Population size, structure and habitat features of Haworthia koelmaniorum var. mcmurtryi, an endemic plant from Mpumalanga Province, South Africa

Abstract

Haworthia koelmaniorum Oberm. & D.S. Hardy var. mcmurtryi (C.L. Scott) M.B. Bayer is an endemic plant restricted to the high-lying areas of Mpumalanga Province in South Africa. There is a serious lack of information on this species; it was known from only two populations at the time of the study but this information did not include population sizes and structures or its habitat requirements. A total count was conducted of one of the two populations to determine its size. Recorded plants were classified into age groups – according to their size and number of leaves – to determine the population structure. A detailed investigation of the habitat features of the studied population was also conducted. It was found that the studied population consisted of 1284 individuals and comprised approximately 4% seedlings, 12% juveniles and 84% mature plants. The species was found to have specialised habitat requirements, occurring only on red rhyolite of the Selons River Formation. The plants were also found to select very specific habitat features within their range of occurrence. The species also seems to be adapted to fire and has developed strategies to survive fire events. It is recommended that future research projects on this species use the same methods and age groups as this study to facilitate comparison. It is also recommended that more research be initiated to determine the population and seed viability, specific pollinators and the optimum fire frequency and intensity for this species.

Conservation implications: This article provides baseline information related to the size, structure and habitat features of one of two known populations of Haworthia koelmaniorum var. mcmurtryi. This information will contribute to the understanding of the ecology of this plant, thus contributing to better management decisions to enhance its in situ conservation.