Coleopteran diversity and abundance in different habitats near Kihansi waterfall, in the Udzungwa Mountains, Tanzania

Coleoptera diversity at the family level was investigated along the Kihansi gorge near a 700 m high waterfall system which will be taken to hydropower use, and the current river flow will be diverted due to dam construction. The coleopteran communities of three micro-habitats: spray zone, forest site and riverine site were compared by sweepnetting and pitfall trap methods. The highest Coleopteran family level diversity was found in the spray zone where the Shannon–Weaver index of diversity was 0.71 (forest site 0.31; riverine site 0.50). Coleopterans were most abundant in the forest site where 44% of all sampled individuals were found (spray zone 31%; riverine site 23%). Most of less frequently recorded families were found in the spray zone. Coleoptera families were found to be unequally partitioned in all three micro-habitats. The highest percentage similarity index (85%) was found between forest and riverine sites (spray/forest 76%; spray/riverine 79%). Distributions of abundances of coleopteran families were significantly different between all studied habitats. The study revealed that the spray generated by the waterfall provide a special micro-habitat for Coleoptera. It is suggested that conservation efforts and monitoring in the study area using selected taxonomic indicator Coleopteran groups should be carried out in order to help to adjust mitigation measures

Arthropod diversity and abundance along the Kihansi Gorge (Kihansi River) in the Southern Udzungwa Mountains, Tanzania

Arthropod diversity and abundance at the order level was investigated along the Kihansi Gorge in the southern Udzungwa Mountains between June and August 1997 by using sweep netting, timed Lepidoptera counts, malaise-traps, solar powered light-¬traps, baited pitfall-traps, sticky-traps and baited butterfly traps. The study was undertaken to predict the possible effects of damming the Kihansi River above the fierce waterfall in the gorge. The gorge was divided into four micro-habitats, two of which are affected by waterfall spray (open spray, forest spray), and two of which were not affected directly by the waterfall (forest and riverine sites). The highest arthropod diversity was found in the forest spray, whereas the open spray contained the least. The forest spray area harboured the rarest arthropod orders. Arthropods are most abundant in the riverine site where 31 % of all sampled arthropods were recorded. The forest spray channel, forest site and open spray channel follow with 28 %, 23 % and 18 % of the sample respectively. It is suggested that the Mhalala Stream should be diverted to the gorge to replace the dammed Kihansi River. This would maintain at least partially the extraordinary micro-climate of the gorge and possibly retain the specialised arthropod community. Journal of East African Natural History Vol. 87 (1&2) 1998: pp. 233-24

Human activities threatening the biodiversity of the Uzungwa Scarp Forest Reserve, Tanzania

Studies of human activities in the Uzungwa Scarp Forest Reserve, Udzungwa Mountains, were conducted in March-April and September 1997, in the western and southern parts of the forest. Different human activities, such as timber and pole cutting and withies harvesting, as well as the collection of non-timber forest products were recorded. Footpaths in the forest interior, past settlements and encroached areas were identified, as well as evidence of poaching. Due to the human activities, some timber species, for example Ocotea usambarensis, Milicia excelsa and Afzelia quanzensis are almost exhausted. It was established that the main cause of the pressure in the reserve is the lack of alternative sources of forest products and other income generating activities. It is suggested that the people living around the reserve should be allowed traditional forest product uses under agreed regulations. Agroforestry involving planting of some desirable indigenous trees and the domestication of wild fruit tree species is also recommended. Other income generating activities should be encouraged. This is likely to reduce the pressure on the natural forest, thus contributing to biodiversity conservation. Journal of East African Natural History Vol. 87 (1&2) 1998: pp. 319-32

Woodfuel consuption and its potentioal effects on the environment in Misungwi district, Mwanza region

This study was conducted in Misungwi Ward, Misungwi District to determine woodfuel consumption trends and its potential effects to the environment. Specifically, the study aimed at examining the current status of wood fuel consumption in the study area, identifying the effects on the environment as a result of wood fuel consumption and assessing the effectiveness of measures taken to enhance sustainability offorest resources in the study area. Data were collected using questionnaire survey, interview with key informants and documentary review. Descriptive statistics, regression model and content analysis were used to analyze the collected data. The findings of this study indicate that, woodfuel is the main source of energy whereas almost 97% of respondents use woodfuel for cooking. Annual woodfuel consumption in the selected villages was 18525 m3 and per capita consumption was 2.5 m3 m. Household size was noted to have influenced the woodfuel consumption at the household level. Results of this study also indicate that the minimum time spent by the respondents was 0.5 hour and maximum time was 3 hours per one trip. In addition, 0.5 kilometer was a minimum distance and the maximum distance was 5 kilometers covered per trip. This implies that, 16% of the production time is spent on firewood collection or looking for charcoal and hence reduce the time for production and also affects the time of children going to school. Effects of woodfuel consumption were reported to have accelerated deforestation, land degradation and climate change. It is therefore recommended that concerted efforts should be put in place as among the many effective mechanisms for ensuring sustainable energy supply in the area. Among the initiatives to be carried out may include diversification of source of energy, intensifying agroforestry farming system and provision of environmental education.Prin

Tanzania planners' handbook : a guide for development planning

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