تعداد مناسب نمونه برای برآورد تاج‌بارش تک‌‌درختان بلوط ایرانی (Quercus brantii) در جنگل‌های زاگرس

نوع مقاله: علمی- پژوهشی


1 دانشجوی دکتری، دانشکده منابع طبیعی و علوم دریایی دانشگاه تربیت مدرس، نور، ایران

2 دانشیار، گروه جنگلداری و اقتصاد جنگل، دانشکده منابع طبیعی دانشگاه تهران، کرج، ایران

3 استادیار، گروه جنگلداری و علوم جنگل، دانشکده منابع طبیعی و علوم دریایی دانشگاه تربیت مدرس، نور، ایران


تغییرات مکانی تاج‌بارش به‌دلیل ساختار ناهمگن تاج‌پوشش و الگوهای متغیر بارندگی بسیار زیاد است. مطالعات موجود در زمینه تعیین تعداد نمونه مناسب برای برآورد این متغیر بسیار ناچیز است. هدف این پژوهش، تخمین تعداد جمع‌آوری‌کننده‌های موردنیاز برای برآورد میانگین تجمعی تاج‌بارش پنج تک‌درخت بلوط ایرانی (Quercus brantii) با درصد خطای معین در جنگل‌های زاگرس نزدیک شهر ایلام است. در جنگلی در نزدیکی شهر ایلام به مدت 14 ماه و در طول دوره رویش، اندازه‌گیری تاج‌بارش توسط 16 عدد جمع‌آوری‌کننده در هشت جهت زیر تاج‌پوشش هر تک‌درخت انجام شد و میزان بارندگی نیز توسط شش عدد جمع‌آوری‌کننده‌ باران مشخص شد. در این دوره، 23 مورد بارندگی با مجموع عمق 257/4 میلی‌متر اندازه‌گیری شد که به‌طور متوسط 68/9 درصد آن به‌صورت تاج‌بارش از تاج‌پوشش عبور و به کف جنگل رسید. میانگین تعداد جمع‌آوری‌کننده‌های لازم با درصد خطای پنج، 10 و 15 درصد از میانگین تجمعی تاج‌بارش و با حدود اعتماد 95 درصد به‌ترتیب 70 (41 تا 138 عدد)، 18 (10 تا 35 عدد) و 8 (5 تا 15 عدد) عدد تخمین زده شد. بنابر نتایج این مطالعه، تعداد 16 عدد جمع‌آوری‌کننده مورداستفاده برای اندازه‌گیری میانگین تجمعی تاج‌بارش با خطای 15 درصد کافی است و برای تخمین آن با درصد خطای کمتر باید تعداد جمع‌آوری‌کننده‌ها افزایش یابد.


عنوان مقاله [English]

The optimum samples size to estimate throughfall for individual Brant`s oaks (Quercus brantii) in Zagros forests

نویسندگان [English]

  • Omid Fathizadeh 1
  • Pedram Atarod 2
  • Hormoz Sohrabi 3
1 Ph. D. Student, Department of Forestry and Forest Sciences, Faculty of Natural Resources and Marine ‎Sciences, Tarbiat Modares University, Noor, I.R. Iran.‎
2 Associate Prof., Department of Forestry and Forest Economics, Faculty of Natural Resources, ‎University of Tehran, Karaj, I.R. Iran
3 Assistant Prof., Department of Forestry and Forest Sciences, Faculty of Natural Resources and Marine Sciences, ‎Tarbiat Modares University, Noor, I.R. Iran.‎
چکیده [English]

Throughfall (TF) has a large spatial variability due to the heterogeneous canopy structure and variable rainfall patterns. In this study, the aim was to estimate the optimum number of collectors needed to obtain a mean cumulative TF value within certain error limits for five individual Brant’s oak trees (Quercus brantii) in the Zagros forests of Ilam in western Iran. Sixteen TF manual gauges were placed beneath the five selected tree canopies in eight geographic directions and the gross rainfall (GR) was measured by the mean of six homemade gauges for a period of 14 months in leaf-on condition. During this period, 23 rainfall events with cumulative depth of 257.4 mm were collected, of which an average TF rate of 68.9% reached the forest floor. An average of 70 (range between 41-138), 18 (range between 10-35), and 8 (range between 5-15) gauges would be required to estimate mean cumulative TF to within ±5, ±10, and ±15% percent errors at the 95% confidence level, respectively. Based on the results of this study, 16 gauges are sufficient to estimate mean cumulative TF with an error of 15% and a confidence interval of 95%. However, the number of gauges should be increased if a lower error rate for the mean cumulative TF estimations is required.

