Governments around the world seek to create programs that will support sustainable agriculture an... more Governments around the world seek to create programs that will support sustainable agriculture and achieve food security, yet they are faced with uncertainty, system complexity and data scarcity when making such choices. We propose decision modeling as an innovative approach to help meet these challenges and offer a case study to show the effectiveness of the tool. We use decision analysis tools to model the possible nutrition-related outcomes of the Ugandan government's long term agricultural development plan termed 'Vision 2040'. The analysis indicates potential shifts in household nutritional contributions through the comparison of the current small-scale diverse systems and the envisioned industrial agricultural systems that may replace them. A Monte Carlo simulation revealed that Vision 2040 plans outperform homegardens in terms of energy and some macronutrients, yet homegardens are likely to be better at producing key vitamins and micronutrients, such as Vitamin A. Value of information calculations applied to Monte Carlo outputs further revealed that gathering more data on the annual yields and nutrient contents of staples, pulses, vegetables, and fruits could improve certainty about the nutrition contribution of both scenarios. We conclude that the development of Uganda's agricultural sector should consider the role that agrobiodiversity in the current small-scale agricultural systems plays in national food and nutrition security. Any changes according to Vision 2040 should also include farmers' voices and current crop management systems as guides for a sustainable food supply in the region. This modeling approach may be a tool for governments to consider agricultural policy implications, especially given the data scarcity and agricultural variability in regions such as East Africa.
Homegardens are traditional food systems that have been adapted over generations to fit local cul... more Homegardens are traditional food systems that have been adapted over generations to fit local cultural and ecological conditions. They provide a year-round diversity of nutritious foods for smallholder farming communities in many regions of the tropics and subtropics. In south- western Uganda, homegardens are the primary source of food, providing a diverse diet for rural marginalized poor. However, national agricultural development plans as well as economic and social pressures threaten the functioning of these homegardens. The implications of these threats are difficult to evaluate, because the structure and functions of the homegardens are not well understood. The aim of the study was to identify patterns and influencing factors in the diversity of homegardens by documenting the floris- tic diversity and its interactions with spatial, environmental and socio-economic factors. A geographically and socially focused assessment of floristic diversity in 102 randomly selected homegardens in three districts of southwest Uganda was conducted along a deforestation gradient following a human ecology conceptual framework and testing multiple quantitative hypotheses regarding the above mentioned fac- tors. A merged mixed-method approach was followed to pro- vide context and feedback regarding quantitative findings. Results show a high total richness of 209 (mean 26.8 per homegarden) crop species (excluding weeds and ornamen- tals) dominated by food species, which constituted 96 per- cent of individuals and 44 percent of all species. Forest-edge homegardens maintained higher plant diversity compared to homegardens in deforested areas and near degraded wet- lands. Multiple linear regression models indicated elevation, location, homegarden size, distance to market, additional land ownership (outside the homegarden) and livestock ownership as significant predictors of crop diversity. Clus- ter analysis of species densities revealed four garden types: ‘diverse tree gardens’, ‘small forest-edge gardens’, ‘large, old, species-rich gardens’, and ‘large, annual-dominated herb gardens’, with 98% correct classification. Location, eleva- tion, and garden size were also important determinants in the cluster assignment. We conclude that the diversity of the studied homegardens may be changing as part of adaptive traditional practices and in response to external drivers. The identified patterns illustrate the importance of homegardens for rural livelihoods and may offer some ways to support farmers to maintain these systems as relevant mechanisms for development in Uganda.
The baobab (Adansonia digitata L.) is a remarkable key tree species with different uses in many A... more The baobab (Adansonia digitata L.) is a remarkable key tree species with different uses in many African countries. International interest in the species has intensified in recent years. Despite the wide distribution of the baobab in many African regions, the tree has been reported to be absent in Uganda. In 2015 and 2016, research trips in the Central, Western, Eastern and Northern Regions of Uganda were conducted to screen the cultivated and natural flora for baobabs. As a result, four vigorous baobab trees aged 9 and 22 years were identified in two gardens in the Iganga and Soroti Districts in the Eastern Region of Uganda. The origins of the planting materials were Nyala in Sudan and Mombasa in Kenya. To our knowledge, these are the first scientific records of baobab in Uganda and some research questions and key propositions are formulated based on this discovery.
