# Vegetation Classification and Habitat Types of Gambella National Park

Authors: Gatluak Rolkier; Kumelachew Yeshitela
Journal: International Journal of Forestry Research
 (2020)

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## Abstract

Gambella National Park has a diverse set of habitat types which Ethiopia shares with its neighbor, South Sudan, and the park is considered as one of the top wildlife areas of Ethiopia. The objectives of this research were to determine vegetation types and identify habitat types on recent satellite imageries. The method used for vegetation data collection was transects lines. PC-ORD software was used for analyzed vegetation data while Rapid Eye image 5 m resolution 2012 was analyzed by ArcGIS version 10.1 to classify the habitats map of Gambella National Park. The cluster analysis classified the Gambella National Park into 6 vegetation communities, and the relative abundance and relative frequency were used for naming vegetation community types. However, the satellite image had classified the Gambella National Park into 5 major habitat types.


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## Body

## 1. Introduction

Gambella National Park was established in 1973 and has a diverse set of habitat types which Ethiopia shares with its neighbor, South Sudan [1]. Vast collections of plains game are found in the park and perhaps that can be considered as one of the top wildlife areas of Ethiopia [1]. The major vegetation types that are observed in the park are woodland, wooded grassland, grassland, and wetlands. Since the 1980s, there has been large scale habitats changed in Gambella National Park mostly due to human pressure. These pressures came from establishment of state farm in Abobo with the area of 3,000 ha of land, situated in the eastern part of Gambella National Park and the Construction of Alewero dam for large scale commercial agriculture [2]. At present, both large scale agricultural investments (e.g., like Karaturi, Rushi, and Saudi Star) [3] and small scale agricultural investments from different national investors reduced the park area from 5,061 km2 to 4,575 km2. It is assumed that these anthropogenic impacts have affected wildlife and their habitats.The development of management plan of the Gambella National Park is hindered by lack of information on habitat types within the park. Although there have been few studies focusing on the vegetation of Gambella region as a whole [4, 5], identification and mapping of the habitat types and distribution of wildlife within the national park have never been attempted. This is particularly important for planning sustainable wildlife management. Mapping of wildlife habitat could be used as a tool in wildlife management, a guide for wildlife viewing, and a gauge for the loss of critical wildlife habitats [6].The main reason for classifying and mapping the habitats of Gambella National Park was to have better understanding on the location of vegetation community types at local level and habitats types at large level. This could allow better understanding of the important habitat types for key conservation species in which the park was established for. This research expected to fulfill a knowledge gap on the information of vegetation communities and habitat types for Gambella National Park.The objectives of this research are as follows:To determine the vegetation types in the Gambella National ParkTo identify the habitat types on the recent satellite imageries and develop a habitat map of Gambella National Park


## 2. Materials and Methods

Gambella National Park is located in the lowland plain of the Gambella People’s National Regional State of Ethiopia. According to Monico et al. [7], the park is situated between 32°59′ and 35°23′ longitude and 6°17′ and 8° 42′ latitude (Figure 1). It is situated between two major rivers Baro and Akobo (Figure 1) and crossed by other three major rivers with three wetlands (Figure 1). It was established in 1973, with new area of 4,575 km2.Figure 1
Location of Gambella National Park within Gambella Regional State.


## 3. Methods of Data Collection and Analysis

### 3.1. Data Collection

#### 3.1.1. Vegetation Data Sampling

The method employed for vegetation data collection was systematic sampling. This sampling was done online transects which were laid down across east to west and north to south depending on habitat information (anthropogenic disturbance, physiognomy, etc.), which was designed based on identified areas with high environmental variability. This technique was used because it is simple for ecological surveys and good for sampling a very large area relatively quickly [8].


