻠﻮب ﺑﻮده اﺳﺖ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪﮔﯿﺮي: ﮔﻮﻧﻪ ﻣﻤﺮز در ﺳﻄﺢ ﻏﺎﻟﺐ ﻓﺸﺎر اﻧﺘﺨﺎﺑﯽ، ﮔﻮﻧﻪ ﻧﻤﺪار در ردﯾﻒ ﮔﻮﻧﻪﻫﺎي ﺑﺎ ﺳﻄﺢ ﺗﻌﺎدل ﺑﺤﺮان و ﮔﻮﻧﻪ ﺑﻠﻮط در ﺳﻄﺢ آﺷﯿﺎن ﺑﺤﺮان ﻧﺰدﯾﮏ ﺑﻪ ﺳﻄﺢ ﺗﻌﺎدل ﻗﺮار ﮔﺮﻓﺖ. ﻧﺘﺎﯾﺞ ﺑﺪﺳﺖ آﻣﺪه از اﯾﻦ ﭘﮋوﻫﺶ ﻧﺸﺎن داد ﮐﻪ ﮐﻤﯽﺳﺎزي ﻓﺸﺎر اﻧﺘﺨﺎﺑﯽ ﯾﮏ ﻋﺎﻣﻞ ﻣﻬﻢ ﺑﺮاي ﺗﻌﯿﯿﻦ ﺟﺎﯾﮕﺎه ﮐﻨﻮﻧﯽ ﮔﻮﻧﻪﻫﺎي در ﺣﺎل اﻧﻘﺮاض ﻣﯽﺑﺎﺷﺪ.

Background and Objective: Understanding the ecological niche of the different species is essentialin many ecological issues. Ecological niches of species are one of the important factors in the tree species distribution pattern and for all species, it can be detected by examining distribution of species distribution. Ecological nest models often help to understand more ecosystems. These models are applicable in predicting ecosystem stability and sustainability ratios and ecosystems. Method: In order to determine the selective pressure of different species, the indicators of the equilibrium level of selected nests, the dominant level of selected nests and the crisis level of selected nests were used and 41.5 hectares of Khirud research and educational forest were fully surveyed (100%). Then, characteristics such as diameter equal to the chest of the trees were measured and using selective nesting indices, the selected pressure and nesting levels of beech, oak, hornbeam and alder species were measured. Findings: The values of the selective pressure were measured for the species on the Fagus orientalis 66.419, Quercus persica 3. 313, Carpinus orientalis 261. 28, Alnus 36. 962 and tilia begonifolia 9. 39 respectively. The final results showed that Carpinus orientalis wasat a Dominates niche level, the Fagus orientalis and Alnus was in the balance niche level and the Quercus persicawas in intermediate between balance and critical level and also tilia begonifolia was in the critical niche levels. Discussion and Conclusion: The Carpinus species were at the dominant level of selective pressure, the Tilla species were at the equilibrium level and the Quercus species were at the equilibrium level of the crisis nest. The results of this study showed that selective strain quantification is an important factor in determining the current status of endangered species.