Browsing by Author "Kelbessa, Ensermu (Professor)"

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    Carbon Stock Estimation Along Altitudinal Gradient in Woodland Vegetation in Ilu Gelan District, West Shewa, Zone of Oromia Region, Central Ethiopia
    (Addis Ababa Universty, 2015-06) Abetu, Deresa; Kelbessa, Ensermu (Professor)
    Forests play a significant role in climate change mitigation by sequestering and storing carbon from the atmosphere which was released by anthropogenic factors. The overall objective of this study was to estimate Carbon stock of above and below ground biomass along altitudinal gradient in the woodland vegetation (Ilu Gelan District, Oromia Region). The study was used allometric models equation of Brown et al. (1989) for above ground and below ground biomass was calculated based on the ratio of below ground biomass to above ground biomass ratio of (MacDicken,1997) using systematic transects line sampling to estimate the above ground biomass data for different trees with diameter ≥5 cm found in the study area. Quadrants of 54 plots were established by dropping a distance of 25 m altitudinal gradient between each plot with square plots of 400 m2 (20 m x 20 m). Parameters such as the diameter at breast height (DBH) and height were used. A total of 86 woody species of 39 families with stem number of 4188 was collected and analyzed. The results of this study showed that the total mean carbon biomass in 54 plots of the study was 87.77 C t /ha for above ground biomass (AGB) and 17.5 C t/ha for below-ground biomass (BGB). In this woodland ecosystem, the total mean carbon stock of AGC was more important compared to the total carbon stock of BGC which was 41.25 t C /ha against 8.25 t C/ha respectively. Similarly, the average carbon stock of lower altitude was larger than that of the higher altitudinal gradient with the same pattern of AGB and BGB (183.23, 60.49C t C/ha) respectively. This result showed that the species density is larger at higher altitude when compared to the lower altitude because of different anthropogenic disturbances and threats in the study area. This research indicates that, this woodland vegetation holds large stores of carbon, yet uncertainty remains regarding their quantitative contribution to global carbon cycle. Key words: Above ground biomass, Altitudinal gradient, below ground biomass, Carbon stock, Mountain Dirki woodland.
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    Chromosome Study of Some Species of Commelina L. and Tradescantia L. (Commelinaceae) From Ethiopia
    (Addis Ababa University, 2012-03) Gebrekiristos, Samuel; Dagne, Kifle (PhD); Kelbessa, Ensermu (Professor)
    Karyotypes and nucleolar number of four species of the genus Commelina L. and two species of the genus Tradescantia L. (Commelinaceae) which were collected from different localities of central and south-western part of Ethiopia (Addis Ababa, Ginchi, Sebeta, Entoto and Jimma), were analysed. Somatic chromosomes were prepared from root tips that emerged from the nodes of stem cuttings that were made to stand submerged in water. The roots were pretreated in 8-hydroxyquinelin 3-5 hrs followed by fixation in 3:1 ethanol: acetic acid for 1-24 hrs at 4OC. Air-dry slides were prepared following cellulase and pectinase maceration at 37OC, the preparation was stained in Giemsa stain (PH 6.4), rinsed and mounted. Nucleoli were stained in silver nitrate solution. Chromosome numbers and Karyotype formula of the six species were found as C. africana (A.A) 2n=2x=30 (12m + 10sm + 8st), C. africana (Sebeta) 2n=2x=30 (14m + 10sm + 6st), C. benghalensis 2n=6x=66 (36m + 24sm + 6st), C. diffusa (Entoto) 2n=2x=30 (16m + 6sm + 8st), C. diffusa (Ginchi) 2n=66 (28m +26sm + 12st), C. diffusa (Jimma) 2n=2x=30 (10m + 8sm + 12st), C. subulata 2n=2x=30 (18m +10sm + 2st), T. zebrina 2n=2x=24 (4m + 6st + 14t), T. fluminensis (green) 2n=60 (8m + 6sm + 