Browsing by Author "Woldu Zerihun (Professor)"
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Item Conservation of Brachylaena huillensis O.Hoffm (Asteraceae) in Dindili Forest Reserve, Morogoro, Tanzania(Addis Ababa University, 2006-07) Perfect Joseph; Woldu Zerihun (Professor); Asfaw Zemede (PhD)A flagship species is a species chosen to represent an environmental cause, such as an ecosystem in need of conservation, it is chosen for its vulnerability, attractiveness or distinctiveness in order to best engender support and acknowledgement from the public at large. Brachylaena huillensis O.Hoffm (Asteraceae) is a threatened economically important tree species commonly found in dry coastal forests of Tanzania and a potential flagship species in conservation of its habitat. The study was done around Dindili forest reserve, Fulwe village, Morogoro, to assess B. huillensis standing and harvested wood stocks, coppice regeneration, use, management and its flagship species potential in conserving its habitat. Data were collected using forest inventory, focus group discussion and quantitative ethnobotany (use values, direct matrix ranking, preference ranking and structured interview). The standing wood stock of B. huillensis, was found to be substantial as revealed by relatively high tree density (15 stems per/ ha), basal area (0.73m2/ha), volume (5.63m3/ha) and IVI (13.87). B. huillensis was found to be highly harvested as indicated by over one-third of previously standing wood stock already harvested. The observed preferential harvesting of female B. huillensis tree presents a serious ecological threat to its future successful reproduction. B. huillensis density distribution by dbh classes showed abnormal trend, which signify poor recruitment and regeneration. The results of coppice regeneration found B. huillensis to be a very poor resprouter. However, its regeneration from seed is promising in the forest reserve. The species (B. huillensis) was found to be known by 84% of respondents and used by 78% of them for different purposes. The species is intensively utilized for poles and posts as mentioned by 76% of respondents, its poles were claimed to be durable and extremely resistant to termites. Results of preference ranking showed that it is the most preferred species for building poles and the most sold tree species; it was also positioned second in carving use category. B. huillensis was found to be a useful multipurpose tree species as it was ranked second and fourth in direct matrix ranking and use values respectively. The ongoing Joint Forest Management (JFM) of the forest reserve does not show positive results, mainly due to lack of important socio-economic considerations during its inception. Frequent fires threaten the perpetuity of the studied coastal forest. Based on the developed criteria, B. huillensis was found to be an excellent flagship species in conservation of its habitat. Among others, the study recommends research on B.huillensis sex-ratio, restoration of its normal regeneration trend in the forest reserve and review of JFM.Item Diversity of Farmers’ Varieties (Landraces) of Cowpea (Vigna Unguiculata (L.) Walp., Fabaceae) In Wag-Himra and North Wollo Zones of Amhara Region, Ethiopia(Addis Ababa University, 2019-06-04) Gufuy Meresa; Asfaw Zemede (Professor); Woldu Zerihun (Professor)This study was conducted on cowpea (Vigna unguiculata (L.) Walp., Fabaceae) varieties identified by farmers of Wag-himra and North Wollo zones in Amhara Region of Ethiopia. The main objective of the study was to investigate on the diversity of cowpea landraces (farmers’ varieties) and to know the ethnobotanical values of the crop. A total of 168 informants (84 men and 84 women) comprising 72 general informants and 12 key informants per zone aged between 19 and 75 years were interviewed. The field data were collected by using purposive sampling and random simpling technique in farmers’ fields, threshing grounds, home gardens, stores and market places. Descriptive statistics, informant consensus, preference ranking, ANOVA (analysis of variance), Shannon- Wiener diversity index, post hoc test and t-test were employed for the analysis of the data by using R-software (R studio) v 3.2.2 and MS Excel spreadsheet 2016. Thirty six accessions were collected and classified under eleven farmer-named varieties. The Tepid sub-moist mid-highland (SM3) agroecological zone of Wag-himra had high varietal diversity (H’=0.978049) while the Cool sub-moist highland (SM4) zone of Wag-himra came up with the least varietal diversity (H’=0.593763). Famers grow cowpea on farm sizes ranging from 0.24 ha and 0.30 ha. Area covered by cowpea by agroecological strata and zone had statistically significant differences (p<0.05). In the study area cowpea is widely intercropped with sorghum and maize and in addition to that in Wag-himra agroecological zone most cowpea is sole-cropped in part due to the sandy soil.Item Diversity, Distribution and Potential values of Vegetables in Mgori