Vegetation Dynamics in Relation to Grazing Management Practices in Semi-arid Grazing Lands of Makueni County, Kenya

الموضوعات :

Hillary Kipngetich Rotich ¹ (Department of land resource and Agricultural technology, University of Nairobi)
Judith Symbua Mbau ² (Land resource management and Agricultural technology, faculty of agriculture, university of Nairobi)
Richard Onwonga ³ (Land resource management and Agricultural technology, faculty of Agriculture, University of Nairobi)
Oscar Kipchirchir Koech ⁴ (Land resource management and agricultural technology, faculty of agriculture, university of nairobi)

تاريخ الإرسال : 24 السبت , شعبان, 1438 تاريخ التأكيد : 20 السبت , ذو القعدة, 1438 تاريخ الإصدار : 17 الأحد , شوال, 1439

الکلمات المفتاحية: Diversity, Richness, biomass, Grazing management, Cover,

ملخص المقالة :

Livestock grazing practices in rangelands are being recognized as management tool for environmental protection and increased livestock productivity. Continuous grazing has been largely reported to reduce pasture productivity and increase environmental degradation. Rotational grazing is an alternative to continuous grazing and is considered to reduce negative environmental effects and provide quality pastures and browse ensuring availability of quality feed for animals while conserving the environment. This study was conducted in a semi-arid grassland in the south eastern rangelands of Kenya which is primarily used for cattle production to establish how grazing management system affects herbaceous biomass yield, cover, plant species richness and diversity (in 2016). Quadrat method was used to collect vegetation samples. In each plot, a 100 m2 sub- plot was demarcated and five 1×1m quadrats laid out. A quadrat was placed at each of the four corners of the 100m2 plot and the 5th quadrant placed at the center of the plot. Herbaceous biomass production was significantly higher (p≤0.05) in rotationally grazed areas compared to both continually grazed and ungrazed areas with average values of 7037, 2478 and 2390 Kgha-1 respectively. Similar trend was obtained for vegetation cover. Vegetation cover of herbaceous plants was significantly higher under rotationally grazed areas compared to both continually grazed and ungrazed areas with average values of 55, 37 and 27%, respectively. There was no significant difference for plant species richness and diversities and between the three sampling blocks. However, the highest values of both latter traits were obtained in rotationally grazed areas, followed by continually and ungrazed areas. Improved biomass yields and high species diversity in rotation grazed areas was largely attributed to the flexibility in the management in which grazing frequency, durations and the rest periods are efficiently controlled compared to continuous grazing areas. This study concludes that rotation grazing allows flexibility of animal utilization of pastures resulting to enhanced soil water retention, increased species diversity; richness and vegetation cover which increase biomass yields.

المصادر:

Alphayo, L., 2015. Effects of holistic grazing management on soil physico-chemical properties and herbaceous vegetation production in Naibunga Conservancy, Laikipia County, Kenya. University of Nairobi.

Asner, G. P., Elmore, A. J., Olander, L. P., Martin, R. E., & Harris, A. T., 2004. Grazing systems, ecosystem responses, and global change. Annu. Rev. Environ. Resour., 29: 261-299.

Belsky, A. J., 1992. Effects of grazing, competition, disturbance and fire on species composition and diversity in grassland communities. Jour. Vegetation Science, 3(2): 187-200.

Bilotta, G., Brazier, R., & Haygarth, P., 2007. The impacts of grazing animals on the quality of soils, vegetation, and surface waters in intensively managed grasslands. Advances in agronomy, 94: 237-280.

Catford, J. A., Daehler, C. C., Murphy, H. T., Sheppard, A. W., Hardesty, B. D., Westcott, D. A., . . . Horvitz, C. C., 2012. The intermediate disturbance hypothesis and plant invasions: Implications for species richness and management. Perspectives in Plant Ecology, Evolution and Systematics, 14(3): 231-241.

Cingolani, A. M., Noy-Meir, I., & Díaz, S., 2005. Grazing effects on rangeland diversity: a synthesis of contemporary models. Ecological Applications, 15(2): 757-773.

