South-eastern Tanzania Research Articles

Soils and vegetation of Angai forest: ecological insights from a participatory survey in South Eastern Tanzania

AbstractSoils and vegetation of a woodland in South Eastern Tanzania were studied in support of a project fostering community participation in the management of a proposed forest reserve. In nine sites within an area of 500 km2, soils were characterized, frequency of occurrence of woody species was assessed and diameter at breast height of timber species recorded. Villagers identified 133 species of which only 56% were scientifically identified. However, as ordination axes derived from the complete data set were highly correlated with those derived from the restricted data set, the latter could be used. On the undulating plains, deep, sandy soils (Hypoluvic Arenosols, Profondic and Arenic Luvisols) occurred low in organic carbon, exchangeable bases and extractable aluminium content. Most common canopy species were Brachystegia spiciformis/B. boehmii and Pterocarpus angolensis. On the dissected plains on shallow, clayey soils (Leptic Cambisols) with higher organic carbon, exchangeable bases and extractable aluminium content, Acacia nigrescens and Markhamia spp. were the most common tree species. On deeper, fertile clayey soils (Profondic Lixisols and Chromic Phaeozems) vegetation consisted of species found in the two vegetation groups. Pterocarpus angolensis and Pericopsis angolensis were the only valuable timber species commonly found, most frequently on the undulating plains. As soils of this area are unfavourable for agriculture, it seems sensible to set this area aside as a forest reserve.

Storms and tsunamis: evidence of event sedimentation in the Late Jurassic Tendaguru Beds of southeastern Tanzania

In Late Jurassic shallow marine siliciclastic sediments of the dinosaur-bearing Tendaguru Beds from the Mandawa Basin of southeastern Tanzania we identified several event deposits. Based on an analysis of their sedimentological and palaeontological features, a storm-induced origin can be assumed for the majority of these deposits. This interpretation is in agreement with the regional palaeogeography and palaeoclimatological data, and is further supported by the widespread evidence of Late Jurassic storm-controlled sedimentation in adjacent basins along the East African margin. A particularly striking feature is a laterally extensive, conglomeratic bed with gravel components up to 30 cm in diameter, and megaripples indicating southward transport directions. The troughs between ripples are filled by cross-bedded fine-grained sandstones and siltsones with inferred transport directions to the north. Giant bedforms, a mixture of clasts of marine and continental origin, and evidence of opposite current directions suggest that this chaotically deposited sediment may have formed from a tsunami. Within the available time resolution this event is synchronous with the Morokweng impact structure in South Africa. However, because of the considerable distance of Morokweng from the Jurassic sea, direct links between both events cannot be established. Alternative mechanisms such as a landslide-generated tsunami are plausible, but not yet supported by geophysical data.

Mr Napite's botanical knowledge: bridging farmers' and scientists' insights during participatory research

When farmers and scientists engage in participatory research, differences in their knowledge systems ought to be taken into account. Mr Napite is a farmer and plant expert with whom we studied relationships between soil fertility and fallow vegetation on the Makonde plateau in South Eastern Tanzania. Though his broad and detailed botanical knowledge is recognised by other local experts, this does not provide him any particular social status. Although he received extensive formal training, his botanical knowledge draws largely on personal and traditional concepts. Clear morphological characteristics, other than the reproductive related organs, are the key features he uses for identifying and classifying plants. His knowledge of plant species and their ecology is of comparable complexity with that of scientific knowledge. Though this is intricately linked to cultural aspects, this study illustrates that it is possible to bridge farmers' and scientists' insights during participatory research. (Indilinga: African Journal of Indigenous Knowledge Systems: 2002 2(2): 45-58)

An estimation of the entomological inoculation rate for Ifakara: a semi-urban area in a region of intense malaria transmission in Tanzania.

