تحلیل وضعیت خشکیدگی جنگل‌های بلوط زاگرس با استفاده از روش‌های آمار مکانی (پژوهش موردی: جنگل زرآب استان ایلام)

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشیار پژوهش، مؤسسۀ تحقیقات جنگل‌ها و مراتع کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران،‌ ایران

2 عضو هیئت علمی گروه علوم جنگل، دانشگاه ایلام

3 کارشناس ارشد جنگل‌داری، اداره منابع طبیعی و آبخیزداری شهرستان دهلران، ایلام، ایران

چکیده

 DOR: 98.1000/1735 0859.1397.16.129.32.2.1578.41

    حدود یک دهه است که پدیده خشکیدگی در جنگل‌های بلوط زاگرس مشاهده شده است. یکی از کانون‌های اصلی و ابتدایی این پدیده جنگل‌های استان‌ ایلام هستند. در این پژوهش جنگلی به مساحت 83 هکتار در منطقه زرآب ایلام که مبتلا به خشکیدگی بود انتخاب و نوع گونه، قطر برابرسینه، فرم پرورشی، ارتفاع کل، درصد خشکیدگی و سطح تاج کلیه درختان خشکیده بررسی و مختصات جغرافیایی آنها تعیین شد. ساختار، الگو و همبستگی مکانی این متغیر‌ها به­ترتیب با استفاده از  تحلیل واریوگرام، آماره او-رینگ و تابع همبستگی نشان‌دار (MCF) بررسی شد. نتایج نشان داد که تراکم درختان دچار خشکیدگی 27 پایه در هکتار است که بیشتر شامل جست‌گروه‌های شاخه‌زاد با بیشترین فراوانی در پایه‌های کم‌قطر و میان‌قطر بوده است. الگوی پراکنش درختان دچار خشکیدگی تا شعاع 35 متری خوشه‌ای و پس از آن یکنواخت بود. تحلیل واریوگرم نشان داد که درصد خشکیدگی و قطر برابرسینه دارای ساختار مکانی قوی قابل مدل‌سازی و سطح تاج و ارتفاع کل دارای ساختار مکانی ضعیف هستند. نمودار MCF نشان داد که قطر برابرسینه درختان خشکیده مجاور مشابه نیستند، اما درصد خشکیدگی آنها به هم شباهت دارند. به‌طور کلی نتایج این پژوهش نشان داد که خشکیدگی در تمام درختان منطقه پژوهش با متغیرهای زیست‌سنجی مختلف و در جهات مختلف جغرافیایی اتفاق افتاده است. نتایج به­دست­آمده می‌تواند راهنمایی برای مدیریت پایدار این توده‌ها و جنگل‌شناسیکاربردی آنها بوده و به­هنگام برش‌های بهداشتی مدنظر قرار گیرد تا براساس نوع الگوی پراکنش و ابعاد لکه‌ها و خوشه‌ها و فواصل موجود دخالت صورت گیرد.

کلیدواژه‌ها


عنوان مقاله [English]

Analysis of the decline status of Zagrosian oak forests using spatial statistics (Case study: Zarab forests of Ilam)

نویسندگان [English]

  • R. Akhavan 1
  • Ali Mahdavi 2
  • M. Kianfar 3
2 Department of Forest Sciences, Faculty of Agriculture, Ilam University, Ilam, Iran
چکیده [English]

Recently, forest decline has outburst in Zagros forests region in the west of Iran, especially in Ilam province. In this research, we selected an 83 ha infected forest area in Zarab, Ilam and the dried trees were fully investigated for variables including dbh, height, drought intensity, crown cover, origin and Cartesian coordinates. Their spatial structure, spatial patterns and spatial correlation were analyzed using variogram analysis, O-ring statistic and Mark correlation function (MCF), respectively. Results showed that the density of dried trees was 27 N/ha which is more comprised of coppice trees in small and medium diameter classes. A cluster spatial pattern of dried trees was determined up to 35 m and after that it was uniform, implying dried trees created patches with 3850 m2 surface area. Variogram analysis showed that only dbh and drought intensity of dried trees had strong spatial structure which was mapped using Kriging interpolation method of Geostatistics. Mark correlation function graph showed that adjacent dried trees were similar according to drought intensity while were not similar based on their dbh. In general, the results illustrated that all of the trees in the studied area were infected by drought with different biometric characteristics as well as at different geographical aspects. These results can be used as an instruction for sustainable management of the stands based on their spatial characteristics. 

