Long-term vegetation monitoring – a 33 year record from table mountain

Abstract

Nearly 40 years ago McLachlan and Moll highlighted the need for a well-defined path system on the Western Table of Table Mountain in the immediate vicinity of the Upper Cable Station (UCS). At that time the numbers of people using the cableway was heavily impacting the vegetation on the Western Table, particularly in the vicinity of the UCS. This prompted a study by Coley (1977) to assess the long-term impacts of trampling in this area. In order to monitor changes in the vegetation through time Coley set up 12 permanently marked plots (each ~4x4 m), arranged at increasing distances from the UCS. Plot positions were carefully selected so that the effects of trampling on the vegetation could be measured at various points (distance being a surrogate for trampling intensity). Field observations in 1977 revealed that Mountain Fynbos vegetation was heavily impacted by cableway tourists. Furthermore the vegetation was most damaged closest to the UCS, with a sharp decrease in damage with increasing distance from the station. In order to monitor the vegetation change Coley used aerial photographs of permanently marked plots, so that visual comparisons of species cover, condition and composition could be made over time. The vegetation was then assessed in terms of percentage cover, and percentage damaged for each plot. My study marks the fifth time data were collected since Coley (1977) and the results show that there has been a marked improvement in vegetation quality since the construction of well-defined paths and a concerted effort by managers to ensure tourists do not leave the paths; which has greatly reduced trampling since the 1997 upgrade. The implications of this study provided evidence of the importance of restricting iv tourist traffic in areas that are regularly visited and, therefore, highly impacted. It also shows that denuded fynbos is resilient and does recover over time, provided that the substrate is not eroded too heavily by trampling. Finally, I present several management recommendations, of which the most controversial, albeit important, is for a rotational block burn programme on the Western Table; since fire is a keystone ecological process that has been absent of the Western Table for at least 80 to 90 years.