The increasing demand for cultivated lands driven by human population growth, escalating consumption and activities, combined with the vast area of uncultivated land, highlight the pressing need to better understand the biodiversity conservation implications of land use change in Sub-Saharan Africa. Land use change alters natural wildlife habitats with fundamental consequences for biodiversity. Consequently, species richness and diversity typically decline as land use changes from natural to disturbed. We assess how richness and diversity of avian species, grouped into feeding guilds, responded to land use changes, primarily expansion of settlements and cultivation at three sites in the Lake Victoria Basin in western Kenya, following tsetse control interventions. Each site consisted of a matched pair of spatially adjacent natural/semi-natural and settled/cultivated landscapes. Significant changes occurred in bird species richness and diversity in the disturbed relative to the natural landscape. Disturbed areas had fewer guilds and all guilds in disturbed areas also occurred in natural areas. Guilds had significantly more species in natural than in disturbed areas. The insectivore/granivore and insectivore/wax feeder guilds occurred only in natural areas. Whilst species diversity was far lower, a few species of estrildid finches were more common in the disturbed landscapes and were often observed on the scrubby edges of modified habitats. In contrast, the natural and less disturbed wooded areas had relatively fewer estrildid species and were completely devoid of several other species. In aggregate, land use changes significantly reduced bird species richness and diversity on the disturbed landscapes regardless of their breeding range size or foraging style (migratory or non-migratory) and posed greater risks to non-migratory species. Accordingly, land use planning should integrate conservation principles that preserve salient habitat qualities required by different bird species, such as adequate patch size and habitat connectivity, conserve viable bird populations and restore degraded habitats to alleviate adverse impacts of land use change on avian species richness and diversity.

Tsetse flies are the primary vector for African trypanosomiasis, a neglected tropical disease that affects both humans and livestock across the continent of Africa. In 1973 tsetse were estimated to inhabit 22% of Kenya; by 1996 that number had risen to roughly 34%. Efforts to control the disease are hampered by a lack of information and costs associated with the identification of infested areas. To aid control efforts we have constructed the Tsetse Ecological Distribution Model (TED Model). The TED Model is a raster based dynamic species distribution model that predicts tsetse distributions at 250 m spatial resolution, based on habitat suitability and fly movement rates, at 16‐day intervals. Although the TED Model can be parameterized to any tsetse subgenus/species requirements, for the purpose of this study the TED Model was parameterized to identify suitable habitat for Glossina subgenus Morsitans. Using the TED Model we have identified where and when Glossina subgenus Morsitans populations should be constrained by unfavorable ecological conditions to particular parcels of suitable habitat. It is our hope that by utilizing the predicted locations of tsetse reservoirs and refugia, control efforts will be better able to target tsetse populations when they are spatially constrained, thus maximizing limited available resources.

Land-use change is one of the main drivers of environmental change. It influences the basic resources of land, including the soil. Its impact on soil often occurs so creepingly that land managers hardly contemplate initiating ameliorative or counterbalance measures. Poor land management has degraded vast amounts of land, reduced our ability to produce enough food, and is a major threat to rural livelihoods in many developing countries. Land use in the basin of lake Victoria like other parts of east Africa is changing fast. While some areas are undergoing expansion of cultivation and grazing, others are intensifying. Common to all is that there are impacts on sustainability of the natural systems on which productivity depends. The nature of landscapes and the geomorphologic processes in the lake basin make land use change highly sensitive to erosion and degradation. There is an urgent need for a regional framework and guidelines for sustainable land management including all sectors of land use like cropping, grazing and urbanization. This paper highlights some of the changes in land use in the lake basin, presents the implications of these changes on productivity and gives some investment options for developing sustainable land use.

Land use changes in East Africa have transformed land cover to farmlands, grazing lands, human settlements and urban centers at the expense of natural vegetation. These changes are associated with deforestation, biodiversity loss and land degradation. A synthesis of results of long term research by an interdisciplinary team reveals the linkages between land use change, biodiversity loss and land degradation. The results indicate that as native vegetation is lost, indigenous plant and animal biodiversity and plant cover are lost. Pastoralism maintains native plant and animal species more effectively than crop cultivation. As croplands expand, soil fertility and moisture drops and soils erode more easily. Farmers who grow many crops conserve native plant species better than those who grow only one crop. Increased crop diversity encourages regeneration of indigenous plant species. Moderate farming as in the less intensive low input rainfed mixed crop farming, in less forested areas increases tree cover thus increasing the biodiversity. Farmers’ who combine livestock rearing with cropping, use livestock manure to replenish soil nutrients in their farms and are thus able to maintain higher productivity. Farming in grasslands, woodlands and bushland areas where there are fewer trees, increases the diversity of habitats due to introduction of agrosystems that attract new species of birds. However, if the farming is intensified and the diversity of habitats is reduced biodiversity is also reduced. This paper presents findings of the investigations on these linkages in a diverse farming and herding systems ranging from lowlands to high mountains land uses.

