بررسی مقاومت گونه‌های درختی در مقابل خسارت برف در جنگل‌های ناو اسالم گیلان

نوع مقاله: علمی- پژوهشی

نویسندگان

1 دانشیار، دانشگاه گیلان

2 استادیار، دانشگاه آزاد خلخال

چکیده

مدیریت جنگل‌های کوهستانی به‌منظور حفاظت بهتر از توده‌های طبیعی نیاز به داشتن اطلاعات دقیق از وسعت و شدت خسارت برف دارد. در این تحقیق خسارت برف بر شش گونه‌ غالب درختی راش، ممرز، شیردار، پلت، توسکای‌ییلاقی و بلندمازو در جنگل‌های ناواسالم در استان گیلان مورد بررسی قرار گرفت. جمع‌آوری داده‌ها به‌روش نمونه‌برداری منظم- تصادفی با پلات‌های دایره‌ای‌شکل 10 آری و فاصله‌های منظم 100 متری از یکدیگر انجام شد. چهار نوع خسارت برف شامل صدمه تاجی (%6/8)، شکستگی تنه (%5/5)،  ریشه‌کن‌شده (%2/3) و خم‌شدگی (%4/1) بر روی درختان تشخیص داده شد. شش گونه موردبررسی در مقابل خسارت برف مقاومت متفاوت داشتند، به‌طوری‌که در توسکای‌ییلاقی، بیشترین فراوانی، ریشه‌کن ‌شدن و شکستگی تنه بود. در بلندمازو، بیشترین فراوانی، صدمه تاجی‌ اندازه‌گیری شد. در راش، کمترین فراوانی، صدمه تاجی و شکستگی تنه بود. توسکای‌ییلاقی، بلندمازو و شیردار جزء درختان با حساسیت زیاد و راش، ممرز و پلت جزء درختان با حساسیت کم در مقابل خسارات برف، دسته‌بندی شدند. ضرایب قدکشیدگی در درختان خم‌شده 7/76، تنه‌شکسته 5/64، ریشه‌کن‌شده 0/64، تاج صدمه‌دیده 1/60 و در درختان سالم 2/50 محاسبه شد. این پژوهش نشان داد درختانی که دارای ضریب قدکشیدگی بیشتری هستند، حساسیت زیادی در برابر خسارت برف دارند.

کلیدواژه‌ها


عنوان مقاله [English]

Resistance of tree species to snow damage in Nav Asalem forests, Guilan province

نویسندگان [English]

  • Amir Eslam Bonyad 1
  • Farzam Tavankar 2
1 Assistant Prof., Islamic Azad University, Khalkhal Branch, Khalkhal, I.R. Iran
2 Associate Prof., University of Guilan, Sowme`eh Sara, I.R. Iran.
چکیده [English]

Management of mountainous forests implies detailed information on the extent and intensity of snow damages. Furthermore, such information is required for improved conservation of natural stands. In this study, snow damages on six dominant tree species including Beech (Fagus orientalis Lipsky), Hornbeam (Carpinus betulus L.), Velvet Maple (Acer velutinum Boiss.), Cappadocian Maple (Acer cappadocicum Gled.), Caucasian Alder (Alnus subcordata C. A. Mey) and Chestnut-leaved Oak (Quercus castaneifolia C. A. Mey.) were investigated across a portion of  the Nav forest in the east of Guilan province. Circular 0.1-ha plots were systematically sampled in a grid with 100m sampling distance. Four types of tree damage were detected including crown damage (8.6%), stem breakage (5.5%), uprooting (3.2%) and bending (1.4%). The six studied tree species have different resistance to snow damage. The highest rates of uprooting and stem breakages were observed in Alder trees. The Oak trees were mostly influenced by crown damages. Furthermore, the Beech trees showed the lowest rate of crown damage and stem breakage. Based on the results, the tree species of Alder, Oak and Cappadocian Maple were categorized as being more vulnerable to snow risk, whereas Beech, Hornbeam and Velvet Maple proved to be less vulnerable. In addition, the slenderness coefficients were calculated for bended trees (76.7), stem broken trees (64.5), uprooted trees (64.0), crown damaged trees (60.1) and intact trees (50.2). This study also showed that trees of higher slenderness coefficient are more vulnerable to the snow risk.

کلیدواژه‌ها [English]

  • Nav forest
  • snow damage
  • uprooting
  • stem breakage
  • Slenderness Coefficient
  • Guilan
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