Title: The effects of brush control on grass species abundance at Semonkong, Lesotho

Final project
Year of publication:
brush control, palatability, species abundance


Shrub encroachment is one of the major threats to Lesotho’s degraded rangelands. The main drivers of rangeland degradation include prolonged droughts, overgrazing and frequent burning of rangelands. The Ministry of Forestry, Range and Soil Conservation, through the Department of Range Resources Management, has engaged in brush control activities for removal of shrub species from the rangelands. The encroaching shrub species include Chrysocoma ciliata, Helichrysum trilineatum, Relhania dieterlenii, Seriphium plumosum, Felicia filifolia, Erica dominans and Pentzia cooperi. The shrubs are usually less than 1.5 m in height, and they are referred to as brush species. This study aimed at investigating the abundance of different grass species on shrub-cleared areas in 2016, 2017 and 2018 as compared to the uncleared brush area in the Semonkong grazing area, and to determine the relative abundance of palatable and less palatable grass species on shrub-controlled areas and an area with brush species. The study was conducted at the Semonkong grazing area in Maseru District, Lesotho. The species composition of the grass community significantly changed in response to the clearance, which was mainly due to changes in the abundance of four species, Merxmuellera disticha, Festuca caprina, Eragrostis curvula and Helictotricon longifolia. The area cleared three years before had the highest abundance of highly palatable grass species and the lowest abundance of less palatable species. However, there was a noticeable regrowth of shrubs and introduction of new shrub species such as Erica dominans and Pentzia cooperi three years after removal of shrubs. The results strongly suggest that brush control activity is a successful rangeland management tool in improving productivity of rangelands in Lesotho due to an increase in the abundance of highly palatable grass species and decreased abundance of less palatable species.

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