An entomological study on vectors of malaria and their relative contribution to Plasmodium falciparum transmission in the semi-urban area of Ifakara, south-eastern Tanzania, was conducted. A total of 32 houses were randomly sampled from the area and light trap catches (LTC) performed in one room in each house every 2 weeks for 1 year. A total of 147 448 mosquitoes were caught from 789 LTC; 26 134 Anopheles gambiae s.l., 615 A. funestus, 718 other anophelines and 119 981 culicines. More than 60% of the total A. gambiae s.l. were found in five (0.6%) LTCs, with a maximum of 5889 caught in a single trap. Of 505 A. gambiae s.l. speciated by polymerase chain reaction, 91.5% were found to be A. arabiensis. Plasmodium falciparum sporozoite enzyme-linked immunosorbent assay tests were performed on 10 108 anopheles mosquitoes and 39 (0.38%) were positive. Entomological inoculation rate (EIR) estimates were generated using a standard method and an alternative method that allows the calculation of confidence intervals based on a negative binomial distribution of sporozoite positive mosquitoes. Overall EIR estimates were similar; 31 vs. 29 [95% confidence interval (CI): 19, 44] infectious bites per annum, respectively. The EIR ranged from 4 (95% CI: 1, 17) in the cool season to 108 (95% CI: 69, 170) in the wet season and from 54 (95% CI: 30, 97) in the east of the town to 15 (95% CI: 8, 30) in the town centre. These estimates show large variations over short distances in time and space. They are all markedly lower than those reported from nearby rural areas and for other parts of Tanzania.

People and protected areas: a study of local perceptions of wildlife crop-damage conflict in an area bordering the Selous Game Reserve, Tanzania

This paper presents an analysis of perceived patterns of wildlife crop-damage in relation to an on-farm assessment of damage in an area bordering the Selous Game Reserve (SGR) in south-eastern Tanzania. Data from an attitudinal questionnaire survey of 202 households in four villages are used to examine local perceptions of wildlife crop-damage in terms of relative impact and which wildlife species were responsible. We explore the influence of wildlife crop-damage on attitudes to the adjacent game reserve. Data on the frequency of crop-damage events and estimated severity of impacts, recorded during a 6-month programme of crop-damage monitoring in one of the survey villages, are used to describe on-farm patterns of crop-damage. Comparison of the two data sets indicates a disjunction between the nature of the wildlife crop-damage conflict as perceived by local villagers, and as it actually occurs in the study area. This disjunction is discussed in relation to the effect of extreme damage events on local people's views, the opportunity costs involved in guarding farm plots against crop-damage, and the tenure arrangements for wildlife that define the relationship with the state wildlife management authority.

Altitudinal species turnover in southern Tanzania shown by anurans: Some zoogeographical considerations

A transect was used to investigate the pattern of altitudinal species turnover shown by the rich fauna of frogs and toads in southeastern Tanzania, and to compare the pattern with those shown by transects taken further south. The transect, taken from the Udzungwa range to the southeastern coast, was divided into 50 m intervals. As with the southern transects, there appears to be a major grouping into lowland and highland sets, with opposing and overlapping subtraction margins that form a replacement‐transition zone. A distributionally complex assemblage of species occurs in this zone. When a similarity value (the Dice‐Sørensen index, expressed as a percentage) taken between the montane ridge and lowland faunas was compared with those of the southern transects, a markedly higher species turnover (low similarity value) is shown in Tanzania. Both lowland and highland faunas have more species than equivalent faunas to the south; the highland fauna is particularly rich in genera not known to occur further south. Yet overall, the pattern of altitudinal turnover shown in the Tanzanian transect is in agreement with the pattern shown in the southern transects. The transects discussed in this paper, combined with other evidence, suggest a need for re‐evaluating the common practice of including all sub‐Saharan Africa in a single so‐called Afrotropical Region.

Vilimani: Labor Migration and Rural Change in Early Colonial Tanzania

Introduction: peasant & worker agency in Tanzanian history - Industrialisation & the labor question in German East Africa, 1885-1914 - Slavery & the genesis of colonial labor relations - Labor migration & the erosion of the plantation imperative - Environmental collapse, household disruption & rebellion in Rufiji district - An antidote to the plantation labor shortage? The peasant cotton campaign in southeastern Tanzania - Migrant labor & the shaping of plantation work culture - 'Wamekwenda Vilimani!': transformations in rural society - Epilogue

Changing land tenure regimes in a matrilineal village of South Eastern Tanzania Stephane Dondeyne Naliendele Agricultural Research Institute, Mtwara, Tanzania Els Vanthournout Centre For Africa Research, Catholic University Of Louvain, Leuven John A.R. Wembah-Rashid Rural Integrated Project Support Programme, Mtwara, Tanzania

Social and cultural factors governing access to land in a village of matrilineal peoples of South Eastern Tanzania were analysed through group interviews and the life stories of 13 women. Land has become scarce with increasing population density. Access to land is mainly obtained through family relations, where people from clans claiming first occupancy of the area have access to more and better land. When relatives cannot provide land, clan members or village government officials are approached. Although clan membership is still defined by maternal line of descent, inheritance happens according to a bilineal pattern and marriages tend to be patrilocal. Women and men have equal rights of ownership, but it is harder for women to keep control over their land when marriages are patrilocal. With the new land law, which recognizes customarily-obtained land as fully legal, jurisdiction over land is vested in the village government. This raises the concern that socio-economically weaker people may further lose control over land. However, the new land law could prove positive for sustainable land management by better securing land rights of better-off people. (Journal of Social Development in Africa: 2003 18 (1): 7-32)

Is sulphur acidifying cashew soils of South Eastern Tanzania?