22st + 24t) and T. fluminensis (variegated) 2n=60. According to Stebbins karyotype asymmetry, the karyotypes of C.africana (A.A), C. diffusa (Entoto), C. subulata were 2A type, while that of C. africana (Sebeta), C. benghalensis and C. diffusa (Ginchi) were 2B type. 3A asymmetry type was obtained for C. diffusa (Jimma) and 3B asymmetry type was also found for T. zebrina and T. fluminensis (green). Karotypes of Tradescantia were found to be bi-modal, while it is monomodal for the Commelina species of the studied plant materials. Satellites were observed for species C. africana, C. diffusa and T. zebrina with variation in number ranging from 2 to 6. The maxiumum number of nucleoli observed varies from two to four for Commelina, while, it is three for Tradescantia. This study reported karyotype and nucleoli of the Ethiopian Commelinaceae for the first time. The current investigation can be considered as an additional karyotype data to the earlier meiosis report for Ethiopian materials. Key words: Commelina L., Ethiopia, Karyotype, Nucleoli, Satellite, Tradescantia L.,
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    Diversity and Ecological Analysis of Vascular Epiphytes in Gera Wild Coffee Forest, Jimma Zone of Oromia Regional State, Ethiopia
    (Addis Ababa,University, 2013-07) Tafesse, Bedilu; Kelbessa, Ensermu (Professor)
    The diver,sifY (llId ecological allaly:,'i:,' of 1'(M'Clilar epiphyte:,' was s flldied ill Cera Foresl in southwesfem Erhiopia af a/fillides befweell 1600 alld 2400 III a .. d . A loral area of 4.5 ha was surveyed ill coffee alld 1101I-coffee forest vegetafion. Fifty salllplillg plofs, each 30 III X 30 III (900 11/ 1), were used for the purpose of daw col/eeliOIl. A lotal of 59 species of vascular epiphyte:,' were recorded alld of which 34(59%) were holo ep'j)hyte:", 111'0 (4%) were hemi epiphyles alld 22 (37%) :,pecies were accidenwl vascular epiphytes. To :,·tudy Ille allitlldinal dislribulioll of vascular epiphYles. altitudes were classified into higher >2000, //Iiddle 1800- 2000 and Jower 1600- 1800//1 a.s.1. accordillg to Shanl/otl- Wiener Index (HI = 3.411) of tJ. alpha dil'ersily file epiphyte COllll111111ily ill the sllldy area is medium. There was a stjlistically sigmjicalll dljerence belween host bark Iype and epiphyte richlless as determined by Olle~way ANOVA (F(3, 91) "'" 21 .833, p = 0.001). The p(w- hoc fesl shows Ihal there is sigllificallf difference of vascular epiphyles riclme.\'S be/lt"eell Slllooll1 bark willi rough jlack and corky bark (P =0,00 I < 0.05), as we/J as rough alld cork bark (p =0.43 <0.05). Howevefjbelll'eetl rough alld j lack bark (p = 0,753 > 0.05) tmd belll'eenjlack alld corky bark (p = 0.854 > 0.05) 110 SigllijiC(lIIt differellce of epipllyte abwu/allce was observed. ROllgh bark had 38%, corky, 26%. jlack, 25%, alld ollly 11% ~'ascular epiphyles abundance occurred oll :"l1/ooth bark. 71te regressioll correlation test, (lr :: 0,773. p "" 0.0001 < 0.05), showed Ihal the /llIll/ ber of species of vascular epiphytes and hosl DBH size are positively correlaled. The regression correlalioll tel'l (If = 0.28, p == 0.0001 < 0.05), showed Illat tlte /lllIlIber of specie:,' ami hosllree height positively correlated. The host Iree preference of vascular epiphyles was recorded for ollly Villaria volkensii species hosted 0 11 Sy=ygiulII guilleellse Irees. The result of similarily mwlysis indicated Ihal Cera Forest showed Ihe higllesl I'ascular epiphytic simi/aril)' (0.35) lI'illl Yayu Fore:,'t alld shared Ihe least l-'CIscular epiphYlic similarity (0.295) lI'ith Haremw Foresl. It was concluded thai horizOlltal siems and branches, large and rough. jlack alld corky bark type Irees are more s uitable for vaSCII/ar epiphytes seedling allachmelllS alld growth. COllsen'atiol1 and prolectioll of Ihese phorophytes are importalll for the surivivlli of vascular epiphytes ami increase Ilteir ecological importtlllce.
