international journal of zambrut · gobelle valley is characterized by semi-arid climatic condition...
TRANSCRIPT
International Journal of Forestry & Plantation ISSN: 2656-6176, Volume 2, Issue 2, page 44 - 52
Zambrut
Zambrut.com. Publication date: December, 2019.
Mereba, F. L. & Chimdessa, M. 2019. Ecological Study of the Woody Vegetation of Gobelle Valley of
Babile Elephant Sanctuary (Studied in Oromia Regional ................
44
Ecological Study of the Woody
Vegetation of Gobelle Valley of
Babile Elephant Sanctuary
(Studied in Oromia Regional State, Eastern Ethiopia)
Firaol Legesse Mereba1 & Meseret Chimdessa
2
1Firaol Legesse Mereba &
2Meseret Chimdessa
1College of Agricultural and Environmental Sciences, School of Animal and Range Sciences,
Department of Range Ecology and Biodiversity, Haramaya University
P. O. Box. 138, Dire Dawa, Ethiopia 2Oromia Agricultural Research Institute, Fadis Agricultural Research Center
Livestock Research Process, Animal Feed Resource and Rangeland Management Research Team
P. O. Box. 904, Harar, Ethiopia
1. INTRODUCTION
Babile Elephant Sanctuary (BES) is one of the protected areas in the semi-arid region of eastern
Ethiopia. There are four drainage valleys (Fafem, Daketa, Erer and Gobelle) which extend
southwards through the sanctuary to join Wabi Shebelle River Basin (Anteneh et al., 2011). The
sanctuary was established to protect the only known population of the isolated and ecologically
distinct subspecies Loxodonta africana orleansi (Barnest et al., 1999). The most recent molecular
Abstract: An ecological study of the natural vegetation was carried out in Gobelle Valley of the
BES, to identify of woody species, and to analyze diversity, richness, evenness, population
structure, and regeneration status of woody species. Vegetation data were collected from 60
quadrats of 20 m x 20 m (400 m2) laid systematically at every 100 m along 3 transects.
Diameter at breast height (DBH), richness, evenness and density of woody species were
recorded. Shannon - Weiner Diversity Index was used to determine species diversity and
evenness. A total of 58 plant species in 36 genera and 18 families were identified in the study
area. The Shannon - Wiener Diversity index (H') and evenness values of Gobelle valley
vegetation were 3.05 and 0.75, respectively. The collected species were composed of 44.8 %
trees, and 55.2 % shrubs. Fabaceae was represented by the highest number of species 15 (26
%). A total basal area of 22.38 m2/ha, and a density of 34687 individuals ha-1 were calculated
for woody species (5159.6 trees and 29738.7 shrubs) individuals ha-1. The highest impact of
invasive species was imposed from Lantana camara which had a density of 1,828 individual’s
ha-1. Furthermore, 3 endemic species which are under the Red Data List of IUCN were also
identified and requires close attention to conserve them in situ. The existence of strong
anthropogenic disturbance in the sanctuary calls for an immediate intervention to conserve and
ensure sustainable biodiversity of the study area.
Keywords: Endemic species, Invasive species, Species diversity, Population structure.
International Journal of Forestry & Plantation ISSN: 2656-6176, Volume 2, Issue 2, page 44 - 52
Zambrut
Zambrut.com. Publication date: December, 2019.
Mereba, F. L. & Chimdessa, M. 2019. Ecological Study of the Woody Vegetation of Gobelle Valley of
Babile Elephant Sanctuary (Studied in Oromia Regional ................
45
analysis indicated that this ecologically isolated relic elephant population is Loxodonta africana
africana (Ishida et al., 2011; Anteneh et al., 2011). Study has shown that the home range of the
elephants has shrunk by about 65.5% since 1976 (Yirmed et al., 2006). This attributed to the mass
influx of a large number of farmers and their domestic stocks mainly from the eastern and northern
part of the sanctuary which directly contributed to declined in size and quality.
