Restoration of the Clanwilliam cedar Widdringtonia cedarbergensis: The importance of monitoring seedlings planted in the Cederberg, South Africa

Abstract

A decline in numbers of the Clanwilliam cedar Widdringtonia cedarbergensis, an endemic conifer in the fynbos vegetation of the Cederberg mountains, has led to the instigation of a restoration programme to reinstate the species. On the one hand, the loss of fire-sensitive adult trees is reduced by practising frequent, low-intensity burning which precludes the occurrence of intense wild fires. On the other hand, large numbers of nursery-reared seedlings are planted out each year in newly burnt areas of typical cedar habitat. This project investigated the effects of microhabitat factors (shade, aspect, competition from surrounding plants, soil depth) on the survival of transplanted seedlings. Seedling survival was high (39·1–61·2%). It was found that increased shade levels led to the greater probability of seedling survival of recent plantings (18 months prior to the study), but not in plantings performed 5 years earlier. None of the other factors measured affected survival. Seedling transplantings were found to be more efficient than earlier reported seed sowing, since the former resulted in greater survival of seedlings. It is recommended that monitoring is carried out to assess overall success of the programme and suggest future improvement.