  -Bellot, J. and Escarre, A. 1991. Chemical characteristics and temporal variations of nutrients in throughfall and stemflow of three species of Mediterranean holm oak forest. Forest Ecology and Management, 41: 125-135.

- Bouten, W., Heimovaara, T.J. and Tiktak, A. 1992. Spatial patterns of throughfall and soil water dynamics in a Douglas fir stand. Water Resource Research, 28: 3227-3233.

 -Cao, Y., Ouyang, Z.Y., Zheng, H., Huang, Z.G., Wang, X.K. and Miao, H. 2008. Effects of forest plantation on rainfall redistribution and erosion in the red soil region of Southern China. Land Degradation Development, 19: 321-330.

- Carlisle, A., Brown, A.H.F. and White, E.J. 1965. The interception of precipitation by oak (Quercus petraea) on a high rainfall site. Quarterly Journal of Forestry, 58: 140-143.

- Carlyle-Moses, D.E., Fores Laureano, J.S. and Price, A. 2004. Throughfall and throughfall spatial variabiltiy in Madrean oak forest communities of northeastern Mexico. Journal of Hydrology, 297: 124-135.

- Czarnowski, M.S. and Olszewski, J.L. 1970. Number and spacing of rainfall-gauges in a deciduous forest stand. Oikos, 21: 48-51.

- Deguchi, A., Hattori, S. and Park, H. 2006. The influence of seasonal changes in canopy structure on interception loss: application of the revised Gash model. Journal of Hydrology, 319: 80-102.

- Fathizadeh, O., Attarod, P., Keim, R.F., Zahedi Amiri, G.H. and Darvishsefat, A.A. 2014. Spatial heterogeneity and temporal stability of throughfall under individual Quercus brantii trees. Hydrological Processes, 28: 1124-1136.

- Ford, E. and Deans, J. 1978. The effects of canopy structure on stemflow, throughfall and interception loss in a young Sitka spruce plantation. Journal of Applied Ecology, 15: 905-917.

- Gomez, J.A., Vanderlinden, K., Giraldez, J.V. and Fereres, E. 2002. Rainfall concentration under olive trees. Agricultural Water Management, 55: 53-70.

- Helvey, J.D. and Patric, J.H. 1965. Canopy and litter interception of rainfall by hardwoods of eastern United States. Water Resource Research, 1: 193-206.

- Holwerda, F., Scatena, F.N. and Bruijnzeel, L.A. 2006. Throughfall in a Puerto Rican lower montane rain forest: A comparison of sampling strategies. Journal of Hydrology, 327: 592-602.

- Kimmins, J.P. 1973. Some statistical aspects of sampling throughfall precipitation in nutrient cycling studies in British Columbian coastal forests. Ecology, 54: 1008-1019.

- Kostelnik, K.M., Lynch, J.A., Grimm, J.W. and Corbett, E.S. 1989. Sample size requirements for estimation of throughfall chemistry beneath a mixed hardwood forest. Journal of Environmental Quality, 18: 274-280.

- Lawrence, G.B. and Fernandez, I.J. 1993. A reassessment of areal variability of throughfall deposition measurements. Ecological Applications. 3: 473-480.

- Levia, D.F. and Frost, E.E. 2006. Variability of throughfall volume and solute inputs in wooded ecosystems. Progress in Physical Geography, 30: 605-632.

- Llorens, P., Poch, R., Latron, J. and Gallart, F. 1997. Rainfall interception by a Pinus sylvestris forest patch overgrown in a Mediterranean mountainous abandoned area I. Monitoring design and results down to the event scale. Journal of Hydrology, 199: 331-345.

- Lloyd, C.R. and Marques, F. 1988. Spatial variability of throughfall and stemflow measurements in Amazonian rainforest. Agricultural and Forest Meteorology, 42: 63-73.

- Loustau, D., Berbigier, P., Granier, A. and El Hadj Moussa, F. 1992. Interception loss, throughfall and stemflow in a maritime pine stand. I. Variability of throughfall and stemflow beneath the pine canopy. Journal of Hydrology, 138: 449-467.

- Madgwick, H.A.I. and Ovington, J.D. 1959. The chemical composition of precipitation in adjacent forest and open plots. Forestry, 32: 14-22.

