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A ministerial peek turns out to be a SAEON peak
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Fresh from a recent meeting of the Group on Earth Observations in Australia where he represented South Africa, the Deputy Minister of Higher Education, Science and Innovation, Mr Buti Manamela, expressed an interest in seeing SAEON in action.
He was subsequently hosted by the SAEON Arid Lands Node in Kimberley on January 10.
The National Research Foundation’s Deputy Chief Executive Officer for Research Infrastructure Platforms, Dr Clifford Nxomani, and the Director of Strategic Science Support and Analysis, Dr Kurt van der Heyden, were in Kimberley to welcome the Deputy Minister and his team along with delegates from the Department of Science and Innovation.
The manager of SAEON’s Arid Lands Node, Dr Joh Henschel, and the office administrator, Joanne Riet, introduced the SAEON team members before taking the visitors on a tour of the offices. Dr Henschel presented an overview of the various projects for which the node has been responsible to give the visitors some perspective on the work done at field sites across the western half of South Africa.
Gaining an understanding of arid lands research and instrumentation
Next on the programme was an excursion to the De Beers-owned Benfontein Nature Reserve, a mere 20 minutes away from the Arid Lands Node office. The visitors were taken on a guided tour of the SAEON eddy covariance flux towers, Stellenbosch University’s primary productivity monitoring sites and the SAEON plant phenology field sites.
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With patches of cloud as a reprieve to the punishing heat, Dr Kerneels Jaars of the Expanded Freshwater and Terrestrial Earth Observation Network (EFTEON) introduced the newly set up test site for eddy covariance carbon dioxide, water and energy flux measurements located in a patch of camel thorn savanna.
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He explained the methods and importance of long-term carbon and water flux measurements in arid ecosystems as well as the vital ecosystem-scale biophysical datasets collected from flux towers towards improving the understanding of climate change and influencing policy and mitigation strategies for South Africa.
Towards the west of the flux tower is a network of sensors of Photochemical Reflectance Index and Normalized Difference Vegetation Index installed by Stellenbosch University’s Department of Botany and Zoology. These sensors measure plant light use and vegetation greenness as proxies for primary productivity.
SAEON PhD candidate Amukelani Maluleke explained how these measurements complemented the eddy covariance measurements towards the partitioning of the net ecosystem exchange signal to its components: gross primary production and ecosystem respiration. He moreover described how the use of these in situ measurements with satellite imagery would provide the ability to upscale and conduct regional assessments of the carbon balance in semi-arid and arid ecosystems.
Lastly, the Deputy Minister heard what he referred to as “an instruction list from a sangoma” while SAEON intern Lehlohonolo Lepholletse demonstrated the plant phenology monitoring of various tree and grass species such as Senegalia mellifera (black thorn), Vachellia tortilis (umbrella thorn) and Schimdtia pappophoroides (vaal grass) at the site. These scientific names certainly made Lehlohonolo sound like a seasoned herbalist.
The project interested the Deputy Minister as he learnt about plant adaptations in arid environments and the environmental (climate and habitat) cues that lead to the flowering and various other seasonal and interannual responses of plants.
SAEON field technician Wynand Calitz then highlighted the discrete size classes of Vachellia erioloba (camel thorn) at Benfontein, where many trees remained smaller than 50 centimetres above ground for several decades. It is surmised that above-ground growth is slow while the trees are developing taproots down to the groundwater before rapidly growing into big trees 5–10 metres high.
At the picnic lunch that followed, the Deputy Minister expressed his gratitude for the research conducted by SAEON. He emphasised the need to broaden the understanding of climate change and build the capacity of young scientists through active participation in scientific projects.
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“The visit presented a platform where I could share my PhD research co-supervised by SAEON’s Dr Gregor Feig (EFTEON manager), Dr Christian Brümmer of Thünen Institute in Germany and Stellenbosch University’s Professor Guy Midgley,” says Amukelani.
The research focuses on carbon, water and energy exchange in semi-arid and arid South African ecosystems. The project intends to compare carbon and water fluxes in the Benfontein Nature Reserve, making use of datasets from EFTEON eddy covariance test sites in the savanna and karoo patches to reveal seasonal and diurnal water-use strategies and the carbon balance of these arid ecosystems.
Also, the project aims to broaden the understanding of the spatial and temporal responses of water and carbon exchange to pulsed resources such as rainfall in semi-arid ecosystems.
Lastly, with the use of satellite-derived vegetation and water indices, the project seeks to quantify the representation of seasonal productivity trends by satellite indices in semi-arid environments towards arranging tools for upscaling eddy covariance site measurements. These objectives aim to contribute to the current discussions on the pressures of climate change and land use and their impacts on the regional cycling of carbon, water and energy in South Africa.
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