Flight to Vulture’s Retreat serves dual research purpose in South Africa’s most critical water catchment
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On 16 May 2018, the technical team from the Grasslands-Forests-Wetlands Node, Paul Gordijn, Siphiwe Mfeka and Kent Lawrence, found themselves hovering above the endangered Cape Vultures of the uKhahlamba Drakensberg as the helicopter pilot carefully maneuvered them to their most remote field research site.
At this research site known as Vulture’s Retreat, located on a small inselberg (free-standing peak) near the Drakensberg escarpment, at an altitude of 3068 m.a.s.l., the highest long-term weather station in South Africa was established in August 2015.
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Only one visit to the station since then, in November 2015, was undertaken to boost the communication ability of the station - now the weather conditions at the site can be viewed live here. This recent visit was to upgrade and repair instrumentation on the station, which takes some preparation (programming behind a computer back in the office and then testing instruments), but the opportunity was also taken to initiate some long-term vegetation monitoring.
The high altitude of this site is associated with occasional winter snowfalls and temperature regularly drops below zero. These chilly conditions with snow and ice have resulted in the weather station’s automatic rain gauge being blocked, which may affect the accuracy of the gauge.
To overcome this problem, a special snow gauge was installed on this visit. The snow gauge has a heater which melts snow and ice. By comparing precipitation from the conventional rain gauge and the snow gauge at the site, the technical team will get an idea of how snow contributes to the water balance.
They will also be able to track long-term changes in these different precipitation forms with a fancy new barometric sensor for air pressure that adds to the unique value of the highest long-term weather station in South Africa. This all feeds into the socio-economic value that SAEON is adding by contributing important weather data to the public and the research community.
Long-term vegetation monitoring
The isolated nature of the Vulture’s Retreat inselberg provides a unique opportunity to assess vegetation dynamics away from the impacts of large herbivores. These inselbergs contain some unique species which have differentiated from their relatives over time, speciation driven by their isolation.
Given that this trip was out of the flowering season, species could not be easily identified. Therefore, the team set up some long-term photo monitoring sites whereby dynamics between the temperate fynbos shrubs and grassy elements can be monitored into the future and climate change signals evaluated. This represents the first long-term monitoring effort of vegetation on Drakensberg inselbergs.
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“We look forward to continued research at this unique long-term monitoring site and specifically anticipate appreciation of this weather and vegetation monitoring data at the ‘top’ of a site known as the “water tower” of southern Africa, which is also an important biodiversity hotspot,” says Sue Van Rensburg, Coordinator of SAEON’s Grasslands-Forests-Wetlands Node.