Integrated Watershed Management

Integrated Watershed Management

Investigating the Effect of Animal Grazing Management on Composition and Spatial Diversity Indices (Case Study: Broujen Rangelands, Charmahal and Bakhtiari)

Document Type : Original Article

Authors
Reza Omidipour 1
Pejman Tahmasebi 2
Ataollah Ebrahimi 2
Mohabat Nadaf 3
1 Ph.D. Graduate, Department of Rangeland Sciences, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran
2 Associate Professor, Department of Rangeland and Watershed Management, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran
3 Assistant Professor, Department of Biology, Payame Noor University, Tehran, Iran
10.22034/iwm.2021.247943
Abstract
Livestock grazing management is one of the main manifestations of integrated watershed management. Lack of awareness of the effects of livestock grazing on biodiversity makes sustainable watershed management impossible. Therefore, awareness of the variation in plant diversity and composition under natural disturbances such as livestock grazing is important for optimal ecosystem management. This study aims to investigate the effects of different grazing intensity (low, moderate, and high) on spatial diversity components (α-diversity, β-diversity and γ-diversity), turnover and nestedness components of β-diversity and species composition in semi-steppe Broujen rangelands in Chaharmahal and Bakhtiari Province. Vegetation sampling was conducted based on a random-systematic sampling design using 60 plots of 2*2m in three grazing intensities including low, moderate and high. Statistical analysis was performed in R software using “vegan” and “betapart” packages. The results showed that an increase in grazing intensity could significantly (P-value < 0.01) decrease α-, β- and γ-diversity indices, which, in low grazing intensity, were 11.77, 7.22, and 19, respectively, while in high grazing intensity they were 3.44, 3.55, and 7, respectively. In addition, an increase in grazing intensity could significantly (P-value < 0.05) increase the turnover component of β-diversity due to species replacement, while there was no significant effect for nestedness components of β-diversity. The NMDS analysis results showed that different animal grazing could drive a significant deviation in plant community composition. The results of this study suggest that the light grazing intensity could be used as a suitable management tool in order to maintain and improve plant biodiversity.
Extended Abstract
1. Introduction
Vegetation is one of the main foundations in watersheds and its proper and principled management has an important role in watershed management. Considering the effects of livestock grazing on vegetation and choosing the appropriate livestock grazing intensity are among the main manifestations in integrated watersheds management. Therefore, without knowledge of livestock grazing effects on biodiversity, sustainable management of watersheds is not possible. So, it is so important to be aware of changes in plant diversity and composition under natural disturbances such as livestock grazing for optimal ecosystem management.
2. Materials and Methods
This study aimed to investigate the effect of different livestock grazing intensities (low, medium and high) on spatial diversity indices (alpha, beta, gamma), beta diversity components including turnover and nestedness, and plant composition in Broujen rangelands in Chaharmahal and Bakhtiari province (mid-June 2017). Sampling was performed based on a random-systematic sampling design using 60 plots of 2 × 2 m in three representative areas in three livestock grazing intensities at the peak season of plant growth. Livestock grazing intensity was determined based on distance from watering points (Omidipour et al., 2021). In this method, the areas near the watering points (distance less than 200 meters) as severe grazing (high grazing intensity) area, the area with a distance of 200 to 800 meters from the watering points as the medium grazing intensity and the area with a distance of more than 800 meters from the watering points was selected as a low-intensity area (Zhao et al., 2007). Calculation of diversity indices was done in "vegan" statistical packages (Oksanen et al., 2018) and partitioning of beta diversity into their components (turnover vs. nestedness) was performed using "betapart" statistical package in R software (Baselga and Orme, 2012). The effect of livestock grazing on the alpha, beta and gamma diversity indices as well as turnover and nestedness component of beta diversity were investigated based on one-way analysis of variance (ANOVA) and their mean comparison using Duncan's test. To evaluate the effect of livestock grazing on the plant structure and composition of the studied communities, the non-metric multidimensional scaling test (NMDS) was used in the "vegan" statistical package in R software (Oksanen et al., 2018).