#### 3.1.2. Data Collection

The vegetation data were collected by transects lines. The first transect was established based on vegetation physiognomy and by avoiding sites of severe human impact, e.g., fire. The remaining transects were put in place systematically at specific intervals of 5 km. In the woodland and wooded grassland areas, sample plots of 40 m × 40 m were laid out at intervals of 500 m along the transect for recording tree and shrub species. For recording herbaceous and grass species, four, 2 m × 2 m sample plots were laid out at the corners of the bigger plot in grassland, savannah, and wetland areas; sample plots of 2 m × 2 m were laid at intervals of 500 m apart for recording herbaceous and grass species. Accordingly, a total of 450 sample plots, woodland (292 plots), wooded grassland (98 plots), grassland (35 plots), savanna (11 plots), and wetland (14 plots), were sampled. Due to inconvenience for these much sample plots for analysis, the screening was done based on species area curve and similarity of the species and, therefore, sample plots with most similar species were excluded from the analysis.Consequently, 80 sample plots, woodland (26 plots), wooded grassland (20 plots), grassland (12 plots), savanna (8 plots), and wetland (14 plots), were taken for final analysis.In each sample plot the GPS point, altitude and species list, which included the habits, were recorded. Every plant species was recorded with its estimated percent cover abundance using the scale of Braun Blanquette 1932 as modified by Westhoff and Vander Maarel [9], with 1–2 individuals covering <5% of the sampled area, 3–10 individuals covering <5% of sampled area, abundance individuals covering <5% of the sampled area, plant cover ranging from 5 to 12%, plant covering from 12 to 25%, plant covering from 25 to 50%, plant covering from 50 to 75%, and plant covering from 75 to 100%.Common plant species were identified in the field and for unidentified 10 species herbarium specimens were taken and identified in the National Herbarium of Ethiopia by comparing them with already identified plant species and referring to the “Flora of Ethiopia and Eritrea” (Vol. 1, Hederg et al. [10]; Vol: 2.1 Edwards et al. [11]; Vol: 2.2 Edwards et al. [12]; Vol: 3 Hederg et al. [13]; Vol 4: 1 Hederg et al. [14]; Vol: 5 Hederg et al. [15, 16]; Vol: 7 Hederg et al. [17]; and Vol: 8 Hederg et al. [10]).


### 3.2. Data Analysis

#### 3.2.1. Vegetation Data Analysis

The data collected were used to generate a plot-versus-species matrix (using the percentage cover/abundance values of each species). Cluster analysis using resemblance index and ward's method of hierarchical grouping was performed to identify community groups [18]. Resemblance index was used because it refers to similarity or dissimilarity between samples in terms of species composition. Sample plots that share the same species with the same abundance indicate the highest similarity and the lowest dissimilarity and, therefore, they become one group. Statistical validity of the identified groups was evaluated using multiresponse permutation procedure (MRPP) [19–21]. Both cluster analysis and MRPP were performed using PC-ORD software [18]. The groups were designated as community types and named by most significant indicator species in the group [22].In this study, the indicator species analysis method proposed by Dufre'n and Legendre [23] was used to identify indicator species. The indicator species are the most characteristic species of each group and present in the majority of the plots belonging to that group (Dufre’n and Legendre [23]).


#### 3.2.2. Habitat Types Identified from Satellite Data Analysis

Rapid Eye satellite imagery (5 m resolution) data acquired in 2012 covering all of the Gambella National Park and its surrounding areas was permitted from Applied Science Department of Berlin University. It was first classified by unsupervised classification. The sensor type used in acquiring this imagery for unsupervised classification was multispectral push broom imager and captured five spectral bands (blue (440–510 nm), green (520–590 nm), red (600–700 nm), Red Edge (690–730 nm), and near-infrared bands (760–850 nm)). ERDAS Imagine 2012 software was used in the preprocessing, pixel-based classification, and postprocessing of the Rapid Eye satellite imagery covering the study area. For the pixel-based classification, the satellite imagery was classified by pixel-based spectral angle mapper (SAM) classifier. The signature file was generated and this involves the training of classes. Areas of interest (AOI) was created and used to train the land cover classes (water body, bare-soil, and vegetation) for every class; random samples were taken across the National Park based on pixel spectra.The SAM algorithm which is supervised classification approach was then applied. The supervised classification was mainly the ground truth or GPS points. The SAM algorithm was based on the assumption that a single pixel of remote sensing images represents one certain ground cover material, which was uniquely assigned to only one ground cover class. This algorithm was based on the measurement of the spectral similarity between two spectra. The spectral similarity was obtained by considering each spectrum as a vector inq-dimensional space, where q is the number of bands.


## 3.1. Data Collection

### 3.1.1. Vegetation Data Sampling

The method employed for vegetation data collection was systematic sampling. This sampling was done online transects which were laid down across east to west and north to south depending on habitat information (anthropogenic disturbance, physiognomy, etc.), which was designed based on identified areas with high environmental variability. This technique was used because it is simple for ecological surveys and good for sampling a very large area relatively quickly [8].


