Density and Regrowth of a Forest Restio (Ischyrolepis eleocharis) under Harvest and Non-harvest Treatments in Dune Forests of Eastern Cape Province, South Africa

摘要

Density and Regrowth of a Forest Restio ( Ischyrolepis eleocharis ) under Harvest and Non-harvest Treatments in Dune Forests of Eastern Cape Province, South Africa. Ischyrolepis eleocharis (Mast.) H.P.Linder is a perennial rush or sedge-like herb in the Restionaceae family and has been harvested for various uses from coastal forest dunes of South Africa. Around 2005, a ban on I. eleocharis harvesting in Bathurst coastal forest was instituted by provincial conservation authorities based on their unsubstantiated impression that the species population was decreasing. Here we report on the population density pre and post the harvest ban, as well as further explore the autecology of the species by assessing plant density relative to environmental factors (slope and aspect) and a controlled experiment on regrowth after harvesting at different intensities. The results show that the shoot density of both living and dead I. eleocharis increased significantly over the past eight years. This concurs with results from the harvesting experiment which showed that I. eleocharis recovered rapidly within a year of harvesting. Both aspect and slope play a key role in the distribution of I. eleocharis, with most plants found in open patches in the forest located on the summit and upper slopes of dunes facing the landward side. These results indicate that I. eleocharis is highly abundant and resilient to harvesting.