Ouhout invading the Drakensberg

Ouhout or Leucosidea sericea is more than well-known in the Drakensberg grasslands, inland in the Eastern Cape and KwaZulu-Natal. Since the 1950s the tree’s prevalence has been notably increasing and more recently escalating in montane grazing areas, along watercourses and near human settlements. As sheep farming increased, the trees or commonly bushes have multiplied. 

The encroachment is a threat to grazing land for livestock in some parts. Sheep eat the small ouhout nuts, contributing much to seed dispersal and thus plant number escalation. L. sericea is a multistemmed resprouter that benefits from fire whereby it invades if the conditions allow.

Changes in veld fire prevalence and overgrazing have added and are adding significantly to grassland transformation in different parts of the country, also here where L. sericea has become dominant in some parts of high-altitude grasslands. This is also happening in certain parts of Zimbabwe, Eswatini and Lesotho (De Villiers, 2012: Fire-mediated succession and reversion of woody vegetation in the KwaZulu-Natal Drakensberg, South Africa. Dissertation, University of the Witwatersrand; Ndamane, et al, 2023: Community Perceptions on the Transformation of a high-altitude Grassland Through Invasion by Leucosidea sericea at Vuvu, South Africa. Human Ecology, 51, pp 439-454; iNaturalist).