Division, Singida-Tanzania(Addis Ababa University, 2004-07) JolIn Raymond; Asfaw Zemede (PhD); Woldu Zerihun (Professor)This study employed both ecological and ethnobotanical approaches to document information about the diversity, distribution and potential values of vegetable plant species at Mgori Division of Singida Rural District, in Central Tanzania. The plant species diversity and distribution in Mgori Forest Reserve (MOF) have been described. A total of 304 plant species were collected and identified representing 53 families. Of these 56 species belonging to 21 families were identified by the local people important for use as vegetables. This accounts for 18.4% of all the identified plant species in the area. About 35.7% of the plant species recognised as vegetables having medicinal values. Such plants with both food and medicinal values are called nutraceutical plants. It was therefore found out that, 90% % of these nutraceuticals are used as remedies of human ailments and only 5.3% are used for the treatment of animal diseases. Adansonia digifata, Solanlllll nigrulIl and Mukia lIladeraspatana are used for the treatment of both human and livestock ailments. Amaranthaceae, Euphorbiaceae and Tiliaceae each contributed 4% to the total vegetables. Of the identified vegetable plant species, 3.6% were trees, 8.9% were sillubs, 32% were climbers and 53.6% were herbs. Further analysis revealed that, plant species belonging to the Family Cucurbitaceae contributed more species for use as vegetables by the indigenous people accounting for 17.9% of the vegetable species in the area. Environmental factors such as % slope, altitude, and fire (the most promincnt disturbance in the area, especially during the dry season) were collccted. Plant species for both dry and wet seasons were classified into 4 and 5 community types respectively, using SYNTAX computer program. The vegetation results revealed instability of plant communities. Fire incidences in the area and the effect of climate were responsible for manifestation of two sets of communities. Thus, the dry season community types are the vegetation types of Mgori Forest Reserve. The distribution of plant species and sample plots in relation to environmental variables were subjected into analysis of variance (ANOVA). Species diversity, richness and evenness were generally found to be high in sample plots belonging to wet season community types and generally low in dly season community types. Plant species diversity and richness decreased with distance from the homesteads. The woodlands and shrub lands had high plant species than the grasslands. Drought and over-harvesting are repolied to be the main cause for the scarcity of some vegetable plant species. However, no vegetable plant species in the IUeN red list of threatened species was identified. A number of indigenous practices used by the local people have been documented. Most wild and cultivated vegetables were found to grow more on disturbed lands, such as farmlands, fallow lands and less in the natural forest. Only 39% of the identified vegetables in the area were found to grow in the natural forest. Their density and cover abundance values recorded higher during the wet season community types and lower in dry season, which means more of these vegetables are annuals. Their density and cover abundance values also decreased as one moved from the villages towards the forest. Recommendations towards the conservation of vegetable plant species in the area are put forward ..Item An Ecological Study of Vegetation Around Lake Abijata(Addis Ababa University, 2005-07) Regassa Tolcha; Bekele Tamrat (PhD); Woldu Zerihun (Professor)Ecological study of the vegetation around Lake Abijata was carried out within the principal objective of describing the plant communities of the study site. In order to determine the plant communities five transects were laid from the shoreline to the open land. Along the laid transects, different sized quadrats 1 m2 (for herbs), 25 m2 (for shrubs) and 100 m2 (for woody species) were systematically laid to collect floristic data following a 1-9 modified Braun Blanquet scale (van der Maarel, 1979). All together a total of 143 quadrats were sampled from the study site. Soil samples were taken from the depth of 0-20 cm using soil auger and analyzed for soil pH, electrical conductivity, cation exchange capacity, soil texture and bulk density. Data were analyzed using various multivariate methods, inter alia, TWINSPAN (Two way indicator species analysis), CCA (Canonical Correspondence Analysis) and DCA (Detrended Correspondence Analysis). A total of 97 plant species belonging to 28 families were identified. The TWINSPAN out put showed that there are 6 different plant communities. The distribution patterns of plant species in the study area shows horizontal stratification with the strata being dominated by its dominant species. The distribution patterns of the plant species in the area appears to be governed by soil as the most important environmental factors.