Effects of grazing pressure, age of enclosures and seasonality on bush cover dynamics and vegetation composition in southern Ethiopia

Journal of Arid Environments

Volumn 74, Issue 1, 2010, Pages 111-120

  Angassa, A ^a   Oba, G ^b  

^a HAWASSA UNIVERSITY   (Ethiopia)

^b NORWEGIAN UNIVERSITY OF LIFE SCIENCES   (Norway)

Author keywords

Bush cover; Diversity; Grazed rangelands; Traditional range enclosures; Vegetation composition

Indexed keywords

FOREST FIRE; GRAZING PRESSURE; HERB; INVASIVE SPECIES; RANGELAND; REINTRODUCTION; SEASONALITY; SPECIES DIVERSITY; VEGETATION COVER;

AFRICA; EAST AFRICA; ETHIOPIA; SUB-SAHARAN AFRICA;

COMMIPHORA; COMMIPHORA AFRICANA;

EID: 71549148667     PISSN: 01401963     EISSN: 1095922X     Source Type: Journal    
DOI: 10.1016/j.jaridenv.2009.07.015     Document Type: Article

References (53)

1. Abebe M.H., Oba G., Angassa A., and Weladji R.B. The role of area enclosures and fallow age in the restoration of plant diversity in northern Ethiopia. African Journal of Ecology 44 (2006) 507-514
2. Allen-Diaz B., and Jackson R.D. Grazing effects on spring ecosystem vegetation of California's hardwood rangelands. Journal of Range Management 53 (2000) 215-220
3. Andersen J.E., and Holte K. Vegetation development over 25 years without grazing on sagebrush-dominated rangeland in south-eastern Idaho. Journal of Range Management 34 (1981) 25-29
4. Angassa A., and Baars R.M.T. Ecological condition of encroached and non-encroached rangelands in Borana, Ethiopia. African Journal of Ecology 38 (2000) 321-329
5. Angassa A., and Oba G. Effects of management and time on mechanisms of bush encroachment in southern Ethiopia. African Journal of Ecology 46 (2008) 186-196
6. Angassa A., and Oba G. Herder perceptions on impacts of range enclosures, crop farming, fire ban and bush encroachment on the rangelands of Borana, southern Ethiopia. Human Ecology 36 (2008) 201-215
7. Asefa D.T., Oba G., Weladji R.B., and Colman J.E. An assessment of restoration of biodiversity in degraded high mountain grazing lands in northern Ethiopia. Land Degradation & Development 14 (2003) 25-38
8. Archer S. Tree-grass dynamics in a Prosopis-thornscrub savanna parkland: reconstructing the past and predicting the future. Ecoscience 2 (1995) 83-99
9. Augustine D.J., and McNaughton S.J. Regulation of shrub dynamics by native browsing ungulates on east African rangeland. Journal of Applied Ecology 41 (2004) 45-58
10. Bille J.C., and Eshete A. Rangeland Management and Range Condition: a Study in the Medhecho and Dida-Hara Areas of the Effects of Rangeland Utilization. JEPSS (Joint Ethiopian Pastoral Systems Study) research report 7 (1983), ILCA (International Livestock Centre for Africa), Addis Ababa, Ethiopia
11. Biot Y. How long can high stocking densities be sustained?. In: Behnke R.H., Scoones I., and Kerven C. (Eds). Range Ecology at Disequilibrium: New Models of Natural Variability and Pastoral Adaptation in African Savannas (1993), ODI/IIED/Commonwealth Secretariat, London 153-172
12. Burrows W.H., Henry B.K., Back P.V., Hoffman M.B., Tait L.J., Anderson E.R., Menke N., Danahar T., Carter J.O., and McKeon G.M. Growth and carbon stock change in eucalypt woodlands in northeast Australia: ecological and greenhouse sink implications. Global Change Biology 8 (2002) 769-784
13. Buttolph L.P., and Coppock D.L. Influence of deferred grazing on vegetation dynamics and livestock productivity in an Andean pastoral system. Journal of Applied Ecology 41 (2004) 664-674
14. Chauchard S., Pille G., and Carcaillet C. Large herbivores control the invasive potential of nonnative Austrian black pine in a mixed deciduous Mediterranean forest. Canadian Journal of Forest Research 36 (2006) 1047-1053