کلیدواژه‌ها [English]

  • Forest decline
  • Geostatistics
  • Spatial patterns
  • Spatial correlation
  • Zagros forests
- Ahmadi, R. 2004. Investigation the effective factors on oak decline and preparing drought mapping model for oak forest stands in middle Zagros. Ph.D. dissertation. Islamic Azad University, Science and Research campus, 91p (In Persian).
- Ahmadi, Sh., Zahedi Amiri, Gh. and Marvie Mohadjer, M.R. 2016. Mapping Brant's oak (Quercus brantii Lindl.) mortality using geostatistical methods in Dasht-e Barm, Fars province. Iranian Journal of Forest and Poplar Research, 24(3): 439-450 (In Persian).
- Ainsworth, E.A. and Long, S.P. 2005. What have we learned from 15 years of free-air CO2 enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy properties and plant production to rising CO2. New Phytologist, 165: 351–372.
- Akhavan, R., Mahdavi, A. and Karami, O. 2016. Spatial patterns and spatial structure of dried trees in Bivareh forests, Ilam province. Iranian Journal of Forest, 8(1): 67-78 (In Persian).
- Anonymous. 2004. Evaluation report of oak forest decline in Ilam province. Natural resources and watershed management main office of Ilam province, 15p (In Persian).
- Anonymous. 2011a. Range management plan of Zarab, Dehloran. Natural resources and watershed management main office of Ilam province, 54p (In Persian).
- Anonymous. 2011b. Meteorological main office of Ilam province. Internal report (In Persian).
- Azizi, Gh., Miri, M., Mohamadi, H. and Pourhashemi, M. 2015. Analysis of relationship between forest decline and precipitation changes in Ilam Province. Iranian Journal of Forest and Poplar Research, 23(3): 502-515 (In Persian).
- Bolte, A., Hilbrig, L., Grundmann, B., Kampf, F., Brunet, J. and Roloff, A. 2010. Climate change impacts on stand structure and competitive interactions in a southern Swedish spruce–beech forest. European Journal of Forest Research, 129: 261–276.
- Brown, N., Jeger, M., Kirk, S., Xu, X. and Denman, S. 2016. Spatial and temporal patterns in symptom expression within eight woodlands affected by Acute Oak Decline. Forest ecology and management, 360: 97-109.
- Cambardella, C.A., Moorman, T.B., Parkin, T.B., Karlen, D.L., Turco, R.F. and Konopka, A.E. 1994. Field scale variability of soil properties in Central Iowa soil. Soil Science Society of America Journal, 58: 1501-1511.
- Fan, Zh., Fan, X., Crosby, M.K., Moser, W.K., He, H., Spetich, M.A. and Shifley, S.R. 2012. Spatio-temporal trends of oak decline and mortality under periodic regional drought in the Ozark highlands of Arkansas and Missouri. Forests, 3: 614-631.
- Hamzehpour, M., Kia-Daliri, H. and Bordbar, K. 2011. Preliminary study of manna oak (Quercus brantii Lindl.) tree decline in Dashte-Barm of Kazeroon, Fars province. Iranian journal of Forest and Poplar Research, 19(2): 352-363 (In Persian).
- Hogg, E.H., Brandt, J.P. and Kochtubajda, B. 2002. Growth and dieback of aspen forests in northwestern Alberta, Canada, in relation to climate and insects. Canadian Journal Forest Research, 32: 823–832.
- Hoseini, A., Hoseini, M., Rahmani, A. and Azadfar, D. 2013. The effect of tree morality on Oak forest structure in Ilam province. Iranian Journal of Forest and Poplar Research, 20(4): 565-577 (In Persian).
