Goro-Bele Ethiopia revealed that, Goro-Bele forest exceeds other

Goro-Bele forest however has less number of species from
some other dry afro montane forests such as 
Biteyu Forest (191 species, Talemos Seta, 2017); Wof-Washa Forest (250
species, Demel Teketay and Tamirat Bekel, 1995); Dry Afromontane Forest at Bale
Mountains National Park (230 species, Haile Yineger et al., 2008); Chilimo forest (213 species, Teshome Soromessa and
Ensermu Kelbessa ,2013).

A comparison
with regard to species richness made with other Afromontane rain forest in
Ethiopia revealed that, Goro-Bele forest exceeds other similar rain forests
like the Harenna forest, in Southeast Ethiopia (128 species; Mesfin Tadesse and
Lisanework Nigatu, 1996), but a recent study made in 2014 revealed  an exceptionally different figure(289 specie;
Feyera Senbeta et al.,2014),  Jibat forest (131
species, Tamrat Bekele, 1994), Bonga forest in Southwest Ethiopia (154
species; Friis et al., 1982) and Bore-Anferara-Wadera Forest (136 species; Mesfin
Weldearegay, 2017). A considerable variation in
species richness and evenness of the studied forests with other forests in
Ethiopia is due to a function of differences in location productivity,
environment heterogeneity and/or disturbance factors (Maestre, 2004).

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The diversity in
the family classification evidently relies upon the quantity of species that
occupy the area. The order of families as far as species richness is concerned
as per different investigations in that Asteraceae is accounted for to be the
richest family somewhere else (Haile Yineger et
al., 2008; Ermias Lulekal, 2014; Talemos Seta, 2017; Zewudie Kassa,
2017) in this study the Asteraceae, which yielded 22
(12.15%) of the total species recorded, is the leading species rich family too.
Moreover Poaceae 9 species (about 5%), Fabaceae 7 species (3.87%), Euphorbiaceae
7 species (3.87%), and Lamiaceae 7 species (3.87%) trailed the leading family.
Thus this is in agreement with (Ensermu Kelbessa and
Sebsebe Demissew, 2014) in which the above mentioned families from the forest
are in the top leading families in Flora of Ethiopia and Eritrea.

With respect to
endemism from the flora area,17 (9.44%) endemic plant species were
distinguished from the Goro-Bele forest, which demonstrates a generally better
species diversity of endemic plants compared to 
other  moist Afromontane forest
such as Yayu forest (three species; Tadesse Woldemariam,2003), Sese forest(10
species: Shiferaw Belachew,2010) in which Moist Afromontane Forest, is noted
with very poor endemic plants diversity, however the  proportion of endemic plant species in Dry
Afromontane Forests of Ethiopia ranges between 10-15% of the total number of
species sampled ( Friis et al.,
2001;Teshome Soromessa and Ensermu Kelbessa, 2013). thus similar to several other studies made in Moist Afromontane Forest in
different part of the country  attempted
to support Friis et al., (2001) who reported on endemism in Afromontane
Forests of Ethiopia and the result of this study is in agreement with such
findings.

5.1.2
New Taxa recorded from Goro-Bele forest to Bale floristic region

Twenty four (13.20%)
in sixteen families of the total 182 identified from Goro-Bele forest were
found to be new taxa not previously reported from Bale floristic region with
Asteraceae and Poaceae the dominant representative families. Thus this study
shows further explorations of the floristic region for more new taxa that could
enrich the species diversity of the flora region.

5.1.3.
Species accumulation curve and species richness estimation

 Species accumulation curve revealed to
illustrate the rate at which new species are included as the sampling effort
proceed. From species accumulation (rarefaction) curve (Figure 8), it is
observed that there are still new species to be recorded in the forest though
at decreasing rate.  A study made from
species diversity patterns derived from species–area models (He and Legendre,
2002), revealed that, area, species abundances, spatial distribution, and
species richness have been focal segments of community ecology. Thus at the
community level, the abundances and spatial distributions of species are the
two quick segments that specifically decide a species–area relationship, while
different variables or systems are circuitous yet ultimate as in they influence
species richness through their effect on the abundance and spatial distribution
(He and Legendre, 2002). In line with this species abundance from the sampling
plots in the forest increases as the sampling area increases step by step.

