نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار دانشکده منابع طبیعی دانشگاه ارومیه

2 دانش آموخته کارشناسی ارشد مرتعداری دانشکده منابع طبیعی دانشگاه تربیت مدرس

3 استادیار دانشکده منابع طبیعی دانشگاه تربیت مدرس

چکیده

به منظور ارزیابی تاثیر گونه Pteropyrum aucheri   بر اجزاء ماده آلی خاک و پراکنش خاکدانه­ها، به عنوان شاخص حساس نسبت به تغییرات مدیریتی مرتع، نمونه­های خاک از دو مکان معرف تیپ­ گیاهی Pteropyrum aucheri - Astragalus microcephalus با خصوصیات فیزیکی تقریبا مشابه(شیب، جهت، ارتفاع) و غالبیت گونه Pteropyrum aucheri  ، اما متفاوت از نظر گونه­های همراه در ترکیب گیاهی، در مراتع خانقاه سرخ ارومیه مطالعه شد. برای این منظور در هر مکان، با توجه به پراکنش پوشش گیاهی و خصوصیات فیزیکی مراتع مورد بررسی، 6 عدد ترانسکت 100 متری که 4 عدد از آنها موازی با جهت شیب و 2 عدد از آنها عمود بر جهت شیب بودند،‌ بطور سیستماتیک در تیپ­های گیاهی مستقر و نمونه­های خاک با سه تکرار از لایه سطحی (عمق 15-0 سانتیمتر) و پائینی (30- 15 سانتیمتر) پروفیل­های حفر شده در ابتدا، وسط و انتهای ترانسکت­ها برداشت شد. سپس مقادیر شاخص­های خاک شامل؛‌ کربن، مواد آلی ذره­ای کربن (POM-C)،‌ ازت، مواد آلی ذره­ای نیتروژن (POM-N)، خاکدانه­های درشت و خاکدانه­های ریز و کربن موجود در خاکدانه­ها اندازه­گیری گردید. اطلاعات مربوط به پوشش گیاهی مکان­های انتخابی نیز در داخل پلات­های یک متر مربعی (60 عدد پلات) که با فواصل 10 متر از همدیگر در امتداد ترانسکت­ها مستقر شده بودند، ثبت و بر مبنای آنها، شاخص­های عددی تنوع و یکنواختی در مکان­های مذکور محاسبه شد. نتایج آنالیز واریانس نمونه­های خاک، نشان داد که بین مقادیر شاخص­ها در عمق­های مختلف خاک مکان­های مورد بررسی، اختلاف معنی­دار وجود دارد و در تمامی موارد بجز مقدار خاک دانه­های ریز، مقادیر شاخص­ها (شامل؛ مقدار کربن، نیتروژن، کربن آلی ذره­ای، نیتروژن آلی ذره­ای، درصد خاکدانه­های درشت، درصد کربن موجود در خاکدانه­های درشت و ریز)، در افق سطحی خاک بیشتر از افق پائینی می­باشد. ضمن اینکه مقادیر هر یک از شاخص­ها در مکان مرتعی شماره 1 به لحاظ تنوع گونه­ای بهتر، بیشتر از مکان مرتعی شماره 2 است. این امر بیانگر این است که اجزاء فیزیکی ماده آلی خاک، تغییرات بوجود آمده حاصل از تاثیر گونه Pteropyrum aucheri  را بر کمیت و کیفیت ماده آلی خاک می‌توانند توجیه کنند. ضمن اینکه نتایج مذکور، ظاهر شدن سریع تاثیر تغییرات مدیریتی در اجزاء نیتروژن و کربن ناپایدار را تایید و همچنین حساسیت پذیری مواد آلی ذره­ای خاک را در واکنش به تغییرات مدیریتی مرتع، اثبات کرد. بنابراین می­توان چنین نتیجه گیری کرد که داشتن اطلاعات پیرامون تغییرات مواد آلی ذره­ای و پراکنش خاکدانه­ها، به منظور مدیریت اکوسیستم­های مرتعی سودمند خواهد بود. 

