Urban fuelwood demand and markets in a small town in South Africa: Livelihood vulnerability and alien plant control

Fuelwood is the primary energy for most households throughout the developing world. With increasing urbanization and declining local availability of fuelwood, a growing proportion of households obtain their fuelwood by purchasing it. These fuelwood markets are the key nexus in supply and demand scenarios and can be potentially significant points for intervention to address energy security amongst the urban poor. This paper reports on the fuelwood demand and marketing in a small town in South Africa. Despite the availability of more modern fuels and state subsidization of electricity, fuelwood was still used by half the households. Annual demand was 1.2 t per household. Over half of the households bought their fuelwood requirements because local stocks were limited. Those households that did collect their own fuelwood were significantly poorer than households that purchased fuelwood, as well as households that did not use fuelwood at all. Fuelwood markets operated through 45-60 vendors who transported fuelwood from further afield. Income from the fuelwood trade was low, but was strongly linked to hours worked. Thus, vendors working a full week did earn a meaningful income, especially in the context of high unemployment in the area. Fuelwood vendors also provided casual employment opportunities for unskilled labour. Most vendors harvested fuelwood from commonage lands, with most of the wood being from alien species. Local stocks of wood are declining in the face of constant transformation of commonage to residential areas, and a national water and biodiversity conservation programme to eradicate alien plants. This decline poses a threat to the financial viability of fuelwood markets. Yet, an opportunity exists to incorporate the vendors into the alien plant clearing programme, since they already perform such a function.     

Perceptions of small-scale fishermen on the value of marine resources and protected areas: case of Claveria,Northern Philippines

Establishing marine protected areas (MPAs) helps to restore and sustain marine and fishery resources, but in the Philippines only 20% of total MPAs are achieving their management objectives. We conducted a case study of a small MPA in Northern Philippines to understand socio-economic status and livelihoods of the fishermen stakeholders, and examine their attitudes and perceptions on marine resource values and conservation. Using an ordered probit model, we also investigated factors affecting these perceptions. We found a lower fish income ratio in higher income quartiles, a small share of local non-fishery income, and an apparent lack of other livelihood opportunities within the rural economy. The majority of fishermen had positive perceptions of the non-market value of marine resources, agreed with the need for MPAs, and perceived positive potential income benefit from MPAs. Level of education and fishing income were consistent significant positive determinants of these perceptions. Policy implications suggest: involving likely-to-be-displaced reef fishers in the crafting of management plans; conducting intensive research on appropriate and feasible livelihood options, for example, marine culture technologies; and designing explicit strategies to increase the propensity of coastal households to invest in children's education as a strategy for long-term sustainability of resource management.     

Towards a sustainable future: a holistic inquiry of waste management behaviors of Singapore households

ABSTRACT

In 2018, Singapore produced a 7.7 million tonnes of waste, which is a significant amount of waste for a small nation-state. In line with the Sustainable Development Goal (SDGs) targets 11.6 and 12.5 of the 2030 Agenda, which addresses cities’ waste generation and management impacts, we ask the question of why Singapore households are not more proactively engaged in waste minimization, despite the presence of local waste minimization public campaigns. This study is the first known study to comparatively apply and test three major theories – social psychological, social-structural, and sociocultural theories, to explain household waste management behavior in Singapore. A national survey followed by regression analysis of 303 households was conducted. In our findings, we firstly describe current trends in household waste management behaviors. Secondly, we compared each applied theory’s ability to predict households’: (1) reuse and (2) recycling of a variety of household items; and (3) recycling frequency. We obtained partial evidence supporting the role of future-orientedness and environmental identity on householders’ variety reuse and recycling. Social-structural (age cohort x income, education) and situational variables (the convenience thesis), also predicted various waste minimization behaviors. Finally, householders’ knowledge of what is recyclable affected all forms of waste minimization behaviors. In view of the study’s findings, we propose a need for targeted planning and policy interventions for different segments of the Singapore population, and different short- and longer-term measures to initiate and achieve sustained household waste minimization.     

Sustainability in manufacturing processes: practices performed in metal forming,casting, heat treatment,welding and electrostatic painting

ABSTRACT

This article aims to list the main sustainable practices developed in the processes of metal forming, casting, heat treatment, welding and electrostatic painting. When analysed the literature about sustainable manufacturing, a predominance of studies about machining is observed and the processes mentioned are few explored in academic studies. The research strategy used to reach the objective was systematic literature review, conducted for each process cited. Many sustainable practices were identified with prominence of better materials use and energy efficiency. The authors of this article believe that the information presented here can be useful for researches in their future studies and for industry professionals interested in improving manufacturing processes.     

Molecular characterisation of high-strength polycyclic aromatic hydrocarbon (PAH)-degrading and phenol-tolerant bacteria obtained from thermal power plant wastewater

This article reports the successful isolation and molecular characterisation of nine different phenol-tolerant and polycyclic aromatic hydrocarbon (PAH)-degrading Gram-positive bacterial species of diverse genera from the effluents of various industries. Based on similarity matrix studies, isolates Corynebacterium sp. DST1, Lysinibacillus sp. and Planococcus sp. showed<97% similarity, suggesting the possibility of new species in their respective genera.     

