تأثیر شیب زمین بر وسعت و شدت برهم‌خوردگی خاک جنگل در اثر عملیات چوبکشی زمینی (مطالعه موردی: جنگل ناو اسالم گیلان)

نوع مقاله : علمی- پژوهشی

نویسندگان

1 استادیار، گروه جنگلداری، دانشکده منابع طبیعی، واحد خلخال، دانشگاه آزاد اسلامی، خلخال، ایران

2 استادیار، گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه گیلان، صومعه‌سرا، ایران

چکیده

یکی از عامل‌های کلیدی برای داشتن جنگل‌هایی با تولید مستمر، حفاظت از خاک جنگل است. در پژوهش پیش‌رو وسعت و شدت برهم‌خوردگی خاک جنگل در اثر خارج کردن تنه‌ها و گرده‌بینه‌های درختان قطع‌شده (m3/ha 20/5) در جنگل ناو اسالم گیلان بررسی شد. پس از اتمام عملیات چوبکشی، برهم‌خوردگی خاک از طریق نمونه‌برداری نقطه- خط‌نمونه و به ‌روش ارزیابی چشمی بررسی شد. نتایج نشان داد که حدود 2/6 ± 19 درصد از خاک منطقه در اثر چوبکشی دچار برهم‌خوردگی شده بود که 11/3 درصد آن با شدت کم و 7/7 درصد آن با شدت زیاد بود. وسعت و شدت برهم‌خوردگی خاک با افزایش فاصله از مسیرهای چوبکشی کاهش یافته بود، اما با افزایش شیب زمین افزایش پیدا کرده بود. وزن مخصوص ظاهری خاک در مناطق برهم‌خورده با شدت کم (g/cm3 1/29) و در مناطق برهم‌خورده با شدت زیاد (g/cm3 1/44) به‌ترتیب 2/4 و 14/3 درصد نسبت به مناطق شاهد افزایش یافته بود. وزن مخصوص ظاهری خاک مناطق برهم‌خورده با افزایش شیب زمین افزایش یافته بود، به‌طوری‌که در شیب‌های بیشتر از 50 درصد، وزن مخصوص ظاهری خاک 20/8 درصد نسبت به مناطق شاهد افزایش یافته بود. کاهش شدت برداشت، قطع و انداختن هدایت‌شده درختان و محدود کردن عملیات چوبکشی به شیب‌های کمتر از 50 درصد، ازجمله راهکارهای کاهش برهم‌خوردگی خاک در این جنگل‌ها است.

کلیدواژه‌ها


عنوان مقاله [English]

Effect of ground slope on extent and intensity of soil disturbance from skidder logging (Case study: Nav-e Asalem forest, Gilan province)

نویسندگان [English]

  • Farzam Tavankar 1
  • Mehrdad Nikooy 2
1 Assistant Prof., Department of Forestry, Faculty of Natural Resources, Khalkhal Branch, Islamic Azad University, Khalkhal, Iran
2 Assistant Prof., Department of Forestry, Faculty of Natural Resources, University of Guilan, Someh Sara, Iran
چکیده [English]

Protection of forest soil is one of key factors in having sustainable productive forests. In this research extent and intensity of soil disturbance due to extraction of logs of felled trees (20.5 m3/ha) were studied in Nav-e Asalem forest in Gilan province. After finishing the skidder logging operations, soil disturbance were studied by point-transect sampling method and visual assessing. Results indicated that about 19 ± 6.2 percent of surface soils were disturbed due to winching of logs that 11.3 percent of them disturbed with shallow intensity and 7.7 percent disturbed with deep intensity. The extent and intensity of soil disturbance were decreased by increasing distance from skid trail. The extent and intensity of soil disturbance were increased by increasing of ground slope. Soil bulk density in the shallow disturbed soils (1.29 g/cm3) and deep disturbed soils (1.44 g/cm3) were increased 2.4 and 14.3 percent, respectively, than control soils. Soil bulk density of disturbed areas were increased by increasing ground slope, so in slopes greater than 50 percent soil bulk density was increased 20.8 percent more than control soils. Including ways to reducing soil disturbance during skidder logging in the study area are reduction in harvest intensity, implementation of felling direction and skidder logging limitation to slopes less than 50 percent.

