Transformations Along the Gradient

Summary of dissertation of Christopher Conte, Michigan State University, written under Prof. Harold Marcus, May 1995

This study presents a history of ecological change in northeastern Tanzania's Usambara mountains during the late pre-colonial, colonial and early independence periods. My thesis considers long-term changes in the interrelationships among the region's local agrarian communities, the regional environment, and the exogenous forces of the world economy and the colonial state. It explains under what circumstances indigenous communities alter land management practices and social relations in the face of changing market forces, environmental uncertainty, and political transformation. Moreover, by carefully collating data collected from interviews with African informants with those of the European documentary sources, this analysis demonstrates how Usambara's inhabitants' changing relationship with nature led to ecological stress.

A growing body of historical literature addresses the relationship between East African societies and the environment. Recently published case studies tend to view rural East African households and communities as part and parcel of local and regional socioeconomic networks designed to mitigate the effects of ecological crises spawned by drought and disease(1). By incorporating oral evidence, these studies represent a revisionist trend in rural history and attempt to broaden the analyses of more general works which rely exclusively on written sources(2).

My study adds to the new scholarship on ecological stress and breakdown by describing a century of ecological change on a Tanzanian mountain massif where pastoralists and farmers exploited three ecological zones differentiated by vegetation and climate. In this varied environment, mountain-based (1600m el.) pastoralists, who during the eighteenth and nineteenth centuries carved out a mode of production dependent on forest conservation, had, by the 1960s transformed themselves into farmers on a completely deforested landscape.

In precolonial times, their neighbors, who lived in permanent villages sited down slope at about 1400m, had cultivated bananas, sorghum and various legumes in well-watered mountain basins ringing the Usambara massif. In response to the opportunities and challenges of the slave trade and later, colonialism, these farmers continually reorganized both production systems and their choice of cultigens.

Moreover, on the semi-arid plains below the mountain escarpments, where a patchwork of forest, pasture and gardens dotted the landscape in 1850, agribusiness plantations dominated by the 1940s. Thus, by Tanganyika's independence in 1961, not only had the precolonial socioeconomic links among the pastoralists and cultivators been broken, but the mountain population had become increasingly vulnerable to food shortages and disease in an environment marked by degradation from accelerated soil erosion.

While appreciating fully the revisionists' emphasis on short-term transformations in regional networks of exchange, this project goes beyond economic history to build into the analysis a discussion of ongoing change in the region's climate, soil, watershed, flora and fauna. My analysis therefore includes the ideas of Africans who witnessed many of the changes, as well as botanists, soil scientists, biogeographers and foresters who consider ecological transformations in East Africa.(3)

This analytical component is especially germane considering the extreme importance of Usambara's rapidly disappearing montane forests as core areas of biological diversity(4). Moreover, because the Usambara region comprises an elevation gradient encompassing several different agroecological zones common to the eastern African Rift Valley, results from my study provides development specialists with a clear understanding of both long-term and short-term historical (biological, intellectual, economic, political and physical) forces which shape East African landscapes.

Notes

(1) See especially Douglas Johnson and David Anderson eds., The Ecology of Survival: Case Studies from Northeast African History (Boulder, 1988); Charles Ambler, Kenyan Communities in the Age of Imperialism (New Haven, 1988); James Giblin, Trypanosomiasis Control in African History: An Evaded Issue?, Journal of African History 31 (1990), p. 59-80 and Famine and Social Change During the Transition to Colonial Rule in Northeastern Tanzania, 1880-1896, African Economic History 15 (1986), p. 85-105; Richard Waller, Ecology, Migration and Expansion in East Africa, African Affairs 84 (1985), p. 347-70.

(2) Kjekshus, Ecology, Control and Economic Development (London, 1977); John Iliffe, A Modern History of Tanganyika (Cambridge, 1979); Juhani Koponen, People and Production in Late Precolonial Tanzania, History and Structures (Uppsala, 1988).

(3) For studies of demographic and technical change across ecological gradients in East Africa, see: F.E. Bernard, David Campbell and Derrick Thom, Carrying Capacity of the Eastern Ecological Gradient of Kenya, National Geographic Research 5.4 (1989), p. 399-421; Pitblado, J. Roger, The North Mkata Plain, Tanzania: A Study of Land Capability and Land Tenure (Toronto, 1981).

(4) Foresters, botanists, ornithologists, ecologists, soil scientists, et al. consider Usambara's forests to be areas of great biological significance. For example, see vol. 19 of The African Journal of Ecology; or W.A. Rodgers and K.M. Homewood, Species Richness and Endemism in the Usambara Mountain Forests, Tanzania, Biological Journal of the Linnean Society 18 (1982), 197-242.