Spatial Gradients of Ecosystem Health Indicators across a Human-Impacted Semiarid Savanna.

Drivers of soil organic carbon (SOC) dynamics involve a combination of edaphic, human, and climatic factors that influence and determine SOC distribution across the landscape. High-resolution maps of key indicators of ecosystem health can enable assessments of these drivers and aid in critical management decisions. This study used a systematic field-based approach coupled with statistical modeling and remote sensing to develop accurate, high-resolution maps of key indicators of ecosystem health across savanna ecosystems in South Africa. Two 100-km landscapes in Bushbuckridge Local Municipality were surveyed, and 320 composite topsoil samples were collected. Mid-infrared spectroscopy was used to predict soil properties, with good performance for all models and root mean squared error of prediction (RMSEP) values of 1.3, 0.2, 5, and 3.6 for SOC, pH, sand, and clay, respectively. Validation results for the mapping of soil erosion prevalence and herbaceous cover using RapidEye imagery at 5-m spatial resolution showed good model performance with area under the curve values of 0.80 and 0.86, respectively. The overall (out-of-bag) random forest model performance for mapping of soil properties, reported using , was 0.8, 0.77, and 0.82 for SOC, pH, and sand, respectively. Calibration model performance was good, with RMSEP values of 2.6 g kg for SOC, 0.2 for pH, and 6% for sand content. Strong gradients of increasing SOC and pH corresponded with decreasing sand content between the study sites. Although both sites had low SOC overall, important driving factors of SOC dynamics included soil texture, soil erosion prevalence, and climate. These data will inform strategic land management decisions focused particularly on improving ecosystem conditions.

Patterns and trends in household food security in rural Mpumalanga Province, South Africa.

This study examines patterns and trends in household food security in Bushbuckridge, Mpumalanga Province, South Africa, from 2010 to 2019. We use data from a household panel nested in the Agincourt Health and Socio- Demographic Surveillance System. Findings indicate that there have been improvements in household food security in this rural setting over the last decade. By polychoric principal component analysis, an aggregate food security index was constructed and we observed a small, yet important, proportion of households (7.8 %) that remained chronically food insecure. An ordered probit model was used to estimate the determinants of food security. Findings reveal that the observed differences in household food security status are as a result of differences in socioeconomic status. We therefore recommend that focus must be placed on identifying economic opportunities and empowering the chronically food insecure households if universal household food security is to be attained in rural South Africa and beyond.

Double malnutrition and associated factors in a middle-aged and older, rural South African population.

INTRODUCTION: Double malnutrition (co-existing overnutrition and undernutrition) is increasingly prevalent in sub-Saharan Africa due to rapid epidemiological and nutritional transitions. In this region, studies of double malnutrition have largely been conducted at country and household level, with individual-level studies primarily limited to children and women of reproductive age. We investigated the prevalence and determinants of individual-level double malnutrition in middle-aged and older adults who constitute an increasing proportion of the sub-Saharan African population. METHODS: 250 individuals aged 40-70 years (50% women) and resident in the Agincourt Health and socio-Demographic Surveillance System in rural Mpumalanga province, South Africa, were randomly selected. Double malnutrition was defined as overweight/obesity and anaemia only, overweight/obesity and iodine insufficiency, or overweight/obesity and any micronutrient deficiency (anaemia and/or iodine insufficiency). The Chi-squared goodness of fit test was used to compare the expected and observed numbers of individuals with the type of double malnutrition. Logistic regression was used to investigate determinants of each type of double malnutrition. RESULTS: Double malnutrition was present in 22-36% of participants, depending on the definition used. All types of double malnutrition were more common in women than in men (overweight/obesity and anaemia: 34% vs. 10.2%, p < 0.01; overweight/obesity and iodine insufficiency: 32% vs. 12.2%, p < 0.01 and overweight/obesity and any micronutrient deficiency: 50.5% vs. 20.4%, p < 0.01). There were no differences between the overall expected and observed numbers of individuals with combinations of overweight and micronutrient deficiencies [overweight/obesity and anaemia (p = 0.28), overweight/obesity and iodine insufficiency (p = 0.27) or overweight/obesity and any micronutrient deficiency (p = 0.99)]. In models adjusted for socio-demographic factors, HIV and antiretroviral drug status, and food security or dietary diversity, men were 84-85% less likely than women to have overweight/obesity and anaemia, 65% less likely to have overweight/obesity and iodine insufficiency and 74% less likely to have overweight/obesity and any micronutrient deficiency. CONCLUSIONS: Individual-level double malnutrition is prevalent in middle-aged and older adults in a rural sub-Saharan African community. Interventions to improve nutrition in similar settings should target individuals throughout the life course and a focus on women may be warranted.

