Document Type : Research Paper

Authors

1 Assistant Professor, Research Division of Natural Resources, Isfahan Agricultural and Natural Resources Research and Education Center, AREEO, Isfahan, Iran

2 Senior, Research Expert, Research Division of Natural Resources, Isfahan Agricultural and Natural Resources Research and Education Center, AREEO, Isfahan, Iran

Abstract

    Plant species diversity always implies ecosystem stability against environmental and biological disturbances. This study was conducted to investigate the effects of grazing management on diversity indices of plant species in grazed and exclosed rangeland sites of Hanna station- Semirom. Sampling was performed using 30 plots (1 m2) along four transects. Canopy area and density of species were recorded in sampling units, and the floristic list was provided in the whole area. Species richness, heterogeneity and evenness indices were calculated from density data and parametric diversity indices including log normal, geometric, and broken stick were fited in both exclosed and grazed areas. The Chi-Square test was used to examine the significance of measured traits. The results of numerical indices showed a higher species richness, evenness and species diversity indices in grazed than in the ungrazed site. The logarithmic diagram in the exclosed and grazed areas followed the broken stick model, indicating the presence of dominant species. The floristic lists of the study sites showed that the number of specific plant species in the grazed site was higher than that of exclosed site. Overall, the results showed that moderate grazing conditions in Hanna station improved plant species diversity indices and increased climax plant species.

