Browsing by Author "Magaya, John Paul"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Savannah Phenological Dynamics Reveal Spatio-Temporal Landscape Heterogeneity in Karamoja Sub-region, Uganda
    (Frontiers in Sustainable Food Systems, 2020) Egeru, Anthony; Magaya, John Paul; Kuule, Derick Ansyijar; Siya, Aggrey; Gidudu, Anthony; Barasa, Bernard; Namaalwa, Jjumba Justine
    Phenological properties are critical in understanding global environmental change patterns. This study analyzed phenological dynamics in a savannah dominated semi-arid environment of Uganda. We used moderate-resolution imaging spectroradiometer normalized difference vegetation index (MODIS NDVI) imagery. TIMESAT program was used to analyse the imagery to determine key phenological metrics; onset of greenness (OGT), onset of greenness value, end of greenness time (EGT), end of greenness value, maximum NDVI, time of maximum NDVI, duration of greenup (DOG) and range of normalized difference vegetation index (RNDVI). Results showed that thicket and shrubs had the earliest OGT on day 85 ± 14, EGT on day 244 ± 32 and a DOG of 158 ± 25 days. Woodland had the highest NDVI value for maximum NDVI, OGT, EGT, and RNDVI. In the bushland, OGT occurs on average around day 90 ± 11, EGT on day 255 ± 33 with a DOG of 163 ± 36 days. The grassland showed that OGT occurs on day 96 ± 13, EGT on day 252 ± 36 with a total DOG of 156 ± 33 days. Early photosynthesis activity was observed in central to eastern Karamoja in the districts of Moroto and Kotido. There was a positive relationship between rainfall and NDVI across all vegetation cover types as well as between phenological parameters and season dynamics. Vegetation senescence in the sub-region occurs around August to mid-September (day 244–253). The varied phenophases observed in the sub-region reveal an inherent landscape heterogeneity that is beneficial to extensive pastoral livestock production. Continuous monitoring of savannah phenological patterns in the sub-region is required to decipher landscape ecosystem processes and functioning.
  • Thumbnail Image
    Item
    Tsetse Invasion as an Emerging Threat to Socioecological Resilience of Pastoral Communities in Karamoja, Uganda
    (Sustainability, 2020) Egeru, Anthony; Opio, Joseph; Siya, Aggrey; Barasa, Bernard; Magaya, John Paul; Namaalwa, Justine J.
    Over 70% of Uganda is infested by the tsetse fly, which has negative e ects on human and livestock health. From colonial to post-independent Uganda, the Government of Uganda has worked to eradicate the tsetse menace. Despite these e orts, recent veterinary reports from the Karamoja sub-region have indicated widespread tsetse invasion. This study investigated the potential impact of tsetse invasion on the socioecological resilience of pastoral communities in the Karamoja sub-region. Results indicated that tsetse invasion is spreading from north to south of Karamoja. The tsetse transmission route emerging from southern Karamoja is perceived to be a continuation of the tsetse belt from West Pokot, Kenya. Cases of livestock deaths, livestock abortions, decreased milk yields, restricted access to prime grazing lands, heightened human-wildlife conflicts and disruption on crop cultivation have been reported. A computed socioecological resilience index in the study area was positive but low. Owing to the transboundary characteristics of tsetse invasions and sources and the associated documented e ects, an urgent, strategic and system-wide intervention should be undertaken to control the tsetse invasion in this sub-region.