Previous studies by Demel (1995) in Daketa and Erer valley were investigated ecologically by
Anteneh et al. (2011), respectively. However, no ecological investigation has been conducted in
Gobelle valley, which is the main part of Babile Elephant Sanctuary inhabited by elephants. Thus,
this study was designed to carry out ecological investigation of Gobelle valley in BES to help design
management strategy.
2. MATERIALS AND METHODS
2.1. Description of the Study area
The study was conducted in the natural vegetation of Gobelle valley in Babile elephant
sanctuary (BES) of East Hararge zone, Oromia regional state, Ethiopia (Fig. 1). BES is found at
about 560km away from Addis Ababa to the East. It is delineated with coordinates of latitudes
08022'30" – 09000'30" N and longitudes 42001'10" – 43005'50" E and its elevations ranges between
850 and 1,785 m a.s.l. (EHPEDO, 2004).
Figure 1. Location of Babile Elephant Sanctuary.
2.2. Climate of the study area
Gobelle valley is characterized by semi-arid climatic condition with mean annual temperature of
19.6oC. Rainfall is bimodal- occurring from March to May (short rain season) and July to October
(long rain season). The mean annual rainfall 419.7 mm year-1
, ranging from 343.4 mm to 505.1 mm
year-1
.
2.3. Reconnaissance Survey and Vegetation Sampling
Prior to actual vegetation sampling, reconnaissance survey was made in the study area to
determine the position, number and length of transects. The three transects that cut across various
vegetation segments were laid down at different sites across altitudinal gradient. A total of 60
sample plots (20 m x 20 m) were systematically laid along the 3 transects at every 100 m interval
and in each transects 20 quadrats were employed. In each of the quadrats, the identity of all live
woody species (WS), number of live individuals of all WS and diameter at breast height (DBH) of
all WS (with DBH > 2 cm), except juveniles (seedling and coppices: height < 1.3 m) were recorded.
In the case of seedling and coppices, the number of individuals of each species were counted
and recorded in each quadrat. For this, 5 sub-plots of 5 m x 5 m four at each corner and one at the
center of the big plot were laid. A caliper was used to measure diameter at breast height (DBH = 1.3
m). For WS that were branched at around the breast height, the DBH were measured separately and
averaged. The woody species were preliminarily identified in the field by using the available
literature (e.g. Flora of Ethiopia and Eritrea). Voucher specimens of each WS were collected, dried
International Journal of Forestry & Plantation ISSN: 2656-6176, Volume 2, Issue 2, page 44 - 52
Zambrut
Zambrut.com. Publication date: December, 2019.
Mereba, F. L. & Chimdessa, M. 2019. Ecological Study of the Woody Vegetation of Gobelle Valley of
Babile Elephant Sanctuary (Studied in Oromia Regional ................
46
and pressed for further identification and confirmation of the authenticity in Haramaya University.
Geographic location of each quadrat was measured using AndroiTS GPS Test.
2.4. Data Analysis
Species richness was determined from the total number of woody species recorded in sample
plots. The diversity of woody species was analyzed by using the Shannon-Weiner Diversity Index
(Krebs, 1989; Magurran, 2004). Equitability or evenness, a measure of similarity of the abundances
of the different woody species in the study site, was analyzed by using Shannon’s Evenness or
Equitability Index (Krebs, 1989; Magurran, 2004).
Density of the woody species were calculated by converting the total number of individuals of
each woody species encountered in all the quadrats and all transects used in the site to equivalent
number per hectare. The frequency was calculated as the proportion (%) of the number of quadrats
in which each woody species were recorded from the total number of quadrats in the site.
Dominance of the woody species, with diameter at breast height (DBH) of >2cm were determined
from the space occupied by a species, usually its basal area. The total basal area of each woody
species was converted to equivalent basal area per hectare (Kent and Coker, 1992).