Most rural households in the semi-arid regions of sub-Saharan Africa practise mixed crop-livestock farming. With population growth and the subsequent scarcity of land available for extensive farming, the only option available for these households is to intensify production. For this to be successful, one must understand the divergent patterns of intensification and their relation to the economic needs of households. In a Rift Valley community in Kenya, inter-household heterogeneities in adopting distinctive combinations of particular crop and livestock productions (they are defined as 'croplivestock diversification' or CLD patterns) were observed. Principal component analysis was used to identify the dominant CLD patterns which reflect complementarities between crop and livestock types. This was followed by an assessment of the association between the CLD patterns and the economic returns and manure use of the households. Among the five dominant CLD patterns identified, households that kept improved cattle and grew fruits were found to earn higher incomes and apply more organic manure. Conversely, households that grew staple crops with or without indigenous animals were found to apply less manure. Education, participation in farmers' groups, access to the training centre, and family size were key factors affecting the adoption of CLD patterns.

AbstractAfrican farmers diversify their livelihood strategies through on‐farm and off‐farm activities. We cluster households according to similar livelihood diversification strategies and explore the implications for income levels and sustainable soil management practices. Five main livelihood diversification strategies were being pursued. Households with off‐farm income, and those pursuing higher return agricultural activities earned more than twice as much as the lowest income groups, which were the least diversified. They also were more likely to implement soil conservation measures. Policies aimed at improving household well‐being need to take into account a wide range of household asset endowments and livelihood strategies being pursued. Copyright © 2007 John Wiley & Sons, Ltd.

International Livestock Research Institute, P.O. Box 30709. Nairobi, Kenya 2 Kenya Agricultural Research Institute, P.O. Box 14733. Nairobi Kenya Institute of Resource Assessment, University of Dar Es Salaam, Box 35097 Dar Es Salaam, Tanzania Botany Department, University of Dar Es Salaam, Box 35097 Dar Es Salaam, Tanzania National Museums of Kenya, P.O. Box 40658, Nairobi Makerere University, Institute of Environment and Natural resources, Makerere University, P. O. Box 7298 Kampala, Uganda.

A total of 191 soil samples were collected from different land uses in the four sites (Tororo, Iganga, Kamuli and Soroti Districts) in Uganda for soil fertility and texture analysis. Soil fertility in respect to organic carbon (organic matter), total nitrogen, available phosphorus, exchangeable potassium, and trace elements were variable but generally ranged from adequate to deficient with a lot of variations across sites and within sites. Mean organic carbon varied from very low (1.41% organic C) in Tororo to adequate (2.27% Organic C) in Iganga. The same trend was observed for total nitrogen, which also varied from very low (0.14% N) in Tororo to adequate (0.26% N) in Iganga. Only one site had adequate carbon levels with the rest (Tororo, Kamuli and Soroti) having low organic carbon levels. This was due to nitrogen fixing crops grown in Iganga (e.g. groundnut), level of inorganic fertilizers applied in coffee or maize farms and substantial bush/fallow fields (47%) in this site unlike in the other sites where no nutrients are added. Available phosphorus ranged from very low (4ppm) to luxury amounts (91 ppm) but the mean available P was low throughout the four sites (4-15ppm). Out of the four sites, 31% and 20% of sites in Tororo and Iganga respectively had potassium deficiency 15% of the farms in the other sites had deficiency problems. Trace elements ranged from very low to luxury amounts or consumption in some sites. In Soroti and Tororo, 100% and 96% land uses respectively had deficiency in zinc levels while 42% and 40% of the points in Kamuli and Soroti respectively were deficient in iron. However, the level of copper in all the sites was almost adequate (82%) in most of the land uses except in few places. Mean soil PH in the four sites indicated that the soil reaction was ranging from strongly acidic (PH <4.5) to medium acidity (PH <6.0). The range in soil PH was from PH 3.61 to PH 7.19. Both non-acidifying and acidifying fertilizers need to be selectively used depending on the soil PH at respective sites. The soil texture analysis showed that soils sampled from the four sites had a mean textural class of sandy clay loam (SCL). At the extreme range e.g. Tororo the soils are of clay nature usually dark/black clacking clays. This implies that the soil have been slightly eroded leading to poor soil fertility problems. FYM or compost must be added to modify the soil texture and improve its water holding characteristics. At Kamuli, Soroti, Iganga and Tororo sites, apply farmyard manure (FYM) or compost at 5t/ha to raise soil organic matter, PH and supply sufficient nitrogen to most of the crops. Apply 2t/ha of lime on maize/millet, maize and coffee at Soroti and Kamuli sites to raise the soil PH to between 5.5 and 6.5 required by most crops for optimal crop growth. It is recommended that compound fertilizer containing N: P: K 17:17:17 at 300kg/ha per year be used at planting time to correct nitrogen, phosphorous and potassium (NPK) deficiencies in the soil for common crops. For coffee, apply one debe or 1 Okg/tree of FYM or compost around the tree base; apply further 50g of TSP by broadcasting around the tree/year and top dress with 25kg/10tonnes CAN or ASN per year in alternate years. Apply 25kg of ASN to coffee at nursery. For maize in all sites top dress with 250kg/ha sulphate of ammonia in two portions at knee high and at flowering stage. Crop diversification noticed in most sites is recommended to utilize available nutrients and for crops to complement each other e.g. maize/groundnuts in terms of nutrients. Foliar feed containing zinc and iron is recommended for application on tree crops like coffee and bananas due to its scarcity in most sites. (Resume d’auteur)