5.1.4 Diversity of the plant community types in
the study forest

The five plant community types of Goro-Bele forest showed a
significant variation in their species richness, diversity, and evenness. This
variation among the plant community types was the direct reflection of the
effects of the environmental variables where these community types occurred,
thus local climatic variations and forest disturbances are mentioned among the
factors most responsible for variations in species diversity and evenness in a
given forest as stated by Feyera Senbeta and Demel Teketay (2003).

The Shannon-Weiner
species diversity and evenness of the whole Goro-Bele forest is 4.1 and 0.85,
respectively. And the Pearson correlation between
Shannon diversity index and evenness values was positive and strong (r =
0.8; P <0.0.05) in the study area. As stated by (Magurran, 1988) Shannon-Weiner diversity index is sensitive to the presence of both rare species and high evenness values. The Fisher's diversity index, decreased consistently with the decrease in number of species in the forest community. However, the Shannon index has a different pattern in the five communities. Pearson correlation of species richness and Fisher alpha have shown a strong correlation(r = 0.980, P-Value = 0.003) The Fisher's ?, which is often known as log-series distribution, thus refers to the relationship between the number of species and abundance (Magurran 1988). However, Fisher's alpha does not discriminate the situations where species number (S) and abundance (N) are constant, even if there is change in evenness. This is to mean that two communities may end up with the same species richness and Fisher's alpha index but different Shannon diversity indices if they have different degrees of dominance of the commonest species. This is due to the fact that Shannon diversity index takes into account the changes in evenness, thus high dominance of few species indicates some sort of disturbance and hence the need for conservation measures. As a result community type-V in the study forest resulted with few species but with relatively higher dominance which is an indicator for conservation measure. Most research on species diversity has focused on inventory diversity, however, research on beta diversity has recently increased (Sfenthourakis and Panitsa, 2012). Consequently it is fundamental to understand the distribution patterns and maintenance mechanisms of species diversity along environmental gradients for the development of strategies and measures for conserving species diversity under environmental change. In the event that ?w is 0 then all sample units have comparable species. ?  <1 is rather low and ?  >5 can be seen as high (McCune and Grace,
2002).

The magnitude of beta diversity indicated the change in
species richness between the adjacent transects along the same environmental
gradient. Beta diversity thus measures the change in the diversity of species
among a set of habitats, i.e. calculates the number of species that are
different in two different habitats. Beta diversity is, therefore, the rate of
change of community along an ecological gradient. As a result the beta
diversity index of the whole forest (Study area) was also high (? =
8.21).  Thus a beta diversity index
higher than five can be considered as high value and this specifies a high
turnover among the forest communities and in the forest as a whole (Zerihun
Woldu,2017). Results of Beta diversity for the whole data frame or beta
diversity of vegetation data with no specific gradient (?w=8.21) implies higher beta
diversity. Results of Beta diversity of pair wise comparisons or mean value of
beta diversity between the sample plots is equal to 0.66 and this is the
Sørensen index of dissimilarity for plots which shows heterogeneous environment
for community in the vegetation. The greatest estimation of ?

 is acquired when no species are shared among
sample units. In spite of the fact that environmental heterogeneity and species
dispersion are firmly identified with beta (?) diversity, a high beta species
diversity within a community type may theoretically infer that the community
occupies a heterogeneous environment. Such high beta diversity along these lines infers the use of the
‘several small’ strategy than the ”single large” technique for possible later
use plan for species diversity conservation in the Goro-Bele forest. Hence this
is in concurrence with (Wiersma and Urban, 2005.Therefore the Goro-Bele forest
is characterized with a high species turnover.

 As stated by Magurran (1988) the
reconsideration of the commonly used measures of diversity, such as the species
richness, Species Abundance model (Fisher’s alpha index for this situation) and
used indices based on species abundance proportion which put up both richness
and evenness (the Shannon diversity index and Shannon evenness for this
situation) is important to examine the overall status of vegetation in the
study area since diversity does not only refer to species richness, but to a
range of phenomena that determine the heterogeneity within a community (Gentry,
1982).