3. Results
The results indicated that all diversity indices (alpha, beta and gamma) were significantly affected by grazing intensity so increasing the livestock grazing intensity causes a significant reduction (P <0.01) of alpha, beta and gamma diversity indices. The highest values ​​of alpha, beta and gamma diversity were 11.77, 7.22 and 19 in low grazing intensity and 3.44, 3.55 and 7 in the region with high grazing intensity, respectively. Partitioning of beta diversity into their component showed that the turnover has a greater role than the nestedness component in deriving beta diversity. The results also showed that increasing the livestock grazing intensity will significantly increase the turnover, which indicates the removal and replacement of plant species while increasing livestock grazing did not have a significant effect on the nestedness component of beta diversity. Finally, the results of the NMDS test showed that different livestock grazing intensities caused a significant difference in the studied communities’ composition so the three grazing areas in the direction of the first axis were separable from each other.
4. Discussion and Conclusion
The results of this study showed that livestock grazing is one of the main factors affecting plant diversity and composition. It is one of the most important factors in rangeland dynamics that has a negative effect on diversity by increasing the livestock grazing intensity. Light and medium grazing create empty spaces (gaps) where other annual plant species can establish. Livestock grazing can increase the number of species in the area by reducing inter-and intraspecific competition between plants at low intensities. Also, the higher amount of turnover in high grazing intensity indicates livestock grazing effect on removal and replacement of most plants under this grazing intensity. Therefore, using light grazing intensity can be used as a suitable management tool to preserve and improve biodiversity.
Keywords
Biodiversity
β-diversity
Ecosystem Management
Grazing Gradient
Species Replacement
Baselga, A. (2010). Partitioning the turnover and nestedness components of beta diversity. Global Ecology and Biogeography, 19(1), 134-143. https://doi.org/10.1111/j.1466-8238.2009.00490.x
Baselga, A. & Orme, C. D. L. (2012). Betapart: an R package for the study of beta diversity. Methods in Ecology and Evolution, 3(5), 808-812. http://www.respond2articles.com/MEE/
Bloor, J. M. & Pottier, J. (2014). Grazing and spatial heterogeneity: implications for grassland structure and function. Grassland Biodiversity and Conservation in a Changing World, 135-162.
Calderon-Patron, J. M., Moreno, C. E., Pineda-LOpez, R., Sanchez-Rojas, G. & Zuria, I. (2013). Vertebrate dissimilarity due to turnover and richness differences in a highly beta-diverse region: the role of spatial grain size, dispersal ability and distance. Plos One, 8(12), e82905. https://doi.org/10.1371/journal.pone.0082905
Cingolani, A. M., Noy-Meir, I. & Diaz, S. (2005). Grazing effects on rangeland diversity: a synthesis of contemporary models. Ecological Applications, 15(2), 757-773. https://doi.org/10.1890/03-5272
Connell, J. H. (1978). Diversity in tropical rain forests and coral reefs. Science, 199, 1302-1310. https://doi.org/0.1126/science.199.4335.1302
Crist, T. O., Veech, J. A., Gering, J. C., & Summerville, K. S. (2003). Partitioning species diversity across landscapes and regions: a hierarchical analysis of α, β, and γ diversity. The American Naturalist, 162(6), 734-743. https://doi.org/10.1086/378901
Dapporto, L., Fattorini, S., VodA, R., Dinca, V. & Vila, R. (2014). Biogeography of western Mediterranean butterflies: combining turnover and nestedness components of faunal dissimilarity. Journal of Biogeography, 41(9), 1639-1650. https://doi.org/10.1111/jbi.12315
Dengler, J., Janisova, M., Torok, P. & Wellstein, C. (2014). Biodiversity of Palaearctic grasslands: a synthesis. Agriculture, Ecosystems & Environment, 182, 1-14. https://doi.org/10.1016/j.agee.2013.12.015
Dobrovolski, R., Melo, A. S., Cassemiro, F. A. & Diniz Filho, J. A. F. (2012). Climatic history and dispersal ability explain the relative importance of turnover and nestedness components of beta diversity. Global Ecology and Biogeography, 21(2), 191-197. https://doi.org/10.1111/j.1466-8238.2011.00671.x
Erfanzadeh, R., Omidipour, R. & Faramarzi, M. (2015). Variation of plant diversity components in different scales in relation to grazing and climatic conditions. Plant Ecology & Diversity, 8(4), 537-545. https://doi.org/10.1080/17550874.2015.1033774
Forest, Range and Watershed Management Organization of Iran. (2021). Natural Resources Overview Section, https://frw.ir/02/Fa/default.aspx (In Persian)
Gamoun, M. (2014). Grazing intensity effects on the vegetation in desert rangelands of Southern Tunisia. Journal of Arid Land, 6(3), 324-333. https://doi.org/10.1007/s40333-013-0202-y
Grime, J. P. (1973). Competitive exclusion in herbaceous vegetation. Nature, 242(5396), 344-347.
