Abstract:
"The reasons for the success of certain alien plant species in the vicinity of Cape Town (i.e. the northern Cape Peninsula and the adjoining Cape Flats) are examined by a consideration of their history at the hands of man," writes the authoress. "Attention is focussed on 13 woody species that are considered to threaten the natural macchia-type vegetation (fynbos) of the region. They comprise Acacia (6 spp.), Albizia lophantha, Hakea (3 spp.) and Leptospermum laevigatum, all from Australia, and Pinus (2 spp.) from the Mediterranean region. The method of approach is historical and the research is based primarily on manuscript documents in the Cape Archives used in conjunction with annual reports of governmental bodies, especially the forestry authorities, and other contemporary accounts. "The date of the first known occurrence of each of the species in the south-western Cape is documented, the earliest being the period 1685-1693 for Pinus pinaster and the latest 1865 for Acacia pycnantha. The introduction of most of the species is shown to be related to the intense interest in exotic plants that was characteristic of Britain and its colonies in the early and middle 19th century." The conclusion of this disappointing study is simply that "wide distribution of alien plants does not necessarily imply that they are invasive. The role of man in creating their distribution must also be taken into account."