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    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, regeneration
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    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
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    Floristic Composition and Diversity Analysis of Vegetation of Awash Melka Kunture Prehistoric Archaeological Site, Ethiopia
    (Addis Ababa University, 2012) Fekadu, Mekbib; Kelbessa, Ensermu (Professor); Awas, Tesfaye (PhD)
    The study was conducted at Awash Melka Kunture Prehistoric Archaeological Site (AMKPAS), in Awash Melka District, Oromia National Regional State, Ethiopia. This study presents the floristic composition, plant community, regeneration status of the area, and recommends further conservation methods. Sixty quadrats of 10 m x 10 m (100 m2) were laid along ten line transects for vegetation data collection. In addition, 1 m x 1 m subplots were laid within the main plot to sample herbaceous plants. A total of 139 plant species in 114 genera and 45 families were identified. Family Poaceae had 24 (14.27%) species followed by Fabaceae 23 (16.55%) species, Asteraceae 16 (11.51) species and Lamiaceae nine (6.47%) species. Out of the 139 plant species collected from the area six species and one subspecies are endemic to Ethiopia. Vegetation classification following R-2.11.1 software package resulted in five communities, namely, Ocimum lamiifolium - Rhus natalensis, Grewia ferruginea – Acacia abyssinica, Acacia seyal - Jasminum grandiflorum, Carissa spinarum - Acacia persiciflora and Acacia lahai - Euclea racemosa. Sorensen’s similarity among the communities revealed that communities 1 and 5 have the highest similarity (71%) followed by communities 1 and 4, and 4 and 5, both exhibited 69% similarity. From nine selected woody species, a total of 183.9 seedlings/ha, 154.79 saplings/ha and 54.38 mature individuals/ha were counted in the sample plots. The study revealed the occurrence of small sized individuals in the study site. Two population distribution patterns were revealed i.e. inverted J 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 AMKPAS. Based on the current study clear demarcation and raising awareness among the surrounding community is deemed necessary. Key words/Phrases: Awash Melka Kunture, Community similarity, Floristic composition, Plant community, and Regeneration
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    Floristic Composition and Diversity of Herbaceous Flowering Plants in Menagesha Suba State Forest, Oromia Region, Ethiopia
    (Addis Ababa University, 2011-06) Etefa, Lema; Kelbessa, Ensermu (Professor)
    The current study was conducted on the dry evergreen montane forest known as Menagesha Suba State Forest, which is situated 30 km away in the south west of Addis Ababa in Oromia National Regional State. The study mainly focuses on the assessment of the diversity of herbaceous flowering plants in the Forest under study. Seventy five quadrats/plots of 20 m x 20 m (400 m2) were laid down along the transect line and the required vegetation data were collected and analyzed. A total of 128 species representing 102 genera and 44 families of herbaceous flowering plants were recorded from the Forest. Asteraceae is the highest in species diversity and richness (24%) followed by Poaceae (8.6%) and Apiaceae (4.7%) respectively. Of the 128 species of herbaceous flowering plants about 14 (11%) are endemic to Ethiopia of which four of them are threatened as vulnerable and endangered. Vegetation classification was done with PC-ORD computer software package which produced five plant communities. Key words/Phrases: Herbaceous Flowering Plant, Menagesha Suba State Forest, diversity
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    Floristic Composition and Structural Analysis of Wooddland Vegetation in Ilu Gelan District, West Shewa Zone of Oromia Region, Central Ethiopia
    (Addis Ababa Universty, 2015-06) Tadesse, Zerihun; Kelbessa, Ensermu (Professor)
    This study was conducted on Dirki and Jato woodland in Ilu Gelan District, West Shewa Zone of Oromia Region, 195 km west of Addis Ababa, to identify floristic composition, structure and community types of the vegetation. Systematic sampling method was used to collect vegetation data from 54 (20 m x 20 m). To collect data for herbaceous plants, five 1 m x 1 m subplots were laid in each of the main plot, where four were at the corners and one at the center. Diameter at breast height was measured for woody species taller than 2 m while height and cover/abundance values were visually estimated. Shannon - Wiener Diversity Index was used to calculate species diversity, richness and evenness whereas Soresen’s Similarity ratio was used to measure similarity between the vegetation and four other related woodlands. Two hundred and thirteen species were recorded from the sample plots, where Fabaceae, Asteraceae and Poaceae were the most dominant families with 23, 22 and 12 species respectively. Eleven endemic and two near endemic species were recorded from the study area. Based on IUCN Red Data List, nine species were least concern, three were near threatened while one was vulnerable. Three plant community types were recognized from the study area. Total density and basal area calculated for woody species were 5,145.83 individuals ha-1 and 18.96 m2 ha-1 respectively. Population structure and regeneration status of selected woody species were assessed and results revealed that some species had regeneration problems and need management measures. Key words/phrases: Endemic, floristic composition, plant community type, structural analysis, Woodland Vegetation.
