Browsing by Author "Graae, Bente Jessen"

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    Land use and land cover change within and around the greater Serengeti ecosystem, Tanzania
    (Science Publishing Group) Kija, Hamza Khalid; Ogutu, Joseph Ochieng; Mangewa, Lazaro Johana; Bukombe, John; Verones, Francesca; Graae, Bente Jessen; Kideghesho, Jafari Ramadhani; Said, Mohammed Yahya; Nzunda, Emmanuel Fred
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    Land use and land cover change within and around the greater Serengeti ecosystem, Tanzania
    (Science Publishing Group, 2020) Kija, Hamza Khalid; Ogutu, Joseph Ochieng; Mangewa, Lazaro Johana; Bukombe, John; Verones, Francesca; Graae, Bente Jessen; Kideghesho, Jafari Ramadhani; Said, Mohammed Yahya; Nzunda, Emmanuel Fred
    Land use and land cover (LULC) changes can pose profound impacts on wildlife habitats, abundance and distribution and on human-dominated landscapes. We investigated LULC changes in the Greater Serengeti ecosystem, Tanzania, for a period of 41 years from 1975 to 2015. Specifically, we mapped LULC types for 1975, 1995 and 2015 and assessed the corresponding changes during 1975-1995, 1995-2015 and 1975-2015. We used the random forest classification algorithm to classify Multispectral Scanner (MSS), Thematic Mapper (TM), Enhanced Thematic Mapper Plus (+ETM) and Operational Land Imager (OLI) into eight main classes. We obtained accuracies of 88.4%, 90.6% and 93.4% with Kappa Indices of Agreement (KIA) of 0.86, 0.87 and 0.91 for 1975, 1995 and 2015, respectively. Grassland, shrubland and woodland were the major LULC types throughout 1975-2015 with percentage coverages of 50.6%, 23.7% and 20.9% for 1975; 54.2%, 23.5% and 15.9% for 1995; and 57.0%, 23.8% and 8.9% for 2015, respectively. Overall, woodland cover (-11.1%) was converted to most of the other cover types during 1975-2015. The loss of woodland cover is due to increasing human population size, agriculture, settlements and policy changes fires and elephant browsing. Effective conservation policies and regulation of socio-economic activities in the ecosystem and its buffer area are essential to ameliorate declining vegetation cover, especially along the protected areas boundaries.
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    Savannah trees buffer herbaceous plant biomass against wild and domestic herbivores
    (John Wiley & Sons Ltd) Smith, Stuart William; Graae, Bente Jessen; Bukombe, John; Hassan, Shombe Ntaraluka; Lyamuya, Richard Daniel; Mtweve, Philipo Jacob; Treydte, Anna C.; Speed, James David Mervyn