Gutierrez-Canovas, C., Millan, A., Velasco, J., Vaughan, I. P. & Ormerod, S. J. (2013). Contrasting effects of natural and anthropogenic stressors on beta diversity in river organisms. Global Ecology and Biogeography, 22(7), 796-805. https://doi.org/10.1111/geb.12060
Haregeweyn, N., Berhe, A., Tsunekawa, A., Tsubo, M. & Meshesha, D. T. (2012). Integrated watershed management as an effective approach to curb land degradation: a case study of the Enabered watershed in northern Ethiopia. Environmental Management, 50(6), 1219-1233. https://doi.org/10.1007/s00267-012-9952-0
Heathcote, I. W. (2009). Integrated watershed management: principles and practice. John Wiley & Sons.
Hendricks, H. H., Bond, W. J., Midgley, J. J. & Novellie, P. A. (2005). Plant species richness and composition a long livestock grazing intensity gradients in a Namaqualand (South Africa) protected area. Plant Ecology, 176(1), 19-33.
Holechek, J. L. (1991). Chihuahuan desert rangeland, livestock grazing, and sustainability. Rangelands Archives, 13(3), 115-120.
Jafarian, Z., Omidipour, R. & Zandi, L. (2021). Effects of Altitude and soil properties on alpha and beta diversity in plour rangelands of Mazandaran. Iranian Journal of Applied Ecology, 10(1), 79-92. https://doi.org/10.47176/ijae.10.1.2022 (In Persian)
Jurasinski, G., Retzer, V. & Beierkuhnlein, C. (2009). Inventory, differentiation, and proportional diversity: a consistent terminology for quantifying species diversity. Oecologia, 159(1), 15-26.
Kinloch, J. E. & Friedel, M. H. (2005). Soil seed reserves in arid grazing lands of central Australia. Part 1: seed bank and vegetation dynamics. Journal of Arid Environments, 60(1), 133-161. https://doi.org/10.1016/j.jaridenv.2004.03.005
Klimek, S., Marini, L., Hofmann, M. & Isselstein, J. (2008). Additive partitioning of plant diversity with respect to grassland management regime, fertilization and abiotic factors. Basic and Applied Ecology, 9(6), 626-634. https://doi.org/10.1007/s11284-015-1304-0
Kruskal, J. B. (1978). Multidimensional scaling (No. 11). Sage Publications, Beverly Hills.
Lafage, D., Maugenest, S., Bouzille, J. B. & Petillon, J. (2015). Disentangling the influence of local and landscape factors on alpha and beta diversities: opposite response of plants and ground-dwelling arthropods in wet meadows. Ecological Research, 30(6), 1025-1035.  https://doi.org/10.1007/s11284-015-1304-0
Lande, R. (1996). Statistics and partitioning of species diversity, and similarity among multiple communities. Oikos, 5-13.
