Ecological Drivers of Ecosystem Diversity in Sahelian Rangeland of Niger

Document Type: Research and Full Length Article

Authors

1 Faculté des Sciences Agronomiques, Université de Diffa

2 Faculty of Agronomic, University of Diffa, Niger

3 Faculty of Agronomic Sciences, University of Niamey, Niger

4 Faculty of Science and Technology, University of Niamey, Niger

Abstract

Description of vegetation patterns associated with environmental factors such as grazing, climate, landforms, substrate variables etc. are helpful for land management planning. This study used new synecological tools to investigate plants composition and to provide ecological descriptions of plants communities of communal pastures in Sahelian Ecological Zone of Niger. Vegetation and several environmental variables were recorded in 197 plots using the Braun-Blanquet cover-abundance scale. A composite soil sample of about 1 kg from each plot was collected for analysis.A total of 252 species were recorded, belonging to 148 genera from 47 families, in which the angiosperms families counting 251 species are more represented and the pteridophytes are represented by one species belonging to the family of Marsileaceae. Poaceae, Leguminosae-Papilionoideae, Convolvulaceae, Cyperaceae and Leguminosae-Mimosoideae are the largest families. High abundance of the Poaceae species reveal the great potential forage value of the Sahelian rangelands. Most of the plants species are Therophytes and widely distributed elements in the tropics, revealing therefore an arid environment with great potential forage value under high disturbance, accordingly poorly managed. Arid ecosystems under heavy disturbance are susceptible to desertification. Nine pasture vegetation communities have been discriminated, distributing along the environmental gradient. Significant abiotic factors of plants distribution and their assemblage to form communities are geomorphology, total alkalinity, magnesium, phosphorous total and the cationic exchange capacity. Significant factors as well as sand, clay, silt, calcium, organic carbon, available phosphorous contents and plants compositionvaried differently with the definite plants communities. Plants communities under depression have great amounts of moisture and soil factors of soil fertility, therefore more resilient. Likely, plants communities located on sandy plains and dunes slopes or summits are more vulnerable to desertification than those located in fertile depression with great water contents.

Keywords

Main Subjects


Abd El-Ghani, M.M. and Amer, W. M., 2003. Soil–vegetation relationships in a coastal desert plain of southern Sinai, Egypt. Jour. Arid Environments, 55: 607–628.

Allen-Diaz, B., 1996. Rangelands in a changing climate: Impacts, adaptations and mitigation. In: Climate Change 1995: Impacts, Adaptations and Mitigation of Climate Change – Scientific –Technical Analysis, Watson, R. T., Zinyowera, M. C., Moss, R. H. and D. J. Dokken (eds.). Cambridge University Press, New York, pp: 131-158.

Black, C.A., 1979. Methods of soil analysis. American Society of Agronomy, 2: 771–1572.

Boudet, G., 1960. Study of the natural pastures of Dallol Maouri (Republic of Niger). Rev. El. Vet. P 313.

Boudet, G. and Duverger, E., 1961. Study of natural Sahelian pastures: Hodh (Mauritania). Rev. El. Vet. P 161.

Bouyoucos, G.J., 1962. Hydrometer method improved for making particle size analysis of soil. Jour. Agronomy, 54, 464–465.

Braun-Blanquet, J., 1932. Plant sociology. The study of plant communities. Ed. McGray Hill, New York, London, p 439.

Briske, D.D. and Heitschmidt, R. K., 1991. An ecological perspective. In: Grazing Management: An Ecological Perspective, Heitschmidt, R.K. and J.W. Stuth (eds.). Timber Press Inc., Portland, OR, pp. 11-27.

Bestelmeyer1, B. T., Okin, G. S., Duniway, M. C., Archer, S. R., Sayre, N. S., Williamson, J. S. and Herrick J. E., 2015. Desertification, land use, and the transformation of global drylands. Frontiers in Ecology and the Environment, 13(1):28-36· 

Casenave, A. and Valentin, C., 1989. The surface states of the Sahelian zone: influence on infiltration. Paris, ORSTOM. Retrieved from http://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers08-01/27816.pdf.

