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تاثیر نوسانات اقلیمی بر درصد پوشش تاجی گونه های علوفه ای شاخص مراتع استپی قوشه سمنان | ||
| تحقیقات مرتع و بیابان ایران | ||
| مقاله 17، دوره 26، شماره 3، مهر 1398، صفحه 717-730 اصل مقاله (844.85 K) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22092/ijrdr.2019.120019 | ||
| نویسندگان | ||
| ناهید عزیزی1؛ حامد جنیدی* 2؛ خالد اوسطی3 | ||
| 1دانش آموخته کارشناسی ارشد، مرتعداری، گروه مهندسی مرتع و آبخیزداری، دانشکده منابع طبیعی، دانشگاه کردستان، سنندج، ایران | ||
| 2استادیاردانشکده منابع طبیعی، دانشگاه کردستان، سنندج، ایران، | ||
| 3استادیارگروه مهندسی مرتع و آبخیزداری، دانشکده منابع طبیعی، دانشگاه کردستان، سنندج، ایران | ||
| چکیده | ||
| در این پژوهش، ضمن پایش روند تغییرات درصد پوشش تاجی گونههای شاخص مراتع استپی منطقه قوشه در استان سمنان طی یک دوره دهساله؛ ارتباط بین دو عامل مهم اقلیمی (بارش و دما) و تغییرات درصد پوشش تاجی نیز بررسی شد. بدین منظور، درصد پوشش تاجی شش گونه گیاهی شاخص (به تفکیک گونه) و گیاهان یکساله بصورت ترکیبی مصــادف بــا رشد کامل گونهها، بر روی دو ترانسکت 250 متری و در 30 پلات دو متر مربعی(به فواصل 15 متر از هم) بصورت سالانه و به مدت 10 سال اندازهگیری شد. نتایج نشان داد که بالاترین مقدار درصد پوشش تاجی، در سال آبی 86-1385 (با بارش بیش از میانگین دوره) و کمترین مقدار آن در سال آبی 92-1391 (با بارش کمتر از میانگین دوره) و به ترتیب معادل 15 و 5/5 درصد بود. مدلسازی درصد پوشش تاجی براساس روش رگرسیونی خطی و با استفاده از متغیرهای بارش و دما انجام گرفت. نتایج نشان داد که بارشهای یک ماهه فروردین، قادر است 65 درصد تغییرات درصد پوشش تاجی گونه A. sieberiرا در سطح اطمینان 95 درصد توجیه نماید (با 26/0=RRMSE و 49/0 =MAE). بهترین مدل ارائه شده برای برآورد درصد پوشش تاجی گونههای S. barbata و Z. eurypterum، مربوط به مدل مبتنی بر بارش چهار ماهه اسفند تا خرداد و مدل مبتنی بر بارش یک ماهه اسفند بود که به ترتیب 77 (در سطح اطمینان 99 درصد) و 67 (در سطح اطمینان 95 درصد) درصد تغییرات تاج پوشش این گونهها را توجیه مینمایند. با توجه به نقش قابل توجه گونـههای A. sieberi، S. barbata و Z. eurypterum در ترکیب پوشش گیاهی مراتع مورد پژوهش، میتوان بیان نمود که بخش عمده تغییـرات پوشش تاجی، براساس تغییـرات بارش دوره رویـش، قابل پیشبینی میباشد. | ||
| کلیدواژهها | ||
| پوشش تاجی؛ نوسانات اقلیمی؛ بارش؛ رگرسیون خطی؛ قوشه | ||
| عنوان مقاله [English] | ||
| The effects of climate variability on canopy cover percentage of forage species in Ghosheh steppe Rangelands, Semnan Province | ||
| نویسندگان [English] | ||
| Nahid Azizi1؛ Hamed Joneidi2؛ Khaled Osati3 | ||
| 1MSc student, Department of Range and Watershed Management, College of Natural Resources, University of Kurdistan,Sanandaj, Iran | ||
| 2Assistant professor, Department of Range and Watershed Management, College of Natural Resources,University of Kurdistan,sanangdaj,Iran | ||
| 3Assistant professor, Department of Range and Watershed Management, College of Natural Resources, University of Kurdistan,sanangdaj,Iran | ||
| چکیده [English] | ||
| This research monitored changes in canopy cover percentage of typical species during a 10-year period in the Ghosheh rangelands to find out the relationship between two important climate variables (precipitation and temperature) and canopy cover changes. Therefore, the canopy cover percentages of six typical species (separately) and annual species (overall) were measured during 10 years at the end of growing season in thirty 2-m2 plots, distributed along two 250–m transect lines. The results demonstrated that the maximum canopy cover percentage for water year 2006-2007 (wet-year) and the minimum value for water year 2012-2013 (drought) were 15% and 5.5%, respectively. The canopy cover percentage modeling was performed based on