Chapter II. The Minziro-Sango Bay Transboundary Site: An Ecological and Historical Description

A. Natural resources and biodiversity values

Five distinct natural biomes or communities make up the broader Minziro-Sango Bay Ecosystem. One biome, the hill slopes, supports the agricultural “banana dominated” landscape. The biomes are as follows:

1. The closed forest itself is in several patches (e.g., Namawa and Kaiso Forest patches in Uganda). Agriculture has separated some patches through history, and some patches have been precariously joined by degraded riverine forest as fire and recent cultivation nibble into the forest cover. Cleistanthus and Bakiaea today dominate the forest, together making up 50 percent of the tree cover. Podo is absent from the slightly wetter eastern forest; and even though it previously existed in the western areas, it was cut out—and regenerating poles are not common.

2. The grasslands (Hyparrhenia & Cymbopogon) with forest—thicket patches on termitaria.

3. The swamps with reeds (Phragmites, Typha) and Papyrus, and occasional fringing forest dominated by palms. These wetlands have considerable biodiversity values.

4. Low but fairly steep hills, to 150–250 m. above the forests, with poor leached soils and fire-maintained grassland. Cultivation is concentrated on the foothills, free from flooding.

5. The freshwater habitats of the Kagera River and Lake Victoria.

There are several ecological interactions among the components. For example:

• The grassland fires impact on the forest edge;
• Many animals feed in the grassland, but take refuge in forest cover;
• Livestock/wildlife are increasingly dependent on swamp systems for dry season grazing; and
• Fish swarms leave the rivers and swamps in the rains, and floodwaters bring them into the rich humus-filled pools in the forest and become an enormous protein source for villagers. (These fish values include several Clarias spp, Haplochromine spp (some presumably of the endemic Lake Victoria swarms), and Labeo victorianus. The swamp forest thus forms an important fish refuge.

The Sango Bay-Minziro forest ecosystem is unique for its biodiversity, being the richest and most extensive swamp forest in Eastern Africa. Swamp forests are not common, most are either small (e.g., Rau, Magombera of Tanzania, and Kitobo of Kenya, which are all under 10 sq. km.), or riverine flood plain forests (e.g., the Tana River forests of Kenya). The focus of conservation is the forest community itself, rather than any one charismatic species. The forest has few strict endemics; most species have a wider distribution in Eastern and particularly West Africa. One notable endemic is the “swamp podo,” recently recognized as a distinct species—Afrocarpus dawei.

Frank White describes the forest in his treatise on the Vegetation of Africa: “The forests, occurring at 1,200 m. asl. on alluvial deposits at the mouth of the River Kagera, are unique in Tropical Africa in being composed of an equal proportion of lowland (mainly western Guinea-Congolian GC) forest species and highland (Afro-Montane AM) forest species. Undisturbed forest is dominated by the GC Baikiaea insignis and the endemic Afrocarpus dawei. Other GC species are: Canarium schweinfurthii, Klainedoxa gabonensis, Maesopsis eminii, Pseudospondias microcarpa, and Symphonia globulifera. Main AM trees are: Apodytes dimidiata, Croton megalocarpus, Ilex mitis, Strombosia scheffleri, and Warburgia salutaris.”

Forest botanists in early colonial history in Uganda (e.g., Dawe in 1905) collected many plants from the forests, but collections were made much later in Tanzania (by Proctor in the 1950s). Tanzanian Minziro was not greatly collected by German botanists. More recent exploration came from the Uganda Biodiversity Forest Surveys in the 1990s (see Howard et al. 1996) and the Makerere University Institute of Environment and Natural Resources (MUIENR) wetland surveys, both funded by the earlier regional GEF Biodiversity Project. Their finds stimulated further survey in Tanzania, looking at butterflies (the late Jan Kielland and then Colin Congden) and birds (Neil and Liz Baker). The Cross-Borders Project commissioned further botanical and bird collections.

The results show interesting differences for each country. In Uganda most forest species are widespread in the west of the country going through to West Africa. In Tanzania, Minziro is continually turning up new national records, i.e., species found nowhere else in Tanzania. Minziro is the southernmost extent of what is principally a West African habitat type. There are many species, including plants, mammals, birds, and butterflies that extend from West Africa finding their eastern and southern limits in the Sango Bay-Minziro area. This means that the species may be widespread in western Uganda (e.g., from Semliki, Budongo southward), but in Tanzanian terms the only locality for many species is Minziro. Examples include the black mangabey monkey, at least 12 bird species, many butterflies, and many plant species. The forest is rich in species, with over 600 species of butterflies being recorded in Minziro, making it the richest forest anywhere in Africa for butterflies. This is all the more remarkable given no altitudinal variation in the site. This forest has extraordinary diversity in trees, especially of the family Euphorbiaceae and other plant groups. However, overall endemism, in terms of species restricted to Sango Bay-Minziro, is low.

Lind and Morrison (1973) in The Vegetation of East Africa, wrote: “Podocarpus-Baikiaea seasonal swamp forest is confined to alluvial deposits on the western shore of Lake Victoria, it is probably the largest area of swamp forest in tropical Africa. The alluvial sands are covered by tussocky grassland, and the forest is on the more clay rich soils. The forest is evergreen with a two-layered canopy; the upper storey reaches 30m and the lower or under storey is seldom more than 15m in height, often lower. In less disturbed forest Afrocarpus dawei and Baikiaea insignis dominate the upper canopy. It is difficult to visualise the structure and composition of the forest under natural conditions since podo has been heavily exploited.”

A short description of the large mammals in the case study area is provided in Box 4.

