Wood Scarcity Research Articles

Econometric analysis of the determinants of adoption of alley farming by farmers in the forest zone of southwest Cameroon

Slash-and-burn agriculture continues to expand in many parts of the forest zone of Cameroon. One alternative land use to slash-and-burn system is alley farming. This paper quantifies, using an econometric model, the factors determining farmers’ adoption and use of alley farming variants in southwest of Cameroon, based on a survey of 156 farmers in 11 villages in the region. The analysis showed that male farmers are more likely to adopt than women. Adoption is higher for farmers with contacts with extension agencies working on agroforestry technologies. Adoption is higher for farmers belonging to farmers’ groups. Adoption is lower for farmers in areas with very high population pressure, as farmers in such areas may have greater labor productivity from use of less labor intensive natural resource management technologies like chemical fertilizers. Adoption is higher for farmers in areas facing fuel wood scarcity. Farmers have made adaptations to the conventional alley farming technology recommended by researchers, the most significant adaptation being the introduction of fallow periods into the system. Farmers use alley farming as a land use option, not as a replacement for the slash-and-burn system, since land supply is still relatively elastic. Achieving increased impact with alley farming variants requires effective targeting. Results showed that econometric modeling using farmer and village characteristics, socioeconomic and institutional variables can lead to more effective targeting to farmers and locations where higher adoption rates may occur.

Économie des combustibles (bois et lignite) dans l'abri moustérien des Canalettes [L'expérimentation à la simulation des besoins énergétiques

The charcoal analysis at the mousterian rock shelter of Les Canalettes reveled the existence of two kinds of fuel : wood and coal. The use of coal raises the problem of intentionallity : is it a constrained use due to wood scarcity during the last glacial or a reasoned management of fuel ? An experimental study of coal combustion combinated with charcoal analysis allowed us to simulate wood consumption at Les Canalettes. It has been thus shown that wood biomass was abondant enough and wood scarcity was never responsible for coal use. We can consider two main explanations : use of coal for specific activities in relation with its properties, or an opportunist collection due to its simple use.

Is There a Forest Transition? Deforestation, Reforestation, and Development1

Abstract Environmental social scientists have recently begun to use the term 'forest transition' to describe how forest cover changes as economic development occurs in nations. The hypothesized transition occurs as follows. An initial surge in economic activity in impoverished societies spurs deforestation, but as economic activity continues to intensify and cities grow larger, a 'turnaround' occurs, and deforestation gives way to reforestation. This paper uses cross‐national data from five successive surveys of world forest resources to assess this empirical claim. A turnaround in forest cover trends does occur in a significant number of nations. The paper also evaluates two explanations for the turnaround, a wood scarcity hypothesis derived from microeconomic theory and an industrialization hypothesis linked to central place theory. It finds period specific support for the industrialization hypothesis. The paper concludes with a brief discussion of the implications of these findings for proposals to alleviate the biodiversity crisis through programs of reforestation.

Biomass yield, botanical fractions and quality of tagasaste, (Chamaecytisus palmensis) as affected by harvesting interval in the highlands of Ethiopia

Tagasaste, a hardy leguminous shrub has potential for wide utilizationin the highlands of East Africa. Establishment and productivity oftagasaste at two, three, four, and six months harvesting intervals wereevaluated from the first to the forth years of age(1991/1992–1994/1995) in the highlands of Ethiopia. Biomass yield,botanical fractions (Leaf, Edible branch and stem) and quality wereassessed. Annual biomass production was substantially greater for sixmonths interval than for the more frequent harvests in a range of 4.7 to10.2 t ha–1. Average biomass yield also increased as theplant got older. Leaf proportion of the biomass yield consistentlydecreased from 71.7 to 45.3% and the stem increased from 0.4 to25.5% as the harvesting interval was prolonged from two to sixmonths, respectively. However, the longest harvesting intervals were stillthe most productive of leaf DM from the increased biomass yield. Theaverage crude protein (CP) content and in vitro dry organic matter digestibility (DOMD) of leaf were not significantly affected by harvestinginterval. They ranged from 18.0–21.2% and65.3–70.5%, respectively. Allowing tagasaste to grow duringthe wet season for four to six months and harvesting during the early dryseason could improve the yield of high quality herbage, fuel wood andincrease persistence in the highlands of Ethiopia. Tagasaste could be thebest browse tree for the highlands of East Africa. It could alleviateproblems of feed shortage, soil degradation, low soil fertility throughmulching and nitrogen fixing ability, and fuel wood scarcity which arepredominantly prevalent in these areas.

