ارزیابی روند تغییرات شاخص‌های رقابت به‌منظور برآورد اثر نشانه‌گذاری در جنگل راش شرقی (Fagus orientalis Lipsky) منطقه لاویج نور

نوع مقاله: علمی- پژوهشی


1 استاد، گروه جنگل‌داری، دانشکده کشاورزی و منابع طبیعی، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران

2 دانشجوی دکتری جنگل‌داری، دانشکده کشاورزی و منابع طبیعی، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران

3 دانشیار، گروه جنگل‌داری، دانشکده کشاورزی و منابع طبیعی، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران


تغییرات بین پایه‌ای رویش متأثر از ترکیب، ساختار و رقابت بین پایه­‌ها است. بر این اساس، آگاهی از الگوی ساختار و درک مناسب از چگونگی پاسخ پایه­‌ها به تعاملات رقابتی از اهمیت قابل توجهی برخوردار است. پژوهش پیش‌رو با هدف ارزیابی روند تغییرات شاخص‌­های رقابت در اثر اقدامات مدیریتی در جنگل­ راش (Fagus orientalis Lipsky) خالص (پارسل مدیریت شده به مساحت 36 هکتار) در منطقه لاویج شهرستان نور، استان مازندران، انجام شد. کلیه پایه­‌های نشانه­‌گذاری شده (58 پایه) پیش از قطع مکان­‌یابی شده و به‌عنوان پایه هدف درنظر گرفته شدند. به مرکزیت پایه هدف و به شعاع 3/5 برابر شعاع تاج پایه هدف، قطعه‌نمونه دایره­‌ای پیاده شد و فاصله، آزیموت، قطر برابر سینه، ارتفاع، ارتفاع شروع تاج و شعاع تاج در جهت­‌های مختلف کلیه پایه­‌ها با قطر بیشتر از 7/5 سانتی‌­متر اندازه­‌گیری شد. به­‌منظور بررسی رقابت، از شاخص‌­های وابسته به فاصله نظیر جرارد، بلا، هگی و براث استفاده شد. نتایج نشان داد که توده‌­های مورد بررسی میانسال و بیشتر دخالت­‌ها در طبقه میان‌قطر انجام شده بود. همچنین، پس از نشانه­‌گذاری، در مقدار شاخص‌­های رقابت تغییر معنی­‌داری ایجاد نشده بود. بر این اساس، اقدامات مدیریتی (نشانه­‌گذاری) در سطح توده هدفمند نبوده و به روند تغییرات رقابت پایه‌­ای توجه نشده است. بنابراین، با توجه به اهمیت عامل رقابت و ارتباط آن با پارامترهای اندازه‌­ای توده، باید در اقدامات مدیریتی به روند تغییرات آن توجه شود.


عنوان مقاله [English]

Evaluation of competition indices to assess the effect of management interventions on oriental beech (Fagus orientalis Lipsky) forest of Lavij- Noor region, Mazandaran province

نویسندگان [English]

  • Asadollah Mataji 1
  • Reza Sheydaei 2
  • Hadi Kiadaliri 3
1 Prof., Department of Forestry, Faculty of Agriculture and Natural Resources, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 Ph.D. Student Forestry, Faculty of Agriculture and Natural Resources, Science and Research Branch, Islamic Azad University, Tehran, Iran
3 Associate Prof., Department of Forestry, Faculty of Agriculture and Natural Resources, Science and Research Branch, Islamic Azad University, Tehran, Iran
چکیده [English]

Tree to tree variation in growth results from compositional complexity, stand structure and competition. Therefore, it is essential to know how trees respond to competitive interactions. This study aims to evaluate of competition indices in order to assessment of management interventions effects in pure beech (Fagus orientalis Lipsky) stands (with 36 hectares) in Lavij- Noor region of Mazandaran province. For this purpose, the positions of all 58 marked trees were recorded as cored trees. Competition plots centered on the cored tree with radius of 3.5 × the cored tree crowns were established. The following attributes were measured for each tree (≥ 7.5 cm diameter at breast height (DBH)) within the plots: X and Y coordinates (m), total height, DBH, crown diameter at the base of the living crown in different directions and crown length. In order to quantify the competition level by each of the cored trees, 4 different distance-independent indices including Gerrard, Bella, Hegyi and Braathe were used. The results showed that the studied stands were middle-aged, the major interventions were in the middle DBH classes, and there was no significant change in the amount of competition indices following the interventions. Accordingly, the management interventions (marking) were not targeted and the process of individual tree competition changes was not measured. Therefore, the process of competition changes is necessary to be considered in stand management due to the high importance of the competition factor and its relation to the stand parameters.

کلیدواژه‌ها [English]

  • Distance-independent indices
  • Hyrcanian forests
  • stand structure

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