1. Two workshops were held in Busia and Teso districts. Five villages from one location in the district were involved in the discussions. Participatory approach was used to gather information and perception of the participants on four themes: i) wetlands and water, ii) livestock and wildlife, iii) land and soils and iv) forests, woodlands and vegetation. The participants discussed the themes in their local dialects with the interpreter translating for the facilitator. It was clear that the changes in the themes were due to mans' activity and these changes were mainly; a) deforestation, b) poor soils, c) loss of wildlife, d) unsustainable cultivation in the wetlands and e) water pollution. 2. The effects of these changes on the incidences of sleeping sickness and Nagana were related to habitat destruction in the forests, woodlands and vegetation and in wetlands. The effect of the changes on human livelihood had great impact on the participants for they had not pictured the unfolding scenario and its consequences before. The groups made a number of recommendations on the way forward in each theme and indicators to evaluate the changes in case the recommendations were followed through. One of the recommendations is the formation of village environmental committees and common interest groups to spearhead conservation and sustainable use of the natural resources at the village level. These groups if formed will require to undergo training in order to see through the implementation of the recommendations. 3. It is hoped that FITCA-EMMC will engage the communities' further in order to develop action plans which would be the village's blue print on environmental conservation, protection and management at the community level. Communities need to be networked to stakeholders with similar interests, who may assist them to implement the action plans. (Resume d’auteur)

Due to the rampant trypanosomosis epidemics in Africa, international organisations developed a Programme Against African Trypanosomosis (PAAT). The Farming in Tsetse Controlled Areas (FITCA) project in Kenya, which was launched in July 2001, is a component of PAAT. Its major objective is to control the tsetse fly populations in selected zones. The tsetse fly is the vector of the pathogen causing trypanosomosis. The selected zones have shown an important rate of trypanosomosis and a high level of tsetse population, which have significant adverse effect on animal production and therefore on agricultural production. Located in Western Kenya, Angurai is one of the selected zones for the project implementation. A tsetse control mechanism expected to increase livestock and therefore agricultural production has been established in the area. The benefits from such mechanisms can however in the long terms lead to serious adverse effects on the environment. If the utilization of natural resources after such tsetse control mechanism is not properly monitored, ecological imbalance between the human population and the environment might occur. The Environmental Monitoring and Management Component (EMMC) of the FITCA programme was developed to monitor these potential changes and anticipate potential negative effects. In order to achieve the above objective, there was a need to establish a database. The selected method to establish the database was a thorough study of the landscape. This was done through a multidisciplinary approach involving all the factors, which could have an impact on environmental changes. The factors monitored included; changes in crop and livestock production, vegetation cover, biodiversity (plant and animal), soil erosion and fertility as well as the control of potential trypanosomosis infections and tsetse fly populations. The establishment of a database was not only necessary to facilitate the monitoring of environmental changes but also to carry out an agro pastoral-ecosystems’ comparative study between the various zones of the FITCA project. The first zones compared included the Angurai in Kenya and the Tororo district in Uganda. Although the Malaba river only separates the two zones, they have numerous differences such as in Angurai there is a relatively low level of trypanosomosis occurrence, lower land area under cultivation and a higher number of habitats favourable to tsetse fly proliferation. The tsetse fly habitats in Angurai are mainly Lantana camara and Tithonia diversifolia shrubby savannah, which proliferate from abandoned fallows or on riverbanks. Glossina pallidipes and Glossina fuscipes are the two major tsetse fly species for which the ecological conditions are favourable to their proliferation. The presence of tsetse flies in an area inhabited by human population is conducive to the spread of trypanosomosis. (Resume d'auteur)