Urban ecology in a developing world: why advanced socioecological theory needs Africa.

Socioecological theory, developed through the study of urban environments, has recently led to a proliferation of research focusing on comparative analyses of cities. This research emphasis has been concentrated in the more developed countries of the Northern Hemisphere (often referred to as the "Global North"), yet urbanization is now occurring mostly in the developing world, with the fastest rates of growth in sub-Saharan Africa. Countries like South Africa are experiencing a variety of land-cover changes that may challenge current assumptions about the differences between urban and rural environments and about the connectivity of these dynamic socioecological systems. Furthermore, questions concerning ecosystem services, landscape preferences, and conservation - when analyzed through rural livelihood frameworks - may provide insights into the social and ecological resilience of human settlements. Increasing research on urban development processes occurring in Africa, and on patterns of kinship and migration in the less developed countries of the "Global South", will advance a more comprehensive worldview of how future urbanization will influence the progress of sustainable societies.

Multiple strategies for resilient livelihoods in communal areas of South Africa.

Livestock farming in communal areas is an activity pursued by rural households as one of a range of livelihood strategies aimed at spreading risk. The cash and non-cash benefits derived from livestock, as well as the wide range of secondary resources harvested from communal rangelands, make an important contribution to livelihood diversification, and hence, resilience. Rural development policy should therefore not focus narrowly on commercialisation of livestock production in communal areas. Rather, it should take a multi-faceted approach to building livelihood resilience while providing pathways for households to escape poverty through enhancing the multiple benefits of livestock, adding value to secondary rangeland resources, and expanding the rural non-farm economy.

Nexus between summer climate variability and household food security in rural Mpumalanga Province, South Africa.

Ongoing climate changes are likely to impact household food security in rural households that depend on rainfed subsistence agriculture. This paper investigates the relationship between summer climate variability and household food security in rural Mpumalanga, South Africa. We used a household panel data set nested in the Agincourt Health and Socio-Demographic Surveillance System, together with rainfall and temperature data for the summer periods 2006-07 to 2018-19 from three weather stations that surround the study area. We quantified the variability of rainfall using coefficient of variation and the standardized rainfall anomaly index, while temperature variability was reflected by the standardised temperature anomaly. In addition, the Mann-Kendall analysis was applied to detect temporal trends in rainfall and temperature. Longitudinal models accounting for socioeconomic and climate factors were used to estimate the relationship between weather and climate. The results reveal significant impact on food security from high inter-annual rainfall variability through fluctuations in food consumption, dietary diversity, and the experience of hunger. This study offers significant insights on how dietary diversity, food availability and overall food security are positively associated with greater average rainfall through subsistence agriculture as a livelihood strategy. These insights have important implications by suggesting seasonal forecasts to predict periods of potential food insecurity in local communities and can guide government policy and interventions to lessen food insecurity in rural areas.

Spatially and Temporally Varying Associations between Temporary Outmigration and Natural Resource Availability in Resource-Dependent Rural Communities in South Africa: A Modeling Framework.

Migration-environment models tend to be aspatial within chosen study regions, although associations between temporary outmigration and environmental explanatory variables likely vary across the study space. This research extends current approaches by developing migration models considering spatial non-stationarity and temporal variation - through examination of the migration-environment association at nested geographic scales (i.e. whole-population, village, and subvillage) within a specific study site. Demographic survey data from rural South Africa, combined with indicators of natural resource availability from satellite imagery, are employed in a nested modeling approach that brings out distinct patterns of spatial variation in model associations derived at finer geographic scales. Given recent heightened public and policy concern with the human migratory implications of climate change, we argue that consideration of spatial variability adds important nuance to scientific understanding of the migration-environment association.

