Micro-climatic monitoring of air and ground was started in 1990 to evaluate climatic controls on the present-day diurnal soil frost environment in the Western Cape mountains of South Africa. To this effect two data logger stations were established in the summit region of the Waaihoek mountains. Two sites were established at Waaihoek Peak and Mount Superior, respectively.
Waaihoek Peak - The Waaihoek Peak monitoring site is positioned on the southeast extension of a small summit plateau at 1900m elevation where it changes into a southeast trending ridge flanked by two small valleys. The station stands on a 4 to 5 degree slope with an aspect of 140 degrees and is underlain by steeply dipping quartzitic sandstone of the Peninsula Formation. A shallow sandy soil here reaches a thickness of 0.35m and supports a sparse vegetation cover of Restio (Cape reeds) species up to 0.2m high with a total cover of around 30%. Initially both daily and hourly records were kept which necessitated frequent visits to replace the data storage tapes. As from 29-11-1992 only daily records were kept, including maximum and minimum temperature and 24 hour precipitation totals. Average daily soil moisture levels were recorded only as the range between daily maximum and minium values proved to be minimal.
Mount Superior - Field observations established the presence of active soil frost features near Mount Superior during December 1991. A second data logger site was consequently established by 1-5-1993 to provide microclimatic data from a site with a different substrate and currently active soil-frost processes. The Mount Superior station is positioned 5km SSE of the Waaihoek Peak site on a flat summit plateau of Cedarberg shale at 1860m elevation. The surface cover is comprised of fractured bedrock and bare shallow soil with tussocks of Restio spp. up to 0.5m high. Daily maximum and minimum temperature were recorded for each sensor as well as daily average relative soil moisture levels and daily precipitation totals.
These data are presented on the CAPS Version 1.0 CD-ROM, June 1998.