Cashew nut, a major cash crop of Tanzania, is mainly produced in the South Eastern part of the country. Sulphur dust is widely used for controlling powdery mildew disease caused by Oidium anacardii Noack. This can cause acidification of soils and thus, may threaten the productivity of cashew and its intercrops. To assess the extent and magnitude of the current acidification, pH of topsoil (0–20 cm) and subsoil (20–40 cm) of 70 farmers’ cashew groves where sulphur had been applied for up to 12 years, was compared to 70 similar undusted groves. On average topsoil pH of sulphur dusted groves on the Makonde plateau was 0.2 U lower than of undusted groves; subsoil pH was 0.1 U lower. However, in 29% of the groves the difference in topsoil pH between dusted and undusted groves was between 0.5 and 0.9 U. For groves of the inland plains, no effect could be established. Soil pH on the Makonde plateau decreased with increasing number of years of sulphur use while it remained stable in the inland plains. Soils of the Makonde plateau have a high risk for acidifying to pH levels between 4.5 and 4.0 which could affect the cashew nut production and would be detrimental to intercrops such as sorghum, finger millet, and maize. This is due to the soils’ inherently low pH and low buffering capacity which is linked to their high sand content. Lime could be used to mitigate the effect of sulphur and can be obtained locally from fossil coral limestone, not exploited yet. Alternatively, the incidence of powdery mildew could be reduced by crop husbandry techniques or by using organic fungicides; the first alternative has the disadvantage of requiring farmers to understand aspects of the epidemiology, the second of being more costly and more toxic than sulphur and of requiring water for its application which is scarce on the Makonde plateau.

Medical syncretism with reference to malaria in a Tanzanian community

What happens when new health information is introduced into a community? We have explored this question in a semi-rural community of Southeastern Tanzania whose population has been in contact with biomedicine for many decades. With the example of malaria, we illustrate how biomedical knowledge transmitted in health messages coexists, interacts and merges with local pre-existing ideas and logics. The results are syncretic models, which may deviate considerably from what health promoters intended to transmit. Some of those may have implications for treatment of malaria, which may include delay in seeking treatment and non-compliance with therapy. Analysing this medical syncretism clearly demonstrates that even if comprehension of health messages is accurate, the way in which people interpret these messages may not be. Disentangling syncretic processes permits us to understand the dynamics of how information is processed by the recipients, and provides orientations for health promoters for adapting messages to the local context.

New records ofStaffia aenigmatica (Mammalia, Allotheria, Haramiyida) from the Upper Jurassic of Tendaguru in southeastern Tanzania, East Africa

New records ofStaffia aenigmatica (Mammalia, Allotheria, Haramiyida) from the Upper Jurassic of Tendaguru in southeastern Tanzania, East Africa

Africa's ‘Last Wilderness’: Reordering Space for Political and Economic Control in Colonial Tanzania

ABSTRACTFocusing on south-eastern Tanzania, this article explores the colonial state's spatial strategies for economic and political control of its citizenry and their concurrence with strategies to control and conserve nature. Analysing British colonial archival documents, it demonstrates that Africa's most famous wilderness, the Selous Game Reserve, is a product of colonisers' economic and political control schemes, not a vestigial pre-modern landscape. The analysis reveals that the control of nature was inseparable from the state's efforts to control African subjects (mostly Ngindo peasants) and ultimately to create a new kind of person: ‘civilised’, productive and surveillable. Control schemes had significant ecological consequences, specifically increasing elephant(Loxondata africana)populations and the creation of vast tracts of tsetse fly-infested bush. The result, sometimes unintended, but more often orchestrated, was the displacement of African land use and settlement and a new geography of society and nature. The article concludes that colonial efforts to reorder south-eastern Tanzania were fundamental to the process of modern nation-state building, a process that was propelled by a particular way of thinking about social order in visual terms.