15. Coppock D.L. Vegetation and pastoral dynamics in the southern Ethiopian rangelands: implications for theory and management. In: Behnke R.H., Scoones Jr. I., and Kerven C. (Eds). Range Ecology at Disequilibrium, New Models of Natural Variability and Pastoral Adaptation in African Savannas (1993), Overseas Development Institute and International Institute for Environment and Development, London, UK 42-61
16. Coppock D.L. The Borana Plateau of Southern Ethiopia: Synthesis of Pastoral Research, Development and Changes 1980-1990 (1994), International Livestock Centre for Africa, Addis Ababa, Ethiopia
17. Dyksterhuis E.J. Condition and management of rangeland based on quantitative ecology. Journal of Range Management 2 (1949) 110-115
18. Eccard J.A., Walther R.B., and Milton S.J. How livestock grazing affects vegetation structures and small mammal distribution in the semi-arid Karoo. Journal of Arid Environments 46 (2000) 103-106
19. Ellis E.J., and Swift M.D. Stability of African pastoral ecosystems: alternate paradigms and implications for development. Journal of Range Management 41 (1988) 450-459
20. Eshete A., Bille J.C., and Corra M. Ecological Map of Southern Sidamo. JEPSS (Joint Ethiopian Pastoral System Study). Research report, 19 (1986), ILCA (International Livestock Centre for Africa), Addis Ababa, Ethiopia
21. Fernandez-Gimenez M.E., and Allen-Diaz B. Testing a non-equilibrium model of rangeland vegetation dynamics in Mongolia. Journal of Applied Ecology 36 (1999) 871-885
22. Fynn R.W.S., and O'Connor T.G. Effect of stocking rate and rainfall on rangeland dynamics and cattle performance in a semi-arid savanna, South Africa. Journal of Applied Ecology 37 (2000) 491-507
23. Gemedo-Dalle, Maass B.L., and Isselstein J. Encroachment of woody plants and its impact on pastoral livestock production in the Borana lowlands, southern Oromia, Ethiopia. African Journal of Ecology 44 (2006) 113-299
24. Gillson L. Testing equilibrium theories in savannas: 1400 years of vegetation change in Tsavo National Park, Kenya. Ecological Complexity 1 (2004) 281-298
25. Hayashi I. Five years experiment on vegetation recovery of drought deciduous woodland in Kitui, Kenya. Journal of Arid Environments 34 (1996) 351-361
26. Hiernaux P. Effects of grazing on plant species composition and spatial distribution in rangelands of the Sahel. Plant Ecology 138 (1998) 191-202
27. Illius A.W., and O'Connor T.G. On the relevance of non-equilibrium concepts to arid and semi-arid grazing systems. Ecological Applications 9 (1999) 798-813
28. Jeltsch F., Milton S.J., Dean W.R.J., and Van Rooyen N. Analysing shrub encroachment in the southern Kalahari: a grid-based modelling approach. Journal of Applied Ecology 34 (1997) 1497-1509
29. Lenzi-Grillini C.R., Viskanic P., and Mapesa M. Effects of 20 years of grazing exclusion in an area of the Queen Elizabeth National Park, Uganda. African Journal of Ecology 34 (1996) 333-341
30. Mengistu T., Teketay D., Hulten H., and Yemshaw Y. The role of enclosures in the recovery of woody vegetation in degraded dryland hillsides of central and northern Ethiopia. Journal of Arid Environments 60 (2005) 259-281
31. Muscha, M.J., Hild, A.L., Munn, L.C., Stahl, P.D., 2004. Impacts of livestock exclusion from Wyoming big sagebrush communities. USDA Forest Service Proceedings. p. 31. In: Hild, Ann, L., Shaw, Nancy, L., Meyer, Susan E., Booth, D., Terrance, McArthur, E. Durant, comps. 2004. Seed and soil dynamics in Shrubland ecosystems. proceedings; 2002 August 12-16; Laramie, WY. Proceedings RMRS-P-31. Ogden, UT. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station.
32. Mwalyosi R.B.B. Vegetation changes following land reclamation in the Kondoa eroded area, central Tanzania. African Journal of Ecology 38 (2000) 265-268
