Journal of Resources and Ecology ›› 2018, Vol. 9 ›› Issue (3): 317-329.doi: 10.5814/j.issn.1674-764x.2018.03.012

• Articles • Previous Articles     Next Articles

Patterns of Changes to Woody Vegetation near Resettlement Sites in Semi-arid Northwestern Ethiopia

Mulubrhan Balehegn1, 2, 3, Kidane Hintsa3   

  1. 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
    2. International Ecosystem Management Partnership, United Nations Environment Programme, Beijing 100101, China;
    3. Department of Animal, Rangeland and Wildlife Sciences, Mekelle University, Mekelle Post Box 231 , Ethiopia
  • Received:2018-03-02 Revised:2018-05-06 Online:2018-05-30 Published:2018-06-06
  • Contact: Mulubrhan Balehegn, E-mail: mulubrhan.balehegn@unep-iemp.org; mulubrhan.balehegn@mu.edu.et
  • Supported by:
    International Foundation for Science, Stockholm, Sweden, through a grant to Mulubrhan Balehegn (D5056-1); Norwegian Research Council (Project 236373); National Natural Science Foundation of China (31361140360).

Abstract: Communal rangelands provide diverse ecosystem services to millions of pastoralists and agro-pastoralists. Resettling destitute communities into hitherto uninhabited communal rangelands and forests, a common practice throughout Sub-Saharan Africa, is a threat to the sustainable use of range and forest land resources. In order to understand the effect of resettlement on a semi-arid woodland in northwestern Ethiopia, satellite imagery of 23 resettlement villages taken over a period of fourteen years, and woody vegetation floristic data for three old resettlements, three new resettlements, two refugee camps and one protected area were analyzed using ANOVA and canonical correspondence analysis (CCA). The normalized differential vegetation index (NDVI) and canopy cover around all village types decreased with disturbance gradients, while the magnitude of change varied according to the type of settlement. Limited canopy cover was observed in refugee camps and new resettlements, compared to old resettlements and protected areas. Woody vegetation height class showed a J shaped distribution in all sites except refugee camps (RC), indicating a decline in vegetation. CCA showed that variables like site type, altitude and disturbance gradient significantly affected the diversity of woody species at the different sites. Comparison of individual species responses to disturbances indicated that low fodder value invaders like Dichrostachys cinerea, and many Acacia species were increasing in proportion and coverage at the expense of some multipurpose species including Tamarindus indica, Diospyros mespiliformis, and Pterocarpus lucens. In the absence of regulated vegetation use, resettlements result in a decline in overall vegetation cover and a shift in floristic diversity in favor of invasive species.

Key words: NDVI, CCA, Ethiopia, resettlement, woodland rangelands, woody vegetation