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Determinants and rates of land degradation: Application of stationary time-series model to data from a semi-arid environment in Kenya

Abstract

The causes of land degradation in the African drylands have been shown to vary. Some researchers consider climate to be the major contributor to degradation, with anthropogenic factors playing a minor role. Others reverse the significance of these two factors. A third group attributes land degradation to climate and anthropogenic factors equally. This study was undertaken to establish the factors influencing land degradation in a semi-arid environment in southeastern Kenya and the rate of change in vegetation types for a period of 35 years (1973–2007). The reduction in grassland cover was used as an indicator of land degradation. Causes of land degradation were determined by a multiple regression analysis. A log-linear regression analysis was used to establish the rate of vegetation change. The multiple and log-linear regression analyses showed: (1) woody vegetation, livestock population and cultivated area to be the main contributors of reduction in grassland cover in the area, and (2) an increase in undesirable woody species, livestock population and cultivated area had a significant (P<0.05) negative effect on grassland vegetation. Increased human population, low amounts of rainfall and drought showed no significant negative effect on grassland vegetation cover. In conclusion, human and livestock population growth and increased agricultural land have contributed to intensive crop cultivation and overgrazing in the semi-arid lands. This overuse of the semi-arid rangelands has worsened the deterioration of the natural grassland vegetation.

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References

  1. Adams W M, Watson E E. 2003. Soil erosion, indigenous irrigation and environmental sustainability, Marakwet, Kenya. Land Degradation & Development, 14(1): 109–122.

    Article  Google Scholar 

  2. Angassa A. 2005. The ecological impact of bush encroachment on the yield of grasses in Borana rangeland ecosystem. African Journal of Ecology, 43(1): 14–20.

    Article  Google Scholar 

  3. Angassa A. 2014. Effects of grazing intensity and bush encroachment on herbaceous species and rangeland condition in Southern Ethiopia. Land Degradation & Development, 25(5): 438–451.

    Article  Google Scholar 

  4. Asner G P, Borghi C E, Ojeda R A. 2003. Desertification in central Argentina: Changes in ecosystem carbon and nitrogen from imaging spectroscopy. Ecological Applications, 13(3): 629–648.

    Article  Google Scholar 

  5. Becerra J X. 2007. The impact of herbivore-plant coevolution on plant community structure. Proceedings of the National Academy of Sciences of the United States of America, 104(18): 7483–7488.

    Article  Google Scholar 

  6. Bennett J E, Palmer A R, Blackett M A. 2012. Range degradation and land tenure change: insights from a ‘released’ communal area of eastern Cape Province, South Africa. Land Degradation & Development, 23(6): 557–568.

    Article  Google Scholar 

  7. Breshears D D, Cobb N S, Rich P M, et al. 2005. Regional vegetation die-off in response to global-change-type drought. Proceedings of the National Academy of Sciences of the United States of America, 102(42): 15144–15148.

    Article  Google Scholar 

  8. Central Bureau of Statistics (CBS). 2000. Republic of Kenya, Ministry of Economic Planning and Development report, Nairobi, Kenya.

    Google Scholar 

  9. Cerdà A. 1998. Effect of climate on surface flow along a climatological gradient in Israel. A field rainfall simulation approach. Journal of Arid Environments, 38(2): 145–159.

    Google Scholar 

  10. Cerdà A, Lavee H. 1999. The effect of grazing on soil and water losses under arid and Mediterranean climates. Implications for desertification. Pirineos, 153–154: 159–174.

    Article  Google Scholar 

  11. Cerdà A. 2000. Aggregate stability against water forces under different climates on agriculture land and scrubland in southern Bolivia. Soil and Tillage Research, 57(3): 159–166.

    Article  Google Scholar 

  12. Cerdà A, Flanagan D C, Le Bissonnais Y, et al. 2009. Soil erosion and agriculture. Soil and Tillage Research, 106(1): 107–108.

    Article  Google Scholar 

  13. Coetzee B W T, Tincani L, Wodu Z, et al. 2008. Overgrazing and bush encroachment by Tarchonanthus camphoratus in a semi-arid savanna. African Journal of Ecology, 46(3): 449–451.

    Article  Google Scholar 

  14. Conant R T, Paustian K. 2002. Potential soil carbon sequestration in overgrazed grassland ecosystems. Global Biogeochemical Cycles, 16(4): 90–1–90-9.

    Article  Google Scholar 

  15. Darkoh M B K. 2003. Regional perspectives on agriculture and biodiversity in the drylands of Africa. Journal of Arid Environments, 54(2): 261–279.

    Article  Google Scholar 

  16. de Souza R G, da Silva D K A, de Mello C M A, et al. 2013. Arbuscular mycorrhizal fungi in revegetated mined dunes. Land Degradation & Development, 24(2): 147–155.

    Article  Google Scholar 

  17. Geist H J, Lambin E F. 2004. Dynamic causal patterns of desertification. Bioscience, 54(9): 817–829.

    Article  Google Scholar 

  18. Gisladottir G, Stocking M. 2005. Land degradation control and its global environmental benefits. Land Degradation & Development, 16(2): 99–112.