### 3.1.2. Data Collection

The vegetation data were collected by transects lines. The first transect was established based on vegetation physiognomy and by avoiding sites of severe human impact, e.g., fire. The remaining transects were put in place systematically at specific intervals of 5 km. In the woodland and wooded grassland areas, sample plots of 40 m × 40 m were laid out at intervals of 500 m along the transect for recording tree and shrub species. For recording herbaceous and grass species, four, 2 m × 2 m sample plots were laid out at the corners of the bigger plot in grassland, savannah, and wetland areas; sample plots of 2 m × 2 m were laid at intervals of 500 m apart for recording herbaceous and grass species. Accordingly, a total of 450 sample plots, woodland (292 plots), wooded grassland (98 plots), grassland (35 plots), savanna (11 plots), and wetland (14 plots), were sampled. Due to inconvenience for these much sample plots for analysis, the screening was done based on species area curve and similarity of the species and, therefore, sample plots with most similar species were excluded from the analysis.Consequently, 80 sample plots, woodland (26 plots), wooded grassland (20 plots), grassland (12 plots), savanna (8 plots), and wetland (14 plots), were taken for final analysis.In each sample plot the GPS point, altitude and species list, which included the habits, were recorded. Every plant species was recorded with its estimated percent cover abundance using the scale of Braun Blanquette 1932 as modified by Westhoff and Vander Maarel [9], with 1–2 individuals covering <5% of the sampled area, 3–10 individuals covering <5% of sampled area, abundance individuals covering <5% of the sampled area, plant cover ranging from 5 to 12%, plant covering from 12 to 25%, plant covering from 25 to 50%, plant covering from 50 to 75%, and plant covering from 75 to 100%.Common plant species were identified in the field and for unidentified 10 species herbarium specimens were taken and identified in the National Herbarium of Ethiopia by comparing them with already identified plant species and referring to the “Flora of Ethiopia and Eritrea” (Vol. 1, Hederg et al. [10]; Vol: 2.1 Edwards et al. [11]; Vol: 2.2 Edwards et al. [12]; Vol: 3 Hederg et al. [13]; Vol 4: 1 Hederg et al. [14]; Vol: 5 Hederg et al. [15, 16]; Vol: 7 Hederg et al. [17]; and Vol: 8 Hederg et al. [10]).


## 3.1.1. Vegetation Data Sampling

The method employed for vegetation data collection was systematic sampling. This sampling was done online transects which were laid down across east to west and north to south depending on habitat information (anthropogenic disturbance, physiognomy, etc.), which was designed based on identified areas with high environmental variability. This technique was used because it is simple for ecological surveys and good for sampling a very large area relatively quickly [8].


## 3.1.2. Data Collection

The vegetation data were collected by transects lines. The first transect was established based on vegetation physiognomy and by avoiding sites of severe human impact, e.g., fire. The remaining transects were put in place systematically at specific intervals of 5 km. In the woodland and wooded grassland areas, sample plots of 40 m × 40 m were laid out at intervals of 500 m along the transect for recording tree and shrub species. For recording herbaceous and grass species, four, 2 m × 2 m sample plots were laid out at the corners of the bigger plot in grassland, savannah, and wetland areas; sample plots of 2 m × 2 m were laid at intervals of 500 m apart for recording herbaceous and grass species. Accordingly, a total of 450 sample plots, woodland (292 plots), wooded grassland (98 plots), grassland (35 plots), savanna (11 plots), and wetland (14 plots), were sampled. Due to inconvenience for these much sample plots for analysis, the screening was done based on species area curve and similarity of the species and, therefore, sample plots with most similar species were excluded from the analysis.Consequently, 80 sample plots, woodland (26 plots), wooded grassland (20 plots), grassland (12 plots), savanna (8 plots), and wetland (14 plots), were taken for final analysis.In each sample plot the GPS point, altitude and species list, which included the habits, were recorded. Every plant species was recorded with its estimated percent cover abundance using the scale of Braun Blanquette 1932 as modified by Westhoff and Vander Maarel [9], with 1–2 individuals covering <5% of the sampled area, 3–10 individuals covering <5% of sampled area, abundance individuals covering <5% of the sampled area, plant cover ranging from 5 to 12%, plant covering from 12 to 25%, plant covering from 25 to 50%, plant covering from 50 to 75%, and plant covering from 75 to 100%.Common plant species were identified in the field and for unidentified 10 species herbarium specimens were taken and identified in the National Herbarium of Ethiopia by comparing them with already identified plant species and referring to the “Flora of Ethiopia and Eritrea” (Vol. 1, Hederg et al. [10]; Vol: 2.1 Edwards et al. [11]; Vol: 2.2 Edwards et al. [12]; Vol: 3 Hederg et al. [13]; Vol 4: 1 Hederg et al. [14]; Vol: 5 Hederg et al. [15, 16]; Vol: 7 Hederg et al. [17]; and Vol: 8 Hederg et al. [10]).


## 3.2. Data Analysis

### 3.2.1. Vegetation Data Analysis

The data collected were used to generate a plot-versus-species matrix (using the percentage cover/abundance values of each species). Cluster analysis using resemblance index and ward's method of hierarchical grouping was performed to identify community groups [18]. Resemblance index was used because it refers to similarity or dissimilarity between samples in terms of species composition. Sample plots that share the same species with the same abundance indicate the highest similarity and the lowest dissimilarity and, therefore, they become one group. Statistical validity of the identified groups was evaluated using multiresponse permutation procedure (MRPP) [19–21]. Both cluster analysis and MRPP were performed using PC-ORD software [18]. The groups were designated as community types and named by most significant indicator species in the group [22].In this study, the indicator species analysis method proposed by Dufre'n and Legendre [23] was used to identify indicator species. The indicator species are the most characteristic species of each group and present in the majority of the plots belonging to that group (Dufre’n and Legendre [23]).