Importance Value Index (IVI), which indicates the relative ecological importance of a given
woody species at a particular site (Kent and Coker, 1992), was determined from the summation of
the relative values of density, frequency and dominance of each woody species. Regeneration status
of the forest was analyzed by comparing saplings and seedlings with the matured trees. Sorensen’s
similarity index was computed to help comparison between species composition of other similar
vegetation of the region.
3. RESULT AND DISCUSSION
3.1. Plant Diversity and Floristic Composition
A total of 58 woody plant species, representing 25 families and 36 genera, were recorded in the
study sites. See table 1. below.
Table 1. Woody plant species abundance with their family distribution
No. Family No. of species Percent from total
1. Fabaceae 15 26
2. Tiliaceae 7 12
3. Anacardiaceae 4 7
4. Burseraceae 3 5.17
5. Apocynaceae
2
3.45
6. Capparidaceae
2
3.45
7. Ebenaceae
2
3.45
8. Euphorbiaceae
2
3.45
9. Moraceae
2
3.45
10. Oleaceae
2
3.45
11. Rhamnacae
2
3.45
12. Sapindaceae
2
3.45
International Journal of Forestry & Plantation ISSN: 2656-6176, Volume 2, Issue 2, page 44 - 52
Zambrut
Zambrut.com. Publication date: December, 2019.
Mereba, F. L. & Chimdessa, M. 2019. Ecological Study of the Woody Vegetation of Gobelle Valley of
Babile Elephant Sanctuary (Studied in Oromia Regional ................
47
13. Agavaceae
1
1.7
14. Balanitaceae
1
1.7
15. Cactaceae
1
1.7
16. Combretaceae
1
1.7
17. Flacourtiaceae
1
1.7
18. Guttiferae
1
1.7
19. Lamiaceae
1
1.7
20. Myrtaceae
1
1.7
21. Olacaceae
1
1.7
22. Salicaceae
1
1.7
23. Salvadoraceae
1
1.7
24. Sterculiaceae
1
1.7
25. Verbenaceae
1
1.7
Fabaceae had 15(26%) species, Tiliaceae had 7(12%) species, Anacardiaceae 4(7%) species,
Burseraceae had 3(5.17%) species, Apocynaceae, Capparidaceae, Ebenaceae, Euphorbiaceae,
Moraceae, Oleaceae, Rhamnacae and Sapindaceae each has 2(3.45%) species, Agavaceae,
Balanitaceae, Cactaceae, Combretaceae, Flacourtiaceae, Guttiferae, Lamiaceae, Myrtaceae,
Olacaceae, Salicaceae, Salvadoraceae, Sterculiaceae and Verbenaceae each has 1(1.7%) species.
The most diverse family was Fabaceae, with 26% of the total number of species, followed by
Tiliaceae and Anacardiaceae constituting 12% and 7% respectively (Table 1).
The family Fabaceae ranks first comprising because they are known for their drought tolerance,
deciduous and well developed spiny species as defense mechanism for the environmental and
human induced hazards and shows the same result for Erer valley (Anteneh et al., 2011). Out of the
total plant species, 32 (55.2%) are shrubs where as trees accounted 26 (44.8%) of the total recorded
species. Shrub that constituted 55.2% of the total recorded species was dominant life form as
compared to tree, accounts only for about 44.8% of the total recorded woody species.
The overall plant diversity and evenness values of Gobelle valley vegetation were 3.05 and
0.75, respectively. The Shannon diversity index values observed in Gobelle valley vegetation fall
within the range (0.70 - 3.57) and agrees with findings reported for other dry forests of the Sub-
Saharan region (Shackleton, 1993; Obiri et al., 2002; Venter & Witkowski, 2010). The overall
species richness of a given vegetation type can give a general impression of their diversity (Tadesse,
2003). Based on this assumption, the diversity index obtained for this forest shows that Gobelle
valley vegetation has relatively high diversity with the different species having uniform abundance.