    Article  Google Scholar 

  19. GoK (Government of Kenya). 2002. Makueni District Development Plan for the period 2002–2008.

    Google Scholar 

  20. Nairobi: Kenya Government Printers. GoK (Government of Kenya). 2009. Ministry of Planning and Development. Nairobi: National population census.

    Google Scholar 

  21. GoK/NAP. 2002. National Action Programme: Framework for combating desertification in Kenya, in the context of the United Nations Convention to Combat Desertification (UNCCD). Nairobi: National Environment Secretariat.

    Google Scholar 

  22. Haddad N M, Tilman D, Knops J M H. 2002. Long-term oscillations in grassland productivity induced by drought. Ecology Letters, 5(1): 110–120.

    Article  Google Scholar 

  23. Hall D O, Scurlock J M O. 1991. Climate change and productivity of natural grasslands. Annals of Botany, 67(Suppl.): 49–55.

    Article  Google Scholar 

  24. Hibbard K A, Archer S, Schimel D S, et al. 2001. Biogeochemical changes accompanying woody plant encroachment in a subtropical savanna. Ecology, 82(7): 1999–2011.

    Article  Google Scholar 

  25. Holdo R M. 2013. Revisiting the two-layer hypothesis: coexistence of alternative functional rooting strategies in savannas. PLoS ONE, 8(8): e69625.

    Article  Google Scholar 

  26. Izzo M, Araujo N, Aucelli P P C, et al. 2013. Land sensitivity to desertification in the Dominican Republic: an adaptation of the ESA methodology. Land Degradation & Development, 24(5): 486–498.

    Google Scholar 

  27. Kassahun A, Snyman HA, Smit GN. 2008. Livestock grazing behaviour along a degradation gradient in the Somali region of eastern Ethiopia. African Journal of Range & Forage Science, 25(1): 1–9.

    Article  Google Scholar 

  28. Lal R. 2004. Carbon sequestration in dryland ecosystems. Environmental Management, 33(4): 528–544.

    Article  Google Scholar 

  29. Lal R. 2009. Sequestering carbon in soils of arid ecosystems. Land Degradation & Development, 20(4): 441–454.

    Article  Google Scholar 

  30. Lázaro R, Rodrigo F S, Gutiérrez L, et al. 2001. Analysis of a 30-year rainfall record (1967–1997) in semi-arid SE Spain for implications on vegetation. Journal of Arid Environments, 48(3): 373–395.

    Article  Google Scholar 

  31. Li X L, Gao J, Brierley G, et al. 2013. Rangeland degradation on the Qinghai-Tibet Plateau: Implications for rehabilitation. Land Degradation & Development, 24(1): 72–80.

    Article  Google Scholar 

  32. Mataix-Solera J, Cerdà A, Arcenegui V, et al. 2011. Fire effects on soil aggregation: a review. Earth-Science Reviews, 109(1–2): 44–60.

    Article  Google Scholar 

  33. Mganga K Z, Musimba N K R, Nyangito M M, et al. 2010. Improving hydrological responses of degraded soils in semi arid Kenya. Journal of Environmental Science and Technology, 3(4): 217–225.

    Article  Google Scholar 

  34. Mganga K Z, Musimba N K R, Nyariki D M, et al. 2011. Different land use types in the semi-arid rangelands of Kenya influence soil properties. Journal of Soil Science and Environmental Management, 2(11): 370–374.

    Google Scholar 

  35. Mganga K Z, Kuzyakov Y. 2014. Glucose decomposition and its incorporation into soil microbial biomass depending on land use in Mt. Kilimanjaro ecosystems. European Journal of Soil Biology, 62: 74–82.

    Article  Google Scholar 

  36. Mureithi S M, Verdoodt A, Njoka J T, et al. 2016. Impact of community conservation management on herbaceous layer and soil nutrients in a Kenyan semi-arid savannah. Land Degradation & Development, 27(8): 1820–1830.

    Article  Google Scholar 

  37. Mwang’ombe A W, Ekaya W N, Muiru W M, et al. 2011. Livelihoods under climate variability and change: an analysis of the adaptive capacity of rural poor to water scarcity in Kenya’s drylands. Journal of Environmental Science and Technology, 4(4): 403–410.

    Article  Google Scholar 

  38. Ngugi R K, Nyariki D M. 2005. Rural livelihoods in the arid and semi-arid environments of Kenya: sustainable alternatives and challenges. Agriculture and Human Values, 22(1): 65–71.

    Article  Google Scholar 

  39. Nyangito M M, Musimba N K R, Nyariki D M. 2008. Range use and dynamics in the agropastoral system of southeastern Kenya. African Journal of Environmental Science and Technology, 2(8): 222–230.

    Google Scholar 

  40. Nyangito M M, Musimba N K R, Nyariki D M. 2009. Hydrologic properties of grazed perennial swards in semiarid southeastern Kenya. African Journal of Environmental Science and Technology, 3(2): 26–33.

