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Application of seasonal forecasts in agriculture has significant potential and realized utility. Other sectors that may also benefit from using seasonal forecasts include (but are not limited to) health, hydrology, water, and energy. This paper shows that seasonal forecast model data, satellite Pour l'Observation de la Terre (SPOT), dry matter productivity (DMP) data (proxy of grass biomass) along with other sets of data are effectively used to estimate grazing capacity (GC) over a 12-year test period (1998/1999–2009/2010) in Limpopo Province. GC comprises a vital consideration in agricultural activities, particularly for a province in South Africa like Limpopo, due to its varying climate. The Limpopo Province capitalizes on subsistence farming, including livestock and crop production. Grazing should thus be regulated in order to conserve grass, shrubs, and trees, thereby ensuring sustainability of rangelands. In a statistical downscaling model, the predictor is the 850 geopotential height fields of a coupled ocean–atmosphere general circulation (CGCM) over Southern Africa to predict seasonal DMP values. This model shows that the mid-summer rainfall totals are important predictors for the November through April (NDJFMA) DMP (as well as grazing capacity) growing season. Forecast verification is conducted using the relative operating characteristics (ROC) and reliability diagrams. The CGCM model shows skill in discriminating high and low DMP (GC) seasons in the Limpopo Province, as well as reliability in the probabilistic forecasts. This paper demonstrates the development of a tailored forecast, an avenue that should be explored in enhancing relevance of forecasts in agricultural production. [ABSTRACT FROM AUTHOR]

The Still Bay (SB) and Howiesons Poort (HP) industries, endemic to southern Africa and dating to approximately 72-59 ka, have received a great deal of archaeological attention by virtue of their striking patterns of technology and their close association with some of the earliest unambiguously symbolic objects found in southern Africa. This paper reviews recent literature concerning SB and HP lithic assemblages, faunal remains, paleoenvironmental contexts, and chronological information. It argues that SB biface-dominated technology was designed to be multifunctional and to economize lithic raw material, a strategy well-suited to foragers moving frequently across a wide range of ecological zones in which access to resources and prey encounters were unpredictable. In contrast, HP blade-based tools, using backed blades as modular components in compound weapons, were efficient and reliable hunting weapons designed for specific tasks. More costly and difficult to maintain, HP technology resulted from the targeting of known, localized, and seasonal resources through planned logistical forays. We argue that these complicated patterns of innovation represent separate cultural responses to environmental instability during Marine Isotope Stage 4 and demographic pressures in southern Africa at this time. Against the backdrop of environmental and demographic shifts, the emergence of these innovative tools and associated symbolic objects reflects distinct but quintessentially modern cultural behaviors ethnographically associated with risk reduction, reciprocity, and information sharing. [ABSTRACT FROM AUTHOR]

The dispossession of agricultural producers from the land has long been considered a condition of successful capitalist development. The main contention of this paper is that such dispossession has in fact become the source of major developmental handicaps for at least some and possibly many countries of the global South. We develop our argument by focusing on the South(ern) African experience as a paradigmatic outlier case of accumulation by dispossession--that is, as one of its extreme instances capable of highlighting in almost ideo-typical fashion its nature and limits. After reconstructing interpretations of capitalist development in Southern Africa that in the early 1970s established the region as a paradigm of accumulation by dispossession, we discuss how useful these interpretations are for understanding the more recent developmental trajectory of South Africa. We then suggest ways in which these interpretations from the 1970s should be reformulated in light of subsequent developments. We conclude by briefly examining the theoretical and policy implications of the analysis. [ABSTRACT FROM AUTHOR]

The idea that many processes in arid and semi-arid ecosystems are dormant until activated by a pulse of rainfall, and then decay from a maximum rate as the soil dries, is widely used as a conceptual and mathematical model, but has rarely been evaluated with data. This paper examines soil water, evapotranspiration (ET), and net ecosystem CO2 exchange measured for 5 years at an eddy covariance tower sited in an Acacia– Combretum savanna near Skukuza in the Kruger National Park, South Africa. The analysis characterizes ecosystem flux responses to discrete rain events and evaluates the skill of increasingly complex “pulse models”. Rainfall pulses exert strong control over ecosystem-scale water and CO2 fluxes at this site, but the simplest pulse models do a poor job of characterizing the dynamics of the response. Successful models need to include the time lag between the wetting event and the process peak, which differ for evaporation, photosynthesis and respiration. Adding further complexity, the time lag depends on the prior duration and degree of water stress. ET response is well characterized by a linear function of potential ET and a logistic function of profile-total soil water content, with remaining seasonal variation correlating with vegetation phenological dynamics (leaf area). A 1- to 3-day lag to maximal ET following wetting is a source of hysteresis in the ET response to soil water. Respiration responds to wetting within days, while photosynthesis takes a week or longer to reach its peak if the rainfall was preceded by a long dry spell. Both processes exhibit nonlinear functional responses that vary seasonally. We conclude that a more mechanistic approach than simple pulse modeling is needed to represent daily ecosystem C processes in semiarid savannas. [ABSTRACT FROM AUTHOR]