بررسی پیامد آتش‌سوزی بر ویژگی‌های فیزیکی و شیمیایی خاک در مراتع منطقه بدره (استان ایلام)

نوع مقاله : مقاله کامل علمی پژوهشی

نویسندگان

1 1دانش آموخته کارشناسی ارشد گروه مهندسی خاک و آب، دانشگاه ایلام

2 استادیار گروه مهندسی خاک و آب، دانشگاه ایلام

3 استادیار گروه علوم خاک دانشکده کشاورزی دانشگاه ایلام

چکیده

سابقه و هدف: آتش‌سوزی یک تهدید بزرگ منابع طبیعی در جهان محسوب می‌شود و به‌عنوان عاملی مهم در تغییر ویژگی‌های فیزیکی و شیمیایی خاک می‌باشد. آگاهی از پیامدهای مثبت یا منفی آتش‌سوزی بر ویژگی‌های خاک از نظر مدیریت منابع طبیعی می-تواند حائز اهمیت باشد. این مطالعه با هدف بررسی اثر آتش‌سوزی در مراتع منطقه بدره استان ایلام بر ویژگی‌های فیزیکی و شیمیایی خاک و نیز مقایسه آن با مناطق بدون آتش‌سوزی (شاهد) اجرا گردید.
مواد و روش‌ها: پس از بررسی‌های صحرایی و میدانی در مراتع منطقه بدره در شرق استان ایلام، پنج نمونه خاک از عمق‌های 5-0 و 20-5 سانتی‌متری به‌صورت تصادفی جمع‌آوری و به آزمایشگاه منتقل شدند و تجزیه‌های فیزیکی (بافت، میانگین وزنی قطر خاکدانه، رطوبت اشباع و جرم مخصوص ظاهری) و شیمیایی (مواد آلی، نیتروژن کل، فسفر قابل جذب، پتاسیم قابل جذب، کلسیم و منیزیم محلول، ظرفیت تبادل کاتیونی) روی نمونه‌های خاک انجام گرفت.
یافته‌ها: بیشترین مقدار شن (4/46 درصد) و سیلت خاک (4/24 درصد) در مرتع سوخته و بیشترین مقدار رس (39 درصد) در مرتع شاهد به‌دست آمد. آتش‌سوزی میزان میانگین وزنی قطر خاکدانه و تخلخل خاک را در مراتع سوخته در مقایسه با مراتع شاهد به‌ترتیب 28/14 و 76/8 درصد به‌طور معنی‌داری (05/0=α) کاهش داد. جرم مخصوص ظاهری خاک در مرتع سوخته در مقایسه با مرتع شاهد 1/9 درصد بیشتر بود. در عمق سطحی خاک آتش‌سوزی باعث افزایش رطوبت اشباع خاک به‌میزان 98/16 درصد در مقایسه با تیمار شاهد گردید. آتش‌سوزی مقدار ماده آلی خاک را از 66/2 درصد در مرتع شاهد به 19/2 درصد در مرتع سوخته به‌طور معنی‌داری (05/0=α) کاهش داد. اسیدیته خاک در مرتع سوخته (45/7pH=) نسبت به مرتع شاهد (07/7pH=) به‌طور معنی‌داری افزایش نشان داد. بیشترین میزان ظرفیت تبادل کاتیونی خاک (82/24 سانتی‌مول بار در کیلوگرم خاک) و کمترین (98/18 سانتی‌مول بار در کیلوگرم خاک) به‌ترتیب در خاک مرتع شاهد و سوخته حاصل گردید همچنین با افزایش عمق خاک، ظرفیت تبادل کاتیونی خاک 14/10درصد کاهش یافت. بیشترین فسفر قابل جذب خاک، منیزیم و کلسیم محلول در مرتع سوخته در عمق سطحی حاصل گردید. آتش‌سوزی در عمق زیرین خاک، تأثیر معنی‌‌داری بر مقدار فسفر قابل جذب، منیزیم و کلسیم محلول خاک نداشت.
نتیجه‌گیری: به‌طور کلی نتایج نشان می‌دهد آتش‌سوزی در مراتع منطقه بدره استان ایلام بر ویژگی‌های فیزیکی و شیمیایی خاک تأثیر داشته است به‌طوری‌که در بیشتر موارد باعث کاهش کیفیت خاک از لحاظ شیمیایی (کاهش ماده آلی، نیتروژن، ظرفیت تبادل کاتیونی) و فیزیکی (تغییر بافت، کاهش میانگین وزنی قطر خاکدانه، تخلخل و جرم مخصوص ظاهری) و در برخی موارد آتش‌سوزی با آزاد شدن عناصر غذایی نظیر فسفر، کلسیم و منیزیم در خاک باعث بهبود چرخه عناصر غذایی در خاک شده است.