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    Impact of Climate and Land use on Plant Diversity, Carbon Storage and Leaf Area Index in the Jimma Highlands, Southwest Ethiopia
    (Addis Ababa Universty, 2016-06) Denu, Dereje; Kelbessa, Ensermu (Professor)
    The study aimed at the impact of climate and land use on plant diversity, live carbon storage (AGC) and leaf area index (LAI) in the Jimma Highlands of Ethiopia. Data on woody species were collected from 155; 20 m × 20 m sample plots which were subdivided into 2 m×2 m subplots for herbaceous species inventory. Thirty-one plots of one ha each were randomly distributed along a study transect for -measuring diameter at breast height for all woody species with DBH 10 cm. Upward hemispherical images of the forest/tree canopy were taken at 12 points in the 20 m × 20 m plots established within each one hectare plot. Two SPOT5 satellite images (path 134 / row 133) captured simultaneously on 17th December and aerial photographs taken in October 2012 were used for LULC mapping. The transect was classified into five major land use types from SPOT5 images and aerial photography. Natural forest was further separated into the natural forest with coffee shrub/tree beneath and those with no coffee under the canopy based on field observation. Two hundred and eight-seven plant species belonging to 220 genera and 82 families were collected and identified. The highest plant species richness per hectare was recorded from woodland and the least was from the cropland. The highest mean abundance of tree species was recorded from the planation forest and the least was from the pasture. Mean annual temperature and soil pH have significantly explained the variation in herbaceous species richness; sand and clay particles significantly explained the variation in tree species richness. Species richness, abundance and diversity also vary along vertical stratification in semi-forest coffee (SFC) and degraded natural forest (DNF). The highest AGC storage was recorded from the plantation forests (152.25±24.98) followed by DNFs (82.03±32.08) and SFCs (61.52±24.98). Land use types showed significant mean difference in AGC and LAI. Tree species abundance and richness combined, have explained about 82% of the variation in AGC across the land use types. There was significant linear relationship between AGC storage and some climate variables such as mean annual temperature, mean annual rainfall and potential evapotranspiration; between AGC and some edaphic factors such as soil cation exchange, sand and pH. Basal area, richness of shrub, tree and entire plant species combined have significantly explained about 82% and 81% of the variations in LAI_true_v6 and LAI_true_v5 respectively. LAI_true_v6 explained about 75% of the variation in AGC. Mean annual temperature and annual temperature range significantly explained about 21% of the variation in LAI_V5. Climate change under the current and projected scenarios affected the distribution of five plant species across Ethiopia. In conclusion, plant richness, abundance, distribution, carbon storage and leaf area index are affected by land use and climate variables. Key words: Carbon storage, climate change, Jimma highlands, LAI, land use change, plant richness
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    A Study on Canopy Gap Regeneration at Gera Forest of Jimma Zone Oromia Regional State, Ethiopia.
    (Addis Ababa University,, 2013) Abebe, Arayaselassie; Kelbessa, Ensermu (Professor)
    Forest is a dynamic place where changes occur continuously and these changes bring about different structural changes in the forest stand. Change in the recruitment and forest community depends on the dynamics and formation of canopy gaps. Canopy gaps and their dynamics in regeneration were investigated in Gera Forest of Jimma Zone Oromia Regional State, located western of Ethiopia at an altitude range of 1600 2400 meter above sea level. In the Forest the main types of natural disturbance occurred through uprooting of trees and broken branch or crown. These causes are directly related with natural causes like thunder and wind. Prunus africana was found to be most affected in the disturbance, forming six gaps in the Forest. Including Prunus africana 13 species were found to be gap formers. The mean DBH of the gap formers is 48.33 cm2 and mean of the gaps formed became I 90. 83. Twenty eight species were investigated as gap filler species in the Forest. Among the gap fWers Millettia ferruginea was found to be in more gap areas than other species. Croton macrostachyus was the most dominant species that occurred in higher number (i.e. I I 8 individual/hectare) in the gap areas. The negative correlation between species density and gap area shows that both factors have low effect on gap regeneration and recruitment in Gera Forest. The replacement probability in the Forest is weak except Millettia ferruginea, Syzygium guineense and Prunus africana, all the rest of the gap formers are replaced by other nongapforming species. Dominant species in the Forest were not found being replaced by their own seedlings or saplings and among the ten woody dominant species only seven had sapling and five had seedling stages.