The relatively high diversity of woody plants was probably a result of relatively high species
richness and abundance of this study area. Therefore, the overall species diversity value shows
relatively high value which indicates relatively high diversity and evenness in the study area. Higher
evenness indicates that almost all species are equally important and there was no dominance of few
species over the others (Feyera, 2006).
International Journal of Forestry & Plantation ISSN: 2656-6176, Volume 2, Issue 2, page 44 - 52
Zambrut
Zambrut.com. Publication date: December, 2019.
Mereba, F. L. & Chimdessa, M. 2019. Ecological Study of the Woody Vegetation of Gobelle Valley of
Babile Elephant Sanctuary (Studied in Oromia Regional ................
48
However, Gobelle vegetation is found to be less diverse than the value recorded in Erer valley
vegetation for BES in which 67 woody species (H’ = 3.55) (Anteneh et al., 2011) and Vegetation of
Sire Beggo in which 117 species with H’ ≥ 3.690 (Abyot et al., 2014). The high diversity may be a
reflection that the area closure or protected area can restore the natural vegetation. In connection to
this, it is also possible that environmental factors such as climate and edaphic factors govern
richness and diversity of given vegetation.
Sorenson's coefficient of similarity was computed to compare the similarity in family, genera
and species composition of Gobelle valley vegetation with some other similar woodland forests of
the country. Results showed that the highest similarity (74%) in family composition was observed
between vegetation’s of Gobelle valley and Erer Valley, which is also found in the BES. The same
similarity trend was also calculated in terms of species and genera composition. Least similarity in
species composition was observed with vegetation of Erer Valley and ANP forest.
Even though Erer and Gobelle valley were found adjacent to each other, they have different
diversity and evenness. The probable reasons for variation in floristic composition between Gobelle
valley and Erer Valley vegetation’s could be variation between the sites in extent of anthropogenic
disturbance, excessive exploitation of same species and variation in environmental conditions for
regeneration. Anthropogenic disturbances, such as logging or cutting trees, charcoal production and
farming practices usually, result in an immediate decline or complete destruction in species diversity
(Noble and Dirzo, 1997). Out of the plants collected from the study area, 3 species viz. Acacia
nigrii, Berchemia discolor and Euphorbia burgeri were endemic species. According to Vivero et al.
(2005), these species are listed in IUCN Red Data List and requires close attention to conserve them
in situ.
3.2. Density, frequency and dominance of woody plant species
The total density of all the woody species with DBH>2.0cm recorded was 34,897 per hectare
out of which trees accounted for 5159.6 individuals per hectare and shrub accounted for 29738.7
individual ha−1
.
Table 2. Lists of species with high densities from the valley
Species Individual ha−1
Percent
Acacia brevispica 2295 6.6
Jasminum floribundum 2017 6
Acacia melifera 1980 5.7
Ozoroa insignis 1919 5.5
Lantara camara 1828 5
Euclea schimperi 1824 5
Grewia tenax 1803 5
Euphorbia burger 1596 4.6
Acacia senegal 1416 4
Grewia flavescens 1295 3.6
Grewia ferruginea 1264 3.6
Grewia bicolor 1136 3
Cryptostegia grandiflora 1011 3
Capparis fasicularis 1011 3
The densities of 14 species viz. Acacia brevispica, Jasminum floribundum, Acacia melifera, Ozoroa
insignis, Lantara camara, Euclea schimperi, Grewia tenax, Euphorbia burger, Acacia senegal,
Grewia flavescens, Grewia ferruginea, Grewia bicolor, Cryptostegia grandiflora, and Capparis
fasicularis, accounted for 64% of the total density of woody species(Table 2). The density of the
rest 44 species constituted 36% of the total density.
The mean density of each recorded species was also seen against DBH class and result showed
that number of individuals varied with DBH class. The least density of the most dominant woody
species such as Balanites aegyptiaca, Berchemia discolor Acacia etabaica, Sterculia africana,
International Journal of Forestry & Plantation ISSN: 2656-6176, Volume 2, Issue 2, page 44 - 52
Zambrut
Zambrut.com. Publication date: December, 2019.
