نشریه علمی - پژوهشی مرتع و آبخیزداری

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکترایدانشجوی کارشناسی ارشد مرتعداری، دانشکدۀ منابع طبیعی، دانشگاه تربیت مدرس مرتع، دانشگاه شهرکرد

2 دانشیار گروه مرتعداری، دانشکدۀ منابع طبیعی، دانشگاه تربیت مدرس

3 استادیار گروه مرتع و آبخیزداری، دانشکدۀ کشاورزی، دانشگاه ایلام

چکیده

چرای شدید دام یکی از مخرب‎ترین عوامل در عرصۀ مراتع نیمه­خشک کشور است که باعث کاهش تنوع و از بین رفتن برخی از گیاهان حساس به چرا می‏گردد. از طرف دیگر با توجه به تغییرپذیری الگوی پراکنش گونه‎های گیاهی در مقیاس‌های مختلف، لزوم استفاده از مقیاس در ارزیابی‎های تنوع ضروی است. بنابراین این تحقیق با استفاده از روش تقسیم‏بندی افزایشی به بررسی تأثیر چرای دام روی مؤلفه‎های تنوع در مقیاس‌های گوناگون در مراتع غرب کشور در ایلام می­پردازد. بدین منظور نمونه‎برداری از 40 پلات 4 مترمربعی در 8 سایت مرتعی شامل 4 سایت قرق و چهار سایت در حال چرا انجام گرفت. بر اساس روش تقسیم‎بندی افزایشی کل تنوع به مؤلفه‏های افزایشی درون و بین نمونه‎ها (پلات و سایت) تقسیم‎بندی گردید. نتایج نشان داد که تنوع بین سایت (بتا2) دارای بیشترین سهم از تنوع کل بود که نشان دهندۀ تفاوت در ترکیب بین سایت‎ها و اهمیت این مقیاس برای امور حفاظتی است. همچنین اعمال قرق سبب افزایش تنوع گونه‎ای در سطح پلات (آلفا 1 و بتا1) گردید، در حالی که سبب کاهش تنوع گونه‎ای در مقیاس‌ سایت (تنوع بین سایت‎ها یا بتا2) شد. بنابراین الزاماً قرق کردن مراتع منجر به افزایش تنوع به­ویژه در سطوح وسیع­تر نخواهد شد. همچنین قرق دراز مدت می‎تواند منجر به افزایش یکنواختی و افزایش رقابت بین گیاهان شده و در نهایت تنوع گونه‏ای را کاهش دهد.

کلیدواژه‌ها

عنوان مقاله [English]

Study on the effect of Livestock Grazing on Plant Species Diversity Components in Semi-arid regions

نویسندگان [English]

  • Reza midipour 1
  • Reza Erfanzadeh 2
  • Marzban Faramarzi 3

1 u

2 u

3 u

چکیده [English]

Intensive livestock grazing is one of the most important destructive factors in rangelands that leads to decrease of diversity and causes disappearance of sensitive plants. On the other hand, considering the scales in assessment of diversity is very importance to study the variability of plant diversity patterns in different scales. Therefore, current study aimed to investigate the impact of livestock grazing on diversity components in different scales using additive partitioning methods in western country rangelands in the Ilam province. Sampling was carried out in 40 plots of 4m2 in 8 rangeland sites including 4 exclosures and 4 grazing sites. Based on additive partitioning diversity methods, the total diversity was partitioned into additively components within and among samples. The results showed that diversity among sites (β‌2) had the highest contribution of total diversity that indicated the importance of this scale for conservation practices, and it was due to the variation of composition between sites. In addition, the results represented that exclosure in the semi-arid areas can increase diversity at plot scale, while in the regional scales (diversity among sites or β‌2) livestock grazing leads to increase in diversity. Therefore, exclosure of rangelands does not necessarily lead to increase in diversity. Also, long terms exclosure can lead to increase evenness that resulting in increasing competition among plants, therefore it could decrease plant diversity.