Legendre, P. (2014). Interpreting the replacement and richness difference components of beta diversity. Global Ecology and Biogeography, 23(11), 1324-1334. https://doi.org/10.1111/geb.12207
Legendre, P. & Legendre, L. (2012). Numerical ecology. Elsevier. Amsterdam, 853 pp.
Leprieur, F., Albouy, C., De Bortoli, J., Cowman, P. F., Bellwood, D. R. & Mouillot, D. (2012). Quantifying phylogenetic beta diversity: distinguishing between ‘True’ Turnover of lineages and phylogenetic diversity gradients. PloS one, 7(10), 1-12. https://doi.org/10.1371/journal.pone.0042760
MacArthur, R. H. & Wilson, E. O. (1967). The theory of island biogeography: Princeton Univ Pr. Press, Princeton.
Melo, A. S., Rangel, T. F. L. & Diniz Filho, J. A. F. (2009). Environmental drivers of beta‐diversity patterns in New‐World birds and mammals. Ecography, 32(2), 226-236. https://doi.org/10.1111/j.1600-0587.2008.05502.x
Meynard, C. N., Devictor, V., Mouillot, D., Thuiller, W., Jiguet, F. & Mouquet, N. (2011). Beyond taxonomic diversity patterns: how do α, β and γ components of bird functional and phylogenetic diversity respond to environmental gradients across France? Global Ecology and Biogeography, 20(6), 893-903. https://doi.org/10.1111/j.1466-8238.2010.00647.x
Milchunas, D. G., Sala, O. E. & Lauenroth, W. K. (1988). A generalized model of the effects of grazing by large herbivores on grassland community structure. The American Naturalist, 132(1), 87-106.
Nadaf, M. (2017). An investigation of relationship between ecological groups and plant diversity with the environmental factors in Chamanbid-Jozak area, North Khorassan Province. PhD Thesis in Plant Ecology, Ferdowsi University of Mashhad. (In Persian)
Navarro, T., Alados, C. L. & Cabezudo, B. (2006). Changes in plant functional types in response to goat and sheep grazing in two semi-arid shrublands of SE Spain. Journal of Arid Environments, 64(2), 298-322. https://doi.org/10.1016/j.jaridenv.2005.05.005
Noy-Meir, I. (1990). The effect of grazing on the abundance of wild wheat, barley and oat in Israel. Biological Conservation, 51(4), 299-310. https://doi.org/10.1016/0006-3207(90)90115-6
Oksanen, J., Blanchet, F. G., Friendly, M., Kindt, R., Legendre, P., McGlinn, D., Minchin, P. R., O’Hara, R. B., Simpson, G. L., Solymos, P. & Stevens, M. H. H. (2018). Vegan: community ecology package. R package version, 2, 5-2.
Olden, A. & Halme, P. (2016). Grazers increase β-diversity of vascular plants and bryophytes in wood‐pastures. Journal of Vegetation Science, 27(6), 1084-1093. https://doi.org/10.1111/jvs.12436
Omidipour, R., Erfanzadeh, R. & Faramarzi, M. (2016). Effects of grazing impacts on the pattern of species diversity in different spatial scale. Rangeland, 9(4), 367-377. (In Persian)
Omidipour, R., Erfanzadeh, R. & Faramarzi, M. (2017). Study on the effect of Livestock Grazing on Plant Species Diversity Components in Semi-arid regions. Journal of Range and Watershed Management, 70(3), 723-734. https://doi.org/10.22059/jrwm.2017.113281.803 (In Persian)
Omidipour, R., Erfanzadeh, R. & Faramarzi, M. (2021). Climatic condition effects on the components of plant diversity in the western Iran grasslands using multiplicative partitioning methods. Caspian Journal of Environmental Sciences, 19(1), 1-10. https://doi.org/10.22124/cjes.2021.4302
Pordel, F., Ebrahimi, A. & Azizi, Z. (2018). Canopy cover or remotely sensed vegetation index, explanatory variables of above-ground biomass in an arid rangeland, Iran. Journal of Arid Land, 10(5), 767-780. https://doi.org/10.1007/s40333-018-0017-y
R Core Team. (2018). R: A Language and Environment for Statistical Computing. Foundation for Statistical Computing, Vienna, Austria.
