Miyuki Iiyama

Understanding patterns of tree adoption on farms in semi-arid and sub-humid Ethiopia

Trees on farms are a widespread feature of landscapes across a large part of Ethiopia with an important role in enhancing the resilience of smallholder livelihoods through the provision of ecosystem services. Despite their importance, little is known about what trees are planted or retained from natural regeneration by different types of farmers that results in the pattern of tree cover found in the region. We address this knowledge gap through analysis of household survey data from semi-arid and sub humid areas of Oromia regional state. A set of composite variables that represent distinctive patterns of tree cover on farms were derived from principal component analysis and Pearson correlation analysis. This revealed two major tree adoption strategies: farmer managed natural regeneration (FMNR) of trees to meet subsistence needs as well as contributing to other ecosystem services; and, high value agroforestry (HVAF) involving planted trees used largely to produce fruits, timber and fodder. Regression analysis further identified fine-scale variation in ecological and socio-economic factors that affect which of these two broad strategies are adopted by farmers. Favorable climatic conditions coupled with institutional arrangements to control free grazing were pre-conditions for HVAF, whereas poor biophysical potential and sloping land provided a positive incentive for farmers to adopt FMNR. Farmers with preferences for tree species with multiple utilities and locational flexibility favored FMNR while adoption of HVAF was more asset-driven. Our findings reveal that farmers integrate many native and exotic tree species on their farms to meet their variable farm conditions, needs and asset profiles in stark contrast to most tree promotion efforts that focus on a few, usually exotic, tree species. We recommend that future agroforestry promotion should embrace a diversity of tree species appropriate to matching the fine scale variation in ecological conditions and farmer circumstances encountered in the field.

Charcoal production through selective logging leads to degradation of dry woodlands: a case study from Mutomo District, Kenya

Provision of woodfuel is an important ecosystem service of dry forests and woodlands. However, charcoal production through selective logging of preferred hardwood species has the potential to alter the physiognomic composition of the residual or re-growth woodlands and may lead to their deterioration and degradation. This study, conducted through forest inventory in Mutomo District in Kenya, assessed the impact of charcoal production on unprotected dry woodlands in terms of tree density, targeted species basal area, species richness, evenness and Shannon diversity. The parameters of the disturbed woodlands were evaluated for significant differences with those of the neighbouring protected Tsavo East National Park, which served as a reference for an ecologically undisturbed ecosystem. By evaluating a consequence of tree harvesting for charcoal production, this study confirmed the overall significant differences between the protected and unprotected woodlands in all the tested parameters. To confirm if the differences in the land-covers of the woodlands had any influence on their degradation, all mentioned parameters were compared between the four differentiated classes and their respective control plots in the protected areas. At the “land-cover level”, the statistically significant difference in the basal area of tree species preferred for charcoal production between the protected and unprotected open trees confirms that the class with a high density of large mature trees is the prime target of charcoal producers. In addition, there seems to be a general trend of lower values of tree species richness, evenness and Shannon diversity for the unprotected woodlands subjected to charcoal production. On the other hand, the disturbed woodlands display the potential to recover through their comparably high saplings density. The findings make an important contribution to the discourse on the impact of charcoal production in dry woodlands, a topic that is highly controversial among researchers.

The socioeconomic and environmental impacts of wood energy value chains in Sub-Saharan Africa: a systematic map protocol

BackgroundThe vast majority of households in Sub-Saharan Africa (SSA) depend on wood energy—comprising firewood and charcoal—for their daily energetic needs. Such consumption trends are expected to remain a common feature of SSA’s wood energy production and supply chains, at least in the short- to medium-terms. Notwithstanding its importance, wood energy generally has low priority in SSA national policies. However, the use of wood energy is often considered a key driver of unsustainable management and negative environmental consequences in the humid and dry forests.To date, unsystematic assessments of the socio-economic and environmental consequences of wood energy use have underplayed its significance, thus further hampering policy debates. Therefore, a more balanced approach which considers both demand and supply dynamics is needed. This systematic map aims at providing a comprehensive approach to understanding the role and impacts of wood energy across all regions and aspects in SSA.MethodsThe objective of this systematic map is to collate evidence from studies of environmental and socio-economic impacts of wood energy value chains, by considering both demand and supply within SSA. The map questions are framed using a Populations, Exposure, Comparators and Outcomes (PECO) approach. We name the supply and demand of wood energy as the “exposure,” composed of wood energy production, harvesting, processing, and consumption. The populations of interest include both the actors involved in these activities and the forest sites where these activities occur. The comparator is defined as those cases where the same wood energy activities occur with i) available/accessible alternative energy sources, ii) regulatory frameworks that govern the sector and iii) alternative technologies for efficient use. The outcomes of interest encompass both socioeconomic and environmental impacts that can affect more than the populations named above. For instance, in addition to the direct socioeconomic impacts felt by participants in the wood energy value chain, forest dwellers may experience livelihood changes due to forest degradation caused by external harvesters. Moreover, intensified deforestation in one area may concurrently lead to forest regeneration in another.