### 3.2.2. Habitat Types Identified from Satellite Data Analysis

Rapid Eye satellite imagery (5 m resolution) data acquired in 2012 covering all of the Gambella National Park and its surrounding areas was permitted from Applied Science Department of Berlin University. It was first classified by unsupervised classification. The sensor type used in acquiring this imagery for unsupervised classification was multispectral push broom imager and captured five spectral bands (blue (440–510 nm), green (520–590 nm), red (600–700 nm), Red Edge (690–730 nm), and near-infrared bands (760–850 nm)). ERDAS Imagine 2012 software was used in the preprocessing, pixel-based classification, and postprocessing of the Rapid Eye satellite imagery covering the study area. For the pixel-based classification, the satellite imagery was classified by pixel-based spectral angle mapper (SAM) classifier. The signature file was generated and this involves the training of classes. Areas of interest (AOI) was created and used to train the land cover classes (water body, bare-soil, and vegetation) for every class; random samples were taken across the National Park based on pixel spectra.The SAM algorithm which is supervised classification approach was then applied. The supervised classification was mainly the ground truth or GPS points. The SAM algorithm was based on the assumption that a single pixel of remote sensing images represents one certain ground cover material, which was uniquely assigned to only one ground cover class. This algorithm was based on the measurement of the spectral similarity between two spectra. The spectral similarity was obtained by considering each spectrum as a vector inq-dimensional space, where q is the number of bands.


## 3.2.1. Vegetation Data Analysis

The data collected were used to generate a plot-versus-species matrix (using the percentage cover/abundance values of each species). Cluster analysis using resemblance index and ward's method of hierarchical grouping was performed to identify community groups [18]. Resemblance index was used because it refers to similarity or dissimilarity between samples in terms of species composition. Sample plots that share the same species with the same abundance indicate the highest similarity and the lowest dissimilarity and, therefore, they become one group. Statistical validity of the identified groups was evaluated using multiresponse permutation procedure (MRPP) [19–21]. Both cluster analysis and MRPP were performed using PC-ORD software [18]. The groups were designated as community types and named by most significant indicator species in the group [22].In this study, the indicator species analysis method proposed by Dufre'n and Legendre [23] was used to identify indicator species. The indicator species are the most characteristic species of each group and present in the majority of the plots belonging to that group (Dufre’n and Legendre [23]).


## 3.2.2. Habitat Types Identified from Satellite Data Analysis

Rapid Eye satellite imagery (5 m resolution) data acquired in 2012 covering all of the Gambella National Park and its surrounding areas was permitted from Applied Science Department of Berlin University. It was first classified by unsupervised classification. The sensor type used in acquiring this imagery for unsupervised classification was multispectral push broom imager and captured five spectral bands (blue (440–510 nm), green (520–590 nm), red (600–700 nm), Red Edge (690–730 nm), and near-infrared bands (760–850 nm)). ERDAS Imagine 2012 software was used in the preprocessing, pixel-based classification, and postprocessing of the Rapid Eye satellite imagery covering the study area. For the pixel-based classification, the satellite imagery was classified by pixel-based spectral angle mapper (SAM) classifier. The signature file was generated and this involves the training of classes. Areas of interest (AOI) was created and used to train the land cover classes (water body, bare-soil, and vegetation) for every class; random samples were taken across the National Park based on pixel spectra.The SAM algorithm which is supervised classification approach was then applied. The supervised classification was mainly the ground truth or GPS points. The SAM algorithm was based on the assumption that a single pixel of remote sensing images represents one certain ground cover material, which was uniquely assigned to only one ground cover class. This algorithm was based on the measurement of the spectral similarity between two spectra. The spectral similarity was obtained by considering each spectrum as a vector inq-dimensional space, where q is the number of bands.