Si, X., Baselga, A. & Ding, P. (2015). Revealing beta-diversity patterns of breeding bird and lizard communities on inundated land-bridge islands by separating the turnover and nestedness components. PLoS One, 10(5), e0127692. https://doi.org/10.1371/journal.pone.0127692
Society of Range Management (SRM). (2003). Biodiversity of rangelands. Rangelands, 25, 60-65.
Talle, M., Deak, B., Poschlod, P., Valko, O., Westerberg, L., & Milberg, P. (2016). Grazing vs. mowing: A meta-analysis of biodiversity benefits for grassland management. Agriculture, Ecosystems & Environment, 222, 200-212. https://doi.org/10.1016/j.agee.2016.02.008
Tahmasebi, P., Ebrahimi, A. & Yarali, N. A. (2012). The Most Appropriate Quadrate Size and Shape for Determining Some Characteristics of a Semi-steppe Rangeland. Journal of Range and Watershed Management, 65(2), 203216. https://doi.org/10.22059/jrwm.2012.30012 (In Persian)
WallisDeVries, M. F., Vries, M. F. W., Bakker, J. P., Bakker, J. P., van Wieren, S. E. & Van Wieren, S. E. (Eds.). (1998). Grazing and conservation management (Vol. 11). Springer Science & Business Media.
Wang, Y., Shiyomi, M., Tsuiki, M., Tsutsumi, M., Yu, X. & Yi, R. (2002). Spatial heterogeneity of vegetation under different grazing intensities in the Northwest Heilongjiang Steppe of China. Agriculture, Ecosystems & Environment, 90(3), 217-229. https://doi.org/10.1016/s0167-8809(01)00217-1
Whittaker, R. H. (1960). Vegetation of the Siskiyou mountains, oregon and california. Ecological Monographs, 30(3), 279-338. https://doi.org/10.2307/1943563
Whittaker, R. H. (1972). Evolution and measurement of species diversity. Taxon, 21(2-3), 213-251. https://doi.org/10.2307/1218190
Zaree, A., Asadi, E., Ebrahimi, A., Jafari, M. & Malekian, A. (2019). Study of temperature and precipitation changes under climate changes scenarios in rangelands of ChaharMahal-va-Bakhtiyari. Rangeland, 12(4), 426-436. (In Persian)
Zhang, Q., Hou, X., Li, F. Y., Niu, J., Zhou, Y., Ding, Y. & Kang, S. (2014). Alpha, beta and gamma diversity differ in response to precipitation in the Inner Mongolia grassland. PLoS One, 9(3), e93518. https://doi.org/10.1371/journal.pone.0093518
Zhang, T. H., Zhao, H. L., Li, S. G. & Zhou, R. L. (2004). Grassland changes under grazing stress in Horqin sandy grassland in Inner Mongolia, China. New Zealand Journal of Agricultural Research, 47(3), 307-312. https://doi.org/10.1080/00288233.2004.9513599
Zhao, W. Y., Li, J. L. & Qi, J. G. (2007). Changes in vegetation diversity and structure in response to heavy grazing pressure in the northern Tianshan Mountains, China. Journal of Arid Environments, 68(3), 465-479. https://doi.org/10.1016/j.jaridenv.2006.06.007
Zhou, Z., Sun, O. J., Luo, Z., Jin, H., Chen, Q. & Han, X. (2008). Variation in small-scale spatial heterogeneity of soil properties and vegetation with different land use in semiarid grassland ecosystem. Plant and Soil, 310(1), 103-112. https://doi.org/10.1007/s11104-008-9633-1

  • Receive Date 26 October 2021
  • Revise Date 12 November 2021
  • Accept Date 13 November 2021