Euryops walterorum, a declining restricted-range endemic of the Greater Gamsberg

Abstract

Euryops walterorum is a perennial shrub, endemic to an extremely limited habitat on the plateau of the Greater Gamsberg. The population of this endemic has been shown to be in decline since the early 1980s. The Gamsberg plateau is identified as one of the world’s best astronomical observatory sites and has been used as an astronomical base since 1971. Due to its position and favourable atmospheric conditions, the establishment of the Africa Millimetre Telescope is planned here. This development may adversely affect the population of Euryops walterorum. In this paper we present information on the ecology and habitat of this plant. We also speculate on possible reasons for the population’s decline. Based on this, we propose a long-term monitoring programme on the population health of this restricted-range endemic, as well as further measures for the conservation of the species. Preliminary results from the initial survey show the population stands in their habitat are unevenly distributed and most monitoring plots contained about two plants or less, and many had none. From the current plot data, the estimated total number of mature plants on the plateau was calculated to be about 22 000. Based on the observed reduction in population, as well as both the extremely small Extent of Occurrence and Area of Occupation, the conservation status of the species has been reassessed following IUCN Red List Criteria, and found to be Critically Endangered B1 ab(iii,iv) + 2ab(iii,v).