## 4. Results

### 4.1. Cluster Classification of Plant Species of Gambella National Park

Six vegetation groups were identified using cluster analysis in combination with multiresponse permutation procedure (MRPP) and the cutoff for this classification was 50% (Figure2).Figure 2
Dendrogram of cluster analysis results of species abundance data of the studied plant species of Gambella National Park. Plots forming the same cluster have similar symbols.From 80 sample plots, 4 plots were considered as outliers and thus were excluded from the cluster analysis.The T value statistic for six groups was −1.28 (P<0.001) which indicated the significant different at P value, while the statistic chance-corrected within group agreement was 0.1. The T statistic is based on Pearson type III distribution. The P value associated with T is determined by numerical integration of type III distribution (Table 1). A statistic is descriptor within a group homogeneity falling between 0 and 1 (Table 1). When the items are identical, A = 1. Therefore, A statistic is equal to 1 when all items are identical within groups while the delta is equal to 0. A = 0 when heterogeneity within groups equals expectation by chance.Table 1
Chance within group agreement.
Chance corrected within group agreement,A = 0.07734179A = 1—(observed delta/expected delta)Amax = 1 when all items are identical within groups (delta = 0)A statistic is descriptor within a group homogeneity falling between 0 and 1A = 0 when heterogeneity within groups equals expectation by chanceA < 0 with more heterogeneity within groups than expected by chanceProbability of a smaller or equal delta,P = 0.00143541Skewness of delta = Pearson type II distributionSource, 2017 source: result of vegetation analysis, Gatluak, [24]