33. Oba, G., 1998. Assessment of indigenous range management knowledge of the Borana pastoralists of southern Ethiopia. Commissioned by GTZ-Borana Lowland Pastoral Development Program in collaboration with the Oromiya Regional Bureau for Agricultural Development, Negelle/Borana Ethiopia.
34. Oba G., Post E., Syvertsen P.O., and Stenseth N.C. Bush cover and range condition assessments in relation to landscape and grazing in southern Ethiopia. Landscape Ecology 15 (2000) 535-546
35. Oba G., and Kotile D.G. Assessments of landscape level degradation in southern Ethiopia: pastoralists versus ecologists. Land Degradation & Development 12 (2001) 461-475
36. Oba G., Vetaas O.R., and Stenseth N.C. Relationships between biomass and plant species richness in arid-zone grazing lands. Journal of Applied Ecology 38 (2001) 836-846
37. O'Connor T.G. Composition and population responses of an African savanna grassland to rainfall and grazing. Journal of Applied Ecology 31 (1994) 155-171
38. O'Connor T.G. Transformation of savanna grassland by drought and grazing. African Journal of Range and Forage Sciences 12 (1995) 53-60
39. O'Connor T.G., and Roux P.W. Vegetation changes (1949-1971) in a semi-arid grassy dwarf Shrubland in the Karoo, South Africa: influence of rainfall variability and grazing by sheep. Journal of Applied Ecology 32 (1995) 612-626
40. Rosenstock S.S. Shrub-grassland small mammal and vegetation responses to rest from grazing. Journal of Range Management 49 (1996) 99-203
41. SAS Institute. Statistical Analysis System/GLM Softeware (2001), Institute Inc., Cary, NC, USA
42. Scholes R.J., and Archer S.R. Tree-grass interactions in savannas. Annual Review of Ecological Systems 28 (1997) 517-544
43. Shannon C.E. A mathematical theory of communication. Bell System Technical Journal 27 (1948) 379-423
44. Sheuyange A., Oba G., and Weladji B.R. Effects of anthropogenic fire history on savanna vegetation in northeastern Namibia. Journal of Environmental Management 75 (2005) 189-198
45. Skarpe C. Shrub layer dynamics under different herbivore densities in an arid savanna, Botswana. Journal of Applied Ecology 27 (1990) 873-885
46. Skarpe C. Structure of the woody vegetation in disturbed and undisturbed arid savanna, Botswana. Vegetation 87 (1990) 11-18
47. Smart N.O.E., Hatton J.C., and Spence D.H.N. The effects of long-term exclusion of large herbivores on vegetation in Murchison Falls National Park, Uganda. Biological Conservation 33 (1985) 229-245
48. Tadesse G., Mohamed Saleem M.A., Abiye A., and Wagnew A. Impact of gracing on plant species richness, plant biomass, plant attributes, and soil physical and hydrological properties of vertisol in East African Highlands. Environmental Management 29 (2002) 279-289
49. Tamene, Y., 1990. Population Dynamics of the Problem Shrubs, Acacia drepanolobium and Acacia brevispica in the Southern Rangelands of Ethiopia. MSc thesis. University of New South Wales, Australia.
50. Trodd N.M., and Dougill A.J. Monitoring vegetation dynamics in semi-arid African rangelands: use and limitations of earth observation data to characterize vegetation structure. Applied Geography 18 (1998) 315-330
51. Van Wijngaarden, W., 1985. Elephant-tree-grass-grazers: relationships between climate, soil, vegetation and large herbivores in a semi-arid ecosystem of Tsavo, Kenya. ITC Publication no.4, Enschede, Netherlands.
52. Western D., and Maitumo D. Woodland loss and restoration in a savanna park: a 20-year experiment. African Journal of Ecology 42 (2004) 111-122
53. Zhang J., Zhao H., Zhang T., Zhao X., and Drake S. Community succession along a chronosequence of vegetation restoration on sand dunes in Horqin sandy land. Journal of Arid Environments 62 (2005) 555-566