Browsing by Author "Soromessa, Teshome (PhD)"
Item Ecology, Carbon Stock and Formulation of Allometric Equation for Selected Tree and Shrub Species In Gerba Dima Forest, Southwestern Ethiopia(Addis Ababa University, 2018-06-02) Dibaba, Abyot; Soromessa, Teshome (PhD); Kelbessa, Ensermu (Professer)Ecology, Carbon Stock and Formulation of Allometric Equation for Selected Tree and Shrub Species in Gerba-Dima Forest, Southwestern Ethiopia Abyot Dibaba Hundie, Ph.D. Dissertation Addis Ababa University, 2018 This study was conducted in Gerba Dima Forest, South Western Ethiopia, to estimate the carbon stock, formulate allometric equations for selected tree and shrub species, determine species diversity, vegetation structure and regeneration status of woody species. A total of 90 sample plots were laid by employing stratified random sampling. Semi destructive method which involves climbing a tree was used to collect data to formulate tree allometry while destructive sampling was used to collect data for development of shrub allometric equation. A total of 180 plant species belonging to 145 genera, 69 families and comprising of 15 endemic species were recorded. Cluster analysis resulted in five different plant communities and this result was supported by the ordination result. RDA result showed altitude was the main environmental variable in determining the plant communities. Structural and regeneration status analysis of tree species revealed different population structures. The mean total carbon stock density of Gerba Dima forest was found to be 586.7 tons Carbon ha-1, out of which 243.8, 45.97, 0.03 and 292tons Carbon ha-1 were stored in the above ground, below ground, litter and as soil organic carbon, respectively. Seven allometric models were developed for 5 tree and 2 shrub species. The best-fit models were selected based on their adjusted r2, RMSE and AIC values. The study forest can play a significant role in biodiversity conservation as well as climate change mitigation since it harbors high species diversity, richness and can sink 2153 tons of Carbon dioxide. However, studies on the structure and regeneration of some woody species indicated that there are species that require urgent conservation measures. Sound management and monitoring, as well as maintenance of biodiversity, cultural and economic values of the forest require conservation activities that promote sustainable uses of the forest and its products.Item the Ecology, Carbon Stock, Bee Forage Diversity in a Moist Afromontane Forest of Gesha and Sayilem Districts in Kaffa Zone, South West Ethiopia(Addis Ababa University, 2018-04-01) Addi, Admassu; Demissew, Sebsebe (Professer); Soromessa, Teshome (PhD)The study was conducted at Gesha and Sayilem districts of the Kaffa Zone, with the objective of documenting the floristic compositions, determining the carbon stock and bee forage diversityof the area.Stratified random sampling technique was followed to establish plot sizes of 25 X 25m. A total of 90 plots were used to collect vegetation and carbon data.The plant community classification was performed using R-software packages.Species diversity and evenness were evaluated using the Shannon diversity and evenness indices respectively.The study revealed that the study area composed of 300 species that belong to 239 genera in 96 families. Asteraceae was the most abundant family followed by Fabaceae, Acanthaceae, Poaceae, Rubiaceae and Euphorbiaceae. Five plant community types were identified and these were Ilex mitis-Syzygium guineense,Pouteria adolfi-friederici-Schefflera abyssinica, Millettia ferruginea-Sapium ellipticum, Arundinaria alpina and Schefflera volkensii-Masea-lanceolata community types.Among the community types,Pouteria adolfi-friedericii–Syzygium guineense community was the most diverse and whereas Arundinaria alpina community was the least diverse community. CCA of vegetaion data indicated that altitude, disturbance,slope, phosphorus and EC were the environmental factors that significantly influence of the plant communities.The structures of woody plant species of the forest showed five general population patterns (inverted J-shape, Gauss type, U-shaped, J-shape and irregular patterns and unknown pattern). The mean total carbon stock density of Gesha-Sayilem forest was found to be 362.04tons of carbon per hectareout ofwhich168.05,32.8, 1.27, 23.8 and 136.8 ton ha-1 were stored in the above ground,below ground,litter, deadwood and in soil organic carbon respectively. The analysis of allometric equation for different woody species indicated that the developed model comprising of DBH and wood density are the reliable model for estimating the above ground biomass for the study species.The assessment of bee forage based on field observation, pollen analysis and key informant interview indicatedthat 79 bee forages were identified of which Schefflera abyssinica,Croton macrostchyus and Vernonia amaygdalina are the the major source of monofloral honey in the area.The high dependency of local communities on the forest resources are affecting the plant biodivresrity and honey production. Thus conservation of the forest through introduction of sustainable forest management interventions including REDD+) seems an appropriate