Chetri, M. and Gurung, C. R., 2004. Vegetation composition, species performance and its relationship among the livestock and wildlife in the grassland of upper Mustang, Nepal. Proceedings of the International Congress on Yak, Chengdu, Sichuan, P.R. China.

de Fabrègue, B.P., 1963. Study of natural Sahelian pastures, ranch of Nord-Sanam (Niger). House-Alfort, IEMVT, 132 p.

de Fabrègues, B.P., 1965. Studies and principles of steppe grazing in the Republic of Niger. Vol. 18, p 329-332.

de Fabrègue, B.P., 1967. Agrostological study of pastures in the Zinder nomadic zone. Rome, FAO, Maison-Alfort, IEMVT, 188 p.

de Fabrègue, B.P., 1970. Sahelian natural pastures of South Tamesna (Niger). House-Alfort, IEMVT, 200 p.

de Fabrègues, B.P. & Lebrun J.P., 1976. Catalog of vascular plants of Niger. IEMVT, Maisons Alfort, p 433.

de Fabrègues. B. P., 1982. Livestock development project in Niger Center-Est. Synthesis report, Zinder (Niger), PDENCE, IEMVT, Maisons Alfort, P 40.

d'Herbès, J.M. & Valentin, C., 1997. Land surface conditions of the Niamey region: ecological and hydrological implications. Jour. Hydrology, 188-189, 18-42. Retrieved from http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_49-50/010013364.pdf.

Djitèye, M., 1984. Composition, structure and production of Sahelian plant communities: Application to the Niono area (Mali). Ph.D. thesis, University of Paris-Sud, Center d'Orsay.

Dufrêne, M. and Legendre, P., 1997. Species assemblages and indicators species: the need for a flexible asymmetrical approach. Ecological Monographs, 67, 345-366.

Dytham, C., 2011. Choosing and using statistics: a biologist's guide. Wiley-Blackwell Malden, MA, USA.

Guinochet, M., 1973. Phytosociologie. Masson and Cie, Paris, 177 p.

Gounot, M., 1969. Method of quantitative study of vegetation. Masson et al., Paris VI. 303 p.

Hein, L. and De Ridder, N., 2006. Desertification in the Sahel: a reinterpretation. Global Change Biology, 12, 751–758.

Hiernaux, P. & Le Houérou, H. N., 2006. The routes of the Sahel. Drought; 17 (1-2): 51-71.

Hill, MO., 1979. DECORANA – A FORTRAN program for detrended correspondence analysis and reciprocal averaging ecology and systematics. Cornell University, Ithaca, New York 14850, USA.

Houinato, M.R.B., 2001. Phytosociology, ecology, production and carrying capacity of grazed vegetation in the Monts Kouffé region (Benin). Ph.D. thesis, Free University of Brussels, Faculty of Sciences, Interfaculty Section of Agronomy, Laboratory of Systematic Botany.

Jouri, M H., D. Patil, R.S. GavaliC, N. Safaian and Askarizadeh,D., 2011. Assessment of health conditions of mountain rangeland ecosystem using species diversity and richness indices, case study: Central Alborz (Iran). Jour. Rangeland Science; 2 (1) : 341-353. (In Persian).

Lebrun, J. P. and Stock, A. L., 1997. Enumeration of flowering plants of tropical Africa. Editions des Conser. And Jard. Bot. Geneve, 4th Edition.

Le Houérou, H.N., 1980. The Rangelands of the Sahel. Jour. Range Management, 33 (1): 41-46

Le Houérou, H.N., 1996. Climate change, drought and desertification. Jour. Arid Env. 34:133–185.

Le Houérou, H.N., 1997. Plant biodiversity and genetic resources in Africa. Drought, 8: 117-22.

Lei, S. A., 1999. Gradient Analysis of Pinyon-Juniper Woodland in a Southern Nevada Mountain Range. In: Ecology and management of pinyon-juniper communities within the Interior, West Stephen, M.B. and R.C Stevens (eds.). Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, pp:15-18.

Liu, S.L., . X.D. Guo, B.J. Fu, G. Lian and Wang, J., 2006. The effect of environmental variables on soil characteristics at different scales in the transition zone of the Loess Plateau in China. Soil Use and Management, 1-8.

Myers, N., Mittermeier, A. R., Mittermeier, C. G., da Fonseca, G. A. B. & Kent, J., 2000. Biodiversity hotspots for conservation priorities. Nature, 403, 853-858.

Mathieu, C., Pieltain, F., 2003. Soil chemical analysis (selected methods). Ed. Thesis Doctorate, 387p.

Mbayngone, E., 2009. Flora and vegetation of the partial wildlife reserve of Pama, South-East of Burkina Faso. Doctoral thesis, University of Ouagadougou, Burkina Faso.