Ugandan homegarden systems are sustainable small-scale solutions for food security and conservati... more Ugandan homegarden systems are sustainable small-scale solutions for food security and conservation; they contain a great diversity of indigenous plant species and act to preserve the associated, and time-tested, traditional knowledge of both nutrition and conservation. These systems and traditions are under threat. Ugandan Organic may hold some of the keys for the revitalization of these oases of diversity and culture. More in-depth investigations of the influences on homegardens biodiversity are necessary.
The Greater Bushenyi region in southwest Uganda is characterized by high ecological and cultural ... more The Greater Bushenyi region in southwest Uganda is characterized by high ecological and cultural diversity, but also by high levels of poverty and malnutrition. Much of the natural vegetation (Guineo-Congolian rainforest) has been transformed into banana-based homegardens (HG), the primary source of food for local people. Inventories of 102 HGs aimed to define HG types in relation to their level of agrobiodiversity as a first step in conceptualizing interventions to help address regional food insecurity. Ward's minimum variance hierarchical cluster analysis, (with Mahalanobis distance measure and squared Euclidean distances of log(e) transformed individual densities of useful plant species per 1000 m2 HG area) divided HGs into four distinct HG floristic diversity types. Clusters 1 (n=39 HGs) and 2 (n=10) had the greatest Shannon H’ and greatest Pielou’s J’. Cluster-3 (n=10) had the highest species richness, but only medium H’ and J’. Cluster-4 (n=43) had the greatest abundance and richness of annual and perennial herbs. Clusters 3 and 4 both had the greatest abundance and density of plants per 1,000 m2. Linear discriminant analysis (LDA) revealed 98% correct classification and a Breiman's random forest model explained 51% of variance. Models of the cluster assignment and plant species densities indicated 13 plant species important to the clustering model. Mean squared error (MSE) values in the random forests model were strongest for eight species Phaseoulus vulgaris, Coffea arabica, Amaranthus dubius, Amaranthus hybridus, Saccharum officinarum, Amaranthus spinosus, Solanum torvum, and Artocarpus heterophyllus (MSE<1.3%). Stepwise variable selection indicated 11 species significantly minimizing the Wilk's λ; A. spinosus, P. vulgaris, C. arabica, A. hybridus, S. torvum, Gynandropsis gynandra, Hibiscus acetosella, Gynura scandens, Grevillea robusta, A. dubius, and Antiaris toxicaria (p<0.001). Increasing the nutritional value of these food systems may begin with a diverse approach based on the identified HG types and important plants.
Introduction: Homegardens are complex and small scale traditional farming systems, predominantly ... more Introduction: Homegardens are complex and small scale traditional farming systems, predominantly in the humid tropics, characterized as intimate multi‐story gardens around homesteads, designed to meet household consumption needs and produce for markets. They are diverse agroforestry systems containing a variety of crops and indigenous plants with an associated diversity of traditional knowledge. Little is known about this diversity in the highland homegardens of the Ugandan Southwest. The study described aimed to bridge this gap. Agriculture is the main economic activity in the region, mainly small‐scale producers engaged in a wide range of crops and other commodities, notably production of Matooke Musa acuminata Colla (AAA‐EA). Homegardens in the region are dominated by bananas and intercropped with coffee, staples, fruits, vegetables, medicinal plants, and trees for fuel wood with few small livestock. Methods: The work described is based on interviews and homegarden inventories with 102 farmers in the Greater Bushenyi region in 2014 and 2015. Categorization of plants into different uses by farmers was done using the quantitative ethnobotany indices including, most importantly, the use report (UR), which occurs when a species is mentioned or observed being used for a certain defined use‐category and the cultural importance index, or UR divided by N. Agro‐ecological importance is here measured with the Summed Dominance Ration (SDR). Results: The 31 plants with a Ci index score above 0.5 included 8 annuals and 13 perennials, 1 liane climber, 3 shrubs, and 6 trees. >60% were used for food, >15% for sale, >2% for hygiene, >1% for technical uses, other use categories were less than 1% of UR. Correlation tests of ecological and ethnobotany scores indicated that those plants with the highest Ci index scores were among those with the greatest SDR (p<0.05) and importance to the diversity of the homegardens. Acknowledgements: This project (031A247B) is financially supported by the Federal Ministry of Education and Research (BMBF) within the collaborative research project GlobE‐RELOAD.