    Google Scholar 

  41. Nyariki D M. 2009. Price response of herd off-take under market liberalization in a developing cattle sector: panel analysis applied to Kenya’s ranching. Environment and Development Economics, 14(2): 263–280.

    Article  Google Scholar 

  42. Oba G, Post E, Syvertsen P O, et al. 2000. Bush cover and range condition assessments in relation to landscape and grazing in Southern Ethiopia. Landscape Ecology, 15(6): 535–546.

    Article  Google Scholar 

  43. Olukoye G A, Kinyamario J I. 2009. Community participation in the rehabilitation of a sand dune environment in Kenya. Land Degradation & Development, 20(4): 397–409.

    Article  Google Scholar 

  44. Omuto C T, Vargas R R, Alim M S, et al. 2010. Mixed-effects modelling of time series NDVI-rainfall relationship for detecting human-induced loss of vegetation cover in drylands. Journal of Arid Environments, 74(11): 1552–1563.

    Article  Google Scholar 

  45. Opiyo FEO, Ekaya W N, Nyariki D M, et al. 2011. Seedbed preparation influence on morphometric characteristics of perennial grasses of a semi-arid rangeland in Kenya. African Journal of Plant Science, 5(8): 460–468.

    Google Scholar 

  46. Pei S F, Fu H, Wan C G. 2008. Changes in soil properties and vegetation following exclosure and grazing in degraded Alxa desert steppe of Inner Mongolia, China. Agriculture, Ecosystems & Environment, 124(1–2): 33–39.

    Article  Google Scholar 

  47. Qadir M, Noble A D, Chartres C. 2013. Adapting to climate change by improving water productivity of soils in dry areas. Land Degradation & Development, 24(1): 12–21.

    Article  Google Scholar 

  48. Roques K G, O’Conner T G, Watkinson A R. 2001. Dynamics of shrub encroachment in an African savanna: relative influences of fire, herbivory, rainfall and density dependence. Journal of Applied Ecology, 38(2): 268–280.

    Article  Google Scholar 

  49. Serneels S, Lambin E F. 2001. Proximate causes of land-use change in Narok District, Kenya: a spatial statistical model. Agriculture, Ecosystems & Environment, 85(1–3): 65–81.

    Article  Google Scholar 

  50. Speranza C I, Kiteme B, Ambenje P, et al. 2010. Indigenous knowledge related to climate variability and change: insights from droughts in semi-arid areas of former Makueni District, Kenya. Climate Change, 100(2): 295–315.

    Article  Google Scholar 

  51. Van der Wal R. 2006. Do herbivores cause habitat degradation or vegetation state transition? Evidence from the tundra. Oikos, 114(1): 177–186.

    Article  Google Scholar 

  52. Visser N, Morris C, Hardy M B, et al. 2007. Restoring bare patches in the Nama-Karoo of South Africa. African Journal of Range & Forage Science, 24(2): 87–96.

    Article  Google Scholar 

  53. Vohland K, Barry B. 2009. A review of in situ rainwater harvesting (RWH) practices modifying landscape functions in African drylands. Agriculture, Ecosystems & Environment, 131(3–4): 119–127.

    Article  Google Scholar 

  54. Wang Q X, Batkhishig O. 2014. Impact of overgrazing on semiarid ecosystem soil properties: a case study of the eastern Hovsgol Lake Area, Mongolia. Journal of Ecosystem & Ecography, 4(1): 140, doi: 10.4172/2157-7625.1000140.

    Article  Google Scholar 

  55. Wang T, Yan C Z, Song X, et al. 2013. Landsat images reveal trends in the Aeolian desertification in a source area for sand and dust storms in China’s Alashan Plateau (1975–2007). Land Degradation & Development, 24(5): 422–429.

    Google Scholar 

  56. Wessels K J, Prince S D, Frost P E, et al. 2004. Assessing the effects of human-induced land degradation in the former homelands of northern South Africa with a 1 km AVHRR NDVI time-series. Remote Sensing of Environment, 91(1): 47–67.

    Article  Google Scholar 

  57. Wessels K J, Prince S D, Malherbe J, et al. 2007. Can human-induced land degradation be distinguished from the effects of rainfall variability? A case study in South Africa. Journal of Arid Environments, 68(2): 271–297.

    Article  Google Scholar 

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Acknowledgements

This research was funded by the European Commission under the Agricultural Innovations for Drylands Africa (AIDA), Grant Number 043863-SSA Africa (2006). We are also grateful to the Kamba Agropastoral Community in Kibwezi sub-County, Makueni County, Kenya for their support and cooperation throughout the research period.

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Correspondence to Kevin Z Mganga.

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Mganga, K.Z., Nyariki, D.M., Musimba, N.K.R. et al. Determinants and rates of land degradation: Application of stationary time-series model to data from a semi-arid environment in Kenya. J. Arid Land 10, 1–11 (2018). https://doi.org/10.1007/s40333-017-0036-0

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Keywords

  • regression analysis
  • land degradation
  • grassland cover
  • semi-arid Kenya
  • Sub-Saharan Africa