Effects of carbonisation temperature on charcoal from some tropical trees

The high cost of conventional fossil fuels has resulted in a rise in the demand for charcoal in developing countries. There has been a problem of wood scarcity and indigenous tree species are being replaced with the fast-growing, short-rotation species. Three short-rotation tree species: Gliricidia sepium, Leucaenea leucocephala and Gmelina arborea were converted to charcoal by a pyrolytic process. The effects of final carbonisation temperature on the yield, heating value and proximate analysis of charcoal from the tree species were determined. Gliricidia sepium gave the highest charcoal yield of 51.6% with a gross heating value of 31.45 MJ/kg at 300°C final carbonisation temperature. There was no significant difference in the charcoal yield of Gmelina arborea and Leucaena leucocephala at 5% level of testing. The charcoal yield decreased with an increase in carbonisation temperature. The percentage volatiles in charcoal decreased with an increase in temperature, while there was an increase in the percentage fixed carbon.

From Resource Scarcity to Pollution Problem: The Production and Environmental Impact of a Swedish Alum Works, 1723-1877

Abstract Wood scarcity at Lovers Alum Works (LAW) restricted the amount of alum produced during a large part of the period of activity (1723-1810s). The increasing local scarcity of wood and the insufficient road network were the main reasons why LAW started to use alum-shale as fuel in the beginning of the nineteenth century. When the fossil energy source replaced wood the short term fluctuations in alum production between different years became much smaller and the production of alum in the region was able to expand. This has been interpreted as an example of how geospheric raw materials enabled the rapid production expansion during the early industrial revolution.Cadmium and sulphur emissions were estimated from element analysis of the shale and data on the use of shale and other raw-materials. During the shale fuel period (1810s-1877) the emissions of volatile substances such as cadmium and sulphur increased.Pollution and resource scarcities are two different forms of environmental impact which tend to have different effects at different times in regard to production. Resource scarcity problems tend to have a regulating effect on production while pollution problems tend to lack this self-regulating effect on production.

Energy, environment and the rural poor in South Africa

The lack of adequate energy services imposes heavy social and environmental costs on poor rural households. The rural energy‐environment interface, however, is prone to oversimplistic analyses, especially in the case of the ‘fuelwood problem’, and to a lack of research. International experience suggests that deforestation is not necessarily an ‘energy problem’ resulting from the cutting of trees for fuelwood ‐ and therefore that it may not have an energy solution, like planting more trees for firewood. Instead, wood scarcity must be understood under multiple use of wood resources, and policies need to be multifaceted if they are to succeed. South African studies show that wood is becoming increasingly scarce in many areas; here fuelwood collection may contribute to deforestation more than suggested by international experience. In addition to the environmental effects of increasing wood scarcity and its social costs, borne largely by women, another serious problem arises from indoor air pollution caused by...

Energy needs, tasks and resources in the Sahel: Relevance to woodstoves programmes

This article reviews the wood fuels situation in the Sahel and the findings of various needs assessment methodologies, especially as these are relevant to the numerous programmes to introduce improved cooking technologies in the region. Most people in West Africa, especially in poor and rural areas, rely primarily on wood fuels and crop wastes for energy needs, with devastating environmental consequences. Most wood is used in cooking. The quantity of fuel used depends on the type of fireplace, utensils used, how and when food is prepared, food preparation methods, types of fuels, how fuelwood is collected, and special customs surrounding the family fire — all of which are intimately associated with the economic, cultural and social fabric of Sahelian societies. Conventional fuel consumption and resource surveys have yielded useful information about quantitative energy needs in the Sahel, but increasingly sociocultural studies are being used to ensure that stove designs will meet the needs of the end-user. Economic analssis is also necessary to establish the dimensions of wood scarcity, to assess the financial attractiveness to consumers of alternative fuels and stoves, and in evaluating the costs and benefits to society of proposed national woodstoves programmes.

Energy economics — a random walk in history

This paper gives a brief historical overview of some main trends in energy technology from ancient times to the mid-18th century. The emphasis is on developments in the UK: the effects of wood scarcity; the rise of coal; technological responses to coal scarcity; and the effect of energy supply on industrial location.