کلیدواژه‌ها [English]

  • Livestock grazing
  • species diversity
  • additive partitioning
  • Rangeland
  • Ilam
 [1] Chandy, S., Gibson, D.J. and Robertson P.A. (2006). Additive Partitioning of Diversity across Hierarchical Spatial Scales in a Forested Landscape. Journal of Applied Ecology, 43, 792-801.
[2] Chiarucci, A., Bacaro, G., Filibeck, G., Landi, S., Maccherini, S. and Scoppola, A. (2012). Scale Dependence of Plant Species Richness in a Network of Protected areas. Biodiversity conservation, 21, 503-516.
[3] Clough, Y., Holzschuh, A., Gabriel, D., Purtauf, T., Kleijn, D., Kruess, A., Steffan-Dewenter, I. and Tscharntke, T. (2007). Alpha and Beta Diversity of Arthropods and Plants in Organically and Conventionally Managed Fields. Journal of Applied Ecology, 44, 804-812.
[4] Coulloudon, B., Eshelman, K. and Gianola, J. (1999). Sampling Vegetation Attributes, Interagency Technical Reference, Bureau of Land Management. Department of the Interior, USA, 171 p.
[5] Crist, T.O. and Veech, J.A. (2006). Additive Partitioning of Rarefaction Curves and Species–Area Relationships: Unifying α, β, and γ Diversity with Sample Size and Habitat Area. Ecology Letters, 9, 923-932.
[6] Crist, T.O., Veech, J.A., Gering, J.C. and Summerville, K.S. (2003). Partitioning Species Diversity across Landscape and Regions: A Hierarchical Analysis of α, β, and γ Diversity. The American Naturalist, 162, 734-743.
[7] Devictor, V. and Robert, A. (2009). Measuring community responses to large-scale disturbance in conservation biogeography. Diversity and Distributions, 15, 122-130.
[8] Erfanzadeh, R., Omidipour, R. and faramarzi. (2015). Variation of plant diversity components in different scales in relation to grazing and climatic conditions. Plant Ecology & Diversity, 4 (1), 437-445.
[9] Faramarzi, M., Kesting, S., Isselstein, J. and Wrage, N. (2010). Rangeland Condition in Relation to Environmental Variables, Grazing Intensity and Livestock Owners’ Perceptions in Semi-Arid Rangeland in Western Iran. The Rangeland Journal, 32 (4), 367-377.
[10] Foxcroft, L.C., Richardson, D.M., Rouget, M. and MacFadyen, S. (2009). Patterns of alien plant distribution at multiple spatial scales in a large national park: implications for ecology, management and monitoring. Diversity and Distributions, 15, 367-378.
[11] Gabriel, D., Roschewitz, I., Tscharntke, T. and Thies. C. (2006). Beta Diversity at Different Spatial Scales: Plant Communities in Organic and Conventional Agriculture. Ecological Applications, 16 (5), 2011-2021.
[12] Gering, J.C., Crist, T.O. and Veech, J.A. (2003). Additive Partitioning of Species Diversity across Multiple Spatial Scales: Implications for Regional Conservation of Biodiversity. Conservation Biology, 17 (2), 488-499.
[13] Golodets, C., Kigel, J. and Sternberg, M. (2011). Plant Diversity Partitioning in Grazed Mediterranean Grassland at Multiple Spatial and Temporal Scales. Journal of Applied Ecology, 48, 1260-1268.
[14] Jost, L. (2007). Partitioning Diversity into Independent Alpha and Beta Components. Ecology, 88, 2427-2439.
[15] Kehinde, T. and Samways, M.J. (2014). Management Defines Species Turnover of Bees and flowering Plants in Vineyards. Agricultural and Forest Entomology, 16, 95-101.
[16] Khani, M., Ghanbarian, G. and Kamali-Maskooni, E. (2011). Comparison between plant species richness and diversity indices along different grazing gradients in southern warm-arid rangelands of Fars. Rangeland, 5(2), 129-136.
