Adoption of residential rooftop solar PV systems in South Africa: A scoping review of barriers.

Global sustainability challenges such as climate change are linked to carbon emissions from fossil fuel powered energy needed for commercial and household consumption. South Africa is highly depended on coal for energy production hence the transition to renewable energy sources such as solar PV is seen as a pathway towards emissions reduction and a sustainable future. Yet, despite the huge potential for solar PV technologies adoption remains very low. This scoping review examines the barriers to household solar PV adoption in South Africa to advance our understanding beyond case study level studies. We analysed all published literature on household solar PV in South Africa as a basis for finding themes, gaps, and trends on solar PV research. Review results show that key barriers can be grouped into financial, personal, institutional, technical and societal barriers, however there were no studies on barriers across an income gradient, a glaring omission given debates on just transitions. Given the complexity of the barriers ranging from personal, societal, to technical barriers, it is not reasonable to expect the government to facilitate transition to solar PV alone. Rather, collective approaches are needed to create enabling conditions for solar PV adoption such as the financial means and information availability. The private sector has a key role to play either in supporting state-initiated programmes or creating the means for solar PV adoption such as power purchase agreements. That said, the state remains a central player in facilitating an enabling economic and political environment to leverage responsiveness from other actors. Without an integrated approach to addressing barriers to solar PV adoption, solar adoption will remain a source of energy for the economically privileged, and the imperative to just transition to renewable energy a pipe dream, in a country characterised by large inequalities among households.

Topsoil and Vegetation Dynamics 14 Years after Eucalyptus grandis Removal in Eastern Cape Province of South Africa.

A great deal of effort has been made to clear invasive alien plants in South Africa, yet it remains unclear if the clearing efforts are yielding positive soil and vegetation recovery trajectories. A few short-term studies have been conducted to monitor soil and vegetation recovery after alien plant removal in South Africa, but convincing, long-term monitoring studies are scarce yet needed. We investigated topsoil and vegetation recovery following Eucalyptus grandis removal 14 years ago by Working for Water in Makhanda, Eastern Cape province of South Africa. The detailed topsoil and vegetation surveys were conducted on forty 10 m × 10 m plots that were in paired cleared and natural sites. The results show no significant differences for the measured soil pH, total N, total C, K, Ca, and Na between the cleared and natural sites, an indication that the two sites are becoming similar. Similarly, the gravimetric soil moisture content shows no significant differences between the two sites, although monthly variations are observed. The topsoils in the cleared sites are hydrophobic as compared to those in the natural sites, which are wettable. We observed no significant vegetation diversity differences between the two sites, with native woody species, such as Crassula pellucida and Helichrysum petiolare, frequently occurring in the cleared sites. We recorded low reinvasion by E. grandis and other secondary invaders like Acacia mearnsii and Rubus cuneifolius in the cleared sites. Based on these results, we conclude that 14 years after E. grandis clearing, both topsoil and vegetation recovery are following a positive trajectory towards the natural sites. However, both reinvasion and secondary invasion have the potential to slow down soil and native vegetation recovery. Recommendations such as timeous follow-up clearing and incorporating restoration monitoring in the WfW clearing programme are discussed.

Effects of Elevated Temperature and High and Low Rainfall on the Germination and Growth of the Invasive Alien Plant Acacia mearnsii.

The impact of climate change on the germination and growth of invasive alien plants varies depending on the plant species and invasion process. We experimentally assessed the responses of the invasive alien plant Acacia mearnsii to future climate change scenarios-namely, elevated temperature as well as high and low rainfall. Acacia mearnsii was grown at an elevated air temperature (+2 °C), high rainfall (6 mm per day), and low rainfall (1.5 mm per day), and its germination and growth performance were measured over five months. We further examined changes in soil nutrients to assess if the above-mentioned climate change scenarios affected soils. Both elevated temperature and high rainfall did not influence A. mearnsii germination and seedling growth. In contrast, we observed reductions in A. mearnsii germination and growth in the low rainfall treatment, an indication that future drought conditions might negatively affect A. mearnsii invasion. We noted that elevated temperature and rainfall resulted in varied effects on soil properties (particularly soil C, N, Ca, and Mg content). We conclude that both elevated temperature and high rainfall may not enhance A. mearnsii invasion through altering germination and growth, but a decrease in A. mearnsii invasiveness is possible under low rainfall conditions.