Biomass production in South Africa largely follows a climatic gradient primarily driven by rainfall, with the highest biomass production occurring within the eastern regions of the country or in close proximity to the coastline. 

Within the content of the BioEnergy Atlas, productivity is described as the rate at which biomass is produced. There are two basic types of productivity: gross and net.

• Gross primary productivity, or GPP, is a measure of the total amount of carbon captured by plants as a result of photosynthesis (Amthor and Baldocchi, 2001)

• Net primary productivity, or NPP, is the difference between gross primary productivity and amount of carbon released back into the atmosphere as a result of Cellular respiration. NPP can this be used as a rate at which energy is stored as biomass by plants or other primary producers and made available to the consumers in the ecosystem (Schultze, 2007).

Net Primary Productivity (Schultze, 2007) is viewed as a raw potential or baseline for biomass production, and this is extensively modified by land use. Hence, the local soil types, current land cover, extent of degradation, and improved yields due to intensive agriculture all play a role in modifying the baseline NPP.

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South Africa is located on the southern tip of Africa (between latitudes 22° and 35°S, and longitudes 16° and 33°E) and is bordered by the Atlantic Ocean on the west and Indian Ocean on the south and east. It encompasses a coastline of 2 798 km and has a surface area of 1 219 602 km2, making South Africa the 25th largest country in the world.

South Africa generally experiences temperate conditions throughout the year, due to its subtropical location, but the moderating effect of the Atlantic and Indian Oceans, and its varied topography result in a great variety of climatic zones, ranging from the dry north-western to the wet eastern regions of the country. Most of South Africa is semi-arid and water stressed, with an average rainfall of about 450 mm, which is approximately 60% of the world average (Schulze 2008). Its precipitation is highly variable with an uneven spatial distribution and seasonality of rainfall. The eastern and southern parts of the country receive significantly more rain than the northern and western regions. While most of the country is generally a summer-rainfall region, the extreme southwest has a Mediterranean climate characterized by marked aridity during summer months. The rainfall in this region occurs predominantly during the winter period (Tyson and Preston-Whyte 2000).  

The coldest days occur in June to August (winter), with the southern and western parts of the country experiencing the lowest temperatures. The warmest areas are the coastal areas of KwaZulu-Natal, the Lowveld of KwaZulu-Natal and Mpumalanga, the Limpopo valley and the interior of the Northern Cape. The warm Agulhas current on the Indain ocean side causes the eastern coastal areas to have a warm and humid climate, whilst the cold Benguela current along the Atlantic west coast contributes to the arid climate and lower temperatures of this region (Tyson and Preston-Whyte 2000).  A detailed overview of the climate of South Africa an be found in (Walker 1990, Tyson and Preston-Whyte 2000, etc.,). Due to the variations in precipitation, primary productivity varies considerably both spatially and temporally

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Land use and Landcover changes dramatically modify the basal Net Primary Productivity. Practices such as intensive agriculture can dramatically increase the volume of biomass being produced in an unproductive area, whereas changes from one land cover type to another, such as forestry to crop agriculture would have the opposite effect. Human activity is one of the biggest drivers of variability in biomass availability and volume. Processes such as urbanisation reduce the areas for biomass production, but at the same time, activities such as the transportation and production of fuel and food for growing urban populations, as well as the resultant waste streams, may make significant point or distributed contributions to the availability of Biomass.

South Africa, being a relatively dry country, is constrained in terms of land availability for biomass production. Competing interests for land use in the relatively more productive areas of the country include:

Current agricultural land and food security: This is probably the most contentious aspect. There are three additional sub-considerations here:

1. Future population: A growing population will require additional food production, and if the relative affluence also improves, consumption patterns are likely to change.
2. Improved yields: It may be possible, all other things being constant, to repurpose some farmland for BioEnergy use if yields of traditional crops increase significantly.
3. Climate change: The far future may require additional farmland for some crops due to changing conditions, while the productivity of others could increase due to higher temperatures and CO2 concentrations. The net effect of this is a change in the quantum of farmland is required to maintain the status quo.

Commercial forestry: High productivity areas of South Africa have a sizeable allocation to commercial forestry, and while the waste products are of some use as bioenergy sources, we are assuming here that the existing plantation area will not be repurposed but that forestry residue is available for beneficiation. 

Urban and mining areas: These are by definition not available for biomass production, but rehabilitated mining land could support biomass feedstock streams, such as future urban growth, which would contribute somewhat to the availability of domestic or industrial waste.

Protected and sensitive areas: We need to consider the following:

1. National protected areas: These are currently proclaimed as national or provincial parks, and it is highly unlikely that biomass will be obtained from these areas, with the exception of invasive species.
2. National protected areas expansion strategy: These areas have been identified, but not proclaimed, as possible future protected areas. Depending on the trade-off between conservation and energy diversification, a variable portion of these areas could be considered for biomass generation. Invasive species from these areas are considered part of the available biomass.
3. Ecosystem services: Some areas of the country, while not protected, are critical to the preservation of ecosystem services, and water is the most important consideration here. Again, a trade-off between conservation and energy diversification determines to what extent these areas are considered for biomass cultivation, and invasive species in these areas are included into estimates.
4. Sensitive biodiversity areas: These are subject to the same trade-offs and considerations discussed above.

Non-usable land These are areas that may or may not be suitable for biomass generation, but are excluded on the basis of accessibility, slope, soil conditions, or other factors that will make sustainable biomass generation difficult.