McCune, B. P. and Grace, J. B., 2002. Analysis of ecological communities. MJM software design, Gleneden beach, Oregon, USA.

Moradi, E., G. A. Heshmati and Bahramian, A. H., 2012. Assessment of range health changes in Zagros semi-Arid rangelands, Iran (Case Study: Chalghafa- Semirom-Isfahan). Jour. Rangeland Science, 3 (1) : 31-43. (In Persian).

Olsen, S. R. and Sommers, L. E., 1982. Phosphorus. In: Methods of soil analysis. Part 2. Chemical and microbiological properties, A.L., Page, R.H. Miller and D.H. Keeney (eds.), Agronomy No. 9, Madison, WI: American Society of Agronomy, Soil Science Society of America: 403-430.

Oumorou, O., 2009. Phytosociology, dynamics and productivity of vegetation in the Arly National Park (South-East Burkina Faso). Ph.D. thesis, University of Ouagadougou, Burkina Faso.

Parkinson, J.A. and Allen, S. E., 1975. A wet oxidation procedure suitable for determination for nitrogen and mineral nutrients in biological material. Communications in Soil Science and Plant Analysis, 6, 1–11.

Peugeot, C., M. Esteves, S. Galle, J.L. Rajot and Vandervaere, J. P., 1997. Runoff generation processes: results and analysis of field data collected at the East Central Supersite of the HAPEX-Sahel experiment. Jour. Hydrology, 188, 179-202. Retrieved from http://horizon.documentation.ird.fr/exl doc/pleins_textes/pleins_ textes_7/b_fdi_55-56/010021604.pdf.

Pierson, F.B. and Mulla, D. J., 1990. Aggregate Stability in the Palouse Region of Washington: Effect of Landscape Position. Soil Sci. Soc. Am. Jour. 54:1407-1412

Poilecot, P., 1999. The Poaceae of Niger. Boissiere 56. Geneva Conservatory and Botanical Garden/ IUCN/ CI-. RAD, Geneva.

Raunkiær, C., 1934. The Life Forms of Plants and Statistical Plant Geography. The Clarendon Press, Oxford.

Reynolds, J. F., and Stafford Smith, D.M., 2002. Global Desertification: Do Humans Cause Deserts? Dahlem University Press, Berlin.

Robert, M., 2001. Soil carbon sequestration for improved land management. World Soil Resources Report No. 96. Rome, Italy: Food and Agriculture Organization. 58 p.

Saadou, M., 1990. The vegetation of Niger's drained environments east of the Niger River. Ph.D., University Niamey, Niger.

Soumana, I., A. Mahamane, Z. Gandou, J.M.K. Ambouta and Saadou, M., 2012. Vegetation and plant diversity pattern study of Central Eastern Niger grasslands. Int. Jour. Biol. Chem. Sci. 6(1): 394-407.

Stanley, A.C., 1950. Life-Forms and Phyto climate. The Botanical Jour., 1(16): 1-32.

Ter Braak C. J. F.,1986. Canonical correspondence analysis: a new eigenvector technique for multivariate direct gradient analysis. Ecology, 67: 1167-1179.

Ter Braak, C. J. F. and Smilauer, P., 1998. CANOCO Reference Manual and User's Guide to Canoco for Windows. Software for Canonical Community Ordination (version 4). Microcomputer Power (Ithaca, NY USA), p 352.

Togola, M., 1982. Contribution to the study of Sahelo-Sudanian vegetation and the pastoral potential of the Kaarta region (Mali). Ph.D. Thesis Specialty Vegetable ecology. University of Paris - South Center of Orsay, p 85.

UNEP, 2012. Sahel Atlas of Changing Landscapes: Tracing trends and variations in vegetation cover and soil condition. United Nations Environment Program, Nairobi.

Ward, J.H., 1963. Hierarchical grouping to optimize an objective function. Am. Stat. Assoc. Jour., 58: 236-44.

Wezel, A. and Lykke, A. M., 2006. Woody vegetation change in Sahelian West Africa: evidence from local knowledge. Environ Dev Sustain, 8:553–567.

White, F., 1986. The vegetation of Africa. Memory accompanying the map of vegetation of Africa. Unesco/ AETFAT/ UNSO, ORSTOM/ UNESCO, p. 384.

Yahdjian, L., E.O. Sala and Havstad, K. M., 2015. Rangeland ecosystem services: shifting focus from supply to reconciling supply and demand. Front Ecol Environ, 13(1): 44–51.