[17] Klimek, S., Marini, L., Hofmann, M. and Isselsteint, J. (2008). Additive Partitioning of Plant Diversity with Respect to Grassland Management Regime, Fertilization and Abiotic Factors. Basic and Applied Ecology, 9, 626-634.
[18] Lande, R. (1996). Statistics and partitioning of species diversity and similarity among multiple communities. Oikos, 76, 5-13.
[19] Lindo, Z. and Winchester, N. (2009). Spatial and environmental factors contributing to patterns in arboreal and terrestrial orbited mite diversity across spatial scales. Oecologia, 160, 817-825.
[20] Noda, T. (2004). Spatial hierarchical approach in community ecology: a way beyond high context-dependency and low predictability in phenomena. Population Ecology, 46, 105-117.
[21] Omidipour, R. (2014). Additive Partitioning of Plant Diversity in relation to Rangeland Management Regime and Environmental variables. MSc. Thesis, Tarbiat Modares University, 70 p.
[22] Omidipour, R., Erfanzadeh, R. and Faramarzi, M. (2015). Investigation of Grazing Impact on Pattern of Species Diversity Components in Different Spatial Scale. Rangeland, 9, 367-377.
[23] Paknia, O. and Pfeiffer, M. (2011). Hierarchical Partitioning of Ant Diversity: Implication for Conservation of Biogeographical Diversity in Arid and Semi-Arid Areas. Diversity and Distributions, 17, 122-131.
[24] Ravolainen, V.T., Yoccoz, N.G., Brathen, K.A., Ims, R.A., Iversen, M. and Gonzalez, V.T. (2010). Additive Partitioning of Diversity Reveals No Scale-dependent Impacts of Large Ungulates on the Structure of Tundra Plant Communities. Ecosystems, 13, 157-170.
[25] Ribeiro, D.B., Prado, P.I., Brown, K.S.Jr. and Freitas, A.V.L. (2008). Additive partitioning of butterfly diversity in a fragmented landscape: importance of scale and implications for conservation. Diversity and Distributions, 14, 961-968.
[26] Rickert, C., Fichtner, A., van Klink, R. and Bakker, J.P. (2012). α- and β-Diversity in Moth Communities in Salt Marshes is Driven by Grazing Management. Biological Conservation, 146, 24-31.
[27] Roschewitz, I., Gabriel, D., Tscharntke, T. and Thies, C. (2005). The Effect of Landscape Complexity on Arable Weed Species Diversity in Organic and Conventional Farming. Journal of Applied Ecology, 42, 873-882.
[28] Rostami, A. (2000). Investigation of Dalab region forest types in Ilam Province, MS Tehis Gorgan Natural Resources and Agriculture Sciences University, 91p.
[29] Schultzl, N.L., Reidl, N., Lodge, G. and Hunter, J.T. (2014). Broad-scale patterns in plant diversity vary between land uses in a variegated temperate Australian Agricultural Landscape. Austral Ecology, 39, 855-863.
[30] Thompson, S.K. (2002). Sampling, (2th ed.), New York: J. Wiley & Sons.
[31] Traill, L.W., Wagner, T.C., de Little, S.C. and Brook, B.W. (2013). Rainfall and temperature variation does not explain arid species diversity in outback Australia. Research and Reports in Biodiversity Studies, 3, 1-8.
[32] Veech, J.A., Summerville, K.S., Crist, T.O. and Gering, J.C. (2002). The additive partitioning of diversity: recent revival of an old idea. Oikos, 99(1), 3-9.
[33] Wagner, H.H., Wildi, O. and Ewald, C.W. (2000). Additive partitioning of plant species diversity in an agricultural mosaic landscape. Landscape Ecology, 15(3), 219-227.
[34] Whittaker, R.H. (1960). Vegetation of the SiskiyouMountains, Oregon and California. Ecological Monographs, 30, 279-338.
[35] Whittaker, R.H. (1972). Evolution and measurement of species diversity. Taxon, 21, 213-251.
[36] Whittaker, R.J., Araujo, M.B., Jepson, P., Ladle, R.J., Watson, J.E.M. and Willis, K.J. (2005). Conservation Biogeography: assessment and prospect. Diversity and Distributions, 11, 3–23.