Governments around the world seek to create programs that will support sustainable agriculture an... more Governments around the world seek to create programs that will support sustainable agriculture and achieve food security, yet they are faced with uncertainty, system complexity and data scarcity when making such choices. We propose decision modeling as an innovative approach to help meet these challenges and offer a case study to show the effectiveness of the tool. We use decision analysis tools to model the possible nutrition-related outcomes of the Ugandan government's long term agricultural development plan termed 'Vision 2040'. The analysis indicates potential shifts in household nutritional contributions through the comparison of the current small-scale diverse systems and the envisioned industrial agricultural systems that may replace them. A Monte Carlo simulation revealed that Vision 2040 plans outperform homegardens in terms of energy and some macronutrients, yet homegardens are likely to be better at producing key vitamins and micronutrients, such as Vitamin A. Value of information calculations applied to Monte Carlo outputs further revealed that gathering more data on the annual yields and nutrient contents of staples, pulses, vegetables, and fruits could improve certainty about the nutrition contribution of both scenarios. We conclude that the development of Uganda's agricultural sector should consider the role that agrobiodiversity in the current small-scale agricultural systems plays in national food and nutrition security. Any changes according to Vision 2040 should also include farmers' voices and current crop management systems as guides for a sustainable food supply in the region. This modeling approach may be a tool for governments to consider agricultural policy implications, especially given the data scarcity and agricultural variability in regions such as East Africa.
Homegardens are traditional food systems that have been adapted over generations to fit local cul... more Homegardens are traditional food systems that have been adapted over generations to fit local cultural and ecological conditions. They provide a year-round diversity of nutritious foods for smallholder farming communities in many regions of the tropics and subtropics. In south- western Uganda, homegardens are the primary source of food, providing a diverse diet for rural marginalized poor. However, national agricultural development plans as well as economic and social pressures threaten the functioning of these homegardens. The implications of these threats are difficult to evaluate, because the structure and functions of the homegardens are not well understood. The aim of the study was to identify patterns and influencing factors in the diversity of homegardens by documenting the floris- tic diversity and its interactions with spatial, environmental and socio-economic factors. A geographically and socially focused assessment of floristic diversity in 102 randomly selected homegardens in three districts of southwest Uganda was conducted along a deforestation gradient following a human ecology conceptual framework and testing multiple quantitative hypotheses regarding the above mentioned fac- tors. A merged mixed-method approach was followed to pro- vide context and feedback regarding quantitative findings. Results show a high total richness of 209 (mean 26.8 per homegarden) crop species (excluding weeds and ornamen- tals) dominated by food species, which constituted 96 per- cent of individuals and 44 percent of all species. Forest-edge homegardens maintained higher plant diversity compared to homegardens in deforested areas and near degraded wet- lands. Multiple linear regression models indicated elevation, location, homegarden size, distance to market, additional land ownership (outside the homegarden) and livestock ownership as significant predictors of crop diversity. Clus- ter analysis of species densities revealed four garden types: ‘diverse tree gardens’, ‘small forest-edge gardens’, ‘large, old, species-rich gardens’, and ‘large, annual-dominated herb gardens’, with 98% correct classification. Location, eleva- tion, and garden size were also important determinants in the cluster assignment. We conclude that the diversity of the studied homegardens may be changing as part of adaptive traditional practices and in response to external drivers. The identified patterns illustrate the importance of homegardens for rural livelihoods and may offer some ways to support farmers to maintain these systems as relevant mechanisms for development in Uganda.
The baobab (Adansonia digitata L.) is a remarkable key tree species with different uses in many A... more The baobab (Adansonia digitata L.) is a remarkable key tree species with different uses in many African countries. International interest in the species has intensified in recent years. Despite the wide distribution of the baobab in many African regions, the tree has been reported to be absent in Uganda. In 2015 and 2016, research trips in the Central, Western, Eastern and Northern Regions of Uganda were conducted to screen the cultivated and natural flora for baobabs. As a result, four vigorous baobab trees aged 9 and 22 years were identified in two gardens in the Iganga and Soroti Districts in the Eastern Region of Uganda. The origins of the planting materials were Nyala in Sudan and Mombasa in Kenya. To our knowledge, these are the first scientific records of baobab in Uganda and some research questions and key propositions are formulated based on this discovery.