Buffering capacity of cashew soils in South Eastern Tanzania

Buffering capacity of cashew soils in South Eastern Tanzania

Buffering capacity of cashew soils in South Eastern Tanzania

Abstract. Cashew soils of South Eastern Tanzania become acidified due to sulphur used for controlling powdery mildew disease (Oidium anacardii Noack). The buffering capacity of surface and subsurface horizons of 35 soil profiles of major cashew growing areas –‐ the Makonde plateau, its piedmont and inland plains –‐ was studied. The buffering capacity of surface and subsurface horizons was strongly correlated with clay content and weakly with organic carbon content. In addition, it was only weakly correlated with total exchangeable bases and available P of the surface horizon, but strongly with soil pH, base saturation and cation exchange capacity of the clay fraction of the subsurface horizon. Highly weathered sandy soils, dominant on the Makonde plateau and common on the Piedmont, had the lowest buffering capacity. Soils from the inland plains had better buffering capacities as they are generally more clayey or are less weathered. The risk of severe acidification and of a decline in productivity of cashew and of food crops is highest on the Makonde plateau. Further development and dissemination of methods which can reduce the use of sulphur are required.

Patterns of population subdivision, gene flow and genetic variability in the African wild dog (Lycaon pictus).

African wild dogs are large, highly mobile carnivores that are known to disperse over considerable distances and are rare throughout much of their geographical range. Consequently, genetic variation within and differentiation between geographically separated populations is predicted to be minimal. We determined the genetic diversity of mitochondrial DNA (mtDNA) control region sequences and microsatellite loci in seven populations of African wild dogs. Analysis of mtDNA nucleotide diversity suggests that, historically, wild dog populations have been small relative to other large carnivores. However, population declines due to recent habitat loss have not caused a dramatic reduction in genetic diversity. We found one historical and eight recent mtDNA genotypes in 280 individuals that defined two highly divergent clades. In contrast to a previous, more limited, mtDNA analysis, sequences from these clades are not geographically restricted to eastern or southern African populations. Rather, we found a large admixture zone spanning populations from Botswana, Zimbabwe and south-eastern Tanzania. Mitochondrial and microsatellite differentiation between populations was significant and unique mtDNA genotypes and alleles characterized the populations. However, gene flow estimates (Nm) based on microsatellite data were generally greater than one migrant per generation. In contrast, gene flow estimates based on the mtDNA control region were lower than expected given differences in the mode of inheritance of mitochondrial and nuclear markers which suggests a male bias in long-distance dispersal.

Diagnostic accuracy and case management of clinical malaria in the primary health services of a rural area in south-eastern Tanzania.

Malaria control continues to rely on the diagnosis and prompt treatment of both suspected and confirmed cases through the health care structures. In south-eastern Tanzania malaria is one of the leading causes of morbidity and mortality. The absence of microscopic examination in most of the health facilities implies that health workers must rely on clinical suspicion to identify the need of treatment for malaria. Of 1558 randomly selected paediatric consultations at peripheral health facilities throughout Kilombero District, 41.1% were diagnosed by the attending health worker as clinical malaria cases and 42.5% prescribed an antimalarial. According to our malaria case definition of fever or history of fever with asexual falciparum parasitaemia of any density, 25.5% of all children attending the health services had malaria. This yielded a sensitivity of 70.4% (IC95% = 65.9-74.8%) and a specificity of 68.9% (IC95% = 66.2-71.5%). Accordingly, 30.4% of confirmed cases left with no antimalarial treatment. Among malaria-diagnosed patients, 10% were underdosed and 10.5% were overdosed. In this area, as in many African rural areas, the low diagnostic accuracy may imply that the burden of malaria cases may be overestimated. Greater emphasis on the functioning and quality of basic health services in rural endemic areas is required if improved case management of malaria is to help roll back this scourge.

The emplacement age of gabbroic rocks and associated granitoids of the Liganga-Msanyo complex, south eastern Tanzania.

The Msanyo Gabbro and the associated Mdando granitoids, which intrude Paleoproterozoic high-grade metamorphic rocks of the Ubendian Belt in southern Tanzania, yield imprecise Sm-Nd whole rock isochron ages of 1608±134 Ma (e (Nd) = 2.1) and 1642±100 Ma (e (Nd) = 1.6), respectively. These ages are indistinguishable at the 95% confidence level, indicating that the two rock suites were intruded at the same time. A more precise estimate of the time of emplacement is provided by a 5-point mineral isochron age of 1505±42 obtained from one of the gabbro samples. Calculated initial e (Nd) values and mean crustal residence ages are similar for both rock suites and range from –0.7 to 1.5 and 1.7 to 1.9 Ga. Respectively. Initial Sr isotope ratios lie between 0.7032 and 0.7039 and these values are similar to those obtained in the mantle and the lower continental crust. The rather evolved Nd isotope systematics, combined with the relatively non-radiogenic Sr isotopic signature, suggest that both suites cystallised from mantle-derived magma that had assimilated a significant amount of lower continental crustal material. Subsequent to their emplacement, the rocks experienced localised shearing and sericitisation during the Ukingan tectonic event. A Rb-Sr plagioclase-whole rock age dates this event at 1137±50 Ma. Tanzania Journal of Science Volume 27A (Special Issue) 2001, pp. 1-14