linear regression method using precipitation and temperature variables. The precipitation of April explained 65% of changes in canopy cover percentage of A. sieberiat 95% confidence level (RRMSE = 0.26 & MAE=0.49). The best simple linear regression model for estimating canopy cover percentage of S. barbata and Z. eurypterum was introduced by total precipitation of March-June and precipitation of March, representing 77% (at 99% confidence level) and 67% (at 95% confidence level) of changes in canopy cover, respectively. Considering the dominant role of A. sieberi, S. barbata and Z. eurypterum in vegetation composition of study areas, it can be concluded that most changes in canopy cover of the studied rangeland are predictable by variabilityofprecipitation during growing seasons. | ||
| کلیدواژهها [English] | ||
| Canopy cover, Climatic variability, Precipitation, Linear regression, Ghosheh | ||
| مراجع | ||
|
- Abdollahi, J., Arzani, H. and Naderi, H., 2011 (B). The investigation of vegetation changes in relation to rainfall variation in Ebrahim abad steppe rangelands, Yazd provience. Journal of Watershed Management Research (Pajouhesh & Sazandegi), 90:68-77. - Abdollahi, J., Arzani, H., Savaghebi, M. H., Azimi, M. S. and Naderi, H., 2012. The effect of precipitationfluctuations on canopy cover and range forage production in Yazd semi-steppe rangelands (Khud area 1378-1386). Iranian Journal of Range and Desert Research,19(1): 45-59. - Abdollahi, J., Savaghebi, M. H., Naderi, H. and Azimi M. A., 2011(A). Influences of rainfall variability on yields of some plant species (Case Study: Mehriz rangeland of Yazad province). Journal of Rangeland, 5(3): 280-291. - Akbarzadeh, M. and Mirhaji, T., 2007. Vegetation changes under precipitation in Steppic rangelands of Rudshur. Iranian Journal of Range and Desert Research, 13(3): 222-235. - Arzani, H. and Abedi, M., 2015. Rangeland assessment; vegetation measurement. University of Tehran Press, 305p. - Arzani, H. and Abedi, M., 2015. Rangeland assessment, survey and monitoring, University of Tehran Press, 224p. - Akbarzadeh, M., Moghadam, M. R., Jalili, A., Jafari, M. and Arzani, H., 2007. Effect of precipitation on cover and production of rangeland plants in Polour. Journal of the Iranian Natural Resources, 60(1): 307-322. - Arzani, H. and King, G. W., 1994. A double Samplingin Australian Rangelands. Rangeland Conference. 201-202p. - Arzani, H., 1997. Project manual of range evaluation in different climatic regions of Iran, Research Institute of Forests and Rangelands, 30p. - Bayat, M., Arzani, H. and Jalili, A., 2016. Effects of climatic conditions on vegetation cover and production in steppe rangelands (Case Study: Alavijeh and Khondab-Isfahan province). Iranian Journal of Range and Desert Research, 23(2): 357-372. - Bradley, B. A. and Mustard, J. F., 2005. Identifying land cover variability distinct from land cover change cheatgrass in the great basin. Journal of Remote Sensing of Environment, 94: 204–213. - Connor, T. G. and Raux, P. W., 1995. Vegetation changes (1949-71) in a semiarid, grassy dwarf shrub lands in the karoo, South Africa: Influence of rainfall variability and grazing by sheep. Journal of Applied Ecology, 32: 612-626. - Ehleringer, J. R., Schwinning, S. and Gebauer, R., 1999. Water use in arid land ecosystems. In: Press, M.C. Scholes, J. D. Barker, M. G. (Eds.), Physiological plant ecology. Blackwell Science, Boston, USA, 347-365. - Ghelichnia, H., Arzani, H., Akbarzadeh, M., Farahpour, M.and Azimi, M., 2012. Investigation on variation trends of vegetation and yield in rangelands of Mazandaran province (2001-2005). Iranian Journal of Range and Desert Research, 19(2): 203-220. - Hein, L., 2006. The impacts of grazing and rainfall variability on the dynamics of a sahelian rangeland. Journal of Arid Environments, 64: 504-488. - Herbel, C. H., Ares, F. N. and Wright, R. A., 1972. Drought effects on a semidesert grasslandrange. Journal of Ecology, 53: 1084-1093. - Hosseini, S. A. and Khatir Namany, J., 2014. Vegetation changes in natural semi-steppe rangelands of Gomishan, Golestan, Journal of Plant Ecosystem Conservation, 2(4): 61-78. - Hosseini, S. A., Khatir Namany, J. and Akbarzadeh, M., 2014. Vegetation changes in semi-steppe rangelands of Golestan province (Case study: Maraveh tapeh). Iranian Journal of Range and Desert Research, 21(4):685- 697. - Jabbogy, E. G. and Sala, O. E., 2000. Control of grass and shrub above ground production in the Patagonian steppe. Journal of Ecological Applications, 10(2):541-549. - Jagerbrand, A. K. Molau, U. Alatalo, J. M. and Chrimes, D., 2009. Plant community responses to 5 years of simulated climate change in meadow and heath ecosystems at a subarctic-alpine site. Journal of Oecologia, 161:601-610. - Jamieson, P. D., Porter, J. R. and Wilson, D. R., 1991. A test of the computer simulation model ARCWHEAT on wheat crops grown in New Zealand. Journal of Fields Crop Research, 27(4): 337 -350. - Joneidi Jafari, H., 2009. Investigating the impact of some ecological and managerial characteristics on the carbon sequestration in Semnan Province. Ph.D. Thesis in Rangeland, Faculty of Natural Resources, University of Tehran. - Kashki, M. T., Shahmoradi, A. and Namdost, T., 2015. Investigation on variation and trend of vegetation fluctuations in desert ecosystems (Case Study: Jajrom area, North Khorasan). Journal of Desert Ecosystem Engineering, 4(7): 87-98. - Moghaddam, M., 1998. Range and range management. Tehran University Press, 470 p. - Munkhtsetseg, E., Kimura, R., Wang, J. and Shinoda, M., 2007. Pasture yield response to precipitation and high temperature in Mongolia. Journal of Arid Environment, 70: 94-110. - Navarro, J. M., Galt, D., Holechek, J., McCormick, J. and Molinar, F., 2002. Long-term impacts of livestock grazing on Chihuahuan desert rangelands. Journal of Range Management, 55(4): 400-405. - Noy-Meir, I., 1973. Desert ecosystems: environment and producers. Annual Review of Ecology and Systematics, 4: 25-51. - Osati, K. H., Karimi, B. and Karami, M., 2008. Comparative Study of Six widely-used meteorological drought Indices in Northern Provinces of Iran in order to monitor past century drought and wet-year by the best Index. 1st International Symposium of Climate Change and Dendrochronology in Caspian Ecosystems, May 14-15, Sari, Iran. - Raynaud, X. and Leadley, P. W., 2004. Soil characteristics play a key role in modeling nutrient competition in plant communities. Journal of Ecology, 85: 2200-2214. - Schwinning, S. Starr, B. I. and Ehleringer, J. R., 2003. Dominant cold desert plants do not partition warm season precipitation by event size. Journal of Oecologia, 136: 252-260 - Sharifi, J., Shahmoradi, A. A., Nouri, A. V. and Mohammadi, D., 2017.Vegetation monitoring in semi-steppe rangelands of Ardabil province (Aghdagh Rangeland, Khalkhal). Journal of Rangeland, 11(3):283-293. - Walter, H., 1979. Vegetation of the earth and ecological systems of the Geo-bioshers. Springer-Verlag, Berlin Heidelberg New York Tokyo, 274 pp. - Zarekia, S., 2015. Trend of Salsola laricina production and consumption in dry rangelands. Journal of Plant Ecosystem Conservation, 3(7):85-98. | ||
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