کلیدواژه‌ها


عنوان مقاله [English]

Impact of fire on soil physical and chemical properties in the pastures of Badreh area in Ilam Province

نویسندگان [English]

  • Zeinab Riahi 1
  • Masoud Bazgir 2
  • Fatemeh Valizadeh-Kakhki 2
  • Mahmoud Rostamnia 3
1 M.Sc. Graduate, Dept. of Soil and Water Engineering, Ilam University, Ilam, Iran
2 2Assistant Prof., Dept. of Soil and Water Engineerin, Ilam University, Ilam, Iran,
3 Assistant Professor in soil science, Agricultural faculty, Ilam University.
چکیده [English]

Abstract
Background and objectives: Fire is a major threat for natural resources in the world and is an important factor in changing physical and chemical properties of soil. Knowledge of the positive or negative effects of fire on soil properties can be a great importance for the management of natural resources. This study was conducted with the aim of the effect of fire on physical and chemical properties of soil in rangelands of Badreh area in Ilam provice and comparison with non-fire areas (control).
Materials and methods: After field studies in Badreh area in the eastern of Ilam province, soil samples were taken from 0-5 and 5- 20cm depths and collected randomly and transferred to the laboratory. Physical analysis (soil texture, mean weight aggregate diameter, saturation moisture and bulk density) and chemical (organic matter, total nitrogen, phosphorus available, potassium available, calcium and magnesium exchangeable, cation exchange capacity) were carried out on soil samples.
Results: The highest amount of sand (46.4%) and soil silt (24.4%) were found in burned pasture and the highest clay content (39%) was found in control rangelands. Fire decreased the stability of aggregates and soil porosity in burned rangelands compared to unprocessed rangelands (14.28 and 8.68%) significantly (α= 0.05). The bulk density of the burned pasture was 9.1% higher than that of the control pasture. In the soil surface layer, the soil moisture content increased 16.98% compared to the control treatment. The fire decreased the amount of soil organic matter from 2.66% in control pasture to 2.19% in burned pasture (α= 0.05). Soil acidity increased significantly in burned pasture (pH=7.45) compared to control pasture (pH=7.07). The highest cation exchange capacity (24.82 cmol kg-1) and the lowest (18.98 cmol kg-1) were obtained in control and burned rangelands respectively. Also, with an increase in soil depth, the cation exchange capacity of soil decreased to 14.10%. The most available phosphorus, magnesium and calcium were obtained in burned pasture at the soil surface. Fire had no significant effect in the subsoil layer, on the amount of soil phosphorus, magnesium and calcium exchangeable.
Conclusion: In general, the results indicate that fire in rangelands of Badreh area in Ilam province affected physical and chemical properties of soil. In most cases, soil quality is decreased chemically (decreasing organic matter, nitrogen, cation exchange capacity) and physically (soil texture changing, soil aggregate stability, porosity and bulk density), and in some cases, fire caused to release the nutrient elements such as phosphorus, calcium and magnesium in the soil and improved the nutrient cycling nutrients in the soil.

کلیدواژه‌ها [English]