The Forest Resources

Lind and Morrison (1973) and Uganda Forest Department describe forest structure. The forest grassland border is governed by soil moisture conditions. Partially waterlogged soils have a tree cover, while wetter sites have grass, reed, and papyrus communities. Within the forest subtle differences affect communities—yielding, for example, more palm-rich associations on wet sites. Podo differs in distribution—being absent from the wetter eastern sites that are closer to Kagera River floods. Fire and conversion to cultivation alter this edaphic pattern, with frequent fires preventing forest regrowth. Local people (backed up by 30 years of aerial photo evidence) suggest that forest boundaries have been constant for a long time, riverine forest connectivity between patches being the only loss. Forest quality has degraded, however, largely through the enormous past logging pressure on podo timber. The forests were gazetted as crown forest reserves, and boundaries declared in the 1920s, but demarcated much later.

In addition to timber, local people use forest resources for fuelwood and poles, bark cloth from fig trees, and some basketry products and mats from both palms (Phoenix reclinata) and grasses. Medicinal plants and a unique forest fishery are both important values. However, the demand for timber, and especially for podo as a source of cash income dominates people’s perceptions of values (see the Annex). The politics of resource use are important—timber and fishing were in theory “off limits” and people are agitating for increased legal access. The project advocates for fishing to be opened up with village regulation, but seeks more information on podo and “teak” stocks. The traded non-timber forest-based products (e.g., palms, medicines, mats) have markets at village and township levels, spreading to neighboring districts and regional towns within Sango-Bay and Bukoba. One non-tradable value of the Minziro-Sango Bay forest is its strong spiritual and cultural value, which dates back to Chief Minziro who moved from Karagwe and settled in Minziro some two centuries ago. The Wahaya people of the area today, the Waganda-Kyaka, maintain their strong cultural history traced to the original Chief Minziro.

B. The people—Economic opportunities and forest interaction

The people who live in and around the forest are predominantly farmers. They cultivate banana, coffee, and annual legumes on smallholdings owned under customary rights. Agriculture is basically poor—owing to a combination of soil that is not very rich, inadequate extension services, growing population densities, and the past two decades of marginalization and conflict. In both Tanzania and Uganda, the fragmented smallholder peasant agriculture is based on multi-male inheritance of tenure—landholdings become ever more fragmented. Settlement sites are scattered, requiring elevated land on lower slopes of hills with no or limited flooding. The culture of people living within the Sango Bay-Minziro area is the same on both sides of the border, with very similar traditions including food and livelihood systems. The languages differ only in minor ways.

Rakai in Uganda earned the dubious distinction in the early 1990s of being the “epicenter of HIV-AIDS” in Eastern Africa. Bukoba was not far behind. The scourge, although slowly declining thanks to awareness campaigns, has caused major demographic changes and social problems.

In Uganda there are four forms of land tenure: freehold, customary (as described above), leasehold (as in the Sango Bay Sugar Estate lands), and mailo-land owned by absentee landlords with tenant squatters. Some of this mailo-land is closed forest. In Tanzania all land is public land, and under the recent village land act, land rights are vested in village governments. A household would hold usufruct rights on such land. The villagers may cultivate and develop a piece of land and demarcate ownership. But if the land is not developed, it could be reallocated to another villager. The Wahaya people around Minziro have three zones of household land. The inner zone, which includes the household, is of high productivity, and is used for intensive agroforestry. The middle zone is used for less diverse production, usually limited to bananas, maize, and beans. The outer zone is reserved for growing grass for thatch, mulch, and grazing, and is reserved for future development. The total area of a homestead for all the three zones is on average 2–3 acres. However, in remote villages very few people would have surveyed land with an official title deed. Of importance to the MSBF ecosystem is the great seasonal influx of Wahima pastoralists with huge herds (up to 500 animals) of large-horned Ankole cattle. The pastoralists themselves are inherently a cross-border people, capable of being Wa-Rwanda in Rwanda, Ugandans in Uganda, and to a lesser extent Tanzanians in Tanzania. Their ecological lifestyle is described in Box 5 below.

Overall economic opportunities are similar in both countries, which is a consequence of six factors:

• The environment on both sides of the border is ecologically similar.
• Economic and development policies are now more similar than they were in the past.
• Minziro and Rakai are far from capital cities and the engines of development. These communities are the “last of the last.” This is accentuated by similar impoverishment of both district governments, with inadequate resources for the development of human or structural capital.
• The constraint mentioned above raises a similar conservation concern in both districts. Districts are short of development funds, as forest exploitation for timber has traditionally been a major source of funding. There is a demand from the private sector and some sections of government to open forest log extraction as soon as possible.
• East African Community cooperation processes have resulted in policy changes on both sides of the border harmonizing tariffs and duties. This means that producer prices and shop prices are similar on both sides of the border, preventing large-scale resource smuggling and other disruptions that took place in the past. However, infrastructure and demand can cause trade inbalances—as evidenced by Nile perch fisheries with Tanzanian fishermen selling catches in Uganda (ice lorries taking catch to Entebbe and Europe), and Tanzanian logs finding good markets via tarmac roads—e.g., by satisfying demand in the Ugandan capital city of Kampala.
• Finally, Tanzania has attracted bilateral support (from the Netherlands, EU, and Belgium) into rural development processes in Bukoba—much of it focused on agricultural enhancement (coffee, disease resistant bananas, etc.). This is only just starting in Rakai (Danish aid scheduled to start flowing in 2002); the CBBP has been networking Ugandan farmers to visit Tanzanian improvement demonstrations. Uganda has had more investment for infrastructure (roads), the private sector (e.g., the Nile perch), and support to NGOs.

The 1970 “war” between Tanzania and Uganda destabilized the social, economic, and commercial situation, as well as prospects for further development (see Box 6).