### 4.2. Naming of Vegetation Communities by Indicator Species of Study Plant of Gambella National Park

The 6 vegetation communities were named based on indicator values indicated by percent prefect indication value (combining relative abundance and relative frequency) (Tables2 and 3). The species in bold for each group is one with the maximum indicator values for combining relative abundance and relative frequency.Table 2
Indicator values (% of perfect indication based on combining values for relative abundance and relative frequency).
GroupSequence123456Identifier156879Number of items301111888Species MaxGrpCombretum collinum14907940Combretum molle14710000Cyperus castaneus30048000Hyparrhenia rufa202602200Oryza barthii20230100Oryza longistaminata20250000Perpyrnuo cypress32840000Terminalia brownii14000000Terminalia laxiflora13200000Ziziphus mucronata46363300MaxGrp = maximum indicator value in group.Table 3
Data for vegetation abundance of Gambella National Park.
Plot no.Species nameAbundance1Combretum aculeatum21Combretum collinum41Combretum molle41Terminalia brownie51Terminalia laxiflora41Terminalia macroptera Guill. & Perr.11Terminalia schimperiana Hochst.11Commiphora africana11Commiphora habessinica11Albizia malacophylla11Sterculia africana11Securidaca longipedunculata12Combretum collinum42Combretum molle42Terminalia brownie52Terminalia laxiflora42Terminalia schimperiana Hochst12Commiphora africana12Commiphora habessinica12Cordia africana12Sterculia africana12Securidaca longipedunculata13Combretum collinum43Combretum molle43Terminalia brownie53Terminalia laxiflora43Terminalia macroptera Guill. & Perr.13Terminalia schimperiana Hochst.13Commiphora africana133Diospyros mespiliformis113Celtis toka13Securidaca longipedunculata14Combretum collinum44Combretum molle54Terminalia brownie44Terminalia laxiflora34Terminalia macroptera Guill. & Perr.14Diospyros mespiliformis14Sarcocephalus latifolius14Sterculia africana15Combretum aculeatum25Combretum collinum45Combretum molle45Terminalia brownie55Terminalia laxiflora45Terminalia macroptera Guill. & Perr.15Terminalia schimperiana Hochst.15Commiphora africana15Diospyros mespiliformis15Sarcocephalus latifolius15Sterculia africana15Securidaca longipedunculata16Combretum collinum46Combretum molle46Terminalia brownie56Terminalia laxiflora46Terminalia schimperiana Hochst.16Commiphora africana16Commiphora habessinica16Sarcocephalus latifolius16Sterculia africana16Securidaca longipedunculata17Combretum collinum47Combretum molle47Terminalia brownie57Terminalia laxiflora47Terminalia macroptera Guill. & Perr.17Terminalia schimperiana Hochst.17Commiphora africana17Commiphora habessinica17Sarcocephalus latifolius17Securidaca longipedunculata18Combretum collinum48Combretum molle58Terminalia brownie48Terminalia laxiflora38Terminalia macroptera Guill. & Perr.18Commiphora africana18Sarcocephalus latifolius18Ficus sycomorus19Combretum aculeatum29Combretum collinum49Combretum molle49Terminalia brownie59Terminalia laxiflora49Terminalia macroptera Guill. & Perr.19Terminalia schimperiana Hochst.19Commiphora africana19Sclerocarya birrea19Ficus sycomorus19Sterculia africana19Securidaca longipedunculata110Combretum aculeatum310Combretum collinum310Combretum molle510Terminalia brownie410Terminalia laxiflora410Terminalia macroptera Guill. & Perr.110Terminalia schimperiana Hochst.110Commiphora africana110Commiphora habessinica110Sarcocephalus latifolius110Sterculia africana110Sclerocarya birrea111Combretum collinum411Combretum molle411Terminalia brownie511Terminalia laxiflora411Terminalia schimperiana Hochst.111Commiphora africana111Commiphora habessinica111Sclerocarya birrea111Sterculia africana111Ficus sycomorus112Combretum collinum412Combretum molle412Terminalia brownie512Terminalia laxiflora412Terminalia macroptera Guill. & Perr.112Terminalia schimperiana Hochst.112Commiphora africana112Sclerocarya birrea112Sarcocephalus latifolius112Securidaca longipedunculata113Combretum collinum413Combretum molle513Terminalia brownie413Terminalia laxiflora313Terminalia macroptera Guill. & Perr.113Commiphora africana113Sarcocephalus latifolius113Sclerocarya birrea114Combretum aculeatum214Combretum collinum414Combretum molle414Terminalia brownie514Terminalia laxiflora414Terminalia macroptera Guill. & Perr.114Terminalia schimperiana Hochst.114Commiphora africana114Ceiba pentandra114Ficus vasta Forssk.114Sterculia africana114Sclerocarya birrea115Combretum aculeatum315Combretum collinum315Combretum molle515Terminalia brownie415Terminalia laxiflora415Terminalia macroptera Guill. & Perr.115Sclerocarya birrea115Commiphora africana115Commiphora habessinica115Sarcocephalus latifolius115Sterculia africana115Securidaca longipedunculata116Combretum collinum416Combretum molle416Terminalia brownie516Terminalia laxiflora416Terminalia schimperiana Hochst116Commiphora africana116Commiphora habessinica116Salvadora persica116Sterculia africana116Ficus vasta Forssk.117Combretum collinum417Combretum molle417Terminalia brownie517Terminalia laxiflora417Salvadora persica117Terminalia schimperiana Hochst.117Commiphora africana117Ficus vasta Forssk117Sarcocephalus