Rural Household Demographics, Livelihoods and the Environment.

This paper reviews and synthesizes findings from scholarly work on linkages among rural household demographics, livelihoods and the environment. Using the livelihood approach as an organizing framework, we examine evidence on the multiple pathways linking environmental variables and the following demographic variables: fertility, migration, morbidity and mortality, and lifecycles. Although the review draws on studies from the entire developing world, we find the majority of micro-level studies have been conducted in either marginal (mountainous or arid) or frontier environments, especially Amazonia. Though the linkages are mediated by many complex and often context-specific factors, there is strong evidence that dependence on natural resources intensifies when households lose human and social capital through adult morbidity and mortality, and qualified evidence for the influence of environmental factors on household decision-making regarding fertility and migration. Two decades of research on lifecycles and land-cover change at the farm level have yielded a number of insights about how households make use of different land-use and natural resource management strategies at different stages. A thread running throughout the review is the importance of managing risk through livelihood diversification, ensuring future income security, and culture-specific norms regarding appropriate and desirable activities and demographic responses. Recommendations for future research are provided.

"Locusts are now our beef": adult mortality and household dietary use of local environmental resources in rural South Africa.

UNLABELLED: There is currently a lack of research on the association between demographic dynamics and household use of natural resources in rural Africa. Such work is important because in rural Africa natural resources buffer households against shocks, offering both sustenance and income-generating potential. AIMS: The article focuses on adult mortality as a household shock, examining use of local environmental resources as related to household dietary needs. METHODS: The authors analyze two sources of data collected during May-December 2004 in the MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt) in rural South Africa. Quantitative analyses use survey data from 240 households, stratified by adult mortality experience. Qualitative data are based on 31 interviews with members of households having recently experienced adult mortality. RESULTS: The interviews provide insight into a variety of household-level mortality impacts and also suggest the importance of proximate resources in the maintenance of food security following the loss of an adult household member. Quantitatively, there are significant differences, both in patterns of usage of the natural environment and in levels of food security, between households that have lost an adult and those that have not. The association between mortality and household use of local environmental resources is further shaped by the gender of the deceased and the time elapsed since the death. CONCLUSIONS: Adult mortality, particularly the death of a male wage-earner, affects household food security. Time allocation is affected as resource collection responsibilities shift, and wild foods may substitute for previously purchased goods.

Exploring the impact of the 2008 global food crisis on food security among vulnerable households in rural South Africa.

Recurring food crises endanger the livelihoods of millions of households in developing countries around the globe. Owing to the importance of this issue, we explore recent changes in food security between the years 2004 and 2010 in a rural district in Northeastern South Africa. Our study window spans the time of the 2008 global food crises and allows the investigation of its impacts on rural South African populations. Grounded in the sustainable livelihood framework, we examine differences in food security trajectories among vulnerable sub populations. A unique panel data set of 8,147 households, provided by the Agincourt Health and Demographic Surveillance System (Agincourt HDSS), allows us to employ a longitudinal multilevel modeling approach to estimate adjusted growth curves for the differential change in food security across time. We observe an overall improvement in food security that leveled off after 2008, most likely resulting from the global food crisis. In addition, we discover significant differences in food security trajectories for various sub populations. For example, female-headed households and those living in areas with better access to natural resources differentially improved their food security situation, compared to male-headed households and those households with lower levels of natural resource access. However, former Mozambican refugees witnessed a decline in food security. Therefore, poverty alleviation programs for the Agincourt region should work to improve the food security of vulnerable households, such as former Mozambican refugees.

Toward Improved Understanding of Food Security: A Methodological Examination Based in Rural South Africa.

Accurate measurement of household food security is essential to generate adequate information on the proportion of households experiencing food insecurity, especially in areas or regions vulnerable to food shortages and famine. This manuscript offers a methodological examination of three commonly used indicators of household food security - experience of hunger, dietary diversity, and coping strategies. Making use of data from the Agincourt Health and Demographic Surveillance Site in rural South Africa, we examine the association between the indicators themselves to improve understanding of the different insight offered by each food security "lens." We also examine how the choice of indicator shapes the profile of vulnerable households, with results suggesting that dietary diversity scores may not adequately capture broader food insecurity. Concluding discussion explores programmatic and policy implications as related to methodological choices.