Africa's 'Last Wilderness': Reordering Space for Political and Economic Control in Colonial Tanzania

Focusing on south-eastern Tanzania, this article explores the colonial state's spatial strategies for economic and political control of its citizenry and their concurrence with strategies to control and conserve nature. Analysing British colonial archival documents, it demonstrates that Africa's most famous wilderness, the Selous Game Reserve, is a product of colonisers' economic and political control schemes, not a vestigial pre-modern landscape. The analysis reveals that the control of nature was inseparable from the state's efforts to control African subjects (mostly Ngindo peasants) and ultimately to create a new kind of person: ‘civilised’, productive and surveillable. Control schemes had significant ecological consequences, specifically increasing elephant (Loxondata africana) populations and the creation of vast tracts of tsetse fly-infested bush. The result, sometimes unintended, but more often orchestrated, was the displacement of African land use and settlement and a new geography of society and nature. The article concludes that colonial efforts to reorder south-eastern Tanzania were fundamental to the process of modern nation-state building, a process that was propelled by a particular way of thinking about social order in visual terms.

The paradox of the cost and affordability of traditional and government health services in Tanzania.

Since the introduction of user fee systems in the government health facilities of most African countries, which shifted part of the burden of financing health care onto the community, affordability of basic health care has been a much discussed topic. It is sometimes assumed that in areas where high levels of spending for traditional treatments are common, people would be able to pay for basic health care at governmental facilities, but may not be willing to do so. However, examining willingness to pay and ability to pay in the broader context of different types of illness and their treatment leads us to a very different conclusion. In the course of a medical-ethnographic study in south-eastern Tanzania, we found evidence that people may indeed be willing, but may nevertheless not be able, to pay for biomedical health care--even when they can afford costly traditional medicine. In this article, we suggest that the ability to pay for traditional treatment can differ from ability to pay for hospital attendance for two main reasons. First, many healers--in contrast to the hospital--offer alternatives to cash payments, such as compensation in kind or in work, or payment on a credit basis. Secondly, and more importantly, the activation of social networks for financial help is different for the two sectors. For the poor in particular, ability to pay for health care depends a great deal on contributions from relatives, neighbours and friends. The treatment of the 'personalistic' type of illness, which is carried out by a traditional healer, involves an extended kin-group, and there is high social pressure to comply with the requirements of the family elders, which may include providing financial support. In contrast, the costs for the treatment of 'normal' illnesses at the hospital are usually covered by the patient him/herself, or a small circle of relatives and friends.

Microhabitat preferences of Biomphalaria pfeifferi and Lymnaea natalensis in a natural and a man-made habitat in southeastern Tanzania.

Schistosoma mansoni is an important human parasitic disease which is widespread throughout Africa. As Biomphalaria pfeifferi snails act as intermediate host, knowledge of their population ecology is an essential prerequisite towards understanding disease transmission. We conducted a field study and assessed the density and microhabitat preferences of B.pfeifferi in a natural habitat which was a residual pool of a river. Repeated removal collecting revealed a density of 26.6 [95% confidence interval (CI): 24.9-28.3] snails/m2. B. pfeifferi showed microhabitat preferences for shallow water (depths: 0-4cm). They were found most abundantly close to the shoreline (distances: 0-40cm), and preferred either plant detritus or bedrock as substratum. Lymnaea natalensis, a snail which may act as a host for human Fasciola gigantica, also occurred in this habitat with a density of 34.0 (95% CI: 24.7-43.3) snails/m2, and preferred significantly different microhabitats when compared to B.pfeifferi. Microhabitat selection by these snail species was also investigated in a man-made habitat nearby, which consisted of a flat layer of concrete fixed on the riverbed, covered by algae. Here, B.pfeifferi showed no preference for locations close to the shoreline, probably because the habitat had a uniform depth. We conclude that repeated removal collecting in shallow habitats provides reliable estimates of snail densities and that habitat changes through constructions may create favourable microhabitats and contribute to additional disease transmission.