EFFECT OF RANGELAND USE ON HERBACEOUS SPECIES COMPOSITION AND DIVERSITY OF NATURAL PASTURES IN PADER DISTRICT
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Date
2025
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Gulu University
Abstract
ABSTRACT
This study investigated the diversity of herbaceous pastures under different grazing and burning intensities, and herders’ perceptions of pasture composition and utility value in Aswa Ranch, Pader district.
Data were collected through a cross-sectional vegetation survey between November and December 2022 using 1m x 1 m quadrats along transects placed in areas with different grazing and burning intensities. Diversity was assessed using indices such as richness (S), Shannon-Wiener (H’), Gini-Simpson (G), and Importance Value Index (IVI). Focus group discussions were also conducted to record local ecological knowledge and perceptions. IVI analysis revealed Hyparrhenia species and Digitaria abyssinica as dominant in minimally grazed plots and Brachiaria decumbens, Sporobolus pyramidalis, Paspalum spp., and Cenchrus ciliaris as dominant in regularly grazed areas. Herders similarly identified Hyparrhenia spp., Brachiaria decumbens, Imperata cylindrica, Panicum maximum, Sporobolus pyramidalis, and Cynodon dactylon as abundant, but highlighted Sporobolus pyramidalis and Cymbopogon afronardus as undesirable for livestock production. Minimally grazed areas had higher Shannon-Weiner, species richness, evenness and Gini-index values. In contrast, regular burning was associated with higher species diversity. Generally, Aswa Main was more diverse than Aswa Zebu. Herdsmen's perceptions revealed high grazing intensity, indiscriminate bush burning, proximity of kraals and animal watering areas as factors affecting pasture composition. While the general state of the
pastures was considered favourable for livestock production by the herdsmen, pastures are experiencing a downward trend in pasture quality, as depicted by the increasing trend of
undesirable species such as Sporobolus pyramidalis and Cymbopogon afronadus, especially in the overgrazed areas. Therefore, to ensure a more uniform distribution of palatable species across the grazing areas, the ranch management should adopt an incremental restoration strategy involving phased oversowing combined with rest periods and proper rotational grazing management to facilitate natural pasture regeneration and increase species richness and evenness. They should also incorporate legume species as part of the restoration strategy to improve the nutritive value of pastures.
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Keywords
RANGELAND, USE, HERBACEOUS SPECIES COMPOSITION, DIVERSITY OF NATURAL PASTURES