Mereba, F. L. & Chimdessa, M. 2019. Ecological Study of the Woody Vegetation of Gobelle Valley of
Babile Elephant Sanctuary (Studied in Oromia Regional ................
49
Commiphora erythraea, and Tamarindus indica might be due to selective overexploitation for
construction, firewood, charcoal and other multipurpose uses by local peoples. Similarly, the highest
densities of few species like Lantana camara, and Acacia brevispica could be due to their
unpalatable nature for both wild and domestic animals and wide range of dispersal mechanisms and
rapid reproduction strategies (Feyera, 2006; Anteneh et al., 2011). The frequency of 86.67% of the
species was between 20 and 60%, while 13.33% were below 20% frequency. The most frequent
woody species in the sampled quadrats were Acacia robusta, Acokanthera schimperi, Boscia
minimifolia, Grewia bicolor, Sterculia africana, and Dichrostachys cinerea, accounting for 57%,
53%, 52%, 51%, 51%, and 50% respectively. The species with the least percent frequency were
Ziziphus spina-christi from Rhamnaceae family and Ficus vallis-choudae from Moraceae family
which occurred in 11.67% and 1.67% of the sampled quadrats respectively.
Dominance of the woody species with diameter at breast height (DBH) of > 2 cm was
determined from the space occupied by a species, usually its basal area. The normal value of basal
area for virgin tropical forests in Africa is 23-37 m2 ha
-1 (Lamprecht, 1989, cited by Anteneh et al.,
2011). The total basal area of each woody species was converted to equivalent basal area per
hectare. Basal area of all woody species in the study area added up to 22.38 m2/h
-1. The most
dominant woody species in Gobelle valley vegetation were Acacia robusta (2.41 m2/ha), followed
by Commiphora erythraea (2.14 m2/ha), Ficus vallis-choudae (1.77 m2/ha), Boswellia neglecta
(1.54 m2/ha), Tamarindus indica (1.33 m
2/ha) and Ficus vasta (1.33m
2/ha). The overall result from
the calculation of basal area shows relatively low dominance of few individuals of woody species.
Comparison of the total woody species dominance (basal area) of Gobelle valley vegetation with
some other vegetation of the country showed that it is higher than that of Erer valley (17.8 m2/ha ),
Sire Bego (19.3 m2/ha), ANP was 0.002787, 0.006613, 0.008613, and 0.004623 m2/ha for the
control, protected, less human interference and high human interference areas of the park. This
might be due to variation in edaphic, physical and anthropogenic factors between Gobelle and
forests in comparison which resulted in the difference in mean density and DBH.
3.3. Importance Value Index (IVI)
IVI was calculated from the summation of the relative dominance, relative frequency and
relative density values of each woody species (Kent & Coker 1992). Results show that Acacia
robusta was found to have the highest IVI (16.44) followed by Commiphora erythraea (11.55), and
Boswellia neglecta (11.2). This suggests that these species are dominant species of the area. They
are species that are well adapted to the environmental factors of the area.
Many researchers (e.g., Zegeye et al., 2006; Feyera et al., 2003; Worku et al., 2012) explain
that IVI is an important parameter that indicates the ecological significance of species in a given
ecosystem. If a species has high IVI value, it will be regarded as more important than those with low
IVI values (Zegeye et al., 2011). Out of the 58 woody species recorded in the study area about 57
species have IVI ˃ 1.0. The least (0.51) IVI ˂ 1.0 value was recorded for Ziziphus spina-christi,
suggesting that this species needs. The Important Value Index (IVI) is useful to compare the
ecological significance of species (Lamprecht, 1989). In the study area, most woody species resulted
in IVI˃10 that could be considered as an important species with respect to ecological management
and conservation plan for intervention. Only three woody species like Acacia robusta, Boswellia
neglecta, and Commiphora erythraea resulted in an IVI value (IVI ˃10).