Connell, J. H., 1978. Diversity in tropical rain forests and coral reefs. Science, 199: 1302-1310.

Einstein, A., 2010. The Future of Big Ecology: IGBP, AmeriFlux, NEON, and Other Major Initiatives. Big Ecology: The Emergence of Ecosystem Science, 145.

Ericksen, P. J., Ingram, J. S., & Liverman, D. M., 2009. Food security and global environmental change: emerging challenges: Elsevier.

Fensham, R., Fairfax, R., & Dwyer, J., 2010. Vegetation responses to the first 20 years of cattle grazing in an Australian desert. Ecology, 91(3): 681-692.

Gamoun, M., 2014. Grazing intensity effects on the vegetation in desert rangelands of Southern Tunisia. Jour. Arid Land, 6(3): 324-333.

Gamoun, M., Hanchi, B., & Neffati, M., 2012. Dynamic of plant communities in Saharan rangelands of Tunisia. Arid Ecosystems, 2(2): 105-110.

Gebremeskel, K., 2006. Rangeland potential, quality and restoration strategies in north-eastern Ethiopia: a case study conducted in the southern Afar region. Stellenbosch: University of Stellenbosch.

Holechek, J. L., 2001. Western ranching at the crossroads. Rangelands, 23 (1): 17-21.

Huang, X., McNeill, M., & Zhang, Z., 2015. Quantitative analysis of plant consumption and preference by Oedaleus asiaticus (Acrididae: Oedipodinae) in changed plant communities consisting of three grass species. Environmental Entomology, nvv172.

Jacobo, E. J., Rodríguez, A. M., Bartoloni, N., & Deregibus, V. A., 2006. Rotational grazing effects on rangeland vegetation at a farm scale. Rangeland Ecology & Management, 59(3): 249-257.

Jaetzold, R., Schmidt, H., Hrnetz, B. & Shisanya, C., 2006. Farm management handbook Vol II, Part C, East Kenya. Subpart C1, Eastern Province. Ministry of Agriculture, Nairobi Kenya.

Jeddi, K., & Chaieb, M., 2010. Changes in soil properties and vegetation following livestock grazing exclusion in degraded arid environments of South Tunisia. Flora-Morphology, Distribution, Functional Ecology of Plants, 205(3): 184-189.

Kamau, P., 2003. Forage diversity and impact of grazing management on rangeland ecosystems in Mbeere District, Kenya.

Kgosikoma, O. E., 2012. Understanding the savanna dynamics in relation to rangeland management systems and environmental conditions in semi-arid Botswana.

Kinyua, P. I., van Kooten, G. C., & Bulte, E. H., 2000. African wildlife policy: protecting wildlife herbivores on private game ranches. European Review of Agricultural Economics, 27(2): 227-244.

Kioko, J., Kiringe, J. W., & Seno, S. O., 2012. Impacts of livestock grazing on a savanna grassland in Kenya. Jour. Arid Land, 4(1): 29-35.

Krebs, C. J., 1989. Ecological methodology: Harper & Row New York.

Lemus, R. W. & Rivera, D., 2011. Pasture and Grazing Management Under Drought Conditions: Mississippi State University Extension Service.

Li, X. L., Gao, J., Brierley, G., Qiao, Y. M., Zhang, J., & Yang, Y. W., 2013. Rangeland degradation on the Qinghai‐Tibet plateau: Implications for rehabilitation. Land Degradation & Development, 24(1): 72-80.

Liebig, M., Gross, J., Kronberg, S., Hanson, J., Frank, A., & Phillips, R., 2006. Soil response to long-term grazing in the northern Great Plains of North America. Agriculture, Ecosystems & Environment, 115(1): 270-276.

Liu, H., Han, X., Li, L., Huang, J., Liu, H., & Li, X., 2009. Grazing density effects on cover, species composition, and nitrogen fixation of biological soil crust in an Inner Mongolia steppe. Rangeland Ecology & Management, 62(4): 321-327.

Mackey, R. L., & Currie, D. J., 2001. The diversity–disturbance relationship: is it generally strong and peaked? Ecology, 82(12): 3479-3492.