کلیدواژه‌ها [English]

  • Ground skidding
  • logging
  • selection cutting
  • soil bulk density
  • soil compaction
- Anonymous, 1998. USDA forest service manual, FSM 2520 (watershed protection and management). R-6 Supplement No. 2500-98-1, Published by USDA, Forest Service, USA, 16p.
- Anonymous, 2002. Soil conservation and rehabilitation in British Columbia. Brochure No. 70, Published by British Columbia Forest Science Program, British Columbia, 20p.
- Anonymous, 2006. Instructions for planning of landing and skid trail. Published by Forest Harvesting Office, Forests, Range and Watershed Management Organization, Tehran, 35p.
- Anonymous, 2008. Forest management plan, Nav watershed. Natural Resources and Watershed Management Office, Asalem, 288p.
- Byblyuk, N., Styranivsky, O., Korzhov, V. and Kudra, V., 2010. Timber harvesting in the Ukrainian Carpathians: ecological problems and methods to solve them. Journal of Forest Science, 56(7): 333-340.
- Froehlich, H.A., 1979. Soil compaction from logging equipment: effects on growth of young ponderosa pine. Journal of Soil and Water Conservation, 34: 276-278.
- Gondard, H., Romane, F., Aronson, J. and Shater, Z., 2003. Impact of soil surface disturbances on functional group diversity after clear-cutting in Aleppo pine (Pinus halepensis) forests in southern France. Forest Ecology and Management, 180: 165-174.
- Hosseini, S.M., Majnounian, B. and Nieuwenhuis, M., 2000. Damage to natural regeneration in the Hyrcanian forests of Iran: a comparison of two typical timber extraction operations. Journal of Forest Engineering, 11(2): 63-72.
- Jackson, S.M., Fredericksen, T.S. and Malcolm, J.R., 2002. Area disturbed and residual stand damage following logging in a Bolivian tropical forest. Forest Ecology and Management, 166(1-3): 271-283.
- Jourgholami, M., Rizvandi, V. and Majnounian, B., 2013. Effects of forest harvesting operations on physical properties and soil penetration resistance (Case study: Kheyroud forest). Journal of Range and Watershed Management, 66(2): 223-236 (In Persian).
- Jusoff, K. and Majid, N.M., 1992. An analysis of soil disturbance from logging operation in a hill forest of Peninsular Malaysia. Forest Ecology and Management, 47(1-4): 323-333.
- Lotfalian, M., Shirvani, Z. and Naghavi, H., 2009. Investigation of effective factors on skid roads erosion. Iranian Journal of Forest, 1(2): 115-124 (In Persian).
- Majnounian, B. and Jourgholami, M., 2013. Effect of rubber-tired cable skidder on soil compaction in Hyrcanian forest. Croatian Journal of Forest Engineering, 34(1): 123-135.
- McMahon, S., 1995. Accuracy of two ground survey methods for assessing site disturbance. Journal of Forest Engineering, 6(2): 27-33.
- Miller, R.E., Mclver, J.D., Howes, S.W. and Gaeuman, W.B., 2010. Assessment of soil disturbance in forests of the interior Colombia river basin: a critique. Published by USDA Forest Service, Pacific Northwest Research Station, Oregon, 154p.
- Miller, J.H. and Sirois, D.L., 1986. Soil disturbance by skyline yarding vs skidding in a loamy hill forest. Soil Science Society of American Journal, 50: 1579-1583.
- Murphy, G., Firth, J.G. and Skinner, M.F., 2004. Long term impacts of forest harvesting related soil disturbance on log product yields and economic potential in a New Zealand forest. Silva Fennica, 38(3): 279-289.
- Naghdi, R., Lotfalian, M., Bagheri, I. and Jalali, A.M., 2009. Damages of skidder and animal logging to forest soils and natural regeneration. Croatian Journal of Forest Engineering, 30(2): 141-149.
- Najafi, A. and Solgi, A., 2010. Assessing site disturbance using two ground survey methods in a mountain forest. Croatian Journal of Forest Engineering, 31(1): 47-55.  
- Nikooy, M. and Ershadifar, M., 2012. Effects of skid trail planning, landing construction and directional felling on normal selective logging in Caspian forest. Proceeding of the FORMEC International Forest Engineering Symposium. Croatia, 8-12 Oct. 2012: 9. 
- Page-Dumroese, D., Jurgensen, M., Elliot, W., Rice, T., Nesser, J., Collins, T. and Meurisse, R., 2000. Soil quality standards and guidelines for forest sustainability in the northwestern North America.  Forest Ecology and Management, 138: 445-462.
- Reeves, D., Page-Dumroese, D. and Coleman, M., 2011. Detrimental soil disturbance associated with timber harvest systems on national forests in the northern region. Research Paper 89, Published by USDA Forest Service, Rocky Mountain Research Station, USA, 17p.
- Sarikhani, N., 2000. Forest Utilization. University of Tehran Press, Tehran, 776p (In Persian).
- Solgi, A. and Najafi, A., 2014. The impacts of ground-based logging equipment on forest soil. Journal of Forest Science, 60(1): 28-34.