action.Item Floristic Composition ; Structure and Regeneration Status of Plant Species In Sanka Meda Forest; Guna Distrct Arsi Zone of Oromia Region Southeast Etoiopia(Addis Ababa University, 2010-06) Bantiwalu, Shambel; Kelbessa, Ensermu (Professor); Soromessa, Teshome (PhD)This study was conducted on Sanka Meda Forest in Guna district, Arsi Zone, Oromia National Region in southeast Ethiopia, which is a dry everygreen afromontane type of forest. The objective of the study was to assess floristic composition, vegetation structure, regeneration pattern and to make a phytogeographical comparison of the forest under study with some similar forests in Ethiopia. Systematic sampling method was used to collect vegetation data from seventy 20m x 20m sapling plots for woody species and five 2m x 2m subplots with in each main plot for herbaceous plants. The sampling plots were placed at every 200 m intervals along the nine transect lines laid at 400 m a part. The floristic composition and population structure data for woody species, DBH > 7cm and height > 2m, sampling (DBH < 7cm and 1 – 2m height) and all seedlings with a hight < 1m and their regeneration status were recorded in each plot. The vegetation classification was performed using PC – ORD software package. The quantitative species diversity, richness and evenness were computed to describe plant diversity in each community type. Species abundance, cover, and environmental variables (altitude, aspect) were recorded in each sampling plot. A total of 139 vascular plants and a lichen species belonging to 118 genera 63 families were identified. The Asteraceae family had the highest number of species with 21 species and 14 genera followed by Lamiaceae with 10 species and 8 genera. Four plant community types: Croton macrostachyus-Lepidotrichilia volkensii, Maytenus undata, Juniperus procera and Osyris quadripartita-Budleja davidii were recognized. Jaccard’s similarity coefficients were below 0.5 for all communities, indicating the prevalance of low similarities among the communities. Thus, all the communities identified are important interms of floristic diversity and sensitive from conservation point of view.Woody species densities for mature individuals were 1060.71 stems ha-1, 416.50 stems ha-1 for saplings and 734.64 stems ha-1 for seedlings. The basal area of the forest was 34.70m2 ha-1. The floristic composition species were priorized for conservation using population structure, important value index and rejuvenation as criteria. The population structure and their regeneration behavior in the forest revealed that there is a need for conservation priority for woody plant species with poor regeneration status. The prevailing of strong anthropogenic disturbances in the area implies the need for its immediate conservation action in order to ensure the sustainable utilization of the forest. Keywords /Phrases: Afromontane forest, floristic composition, plant community, population structure, phytogeographical comparison, regenerationItem Floristic Composition and Diversity Analysis of Vegetation at Aba Asrat Monastery Forest, East Gojjam, Ethiopia(Addis Ababa University, 2013-06) Bayeh, Gojjam; Kelbessa, Ensermu (Professor); Soromessa, Teshome (PhD)The study was conduct at Aba Asrat Monastery Forest in Debre Markos District, East Gojam Zone, Amahara Region, Northwestern Ethiopia. The objective of this study was to determine the floristic composition, plant community and regeneration status of the forest .Sixty two quadrates of 10mx10m (100m2) were laid along ten lines transects for vegetation data collection. In addition 1mx1m subplots wereliad with in the main plot to sample herbaceous plants. A total of 120 plant species in 96 genera and 53 families were identifeied. Family Asteraceae had eleven (9.17%) species followed by Fabaceae nine (7.5%) species, Poaceae six (5%) species and Lamiaceae five (4.17%) species. Vegetation classification following R 2.11.1 software package resulted in five communities namely: Rosa abysinica_Acacia pilispina Community type,Urera hypselodendron-Phytolacca dodeccandra community type,Allophylus abysinicus-Cluita abysinica community type, Acanthus pubescens-Combretum molle community type and Croton macrostachyus-Pavetta abysinica community type. Sorensen’s similarity analysis among the communities revealed that community type 1 and 5 have the highest similarity (66%) followed by community type 3 and 5 which exhibited 57% similarity. From twelve representative woody species a total of 230 seedlings/ha, 184 saplings/ha and 63/ha mature individuals/ha were counted in the sample plots. Two population distribution patterns were revealed i.e. Inverted J -shape and bell-shaped. Moreover, there were more seedlings than saplings which could be attributed to factors that prevent the seedlings from reaching sapling stage. These factors may include expansion of farmlands, browsing by animals and prolonged dry period. On the other hand, some woody species lacked seedlings and saplings in the AAM. Based on the current study clear demarcation and raising awareness among the surrounding community are deemed necessary. Key words/Phrases: Aba Asrat Monastery, Endemic species, Floristic composition, Plant community and Regeneration