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The ecosystem processes and dynamics research group (EPDRG) works on understanding the behaviour of complex ecological systems (including those influenced by people).
The EPDRG focuses on science-based solutions for the sustainable use of terrestrial natural resources using systems theory, modelling and advanced earth observation techniques to understand the dynamics of southern African ecosystems under human use. Much of the research falls in the general area of ‘global change’ (including climate change) and ’earth system science’. The core competencies in the group include ecosystem analysis, modelling, advanced statistical analysis, earth observation (both from space and in situ), biogeochemistry and environmental isotope analysis. The group operates a laboratory for light isotope analysis - unique in Africa - and two flux measurement sites.
The group’s current work on global change is executed in two projects. The first looks at the impact of climate change on the carbon and water balance of savannas and their fire regime, and the paleaoclimatology of southern Africa. Palaeoclimatic proxies are an important source of information when assessing the veracity of future climate change scenarios. Low latitude archives are scarce, and are derived almost exclusively from deep sea cores and speleothems (stalagmites). This project is generating a high resolution isotope proxy record for the past 50 000 years using a speleothem from the Cango Caves. Oxygen isotopes have been used to reconstruct temperature and rain, and carbon isotopes to reconstruct past plant communities. This project will provide a very important southern hemisphere indicator of atmospheric 14C, a key tracer in the global carbon budget. The project enables the CSIR to be involved in the Intergovernmental Panel on Climate Change, the Diversitas research programme on biodiversity and the National Climate Change Committee. The CSIR contact person is Dr Bob Scholes.
The second global change project is shared with several other research groups within the CSIR, namely with CSIR Natural Resources and the Environment, CSIR Built Environment and the Meraka Institute. The common thread is evaluation of the risks that climate change poses to key South African resources, such as coastal infrastructure, fisheries, housing on urban fringes, groundwater and climate amelioration by natural ecosystems, with and without adaptive actions. For more information, contact Dr Stephan Woodborne.
The CarboAfrica project is funded by the European Union (EU), the CSIR and the Department of Science and Technology (DST). It is setting up a network of flux measurement sites in Africa. Ass the oldest site running continuously in Africa, the processes and dynamics research group’s site at Skukuza is an important part of the network. An additional site near Phalaborwa is under construction. For more information, contact Dr Bob Scholes.
GEO-BENE is a project that aims to determine the economic benefits of improved earth observation systems worldwide. It is funded by the EU, the DST and CSIR, and is coordinated by the International Institute for Applied Systems Analysis (IIASA) in Vienna. The CSIR is one of several partners, and within the CSIR the work is shared with the biodiversity and ecosystem services research group in Stellenbosch. The processes and dynamics research group focuses mainly on biodiversity observation systems. Contact Dr Bob Scholes.
The Re–Impact project is also funded by the EU, the CSIR and the DST. It aims to build a framework for the evaluation of biofuels projects for global application. It considers the impacts of biofuels on the climate, water resources, biodiversity and people. For more information, contact
The Observations of Land Quality applies new techniques to an old ,but important problem – how do we know what is happening on the land surface? The objective is firstly to attribute user-required descriptive information to the land surface (such as its productivity and state of degradation in natural environments, and the extent, habitation density and degree of planning and service provision in urban areas) by combining remote sensing, in situ observations and models. Secondly, the project aims to demonstrate the capability to classify the land cover according to user needs, using multiple sources of evidence, with greater accuracy and lower cost than current methods. The approach seamlessly integrates nationwide low spatial resolution, high temporal resolution imagery with high resolution, infrequent imagery in areas of intensive agriculture or human settlement. It also integrates a variety of contextual information and modelling approaches to provide accurate classification and attribute information. The novel techniques involved are the derivation of sensor-independent vegetation functional information from ‘hypertemporal’ (i.e. daily to 10-times per day) remote sensing; the extraction of features from high-spatial resolution datasets using textural analysis; and the fusion of data sources with dissimilar spatial, spectral and temporal properties. The contact person is Graham von Maltitz.
The South African Scientific Assessment of Elephant Management is coordinated by the CSIR, with participation from many leading experts in the field. It aims to synthesise and evaluate all the scientific information available on this contentious topic to facilitate consensual policy. For more information, contact Kathleen Mennell.