Extreme events and environmental changes: Tracing sedimentary processes in Central Vietnam coastal lagoons

Sediment cores, obtained in 2004–2005 and in 2008 from seven coastal lagoons of Central Vietnam (Lang Co, Nuoc Man, Nuoc Ngot, Thi Nai, O Loan, Thuy Trieu and Dam Nai), were analysed to assess changes in ²¹⁰Pb, porosity, grain size, and depth distributions of selected major and trace elements (Al, As, Ni, and Zn). The aim was to trace sedimentary processes in areas periodically subject to extreme events. The occurrence of lateral sedimentary inhomogeneities has been hypothesised to explain the differences observed at depth for some tracer profiles, whereas topmost levels present evidence that accounts for the loss of a sediment layer (from 2.0 to 7.5 cm thick) between the two samplings. These losses might be attributed to major typhoons that impacted the coasts of Central Vietnam during the study period.     

Impact of heavy metals on bacterial communities from mangrove soils of the Mahanadi Delta (India)

This study aimed to assess soil nutrient status and heavy metal content and their impact on the predominant soil bacterial communities of mangroves of the Mahanadi Delta. Mangrove soil of the Mahanadi Delta is slightly acidic and the levels of soil nutrients such as carbon, nitrogen, phosphorous and potash vary with season and site. The seasonal average concentrations (μg/g) of various heavy metals were in the range: 14 810–63 370 (Fe), 2.8–32.6 (Cu), 13.4–55.7 (Ni), 1.8–7.9 (Cd), 16.6–54.7 (Pb), 24.4–132.5 (Zn) and 13.3–48.2 (Co). Among the different heavy metals analysed, Co, Cu and Cd were above their permissible limits, as prescribed by Indian Standards (Co=17 μg/g, Cu=30 μ g/g, Cd=3–6 μ g/g), indicating pollution in the mangrove soil. A viable plate count revealed the presence of different groups of bacteria in the mangrove soil, i.e. heterotrophs, free-living N₂ fixers, nitrifyers, denitrifyers, phosphate solubilisers, cellulose degraders and sulfur oxidisers. Principal component analysis performed using multivariate statistical methods showed a positive relationship between soil nutrients and microbial load. Whereas metal content such as Cu, Co and Ni showed a negative impact on some of the studied soil bacteria.     

Heavy metals contents of roadside mosses in the northern and south-eastern regions of Nigeria

Levels of lead, zinc, cadmium, copper and nickel were determined in roadside moss samples within towns in the northern and south-eastern regions of Nigeria. Average lead level in the south-east (59 ppm) was higher than the average for the northern region (44 ppm). Average levels of zinc, cadmium, copper and nickel did not differ significantly between the two regions, with overall averages for the entire study area being 50.9, 1.2, 11.3 and 5.6 ppm for these metals. Lead levels were poorly correlated with those of the other metals, indicating that automobile emissions may not be the main source for these metals in the moss. In comparison with a previous study of the south-west region, the results indicate a generally slightly higher level of metal pollution in the south-west region than in both the northern and south-eastern regions.     

Forms of Nitrogen (NO 3 - -N; NO 2 - -N and NH 2 CONH 2 -N) and their relations to A.O.U. in the Indian coastal waters of Arabian Sea

The distribution of three important dissolved forms of nitrogen, viz. nitrate, nitrite and urea in the surface and bottom water samples collected from 27 selected hydrographic profiles, in the Arabian Sea, along the west coast of India is described. Of the three forms, nitrate concentrations were the highest and comparatively higher concentrations were observed in the bottom water. Decomposition of organic matter resulting in the release of the thermodynamically stable nitrogen species, i.e. nitrate, may be the major factor resulting in higher nitrate concentrations at these depths, where the water is also characterized by low values of dissolved oxygen and temperature. The significant positive correlation between A.O.U. and nitrate of the bottom water samples emphasizes the role of oxidative decomposition of organic matter which plays an active role in reducing the oxygen concentrations below the theoretical values since at this depth ( , 200 m) the net production is taken to be zero. This is also evidenced by the negative correlation of nitrate with dissolved oxygen and temperature, for the bottom samples.     

The impact of enhanced ammonium sulphate inputs exceeding critical load on calluna vulgaris /peat soil microcosms

Ammonium sulphate at six concentrations in simulated precipitation has been applied weekly over two years to Calluna vulgaris growing in peat soil. The nitrogen deposition treatments were chosen to embrace and exceed critical load. The growth and composition of the Calluna and the changes over time in the chemistry of the peat soil and its soil solution were monitored. In spite of significant increases in foliar nitrogen concentration in new shoots, especially in the first year, growth did not increase significantly in response to nitrogen treatment. Several factors could be contributing to the lack of significant growth response. (1) Increasing ammonium input significantly acidified the soil solution, which could adversely effect growth directly. (2) Foliar calcium concentration was reduced significantly in both years by the ammonium sulphate treatments, and more calcium was undoubtedly lost from the rooting zone at higher nitrogen inputs. (3) Foliar phosphate declined significantly between the first and second year, so lack of growth response might also reflect a phosphorus limitation. There was a distinctly visible darkening of the leaves in response to increasing ammonium applications, especially for the first year's growth, and the chlorophyll a and b concentrations in leaves from new growth at the three highest nitrogen treatments were significantly (at P <0.05) higher than those for the control. The pigment concentrations fell markedly by the end of the second season, and treatment effects were much less consistent. It is suggested that pigment analysis therefore probably has little diagnostic value for assessing damage from pollutant nitrogen effects.