3.4. Population structure and Regeneration status of Gobelle Vegetation
Woody species of Gobelle forest were sub-divided into 10 DBH classes. Comparison between
the DBH classes, about 27.5% of the total counted individuals of the entire species fall within DBH
class of ˂ 2cm followed by 19.6% with DBH class of 2-5cm, 15.7% with DBH class of 5-10cm and
11.8% with DBH class of 10-15cm. The density of individuals of the entire species with DBH class
>40cm accounted only for 1.2%.
The statistical result indicated that the numbers of individuals in the lower DBH classes are
higher with subsequent decrement of densities of higher DBH classes. This tells us that seedlings
and saplings are more a stable regeneration status to replace the older individuals.
International Journal of Forestry & Plantation ISSN: 2656-6176, Volume 2, Issue 2, page 44 - 52
Zambrut
Zambrut.com. Publication date: December, 2019.
Mereba, F. L. & Chimdessa, M. 2019. Ecological Study of the Woody Vegetation of Gobelle Valley of
Babile Elephant Sanctuary (Studied in Oromia Regional ................
50
This result shows the presence of more seedlings than saplings and matures individuals, which
shows that the Gobelle forest is under regeneration. In this study, different species have different
densities of seedlings and saplings. The highest density of seedlings and saplings were found in the
species Euclea schimperi, Acacia brevispica, Acacia melifera, Acacia senegal, Jasminum
floribundum, Lantana camara and Ozoroa insignis. Moreover, densities of seven densest species
was assessed and graphed against DBH classes. The result showed that majority of individuals of
each species was found to be in lower DBH class (s) with decreasing number of individuals in
higher DBH class. According to Neelo et al. (2015) this population structure pattern is a stable one
with good regeneration status.
4. SUMMARY, CONCLUSIONS AND RECOMMENDATIONS
Ecological assessments of this vegetation would serve as a basis for meaningful planning,
sustainable utilization and conservation of biodiversity in this sanctuary. Woody Species
Composition and Diversity Gobelle natural vegetation have been studied. The result obtained from
the study area showed that a total of 58 plant species in 36 genera and 25 families were identified
from the forest. Of these, trees and shrubs constituted 44.8% and 55.2%, respectively. The current
finding indicated that shrubs were the most dominant species. Top four plant families with the
highest proportion of the total recorded species were Fabaceae 15 (26%) species, Tiliaceae 7(12%)
species, Anacardiaceae 4(7%) species, and Burseraceae 3(5.17% species. Fabaceae was represented
by the highest number of species 15 (26%) species. Shannon-Wiener diversity index (H`) and
evenness values (E’) were 3.05 and 0.75, respectively.
The total basal area of the recorded woody species was computed from DBH of all individuals
in sampled quadrats. Therefore, the total basal area of the vegetation of the study area was added up
to 22.38 m2/ha. In this study area, shrubs are found to be dominant than trees where most of the
trees are found at lower DBH classes. The overall density of trees/shrubs species with DBH>2cm
recorded was 34,897 individuals ha-1
. The density of trees/shrubs decreased with increasing DBH
indicating the dominance of small-sized individuals in the area. The importance value index (IVI) of
the recorded woody species of Gobelle was also calculated and Acacia robusta was found to have
the highest IVI (16.44) followed by Commiphora erythraea (11.55), and Boswellia neglecta (11.2).
Furthermore, from the total species recorded in the study area, 3 species viz. Acacia nigrii,
Berchemia discolor and Euphorbia burgeri were endemic species. According to Vivero et al.
(2005), these species are listed under the Red Data List of IUCN and requires close attention to
conserve them in situ. The regeneration status of the woody species at Gobelle vegetation was
determined and seven woody species were assessed through histogram. The highest density of
seedlings and saplings were found in the species like Euclea schimperi, Acacia brevispica, Acacia
melifera, Acacia senegal, Jasminum floribundum, Lantana camara and Ozoroa insignis.