- Hoseini, A., Hoseini, M., Rahmani, A. and Azadfar, D. 2014. Compare the characteristics of competitive environments in of healthy stand and declined stand. Iranian Journal of Forest and Poplar Research, 21(4): 606-616 (In Persian).
- Hoseinzadeh, J. and Pourhashemi, M. 2015. The study of crown indicators in Quercus brantii tress in relationship with mortality phenomenon in Ilam forests. Iranian Journal of Forest, 7(1): 57-66 (In Persian).
- Hoseinzadeh, J., Azami, A. and Mohammadpour, M. 2015. Study of the topography with Oak decline in Melah-siah forests in Ilam province. Iranian Journal of Forest and Poplar Research, 23(1): 190-197 (In Persian).
- Illian, J., Penttinen, A., Stoyan, H. and Stoyan, D. 2008. Statistical analysis and modeling of spatial point patterns. John Wiley and Sons, 556p.
- Khan, M.N.I., Sharma, S., Berger, U., Koedam, N., Dahdouh-Guebas, F. and Hagihara, A. 2013. How do tree competition and stand dynamics lead to spatial patterns in monospecific mangroves? Biogeosciences, 10: 2803–2814.
- Luis, M.D., Raventos, J., Wiegand, T. and Hidalgo, C.H. 2008. Temporal and spatial differentiation in seedling emergence may promote species coexistence in Mediterranean fire-prone ecosystems. Ecography, 31: 620-629.
- Mahdavi, A., Mirzaei Zadeh, V., Niknezhad, M. and Karami, O. 2015a. Assessment and prediction of oak trees decline using logistic regression model. Iranian Journal of Forest and Range protection, 13(1): 20-33 (In Persian).
- Mahdavi, A., Mirzaee, J. and Karami, O. 2015b. Condition of declined trees in Zagros forests (Case study: Bivareh local area in Ilam province). Journal of Sustainable Forest Development, 1(4): 329-340 (In Persian).
- Parvaneh, E., Etemad, V., Marvie Mohajer, M.R., Zahedi Amiri, Gh. and Attarod, P. 2016. The relationships between the rate of oak trees decline and forest types, soil characteristics and topographic conditions in Ghalaje forests of Kermanshah, west of Iran. Iranian Journal of Forest, 8(3): 263-275 (In Persian).
- Pourhashemi, M., Jahanbazi Goujani, H., Hoseinzade, J., Bordbar, S.K., Iranmanesh, Y. and Khodakarami, Y. 2017. The history of oak decline in Zagros forests. Journal of Iran nature, 2(1): 30-37 (In Persian).
- Quinn, J.F. and Dunham, A.E. 1983. On hypothesis testing in ecology and evolution. American Naturalist, 122: 602-617.
- Stoyan, D. 1984. On correlations of marked point processes. Mathematische Nachrichten, 116: 197–207.
- Webster, R. and Oliver, M.A. 2000. Geostatistics for environmental scientists. Wiley press, 271p.
- Wiegand, T., Moloney, K.A., Naves, J. and Knauer, F. 1999. Finding the missing link between landscape structure and population dynamics: a spatially explicit perspective. American Naturalist, 154: 605-627.
- Wiegand, T. and Moloney, K.A. 2004. Rings, circles, and null-models for point pattern analysis in ecology. OIKOS, 104: 209-229.
- Zandebasiri, M., Soosani, J. and Pourhashemi, M. 2017. Evaluation of the crisis severity in forests of Kohgiluye and Boyerahmad province. Iranian Journal of Forest and Poplar Research, 24(4): 665-674 (In Persian).