- Mamanteo, B.P. and Veracion, V.P. 1985. Measurements of fog drip, throughfall and stemflow in the mossy and Benguet pine (Pinus kesiya Royle ex Gordon) forest in the Upper Agno River Basin. Sylvatrop-Philippines Forestry Research Journal, 10: 271-282.

- Manderscheid, B. and Matzner, E. 1995. Spatial and temporal variation of soil solution chemistry and ion fluxes through the soil in a mature Norway spruce (Picea abies (L.) Karst.) stand. Biogeochemistry, 30: 99-114.

- Marvie Mohadjer, M.R. 2006. Silviculture. University of Tehran Press, Tehran, 387p (In Persian).

- Masukata, H., Ando, M. and Ogawa, H. 1990. Throughfall, stemflow and interception of rainwater in an evergreen broadleaved forest. Ecological Research, 5: 303-316.

- Möttönen, M., Järvinen, E.T., Hokkanen, J., Kuuluvainen, T. and Ohtonen, R. 1999. Spatial distribution of soil ergosterol in the organic layer of a mature Scots pine (Pinus sylvestris L.) forest. Soil Biology and Biochemistry, 31: 503-516.

- Navar, J., Carlyle-Moses, D.E. and Martinez, M.A. 1999. Interception loss from the Tamaulipan matorral thornscrub of north-eastern Mexico: an application of the Gash analytical interception loss model. Journal of Arid Environments, 41: 1-10.

- Parker, G.G. 1983. Throughfall and stemflow in the forest nutrient cycle. Advances in Ecological Research, 13: 57-133.

- Pressland, A.J. 1973. Rainfall partitioning by an arid woodland (Acacia aneura F. Muell.) in South-West Queensland. Australian Journal of Botany, 21: 235-245.

- Price, A.G., Dunham, K., Carleton, T. and Band, L. 1997. Variability of water fluxes through the black spruce (Picea mariana) canopy and feather moss (Pleurozium schreberi) carpet in the boreal forest of Northern Manitoba. Journal of Hydrology, 196: 310-323.

- Price, A.G., Watters, R.J. 1989. The influence of overstory, understory and upper soil horizons on the fluxes of some ions in a mixed deciduous forest. Journal of Hydrology, 109: 185-197.

- Puckett, L.J. 1991. Spatial variability and collector requirements for sampling throughfall volume and chemistry under a mixed hardwood canopy. Canadian Journal of Forest Research, 21: 1581-1588.

- Robson, A.J., Neal, C., Ryland, G.P., Harrow, M. 1994. Spatial variation in throughfall chemistry at the small plot scale. Journal of Hydrology, 158: 107-122.

- Rodrigo, A. and Avila, A. 2001. Influence of sampling size in the estimation of mean throughfall in two Mediterranean holm oak forests. Journal of Hydrology, 243: 216-227.

- Schume, H., Jost, G. and Katzensteiner, K. 2003. Spatio-temporal analysis of the soil water content in a mixed Norway spruce (Picea abies (L.) Karst.)-European beech (Fagus sylvatica L.) stand. Geoderma, 112: 273-287.

- Sraj, M., Brilly, M. and Mikos, M. 2008. Rainfall interception by two deciduous Mediterranean forests of contrasting stature in Slovenia. Agricultural and Forest Meteorology, 148: 121-134.

- Staelens, J., De Schrijver, A., Verheyen, K. and Verhoest, N.E.C. 2008. Rainfall partitioning into throughfall, stemflow, and interception within a single beech (Fagus sylvatica L.) canopy: Influence of foliation, rain event characteristics, and meteorology. Hydrological Processes, 22: 33-45.

- Thimonier, A. 1998. Measurement of atmospheric deposition under forest canopies: Some recommendations for equipment and sampling design. Environmental Monitoring and Assessment, 52: 353-387.

- Veneklaas, E.J. 1990. Nutrient fluxes in bulk precipitation and throughfall in two montane tropical rain forests, Colombia. Journal of Ecology, 78: 974-992.

- Wullaert, H., Pohlert, T., Boy, J., Valarezo, C. and Wilcke, W. 2009. Spatial throughfall heterogeneity in a montane rain forest in Ecuador: Extent, temporal stability and drivers. Journal of Hydrology, 377: 71-79.

- Xiao, Q.F., McPherson, E.G., Ustin, S.L., Grismer, M.E. and Simpson, J.R. 2000. Winter rainfall interception by two mature open-grown trees in Davis, California. Hydrological Processes, 14: 763-784.