In conclusion, the analysis of population structure showed that some tree species have normal
population structures with many individuals at lower size classes. The assessment of regeneration
status based on seedling and sapling count in comparison with mature individuals also showed that a
significant proportion of woody species were regenerating. Overall vegetation of Gobelle showed
stable population structure that suggests good regeneration status. It is therefore imperative to
develop and implement effective conservation measures to ensure the sustainable use of this natural
vegetation and save the biodiversity of this area.
Based on the results, the following recommendations have been given.
As it is not protected, Gobelle vegetation was exposed to human interference that may endanger
some species of the area in the future. Therefore, creating awareness for communities on the
importance of forest resources and ecological consequences of deforestation and device
mechanisms by which human impacts can be minimized through discussion and consultation
with the local communities as to be developing sense of ownership and responsibility for the
management and conservation of the Forest.
Private and community plantation areas for particular uses such as fuel wood and charcoal
production should be established to ease anthropogenic pressure.
International Journal of Forestry & Plantation ISSN: 2656-6176, Volume 2, Issue 2, page 44 - 52
Zambrut
Zambrut.com. Publication date: December, 2019.
Mereba, F. L. & Chimdessa, M. 2019. Ecological Study of the Woody Vegetation of Gobelle Valley of
Babile Elephant Sanctuary (Studied in Oromia Regional ................
51
The present study was limited to woody species composition and diversity in Vegetation of
Gobelle valley hence; further studies on soil seed bank, seed physiology, and land use
management system in the study area are recommended.
5. REFERENCES
Abyot Dibaba, Teshome Soromessa, Ensermu Kelbessa and Abiyou Tilahun. 2014. Diversity,
Structure and Regeneration Status of the Woodland and Riverine Vegetation of Sire Beggo
in Gololcha District, Eastern Ethiopia
Anteneh Belayneh, Sebsebe Demisew and Tamirat Bekele. 2011. Diversity and population structure
of woody species browsed by elephants in Babile Elephant Sanctuary, eastern Ethiopia: an
implication for conservation. Ethiopian e-Journal for Research and Innovation Foresight.
2011, 3(1):20–32. Agriculture and Forestry Issues.
Barnest, R.F.W., Craig, G.C., Dublin, H.T., Overton, G., Simons, W. and Thouless, C.R. 1999.
African Elephant Database 1998. IUCN/SSC Africa Elephant Specialist Group. IUCN,
Gland, Switzerland and Cambridge, UK.
Demel Teketay. 1995. Floristic composition of Daketa valley, Southeastern Ethiopia: An
implication for the conservation of biodiversity. Mt. Res. Dev. 15: 183-186.
East Hararge Planning and Economic Development Office (EHPEDO). 2004. Statistical Abstract of
East Hararge Administrative Zone, Birhanena Selam Printing Press.Harar.
Feyera Senbeta and Demel Teketay. 2003. Diversity, Community type and population structure of
woody species in Kimphee Forest: a unique Natural reserve in Southern Ethiopia. Eth. J.
Biol. Soc. 2(2): 169-187.
Feyera Senbeta. 2006. Biodiversity and Ecology of Afromontane Rainforests with Wild Coffea
arabica L. Populations in Ethiopia, Ecology and Development Series no. 38, Cuvillier,
Göttingen, Germany.
Ishida Y, David VA, Eizirik E, Schaffer AA, Neelam BA, Roelke ME, Hannah SS, O’Brien SJ,
Menotti-Raymond M. 2006. A homozygous single base deletion in MLPH causes the dilute
coat color phenotype in the domestic cat. Genomics. 88:698–705.
Kent, M. and Coker, P. 1992. Vegetation Description and Analysis: A practical approach. Belhaven
press, London, 363 p.
Lamprecht, H. 1989. Silviculture in the tropics – Tropical Forest Ecosystems and their Tree species-
possibilities and methods for their long-term utilization. T2-verlagsgesellschaft mbH,
Federal Republic of Germany, 296 pp.
