Browsing by Author "Unbushe, Dikaso"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    The Floristic Composition and Diversity of Wetland Vegetation in Tello Wereda in Kefa Zone, Southwest Ethiopia
    (Addis Ababa University, 2006-06) Unbushe, Dikaso; Demissew, Sebsebe (professor); Woldu, Zerihun (Professor)
    The present study was carried out in Kaffa Zone in general and Tello Wereda in particular, southwest Ethiopia. The study in wetland vegetation of the area was conducted between October 2005 and June 2006. The vegetation and environmental data were collected from 88 quadrats (during wet season) and 77 quadrats (during dry season) from the six study sites. The Purpose of the study was to investigate floristic composition and diversity of wetland vegetation in the area. The major issues addressed include floristic diversity, vegetation description, community type identification, site diversity, measurement of aboveground biomass and wetland plant inventory. During the study, the percentage cover abundance of each species was estimated and later converted into modified Braun-Blanquet 1-9 scale. Clipping of all the aboveground vegetation was carried out in 1 m2 plot size, which is placed at the center of each 4 m2 quadrat, used for plant community description. Some environmental variables and disturbance scale was recorded for each site. A total of 69 and 56 plant species representing 28 and 27 families were identified during wet and dry seasons respectively. The families Cyperaceae, Poaceae and Lamiaceae were represented by the highest number of species. All the vegetation data were analyzed with SYNTAX-2000, computer program. Three and four reasonable plant community types were obtained and described. The resulting clusters were interpreted as community types and were given names after two dominant plant species. Shannon-wiener diversity index was employed to analyze species diversity in the plant community types and the study sites. The clusters of stands were found to show variation due to differences in altitude, moisture contents, and other site conditions. Recommendations for the sustainable utilization of the vegetation resources at the study sites are provided.
  • No Thumbnail Available
    Item
    Wetland Vegetation Composition and Ecology of Abaya and Chamo in Southern and Fincha'a Chomen and Dabus in Western Ethiopia
    (Addis Ababa, Ethiopia, 2013-05) Unbushe, Dikaso; Woldu, Zerihun (Professor)
    Wetland Vegetations ofChamo and Abaya Lakes in the sOllthern and Fincha 'a-Chomen and Dabus marshes in western Ethiopia were stlldied 10 determine floristic composition. I'egetotion ecology. plant community types and to identify environmental factors significantl), influencing the distriblltion of plant species and community types. A total of 339 relevr}s were laid along transects that were set up preferentially across areas where there were rapid changes in vegetalion or marked environmental gradients to collect data on estimate of percentage aerial cover of planl species and environmental variables. A total of 302 plant species belonging to 194 genera and 72 families were identified. The most dominant fap/ilies in all the sites were Asteraceae, Poaceae. Cyperaceae and Fabaceae. Multivariate data analyses were performed using appropriate packages in R version 2.14.0. Vegef(ltion data were analyzed by agglomerative hierarchical cluster analysis IIsing similarity ratio as a resembl{/nce index and Ward 's linkage method. Canonical Correspondence Analysis (eCA) was used to explore the relationship between the species composition and environmemal variables. The environmental data to be included in the CCA were determ ined using stepwise backward (md fonvard selection of variables by ANOVA lest. Statistical measurement regarding species diversity, richness and evenness of the plant community types was carried 0 1/1 by /Ising Shannon-Wiener (1949) diversity indices. Sample-based raref action curves were computed in the program EstimateS (Colwell. 2005) 10 estimare and compare species richness across sites of different sizes. Comparison of the floristic diversity of the wetlands showed that Dab/ls marsh had the highest alpha diversity. From all the study sites, relmively the highest number of plam community types was recorded f rom wetlands of Lake Abaya during both seasons. The most important factors influencing the plant species composition and pattern of wetland plant communities were drainage. water depth. land use, slope. altitude and hydrogeomorphology (in wetlands of ulke Abaya) and water depth. disturbance alld hydrogeomorphology (in wetlands of Lake Chamo). All of the measured faCial'S had significanl role in Dablls and Finclla 'o-Chomen marshes. Therefore, these should be considered in I ll/lire f1I(magemenl and prorection under the circumstance 01 climate chOflge and human activities.