latifolius118Securidaca longipedunculata118Combretum collinum418Combretum molle518Terminalia brownie418Terminalia laxiflora318Terminalia macroptera Guill. & Perr.118Commiphora africana118Sarcocephalus latifolius118Sterculia africana119Terminalia brownie519Capparis erythrocarpus119Terminalia laxiflora419Salvadora persica119Tamarindus indica219Acacia oerfota119Maytenus senegalensis119Ziziphus mucronata220Terminalia brownie420Capparis erythrocarpus120Terminalia laxiflora420Boswellia rivae120Tamarindus indica220Acacia oerfota120Maytenus senegalensis120Grewia bicolor220Terminalia brownie520Capparis erythrocarpus120Terminalia laxiflora420Boswellia rivae120Tamarindus indica220Acacia oerfota120Grewia bicolor120Ziziphus mucronata121Terminalia brownie421Capparis erythrocarpus121Terminalia laxiflora421Boswellia rivae121Tamarindus indica221Grewia bicolor121Maytenus senegalensis121Ziziphus mucronata123Terminalia brownie523Terminalia laxiflora523Boswellia rivae123Tamarindus indica123Maytenus senegalensis123Ziziphus mucronata124Terminalia brownie524Capparis erythrocarpus124Terminalia laxiflora424Boswellia rivae124Tamarindus indica224Acacia oerfota124Maytenus senegalensis124Ziziphus mucronata225Terminalia brownie425Capparis erythrocarpus125Terminalia laxiflora425Boswellia rivae125Tamarindus indica225Acacia oerfota125Maytenus senegalensis125Ziziphus mucronata226Terminalia brownie526Capparis erythrocarpus126Terminalia laxiflora426Boswellia rivae126Tamarindus indica226Acacia oerfota126Maytenus senegalensis126Ziziphus mucronata127Terminalia brownie427Capparis erythrocarpus127Terminalia laxiflora427Boswellia rivae127Tamarindus indica227Acacia oerfota127Maytenus senegalensis127Ziziphus mucronata128Terminalia brownie528Terminalia laxiflora528Boswellia rivae128Tamarindus indica128Maytenus senegalensis128Ziziphus mucronata129Terminalia brownie429Terminalia laxiflora529Boswellia rivae129Tamarindus indica229Maytenus senegalensis129Ziziphus mucronata130Terminalia brownie530Terminalia laxiflora530Boswellia rivae130Tamarindus indica130Ricinus communis130Ziziphus mucronata131Terminalia brownie531Terminalia laxiflora531Boswellia rivae131Tamarindus indica131Maytenus senegalensis131Ricinus communis132Tamarindus indica532Terminalia brownie432Terminalia laxiflora332Steganotaenia araliacea132Strychnos innocua132Sterculia africana232Vitellaria paradoxa233Tamarindus indica533Terminalia brownie433Terminalia laxiflora433Ricinus communis133Strychnos innocua133Sterculia africana133Vitellaria paradoxa234Tamarindus indica434Terminalia brownie434Terminalia laxiflora334Steganotaenia araliacea134Ricinus communis134Sterculia africana134Vitellaria paradoxa135Tamarindus indica535Terminalia brownie435Terminalia laxiflora435Steganotaenia araliacea135Strychnos innocua135Sterculia africana135Vitellaria paradoxa236Tamarindus indica536Terminalia brownie436Terminalia laxiflora436Steganotaenia araliacea136Grewia mollis A.Juss.136Sterculia africana236Vitellaria paradoxa137Tamarindus indica537Terminalia brownie437Terminalia laxiflora437Steganotaenia araliacea137Strychnos innocua137Sterculia africana137Vitellaria paradoxa238Tamarindus indica438Terminalia brownie438Terminalia laxiflora338Grewia mollis A.Juss.138Strychnos innocua138Sterculia africana138Vitellaria paradoxa139Tamarindus indica539Terminalia brownie439Terminalia laxiflora439Steganotaenia araliacea139Strychnos innocua139Sterculia africana239Vitellaria paradoxa140Balanites aegyptiaca540Acacia seyal340Acacia senegal340Acacia polyacantha240Acacia tortilis240Acacia oerfota240Tamarindus indica140Flueggea virosa140Ziziphus mucronata140Piliostigma thonningii141Balanites aegyptiaca541Acacia seyal341Acacia senegal341Acacia polyacantha241Acacia tortilis241Acacia oerfota241Tamarindus indica141Flueggea virosa141Saba Florida (Benth.) Bullock142Balanites aegyptiaca542Acacia seyal442Acacia senegal342Acacia polyacantha242Acacia tortilis242Acacia oerfota242Flueggea virosa142Grewia mollis A.Juss.142Piliostigma thonningii143Balanites aegyptiaca543Acacia seyal343Acacia senegal343Acacia polyacantha243Acacia tortilis243Acacia oerfota243Tamarindus indica143Flueggea virosa143Ziziphus mucronata143Saba Florida (Benth.) Bullock144Balanites aegyptiaca544Acacia seyal344Acacia senegal344Acacia polyacantha244Acacia tortilis244Acacia oerfota244Tamarindus indica144Piliostigma thonningii144Saba Florida (Benth.) Bullock145Balanites aegyptiaca445Acacia seyal445Acacia senegal345Acacia polyacantha245Acacia tortilis345Acacia oerfota245Tamarindus indica145Grewia mollis A.Juss.145Capparis tomentosa146Balanites aegyptiaca546Acacia seyal446Acacia senegal346Acacia polyacantha246Acacia tortilis246Piliostigma thonningii246Flueggea virosa146Ziziphus mucronata146Capparis tomentosa147Balanites aegyptiaca547Acacia seyal347Acacia senegal347Acacia polyacantha247Acacia tortilis247Piliostigma thonningii247Tamarindus indica147Flueggea virosa147Ziziphus mucronata148Balanites aegyptiaca448Acacia seyal448Acacia senegal348Acacia polyacantha248Acacia tortilis348Acacia oerfota248Tamarindus indica148Flueggea virosa148Grewia tenax (Forssk.) Fiori149Balanites aegyptiaca549Acacia seyal449Acacia