Adult mortality and household food security in rural South Africa: Does AIDS represent a unique mortality shock?

HIV/AIDS has been described as a household shock distinct from others faced by rural households. This study examines this characterisation by analysing the impact of an adult HIV/AIDS-related death on household food security, compared with households experiencing either no mortality or a sudden non-HIV/AIDS adult death. The research is based in the Agincourt Health and Demographic Surveillance Site in rural South Africa, and focuses on a sample of 290 households stratified by experience of a recent prime-age adult death. HIV/AIDS-related mortality was associated with reduced household food security. However, much of this negative association also characterised households experiencing a non-HIV/AIDS mortality. In addition, other household characteristics, especially socioeconomic status, were strong determinants of food security regardless of mortality experience. We therefore recommend that development policy and interventions aimed at enhancing food security target vulnerable households broadly, rather than solely targeting those directly affected by HIV/AIDS mortality.

Adult Mortality and Natural Resource Use in Rural South Africa: Evidence From the Agincourt Health and Demographic Surveillance Site.

There is little empirical evidence on the association between household experience with HIV/AIDS and shifts in the use of natural resources in developing countries, where residents of rural regions remain highly dependent on often-declining local supplies of natural resources. This study examines household strategies with regard to fuelwood and water among impoverished rural South African households having experienced a recent adult mortality and those without such mortality experience. Quantitative survey data reveal higher levels of natural resource dependence among mortality-affected households, as well as differences in collection strategies. Qualitative interview data provide insight into subtle and complex adjustments at the household level, revealing that impacts vary by the role of the deceased within the household economy. Resource management and public health implications are explored.

Environmental Perceptions of Rural South African Residents: The Complex Nature of Environmental Concern.

The state of the local environment shapes the well-being of millions of rural residents in developing nations. Still, we know little of these individuals' environmental perceptions. This study analyzes survey data collected in an impoverished, rural region in northeast South Africa, to understand the factors that shape concern with local environmental issues. We use the "post-materialist thesis" to explore the different explanations for environmental concern in less developed regions of the world, with results revealing the importance of both cultural and physical context. In particular, gendered interaction with natural resources shapes perceptions, as does the local setting. Both theoretical and policy implications are discussed.

Assessing a population's exposure to heat and humidity: an empirical approach.

BACKGROUND: It is widely accepted that assessing the impact of heat on populations is an important aspect of climate change research. However, this raises questions about how best to measure people's exposure to heat under everyday living conditions in more detail than is possible by relying on nearby sources of meteorological data. OBJECTIVE: This study aimed to investigate practical and viable approaches to measuring air temperature and humidity within a population, making comparisons with contemporaneous external data sources. This was done in a rural South African population during the subtropical summer season. RESULTS: Air temperature and humidity were measured indoors and outdoors at three locations over 10 days and the datalogger technology proved reliable and easy to use. There was little variation in measurements over distances of 10 km. CONCLUSIONS: Small battery-powered automatic dataloggers proved to be a feasible option for collecting weather data among a rural South African population. These data were consistent with external sources but offered more local detail. Detailed local contemporary data may also allow post hoc modelling of previously unmeasured local weather data in conjunction with global gridded climate models.

"The Bush is No More": Insights on Institutional Change and Natural Resource Availability in Rural South Africa.

The past decade has brought substantial transition to South Africa. The introduction of democracy in 1994 has yielded important political and socioeconomic transformations affecting millions of people. Here, we explore the impact of institutional and structural changes on the availability and management of fuelwood, a key natural resource in rural South Africa. As in other developing regions, many households depend on natural resources for both sustenance and energy needs. Drawing on qualitative data from 32 interviews, our objective is to describe, from the perspective of the respondents, (1) resource scarcity, (2) the underlying causes of resource scarcity, (3) the role of traditional authority in managing resources, and (4) strategies used by community members in the face of resource scarcity. The results have important implications for the well-being of both social and natural systems in many transitional, rural developing societies.