کلیدواژه‌ها

عنوان مقاله [English]

Assessing the Impact of Pteropyrum Aucheri Species on Particulate Organic Matter and Soil Aggregate Dispersion

نویسندگان [English]

  • Javad Motamedi 1
  • Behnam Bahrami 2
  • Reza Erfanzadeh 3

1 Assistant Professor, Faculty of Natural Resources, Urmia University

2 Graduate Student of Range management, Faculty of Natural Resources, Tarbiat Modares University

3 Associate Professor, Faculty of Natural Resources, Tarbiat Modares University

چکیده [English]

In order to assess the impact of Pteropyrum aucheri on soil organic matter components and the soil aggregate dispersion, as the sensitive index of grassland management changes, soil samples were taken from two locations in area rangelands representing the Pteropyrum aucheri - Astragalus microcephalus vegetation types with similar physical properties (Slope, Aspect, Elevation) and dominance of Pteropyrum aucheri species but with different coexisting species in the species composition. For this purpose, in each location regarding the vegetation distribution and physical characteristics of the ranges under study, 6 transects that were 100 meters long were placed systematically in vegetation types while 4 of them were parallel to slope and 2 of them were perpendicular to the slope. Soil samples were taken with three replicates from surface horizons (depth of 0-15 cm) and lower horizons (depth of 15-30 cm) of drilled profiles at the beginning, middle, and end of transects. Then, the values of soil characteristics, including carbon, particulate organic matter carbon (POM-C), nitrogen, particulate organic matter nitrogen (POM-N), micro-aggregate, macro-aggregate, and the Carbon in the aggregate, were measured. The information related to the vegetation of selected areas inside one-squared meter plots (60 plots) with 10 meters long intervals deployed along the transects were recorded, and based on this information, numerical indices of diversity and evenness in the selected areas were calculated. The results of the ANOVA test of soil samples revealed that there is a significant difference between index values at different soil horizons of studied areas, and in all of the cases, excluding the amount of the micro-aggregate, the indices values (Including; C, N, POM-C, POM-N, Macro-aggregate, C-associated with macro and micro- aggregates) are more in surface horizons than the lower ones. Moreover, the values of each of the indices in number 1 grassland location was more than number 2 location since number 1 location has a better species diversity. This suggests that the physical components of soil organic matter justifies the changes resulted from the Pteropyrum aucheri species impact on the quantity and quality of soil organic matter. Furthermore, the above results confirm the hypothesis suggesting the rapid emergence of management changes in the components of nitrogen and unstable carbon. The results also prove the sensitivity of soil particulate organic matter to the pasture management changes. Therefore, having information regarding the changes of particulate organic matter and soil aggregate dispersion would be beneficial for the pasture ecosystem management. 

کلیدواژه‌ها [English]