Magurran, A. E. 2004. Measuring Biological Diversity. Malden and Oxford: Blackwell Publishing.
Neelo, J., Teketay, D.,Kashe,K., &Masamba,W. 2015. Stand Structure, Diversity and Regeneration
Status of Woody Species in Open and Exclosed Dry Woodland Sites around Molapo
Farming Areas of the Okavango Delta, Northeastern Botswana. Open Journal of Forestry.
5,313-328. http://dx.doi.org/10.4236/ojf.2015.54027.
Noble, I. R., & Dirzo, R. 1997. Forests as Human-Dominated Ecosystems. Science. 277, 522-525.
http://dx.doi.org/10.1126/science.277.5325.522
Obiri, J., Lawes, M., & Mukolwe, M. 2002. The Dynamics and Sustainable Use of High-Value Tree
Species of the Coastal Pond land Forests of the Eastern Cape Province, South Africa. Forest
Ecology and Management. 166, 131-148. http://dx.doi.org/10.1016/S0378-1127 (01)00665-
X
Shackleton, C. M. 1993. Demography and Dynamics of the Dominant Woody Species in a
Communal and Protected Area of the Eastern Transvaal Lowveld. South African Journal of
Botany. 59, 569-574.
Tadesse Woldemariam. 2003. Vegetation of the Yayu forest in Southwest Ethiopia: Impacts of
human use and Implications for In situ conservation of Wild Coffea arabica L. populations.
Ecology and Development Series No. 10. Cuvillier Verlag. Gottingen.
Venter, S. M., & Witkowski, E. T. F. 2010. Baobab (Adansonia digitata L.) Density, Size-Class
Distribution and Population Trends between Four Land-Use Types in Northern Venda,
International Journal of Forestry & Plantation ISSN: 2656-6176, Volume 2, Issue 2, page 44 - 52
Zambrut
Zambrut.com. Publication date: December, 2019.
Mereba, F. L. & Chimdessa, M. 2019. Ecological Study of the Woody Vegetation of Gobelle Valley of
Babile Elephant Sanctuary (Studied in Oromia Regional ................
52
South Africa. Forest Ecology and Management. 259, 294-300.
http://dx.doi.org/10.1016/j.foreco.2009.10.016
Vivero, J.L., Ensermu Kelbessa and Sebsebe Demisew 2005. The Red list of Endemic Trees and
Shrubs of Ethiopia and Eritrea. Fauna and Flora International, Cambridge, UK, 23 Pp.
Worku, A., Teketay, D., Lemenih, M., & Fetene, M. 2012. Diversity Regeneration Status and
Population Structure of Gum and Resin Producing Woody Species in Borana, Southern
Ethiopia. Forests, Trees and Livelihoods, First Article, 1-12.
Yirmed Demeke, Marilyn, B.R., Roger, V.S. and Richard, F.B. 2006. The undisclosed facts about
the relic elephant population in the horn of Africa. In: Proceeding of 16th Annual
Conference and Workshop, pp13. Biological Society of Ethiopia, Addis Ababa.
Zegeye, H., Teketay, D., & Kelbessa, E. 2006. Diversity, Regeneration Status and Socio-Economic
Importance of the Vegetation in the Islands of Lake Ziway, South-Central Ethiopia. Flora.
201, 483-498. http://dx.doi.org/10.1016/j.flora.2005.10.00.
Zegeye, H., Teketay, D., & Kelbessa, E. 2011. Diversity and Regeneration Status of Woody Species
in Tara Gedam and Abebaye Forests, Northwestern Ethiopia. Journal of Forestry Research.
22, 315-328. http://dx.doi.org/10.1007/s11676-011-0176-6
Zambrut Journal, Link Access;
https://zambrut.com
https://zambrut.com/ecological-vegetation/
© Copyright International Journal of Zambrut | Zambrut, Inc.