  • Fire
  • Soil pasture
  • Mean weight diameter
  • Soil depth
  • Soil Matter
1.Abdi, O., Kamkar, B., Shirvani, Z., Teixeira da Silva, J.A., and Buchroithner, M.F. 2016. Spatial-statistical analysis of factors determining forest fires: a case study from Golestan, Northeast Iran. Geomatics, Natural Hazards and Risk, Pp: 1-14.
2.Abrantes, J.R., de Lima, J.L., Prats, S.A., and Keizer, J.J. 2017. Assessing soil water repellency spatial variability using a thermographic technique: An exploratory study using a small-scale laboratory soil flume. Geoderma. 287: 98-104.
3.Arocena, J.M., and Opio, C. 2003. Prescribed fire-induced changes in properties of sub-boreal forest soils. Geoderma. 113: 1. 1-16.
4.Badía-Villas, D., González-Pérez, J.A., Aznar, J.M., Arjona-Gracia, B., and Martí-Dalmau, C. 2014. Changes in water repellency, aggregation and organic matter of a mollic horizon burned in laboratory: soil depth affected by fire. Geoderma. 213: 400-407.
5.Bisdom, E.B.A., Dekker, L.W., and Schoute, J.T. 1993. Water repellency of sieve fractions from sandy soils and relationships with organic material and soil structure. Geoderma. 56: 1-4. 105-118.] 
6.Busse, M.D., Hubbert, K.R., Fiddler, G.O., Shestak, C.J., and Powers, R.F. 2005. Lethal soil temperatures during burning of masticated forest residues. Inter. J. Wildland Fire. 14: 3. 267-276.
7.Chen, Y., and Schnitzer, M. 1978. The surface tension of aqueous solutions of soil humic substances. Soil Science. 125: 1. 7-15.
8.Debano, L.F., and Krammes, J.S. 1966. Water repellent soils and their relation to wildfire temperatures. Hydrol. Sci. J. 11: 2. 14-19.
9.Dekker, L.W., and Ritsema, C.J. 2000. Wetting patterns and moisture variability in water repellent Dutch soils. J. Hydrol. 231: 148-164.
10.Dlapa, P., Simkovic, I., Doerr, S.H., Kanka, R., and Mataix-Solera, J. 2008. Application of thermal analysis to elucidate water-repellency changes in heated soils. Soil Sci. Soc. Amer. J. 72: 1. 1-10.
11.Doerr, S.H., Blake, W.H., Shakesby, R.A., Stagnitti, F., Vuurens, S.H., Humphreys, G.S., and Wallbrink, P. 2004. Heating effects on water repellency in Australian eucalypt forest soils and their value in estimating wildfire soil temperatures. Inter. J. Wildland Fire. 13: 2. 157-163.
12.Doerr, S.H., Shakesby, R.A., and MacDonald, L.H. 2009. Soil water repellency: A key factor in post-fire erosion? In A. Cerdà and P.R. Robichaud (ed.) Fire effects on soils and restoration strategies. Science Publ., Enfield, NH.
13.Doerr, S.H., Shakesby, R.A., and Walsh, R. 2000. Soil water repellency: its causes, characteristics and hydro-geomorphological significance. Earth-Science Reviews. 51: 1. 33-65.
14.Fér, M., Leue, M., Kodešová, R., Gerke, H.H., and Ellerbrock, R.H. 2016. Droplet infiltration dynamics and soil wettability related to soil organic matter of soil aggregate coatings and interiors. J. Hydrol. Hydromech. 64: 2. 111-120.
15.Gee, G.W., and Or, D. 2002. 2.4 Particle-size analysis. Methods of soil analysis. Part. 4: 598. 255-293. 
16.González-Peñaloza, F.A., Zavala, L.M., Jordán, A., Bellinfante, N., Bárcenas-Moreno, G., Mataix-Solera, J., Granged, A.J., Granja-Martins, F.M., and Neto-Paixão, H.M. 2013. Water repellency as conditioned by particle size and drying in hydrophobized sand. Geoderma. 209: 31-40.
17.Inbar, A., Lado, M., Sternberg, M., Tenau, H., and Ben-Hur, M. 2014. Forest fire effects on soil chemical and physicochemical properties, infiltration, runoff, and erosion in a semiarid Mediterranean region. Geoderma. 221: 131-138.
18.Jiménez-Pinilla, P., Doerr, S.H., Ahn, S., Lozano, E., Mataix-Solera, J., Jordán, A., Zavala, L.M., and Arcenegui, V. 2016. Effects of relative humidity on the water repellency of fire-affected soils. Catena. 138: 68-76.