Maitima, J. M., Mugatha, S. M., Reid, R. S., Gachimbi, L. N., Majule, A., Lyaruu, H., Mugisha, S., 2009. The linkages between land use change, land degradation and biodiversity across East Africa. African Jour. Environmental Science and Technology, 3: 310-325.

Metera, E., Sakowski, T., Słoniewski, K., & Romanowicz, B., 2010. Grazing as a tool to maintain biodiversity of grassland-a review. Animal Science Papers and Reports, 28(4): 315-334.

Milton, S. J., du Plessis, M. A., & Siegfried, W. R., 1994. A conceptual model of arid rangeland degradation. Bioscience, 44(2): 70-76.

Oba, G., Vetaas, O. R., & Stenseth, N. C., 2001. Relationships between biomass and plant species richness in arid‐zone grazing lands. Jour. Applied Ecology, 38(4): 836-845.

Patton, B. D., Dong, X., Nyren, P. E., & Nyren, A., 2007. Effects of grazing intensity, precipitation, and temperature on forage production. Rangeland Ecology & Management, 60(6): 656-665.

Pekin, B. K., Endress, B. A., Wisdom, M. J., Naylor, B. J., & Parks, C. G., 2015. Impact of ungulate exclusion on understorey succession in relation to forest management in the Intermountain Western United States. Applied Vegetation Science, 18(2): 252-260.

Pekin, B. K., Wisdom, M. J., Endress, B. A., Naylor, B. J., & Parks, C. G., 2014. Ungulate browsing maintains shrub diversity in the absence of episodic disturbance in seasonally-arid conifer forest. PloS one, 9(1): e86288.

Polley, H. W., Derner, J. D., & Wilsey, B. J., 2005. Patterns of plant species diversity in remnant and restored tallgrass prairies. Restoration Ecology, 13(3): 480-487.

Porqueddu, C., Ates, S., Louhaichi, M., Kyriazopoulos, A., Moreno, G., Pozo, A., Nichols, P., 2016. Grasslands in ‘Old World’ and ‘New World’ Mediterranean‐climate zones: past trends, current status and future research priorities. Grass and Forage Science, 71(1): 1-35.

Radford, B., Yule, D., Braunack, M., & Playford, C., 2008. Effects of grazing sorghum stubble on soil physical properties and subsequent crop performance. American Jour. Agricultural and Biological Sciences, 3(4): 734-742.

Roberts, M. R., & Gilliam, F. S., 2003. Response of the herbaceous layer to disturbance in eastern forests. The herbaceous layer in forests of eastern North America. Oxford University Press, Oxford, 302-320.

Rooney, T. P., & Waller, D. M., 2003. Direct and indirect effects of white-tailed deer in forest ecosystems. Forest Ecology and Management, 181(1): 165-176.

Rutherford, M., & Powrie, L., 2013. Impacts of heavy grazing on plant species richness: A comparison across rangeland biomes of South Africa. South African Jour. Botany, 87: 146-156.

Steffens, M., Kölbl, A., Totsche, K. U., & Kögel-Knabner, I., 2008. Grazing effects on soil chemical and physical properties in a semiarid steppe of Inner Mongolia (PR China). Geoderma, 143(1): 63-72.

Svensson, J. R., Lindegarth, M., Jonsson, P. R., & Pavia, H., 2012. Disturbance–diversity models: what do they really predict and how are they tested? Paper presented at the Proc. R. Soc. B.

Tarhouni, M., Belgacem, A. O., Neffati, M., & Henchi, B., 2007. Qualification of rangeland degradation using plant life history strategies around watering points in southern Tunisia. Pakistan journal of biological sciences: PJBS, 10(8): 1229-1235.

Van Auken, O., 2009. Causes and consequences of woody plant encroachment into western North American grasslands. Jour. Environmental Management, 90(10): 2931-2942.

Westoby, M., Walker, B., & Noy-Meir, I., 1989. Opportunistic management for rangelands not at equilibrium. Jour. Range Management, 42: 266-274.