  • vegetation distribution
  • Pteropyrum aucheri
  • soil aggregate
  • soil particulate organic matter
Referances
Allison LE. 1975. Organic carbon. In: BlackCA, Evans DD, White JL, Ensminger LE and Clark FE. (eds.). Methods of soil analysis, part 2, chemical and microbiological properties. American Society of Agronomy, Madison, Pp. 1367-1411.
Angers DA. 1992. Changes in soil aggregation and organic carbon under corn and alfalfa. American Journal of Soil Science, 56: 1244-1249.
Barrios E, Buresh RJ and Sprent JI. 1996. Nitrogen mineralization in density fractions of soil organic matter from maize and legume cropping systems. Soil Bio. Biochem. 28: 1459-1465.
Bremner JM and Mulvaney CS. 1982. Nitrogen-total. In: Page AL, Miller RH and Keeney RR. (eds.). methods of soil analysis, Part 2. 2nd Ed. American Society of Agronomy, Madison, WI, Pp. 595–624.
Cambardella CA and Elliott ET. 1992. Particulate soil organic matter changes  across a grassland cultivation sequence. American Journal of Soil Science, 56: 777-783.
Canqui HB, Lal R and Lemus R. 2005.  Soil aggregate properties and organic carbon for switch grass and traditional agricultural systems in the Southeastern United States. Journal of Soil Science, 12: 998- 1012.
Caravaca F, Figueroa D, Barea JM, Azcon- Aguilar C, Palenzuela J and Roldan A. 2010. The role of relict vegetation in maintaining physical, chemical, and biological properties in an abandoned stipa-grass agroecosystem. Arid Land Res. Manag. 17(2): 103-111.
Carter MR, Angers DA, Gregorich EG and Bolinder MA. 2003. Characterizing organic matter retention for surface soils in Eastern Canada using density and particle size fraction. Canadian Journal of Soil Science, 83: 11-23.
Chaney K and Swift RS. 1984. The influence of organic matter on aggregate stability in some british soils. Journal of Soil Science, 35: 223-230.
Clement CR and Williams TE. 1967. Leys and soil organic matter II. The accumulation of nitrogen in soils under different leys. Journal of Agricultural Science, 69: 133-138.
Dormaar IF. 1984. Monosacharides in hydrolysates of water-stable aggregate after 67 years of Cropping to Spring Wheat. Plant and Soil, 75: 51-61.
Elliot ET and Cambardella CA. 1991. Physical separation of organic matter. Agriculture, Ecosystems and Environment, 34: 407-419.
Feller C, Albrecht A and Tessier D. 1997. Aggregation and organic  matter storage in kaolinitic and smesitic tropical soils, In: stucture and organic matter storage in agricultural soils, Carter MR and Stewart BA. (Eds), CRC press, ISBN: 1-56670-033-7, Boca Raton, fl.
Franzluebbers AJ and SttuedemannGA. 2002. Particulate and nonparticulate farticulate of soil organic carbon under pastures in the Sounthern Piedmont USA. Enviro. Pollut. 116:53-62.
Franzluebbers AJ, Haney RL and Hones FM. 1999. Relationship of chloroform fumigation-incubation to soil organic matter pools. Soil Biol Biochem. 31: 395-405.
Garwood EA, Clement CR  and Williams TE. 1972. Leys and soil organic matter III. The accumulation of macro-organic matter in the soil under different swards. Journal of Agricultural Science, 78: 333-341.
Gregorich EG,  Carter MR,  Angers DA, Moneral CM and Ellert BH. 1994. Towards a minimum data set to assess soil organic matter quality in agricultural soils. Canadian Journal of Soil Science, 74: 367-385.
Handayani IP, Coyne MS and Tokosh RS. 2010. Soil organic matter fractions and aggregate distribution  in  response to tall fescue stands. Journal of Soil Science, 5: 1-10.
Handayani IP, Coyne MS, Barton C and Workman S. 2008. Soil carbon pools and aggregation following land restoration: Bernheim Forest, Kentucky. Journal of Environ. Monitor. Restoration, 4: 11-28.
Handayani IP, Prawito P and Muktamur Z. 2002. The role of natural-bush fallow in abandoned land during shifting cultivation in Bengkulu II. The role of follow vegetation. Journal of Agricultural Science, 4: 10-17.
Handayani IP. 2004. Soil quality changes following forest clearance in Bengkulu, Sumatra, Indonesia, Biotropia, 22: 1-15.
Hu SDC, Coleman CR, Carroll PF, Hendrix F and Beare MH. 1997. Labile soil carbon pools in subtropical forest and agricultural Ecosystem as influenced by management practices and vegetation types. Agriculture, Ecosys. and Environ. 65: 69-78.
Koutika LS, Hauser S and Henrot J. 2001. Soil organic matter assessment in natural regroeth pueraria phaseoloides and mucuna pruriens fallow. Soil Bio. Biochem. 33: 1095-1101.
Liang  BC, McKonkey BG, Schoenau J, Curtin D and  Campell CA. 2003. Effects of tillage and crop rotation on the light fraction of organic carbon and carbon mineralization in chermozemic soilsd of Saskatchewan. Canadian J. Soil Sci. 83: 65-72.
Moghimi J. 2005. Introduction some of important range species, suitable for range improvement in Iran, Arvan Press, 669p.
Motamedi J. 2006. The report on rangeland and vegetation cover feasibility studies in the Khanghah-e-Sorkh basin. Faculty of Natural Resources, Iran. UrmiaUniversity.
Oades JM. 1984. Soil organic matter and structural stability mechanisms and implications for management . Plant and Soil, 76: 319-337.
Oedraogo EA, Mando R and Stroosnijder L. 2006. Effect of tillage, organic resources and nitrogen fertilizer on soil carbon dynamics and crop nitrogen uptake in semi-arid West Africa. Soil Tillage Res. 91: 57-67.
Sparling GP. 1992. Ratio of microbial biomass to soil organic carbon as a sensitive indicator of changes in soil organic matter. Aus. J. Soil Res. 30 (2): 195-207.
Tisdall  J. 1991. Fungal hyphae and structural stability of soil. Aus. J. of Soil Rese. 29: 729-743.
Tisdall JM  and  Oades JM. 1982. Organic matter and water-stable aggregates in soils. J. Soil Sci. 33 (2): 141-163.
Tisdall JM and Oades JM. 1980. The management of ryegrass to stabilize aggregates of a red-brown earth. Aus. J. Soil Res. 18 (4): 415-422.