19.Jordán, A., Zavala, L.M., Mataix-Solera, J., and Doerr, S.H. 2013. Soil water repellency: origin, assessment and geomorphological consequences. Catena. 108: 1-5.
20.Jordán, A., Zavala, L.M., Mataix-Solera, J., Nava, A.L., and Alanís, N. 2011. Effect of fire severity on water repellency and aggregate stability on Mexican volcanic soils. Catena. 84: 3. 136-147.
21.Lebron, I., Robinson, D.A., Oatham, M., and Wuddivira, M.N. 2012. Soil water repellency and pH soil change under tropical pine plantations compared with native tropical forest. J. Hydrol. 414: 194-200.
22.Leue, M., Gerke, H.H., and Godow, S.C. 2015. Droplet infiltration and organic matter composition of intact crack and biopore surfaces from clay‐illuvial horizons. J. Plant Nutr. Soil Sci.
178: 2. 250-260.
23.Martínez-Zavala, L., and Jordán-López, A. 2009. Influence of different plant species on water repellency in Mediterranean heathland soils. Catena. 76: 3. 215-223.
24.Morgan, R.P.C. 2005. Soil Erosion and Conservation, 3rd. edition. Blackwell Publishing, Oxford.
25.Nelson, D.W., and Sommers, L.E. 1996. Total carbon, organic carbon and organic matter. Methods of soil analysis part 3-chemical methods, (methods of soil an 3). Pp: 961-1010.] 
26.Oostindie, K., Dekker, L.W., Wesseling, J.G., Ritsema, C.J., and Geissen, V. 2013. Development of actual water repellency in a grass-covered dune sand during a dehydration experiment. Geoderma. 204: 23-30.
27.Pardini, G., Gispert, M., and Dunjó, G. 2004. Relative influence of wildfire on soil properties and erosion processes in different Mediterranean environments in NE Spain. Science of the total Environment. 328: 1. 237-246.
28.Pierson, F.B., and Williams, C.J. 2016. Ecohydrologic impacts of rangeland fire on runoff and erosion: A literature synthesis.
29.Schaumann, G.E., Braun, B., Kirchner, D., Rotard, W., Szewzyk, U., and Grohmann, E. 2007. Influence of biofilms on the water repellency of urban soil samples. Hydrologicalprocesses. 21: 17. 2276-2284.
30.Shakesby, R.A., Coelho, C.D.A., Ferreira, A.D., Terry, J.P., and Walsh, R.P.D. 1993. Wildfire impacts on
soil-erosion and hydrology in wet Mediterranean forest, Portugal. Inter. J. Wildland Fire. 3: 2. 95-110.
31.Terefe, T., Mariscal-Sancho, I., Peregrina, F., and Espejo, R. 2008. Influence of heating on various properties of six Mediterranean soils. A laboratory study. Geoderma. 143: 3. 273-280.
32.Urbanek, E., Hallett, P., Feeney, D., and Horn, R. 2007. Water repellency and distribution of hydrophilic and hydrophobic compounds in soil aggregates from different tillage systems. Geoderma.140: 1. 147-155.
33.Varela, M.E., Benito, E., and Keizer, J.J. 2010. Effects of wildfire and laboratory heating on soil aggregate stability of pine forests in Galicia: The role of lithology, soil organic matter content and water repellency. Catena. 83: 2. 127-134.
34.Vogelmann, E.S., Reichert, J.M., Prevedello, J., Consensa, C.O.B., Oliveira, A.É., Awe, G.O., and Mataix-Solera, J. 2013. Threshold water content beyond which hydrophobic soils become hydrophilic: The role of soil texture and organic matter content. Geoderma. 209: 177-187.
35.Vogelmann, E.S., Reichert, J.M., Reinert, D.J., Mentges, M.I., Vieira, D.A., de Barros, C.A.P., and Fasinmirin, J.T. 2010. Water repellency in soils of humid subtropical climate of Rio Grande do Sul, Brazil. Soil and Tillage Research. 110: 126-133.
36.Watson, C.L., and Letey, J. 1970. Indices for characterizing soil-water repellency based upon contact angle-surface tension relationships. Soil Sci. Soc. Amer. J. 34: 6. 841-844.
37.Wijewardana, N.S., Müller, K., Moldrup, P., Clothier, B., Komatsu, T., Hiradate, S., de Jonge, L.W., and Kawamoto, K. 2016. Soil-water repellency characteristic curves for soil profiles with organic carbon gradients. Geoderma. 264: 150-159.