Trade in medicinal tree and shrub products in three urban centres in Kenya

As pressures on agricultural and rural land increase, forest products are becoming a main source of non-farm income for many rural and urban households in sub-Saharan Africa. The trading of wild harvested medicinal tree and shrub material, mostly sourced from natural forest stands, bush, and savannah woodland, is poorly documented, particularly in Kenya. This study (a) profiles the socio-economic characteristics of traders and key species traded and (b) identifies the supply chain and quantities of material stocked and traded and assesses the economic value of the trade. Trading in medicinal tree and shrub products constitutes an important source of income for households and is often the only income generator, as 60% of the traders stated that they had no additional income-generating activities. There is a wide range in the quantities of material stocked and sold. There are significant differences regarding quantities and pricing of material between traders by location and gender. The material that supplies the markets is almost exclusively sourced through collection from the wild with little or no indication of sustainable supply from cultivated sources. And as the total volume of material collected from the wild and traded is largely unknown and potentially much greater than previously thought, this raises serious concerns for the sustainability of natural resources. Further species-specific research on the trade of medicinals is required to evaluate the extent of threat to natural populations, to analyse the value chains for sustainable production and marketing, and to assess the economic and ecological benefits from cultivating medicinal tree and shrub species on smallholder farms.

Conceptual Analysis: The Charcoal-Agriculture Nexus to Understand the Socio-Ecological Contexts Underlying Varied Sustainability Outcomes in African Landscapes

The production of charcoal is an important socio-economic activity in sub-Saharan Africa (SSA). Charcoal production is one of the leading drivers of rural land-use changes in SSA, although the intensity of impacts on the multi-functionality of landscapes varies considerably. Within a given landscape, charcoal production is closely interconnected to agriculture production both as major livelihoods, while both critically depend on the same ecosystem services. The interactions between charcoal and agricultural production systems can lead to positive synergies of impacts, but will more often than not result in trade-offs and even vicious cycles. Such sustainability outcomes vary from one site to another due to the heterogeneity of contexts, including agricultural production systems that affect the adoption of technologies and practices. Trade-offs or cases of vicious cycles occur when one-off resource exploitation of natural trees for charcoal production for short-term economic gains permanently impairs ecosystem functions. Given the fact that charcoal, as an important energy source for the growing urban populations and an essential livelihood for the rural populations, cannot be readily substituted in SSA, there must be policies to support charcoal production. Policies should encourage sustainable technologies and practices, either by establishing plantations or by encouraging regeneration, whichever is more suitable for the local environment. To guide context-specific interventions, this paper presents a new perspective - the charcoal-agriculture nexus - aimed at facilitating the understanding of the socio-economic and ecological interactions of charcoal and agriculture production. The nexus especially highlights two dimensions of the socio-ecological contexts: charcoal value chains and tenure systems. Combinations of the two are assumed to underlie varied socio-economic and ecological sustainability outcomes by conditioning incentive mechanisms to affect the adoption of technologies and practices in charcoal and agriculture productions. Contrasting sustainability outcomes from East Africa are presented and discussed through the lens of the charcoal-agriculture nexus. The paper then concludes by emphasizing the importance of taking into account the two-dimensional socio-ecological contexts into effective policy interventions to turn charcoal-agriculture interactions into synergies.

Links between energy access and food security in sub Saharan Africa: an exploratory review

Three quarters of the population in Sub Saharan Africa lacks access to modern energy, and relies instead on biomass fuels for cooking and heating. The environment and health implications of the use of biomass fuel has been widely documented in the literature, and has raised the topic of energy access in various policy and development arenas. Still, the impact of energy access on food security at the household level has not been explored in detail; consequently the two sectoral policies remain unaligned. Our aims for this review were to document how lack of access to energy can impact on food security through influence on dietary choices and cooking practices; and how reallocation of household resources from food to energy procurement causes a switch to biomass energy forms of lower grade. We searched the literature for published peer-reviewed articles available through major online publication databases, initially identifying 132 articles but finally reviewing a set of 19 that met our criteria. While most studies suggested that fuelwood scarcity can affect food security through three hypothesised pathways, very few of them provided empirical data to support this argument. Overall, the review found coping measures for woodfuel scarcity to be highly contextual and influenced by geography, household economy and labour availability. Due to the limited number of studies with detailed data, it was not possible to perform a comparative analysis that could support or refute a hypothesis that lack of access to energy can impact on food security. More rigorous studies on this topic are needed which could provide evidence for policy action.

Tree establishment and management on farms in the drylands: evaluation of different systems adopted by small-scale farmers in Mutomo District, Kenya

Abstract Agroforestry systems in Sub-Saharan African drylands are complex and heterogeneous in nature even under similar biophysical conditions. This can be attributed to household needs and socioeconomic status which influence the species and utility of the adopted trees. This has an impact on the trees establishment and management system through planting or Farmer Managed Natural Regeneration (FMNR). This study evaluates how trees for different utilities are managed and which socioeconomic factors influence these decisions. The study used primary data collected in Mutomo District, Kenya through a household survey based on a structured questionnaire. A paired sample t-test was done to assess the preferred mode of adopting trees for different utilities while factor analysis was used to characterize the households as either planting trees or practicing FMNR. Multiple linear regression using household regression factor scores as independent variables and socioeconomic indicators as dependent variables was done to ascertain which socioeconomic factors affect tree adoption. The results show that trees planted were mostly exotic species valued for their nutrition and commercial value, while FMNR was used for subsistence products and environmental services. Household size, livestock levels and mobility had a positive correlation with tree planting, while income, access to markets and roads had an inverse correlation. Access to natural woodland, distance to the nearest motorable road and land size had a positive correlation with tree protection. It is hoped that this knowledge will act as a reference point when designing agroforestry projects in similar areas to ensure they are more aligned to specific site and household conditions.

Replication Data for: Evidence Based Forestry on socio-economic and environmental consequences of wood energy

This systematic map aims at providing a comprehensive approach to understanding the role and impacts of wood energy across all regions and aspects in Sub-Saharan Africa.