Ugandan homegarden systems are sustainable small-scale solutions for food security and conservati... more Ugandan homegarden systems are sustainable small-scale solutions for food security and conservation; they contain a great diversity of indigenous plant species and act to preserve the associated, and time-tested, traditional knowledge of both nutrition and conservation. These systems and traditions are under threat. Ugandan Organic may hold some of the keys for the revitalization of these oases of diversity and culture. More in-depth investigations of the influences on homegardens biodiversity are necessary.
The Greater Bushenyi region in southwest Uganda is characterized by high ecological and cultural ... more The Greater Bushenyi region in southwest Uganda is characterized by high ecological and cultural diversity, but also by high levels of poverty and malnutrition. Much of the natural vegetation (Guineo-Congolian rainforest) has been transformed into banana-based homegardens (HG), the primary source of food for local people. Inventories of 102 HGs aimed to define HG types in relation to their level of agrobiodiversity as a first step in conceptualizing interventions to help address regional food insecurity. Ward's minimum variance hierarchical cluster analysis, (with Mahalanobis distance measure and squared Euclidean distances of log(e) transformed individual densities of useful plant species per 1000 m2 HG area) divided HGs into four distinct HG floristic diversity types. Clusters 1 (n=39 HGs) and 2 (n=10) had the greatest Shannon H’ and greatest Pielou’s J’. Cluster-3 (n=10) had the highest species richness, but only medium H’ and J’. Cluster-4 (n=43) had the greatest abundance and richness of annual and perennial herbs. Clusters 3 and 4 both had the greatest abundance and density of plants per 1,000 m2. Linear discriminant analysis (LDA) revealed 98% correct classification and a Breiman's random forest model explained 51% of variance. Models of the cluster assignment and plant species densities indicated 13 plant species important to the clustering model. Mean squared error (MSE) values in the random forests model were strongest for eight species Phaseoulus vulgaris, Coffea arabica, Amaranthus dubius, Amaranthus hybridus, Saccharum officinarum, Amaranthus spinosus, Solanum torvum, and Artocarpus heterophyllus (MSE<1.3%). Stepwise variable selection indicated 11 species significantly minimizing the Wilk's λ; A. spinosus, P. vulgaris, C. arabica, A. hybridus, S. torvum, Gynandropsis gynandra, Hibiscus acetosella, Gynura scandens, Grevillea robusta, A. dubius, and Antiaris toxicaria (p<0.001). Increasing the nutritional value of these food systems may begin with a diverse approach based on the identified HG types and important plants.
Introduction: Homegardens are complex and small scale traditional farming systems, predominantly ... more Introduction: Homegardens are complex and small scale traditional farming systems, predominantly in the humid tropics, characterized as intimate multi‐story gardens around homesteads, designed to meet household consumption needs and produce for markets. They are diverse agroforestry systems containing a variety of crops and indigenous plants with an associated diversity of traditional knowledge. Little is known about this diversity in the highland homegardens of the Ugandan Southwest. The study described aimed to bridge this gap. Agriculture is the main economic activity in the region, mainly small‐scale producers engaged in a wide range of crops and other commodities, notably production of Matooke Musa acuminata Colla (AAA‐EA). Homegardens in the region are dominated by bananas and intercropped with coffee, staples, fruits, vegetables, medicinal plants, and trees for fuel wood with few small livestock. Methods: The work described is based on interviews and homegarden inventories with 102 farmers in the Greater Bushenyi region in 2014 and 2015. Categorization of plants into different uses by farmers was done using the quantitative ethnobotany indices including, most importantly, the use report (UR), which occurs when a species is mentioned or observed being used for a certain defined use‐category and the cultural importance index, or UR divided by N. Agro‐ecological importance is here measured with the Summed Dominance Ration (SDR). Results: The 31 plants with a Ci index score above 0.5 included 8 annuals and 13 perennials, 1 liane climber, 3 shrubs, and 6 trees. >60% were used for food, >15% for sale, >2% for hygiene, >1% for technical uses, other use categories were less than 1% of UR. Correlation tests of ecological and ethnobotany scores indicated that those plants with the highest Ci index scores were among those with the greatest SDR (p<0.05) and importance to the diversity of the homegardens. Acknowledgements: This project (031A247B) is financially supported by the Federal Ministry of Education and Research (BMBF) within the collaborative research project GlobE‐RELOAD.
Uploads
Papers by Jens Gebauer
Conference Presentations by Jens Gebauer
Books by Jens Gebauer