Keywords

-  Akbarlou, M., 2009. Current utilization impacts on vegetation parameters of mountain meadows in chaldran, west   Azarbaijan. Ph.D. thesis, Agricultural Sciences and Natural Resources, Gorgan University, 113p.
-  Amrolahi, A. and Zare, A., 2001. Plant diversity under three grazing intensities (enclosure, moderate and heavy). Forest and Rangeland Journal, 48: 44-47.
-  Bassiri, M. and Iravani, M., 2009. Vegetation change after 19 years of grazing enclosure in the central Zagros region, Journal of Rangeland, 3(2): 155-170.
-  Burnham, K. P. and Overton, P. S., 1978. Estimation of the size of a closed population when capture probabilities vary among animals. Biometrika Journal, 65: 927-936.
-  Burnham, K. P. and Overton, W. S., 1979. Robust estimation of population size when capture probabilities vary among animals, Journal of Ecology, 60: 927-936.
-  Chapin, E. S., Zavaleta, E. S., Eviner, V.T., Naylor, R.L., Vitousek, P.M., Reynolds, H.L., Hooper, C.U., Lavrel, S., Sala, O. E., Hobbie, S. E., Mack, M. C. and Diaz, S., 1999. Functional and societal consequences of changing biotic diversity, Journal of Nature, 405: 234-242.
-  Connell, J. H., 1978. Diversity in tropical rainforests and coral reefs. Science, 199: 1302–1310.
-  Ejtehadi, H., Sepehri, A. and Akafi, H. R., 2014. Methods of measuring biodiversity. Ferdousi University Publication, Iran, 226p.
-  Eldrige, D. J. and Robson, A. D., 1997. Blade ploughing and enclosure influence soil properties in a semiarid Australian woodland. Journal of Range Management, 50: 191-198.
-  Ghilichnia, H., 1996. Comparison of plant vegetation in enclosed and grazed rangeland sites of Golestan national park (key area, critical area and reference area), Journal of Pajouhesh & Sazandegi, 30(1): 72-74.
-  Gholami-Baghi, N. and Mesdaghi, M., 2006. Investigation of range plant diversity in Golestan park and neighborhood areas, Journal of Agricultural Sciences and Natural Resources, 13(11):142-161.
-  Gray, J. S., 2000. The measurement of marine species diversity, with an application to the benthic fauna of the Norwegian continental shelf. Journal of Experimental Marine Journal of Biology and Ecology, 250: 23-49.
-  Harrison, S., 1999. Native and alien species diversity at the local and regional scales in a grazed California grassland. Ecologies Journal, 121:99-106.
-  Harrison, I., Laverty, M. and sterling, E., 2004. Species diversity, Connexions module: m12174, 1-7. (http://cnx.org/content/m12174/latest/).
-  Heltshe, J. and Forrestor, N. E., 1983. Estimating species richness using the jackknife procedure. Journal of Biometrics, 39: 1-11.
-  Hossienzadeh, G., Jalilvand, H. and Tamartash, R., 2007. Vegetation cover changes and some chemical soil properties in pastures with different grazing intensities. Iranian Journal of Range and Desert Research, 14(4): 500-512.
-  Jahantab, E., Sepehry, A., Hanafi, B. and Mirdeilamy, S. Z., 2010. Comparison of plant species diversity in two grazed and enclosed rangeland sites in mountainous rangelands of central Zagros (Case study: Dishmook in Kohgiluyeh & Buyer Ahmad province). Iranian journal of Range and Desert Research, 17(2): 292-300.
-  Jouri, M. H., Tomzad, B., Shokri, M. and Banihashemi, B., 2009. Comparison of diversity and richness indices for evaluation of mountain rangeland health (Case study: rangelands of Javaherdeh of Ramsar). Journal of Rangeland, 2(4): 330-344.
-  Karami, P., Heshmati, G., Soltani, A. and Golchin, A., 2010. Effects of different managements (grazing, exclosure, harvesting) on production and plant composition of rangeland ecosystems in the western part of Iran؛ (Case study: Saral of Kurdistan), Journal of Rangeland, 4(2): 241-250.
-  Karimi, Gh., Mozafari, S. and Nikbakht, M., 2009. Effect of range and livestock management on vegetation of Margon station in Kohkiloyeh and Boyerahmad province, Iran. Iranian Journal of Range and Desert Research, 16(3): 353-361.
-  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. Journal of Rangeland, 5(2): 129-135.
-  -Krebs, C. J., 1998. Ecological methodology, Second Edition, Jim green publishers, England, 620p.
-  Liang, Y., Han, G., Zhou, H., Zhao, M., Snyman, H. A., Shan, D. and Havstad, K. M., 2009. Grazing intensity on vegetation dynamics of typical steppe in northeast inner Mongolia, Journal of Rangeland Ecology & Management, 62: 328-336.
-  Magurran, A. E., 2003. Measuring biological diversity, Blackwell publishing, Australia, 256p.
Mahmoudi, J., CHoopani, H.V. and Akbarlo, M., 2011. The impact of exclusory on the steppes rangeland biodiversity (case study: Bozdaghi catchment in Northern Khorasan). Journal of Natural Ecosystems of Iran, 1(2): 136-144.
-  Mc Cann, K. S., 2000. The diversity- stability debate. Journal of Nature, 405: 228-233.
-  Mesdaghi, M., 2005. Plant Ecology, Mashad jehad daneshgahi publication, Iran, 187p.
-  -Moeinpour, N., 2008. Studying the effect of enclosure on plant diversity in Kalpoosh rangelands. M.Sc. Thesis, Agricultural Sciences and Natural Resources, Gorgan University, 81p.
-  Olff, H. and Ritchie, M. E., 1998. Effects of herbivores on grassland plant diversity. Journal of Trends in Ecology & Evolution, 13: 261–265.
-  Paruelo, C. A., 2001. Changes in plant functional types induced by grazing in the Patagonian steppes. Faculty of Agronomy, National University of Buenos Aires.
-  Roxburgh, S. H. and Rauschert, E. S. J., 2004. Moving from pattern to process: coexistence mechanisms under intermediate disturbance regimes. Journal of Ecology Letters, 7: 491–508.
-  Salami, A., Zare, H., Amini Eshkevari, T. and Jafari, B., 2007. Comparison of plant species diversity in the two grazed and ungrazed rangeland sites in Kohneh Lashak, Nowshahr. Journal of Pajouhesh & Sazandegi, 75: 37-46.
-  Salarian, F., Ghorbani, J. and Safaeian, N. A., 2013. Vegetation changes under enclosure and livestock grazing in Chahar Bagh rangelands in Golestan province. Iranian Journal of Range and Desert Research, 20(1): 115-129.
-  Smith, E. P. and Bell, G. V., 1984. Nonparametric estimation of species richness. Journal of Biometrics, 40: 119-129.
-  Whittaker, R. H., 1975. Communities and ecosystems, Second Edition, Macmillan, New York, 385p.
-  Whittaker, R. H., 1977, Evolution of species diversity in land communities. Journal of Evolutionary Biology, 10: 1-67.