The project Inverse Modelling in Geosciences involves the use of data assimilation to describe complex systems in earth sciences. Data assimilation is a novel and versatile methodology, which involves the combination of observational data with the underlying dynamical principles that govern a system in order to estimate a quantity of interest. The goal of this research is to elucidate the consequences of global change on water resources in southern Africa, using mathematical modelling. More information can be obtained from Dr Rebecca Maserumule.
The African Centre for Earth Stewardship Science (ACCESS) will develop a graduate research programme as well as a core research programme using South Africa’s unique geographic location. It is funded by the DST, jointly led by the CSIR and the University of Cape Town, and has many other collaborating institutions. At the interface between the
cold Atlantic and warm Indian oceans, and the abundant Southern Ocean, the centrepiece of this project will be a coupled ocean/atmosphere general circulation model. This will be tuned to local conditions and allow South African scientists to enter the global warming debate. A key approach will be the generation of high resolution palaeo-data to provide analogous proxies for climate change in the past; a capability that is provided by the EPDRG. Contact Dr Stephan Woodborne.
The Department of Water Affairs and Forestry (DWAF) is the custodian of the South African water reserve. The groundwater section uses isotopes of hydrogen and oxygen as well as radiocarbon dating to better understand the sustainability of water-use strategies. Its isotope facility is part of a national network of laboratories that undertakes these analyses on behalf of DWAF. More information is available from Dr Stephan Woodborne.
A multidisciplinary team of CSIR researchers, led by the processes and dynamics research group, has been examining the ecological drivers of cholera, a waterborne disease caused by V. cholerae 01 and 0139. Environmental and cholera case data for Beira, a coastal town in Mozambique, were analysed and modelled using advanced mathematical techniques. Patterns and consistencies between environmental factors - mainly runoff and air temperature - and the cholera cases have been established. Isotope analysis of the water samples was also done to determine whether samples that tested positive for V. cholerae were from a marine or land-based origin. Previous cholera research conducted in other parts of the world, notably Bangladesh, suggest a strong marine link with the cholera bacteria. Preliminary findings by the CSIR team indicate that the sea as well as inland, i.e. freshwater, waterways and aquatic sediments are reservoirs of the bacteria. Another research finding is the discovery of the presence of V. cholerae 0139 in the sea-based samples. Only V. cholerae 01 has been reported to occur in the natural environment in Africa. The research findings contribute towards anticipating and mitigating future cholera outbreaks and the spread of the disease under different climate change scenarios. For more information on this research, contact Marna van der Merwe
The CSIR’s processes and dynamics laboratory is one of the few facilities in South Africa that can perform 14C radiocarbon dating of archaeological materials up to 50 000 years old, as well as a range of other services based on light isotope analysis, such as determination of sustainable use of groundwater, tracking the origin of pollution, and adulteration of foodstuffs. For more information, contact carbon dating expert Dr Stephan Woodborne.
Sally Archibald: ecologist, fires in Africa, savanna ecology
Helen de Beer: research group administrator
Walter Kubheka: flux tower technician, based at Skukuza
Kathleen Mennell: ecologist, coordinator of the Elephant Assesment
Marc Pienaar: isotope analyst, signal processing specialist
Dr Bob Scholes: research group leader, systems ecologist
Marna van der Merwe: systems analyst, neural networks, time series analysis
Graham von Maltitz: ecologist, desertification, community-based management
Dr Stephan Woodborne: environmental isotopes, 14C dating
Research group leader: Dr Bob Scholes
Research group administrator: Helen de Beer
Isotopes laboratory: Dr Stephan Woodborne
Communication and media: Wiida Basson
Published research highlights
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Remotely sensed phenology for mapping biomes and vegetation functional types
Satellite-derived vegetation phenology data have tremendous potential since they capture the spatial patterns of vegetation dynamics through repetitive observations at regional scales. In this study remotely-sensed phenology data derived from Advanced Very High Resolution Radiometer (AVHRR) was used in a fully supervised decision-tree classification based on the new biome map of South Africa.
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