Ecological-edaphic and Socio-economic drivers of on-farm tree farming enterprises in Wakiso District, Central Uganda

Uganda has got approximately 14,900 km2 of gazetted forest reserves of which some 7,500 km2 (4%) is savannah woodland and forest plantation, 5,900 km2 (3%) is tropical high forest and 1,500 k2 (1%) montane catchment forest (Uganda Forest Department, 1951; Banana and Gombya-Ssembajjwe, 2000). Conversion of natural forests into agricultural land became a serious problem in Uganda in 1970's of which 12% of forested land had been affected by this agricultural encroachment (Banana and Gombya-Ssembajjwe, 2000).

About 53% of forestland within Uganda'sforest reserves remains essentially undisturbed (MWLE, 2001a). Deforestation was particularly severe between 1970 and 1985 when government control over forests deteriorated. A high population growth rate, conversion of forestland to agricultural uses as well as breakdown in law and order have been the major causes for deforestation in Uganda (MWLE, 2002b).

These forests are an essential foundation for the country’scurrent and future livelihood and growth. Sustainable management of these forests, however, poses great challenges given that the population is heavily dependent on them for timber, agriculture, and energy production (Buyinza and Nabalegwa, 2007). Forests and woodlands covered approximately 45% of the total land area of Uganda in 1898. At present, forest cover has been reduced to approximately 4.9 million hectares or about 20% of the total land area (MWLE, 2002b). About 30% of the tropical high forests are degraded and the degradation trend continues. Without effective institutions to limit and regulate harvesting levels and management practices, forest resources can be over-harvested and even irreversibly destroyed, as is the casein “open access” forests (Galabuzi et. al., 2014).

Many contemporary on-farm tree management policies in both developed and developing countries are therefore seeking to shift control of tree resources to the community level in an attempt to improve management of local tree resources. Empowering local communities to monitor and enforce tree management rules significantly lowers monitoring costs and improves effectiveness because, according to Galabuzi et. al., 2014, when compared to central government institutions, local institutional arrangements are considered better at providing, inter alia, rules related to access, harvesting, and management; a forum that can respond to conflict quickly and cheaply; and monitoring and sanctioning methods that are efficient. The goal of this study was to examine the biophysical-edaphic and socio-cultural-economic factors that influence the potential of the on-farm tree farming practices. The specific objectives were to (a) identify the relationship that exists between the socio-cultural-economic condition of the farmer with the potential of the on-farm tree farming enterprises, (b) to discover the relationship between the size of landholding and farmer'sinteraction (work-time) with the on-farm tree enterprises.

The research hypothesis were (1) the biophysical-edaphic and socio-cultural-economic factors influence the performance of the on-farm tree enterprises as indicated by tree volume (m3), tree species diversity index and tree stand density / ha; (2). The farmer'sinteraction (work-time) with the on-farm tree enterprises depends on the size of landholding and total number of livestock held. 1.1 Description of the study area Nsangi Sub-county is located in Wakiso District, SouthWest Uganda. It lies between latitude 0o13oN and 0o20o N and longitude 32o24oE and 32o33oE. It covers a surface area of 107 km2, supports a population of 44,117 people with an average population density of 412 inhabitants per km2. The area is found within the Lake Victoria basin characterized by a relatively favorable climatei.ereliable rainfall amounting to 1000 mm annually, bi-modal type of rainfall with peak falls in March to May and October to November, has a mean annual maximum temperature of 260c and annual minimum temperature of 170c. The area has under undifferentiated gneiss including elements of Pre-cambrian partly granitized and metamorphosed formations. Geologically, the area follows under the Buganda-Toro systems comprised of agilities, phyillites and schist with basal quartzite and amphibolites. It is characterized by flat-topped mesa like hills, which show considerable uniformity of elevation. Like other areas in southwestern Uganda, Nsangi sub-county has got dissected slopes of 1260 meters and at a much higher altitude of 1290 meters associated with many ridges.

The dominant soil type is sandy loams (ferrallitic soils) which represent almost the final stage in tropical weathering. From field observations, the soils of most ridges are ferrallitic, shallow soils ranging from course to stony and bare rock (skeletal soils) or rock out-crops on hill slopes with lateritic soils at the top of hills. The valleys are filled with deeply leached and weathered lateritic soils. The rest of the lowland is covered by clay loams, which support agriculture in the area. The dominant vegetation is savannah mosaic, which covers elephant grass (pennisetum perpurem) with isolated forest and savannah trees, which are remnants of a previous forest cover and cultivation demonstrating its intermediate and mixed character. However, today with the increasing population, the vegetation has been cleared for other intensive land use practices such as grazing, brick making, and excavation of stones and extension of land for cultivation and settlement.