senegal349Acacia polyacantha249Acacia tortilis249Acacia oerfota249Flueggea virosa149Grewia tenax (Forssk.) Fiori149Capparis tomentosa150Balanites aegyptiaca550Acacia seyal350Acacia senegal350Acacia polyacantha250Acacia tortilis250Acacia oerfota250Grewia tenax (Forssk.) Fiori150Flueggea virosa150Ziziphus mucronata150Balanites aegyptiaca450Acacia seyal350Acacia senegal350Acacia polyacantha250Acacia tortilis350Acacia oerfota250Tamarindus indica150Flueggea virosa150Capparis tomentosa151Balanites aegyptiaca551Acacia seyal451Acacia senegal351Acacia polyacantha251Acacia tortilis251Acacia oerfota251Flueggea virosa151Ziziphus mucronata151Capparis tomentosa152Balanites aegyptiaca552Acacia seyal352Acacia senegal352Acacia polyacantha252Acacia tortilis252Acacia oerfota252Tamarindus indica152Flueggea virosa152Ziziphus mucronata152Capparis tomentosa153Balanites aegyptiaca553Acacia seyal353Acacia senegal353Acacia polyacantha253Acacia tortilis253Acacia oerfota253Tamarindus indica153Flueggea virosa153Ziziphus mucronata154Balanites aegyptiaca454Acacia seyal454Acacia senegal254Acacia polyacantha254Acacia tortilis354Acacia oerfota254Tamarindus indica154Flueggea virosa154Capparis tomentosa155Balanites aegyptiaca555Acacia seyal455Acacia senegal355Acacia polyacantha255Acacia tortilis255Acacia oerfota255Flueggea virosa155Ziziphus mucronata155Capparis tomentosa156Balanites aegyptiaca556Acacia seyal356Acacia senegal356Acacia polyacantha256Acacia tortilis256Acacia oerfota256Tamarindus indica156Flueggea virosa156Ziziphus mucronata156Capparis tomentosa157Balanites aegyptiaca557Acacia seyal357Acacia senegal357Acacia polyacantha257Acacia tortilis257Acacia oerfota257Tamarindus indica157Flueggea virosa157Ziziphus mucronata158Balanites aegyptiaca458Acacia seyal458Acacia senegal358Acacia polyacantha258Acacia tortilis358Acacia oerfota258Tamarindus indica158Flueggea virosa158Capparis tomentosa159Balanites aegyptiaca559Acacia seyal359Acacia senegal359Acacia polyacantha259Acacia tortilis259Acacia oerfota259Tamarindus indica159Flueggea virosa159Ziziphus mucronata159Capparis tomentosa160Balanites aegyptiaca560Acacia seyal360Acacia senegal360Acacia polyacantha260Acacia tortilis260Acacia oerfota260Tamarindus indica160Flueggea virosa160Ziziphus mucronata161Balanites aegyptiaca461Acacia seyal461Acacia senegal361Acacia polyacantha261Acacia tortilis361Acacia oerfota261Tamarindus indica161Flueggea virosa161Capparis tomentosa162Balanites aegyptiaca562Acacia seyal462Acacia senegal362Acacia polyacantha262Acacia tortilis262Acacia oerfota262Flueggea virosa162Ziziphus mucronata162Capparis tomentosa163Balanites aegyptiaca563Acacia seyal363Acacia senegal363Acacia polyacantha263Acacia tortilis263Acacia oerfota263Tamarindus indica163Flueggea virosa163Ziziphus mucronata163Capparis tomentosa164Balanites aegyptiaca564Acacia seyal364Acacia senegal364Acacia polyacantha264Acacia tortilis264Acacia oerfota264Tamarindus indica164Flueggea virosa164Ziziphus mucronata165Balanites aegyptiaca465Acacia seyal465Acacia senegal365Acacia polyacantha265Acacia tortilis365Acacia oerfota265Tamarindus indica165Flueggea virosa165Capparis tomentosa166Balanites aegyptiaca566Acacia seyal366Acacia senegal366Acacia polyacantha266Acacia tortilis266Acacia oerfota266Tamarindus indica166Flueggea virosa166Ziziphus mucronata166Capparis tomentosa167Balanites aegyptiaca567Acacia seyal367Acacia senegal367Acacia polyacantha267Acacia tortilis267Acacia oerfota267Tamarindus indica167Flueggea virosa167Ziziphus mucronata168Balanites aegyptiaca468Acacia seyal368Acacia senegal368Acacia polyacantha268Acacia tortilis368Acacia oerfota268Tamarindus indica168Flueggea virosa168Capparis tomentosa169Balanites aegyptiaca569Acacia seyal469Acacia senegal369Acacia polyacantha269Acacia tortilis269Acacia oerfota269Flueggea virosa169Ziziphus mucronata169Capparis tomentosa170Balanites aegyptiaca570Acacia seyal370Acacia senegal370Acacia polyacantha270Acacia tortilis270Acacia oerfota270Tamarindus indica170Flueggea virosa170Ziziphus mucronata171Balanites aegyptiaca471Acacia seyal471Acacia senegal371Acacia polyacantha271Acacia tortilis371Acacia oerfota271Tamarindus indica171Flueggea virosa171Capparis tomentosa172Balanites aegyptiaca572Acacia seyal472Acacia senegal372Acacia polyacantha272Acacia tortilis272Acacia oerfota272Flueggea virosa172Ziziphus mucronata172Capparis tomentosa173Balanites aegyptiaca573Acacia seyal373Acacia senegal373Acacia polyacantha273Acacia tortilis273Acacia oerfota273Tamarindus indica173Flueggea virosa173Ziziphus mucronata174Balanites aegyptiaca574Acacia seyal374Acacia senegal374Acacia polyacantha274Acacia tortilis274Acacia oerfota274Tamarindus indica174Flueggea virosa174Ziziphus mucronata175Balanites aegyptiaca475Acacia seyal375Acacia senegal375Acacia polyacantha275Acacia tortilis375Acacia oerfota275Tamarindus indica175Flueggea virosa175Capparis tomentosa176Balanites aegyptiaca576Acacia senegal376Acacia polyacantha276Acacia tortilis276Acacia oerfota276Flueggea virosa176Ziziphus mucronata177Balanites aegyptiaca577Acacia seyal377Acacia senegal377Acacia polyacantha277Acacia tortilis277Acacia oerfota277Tamarindus indica177Flueggea virosa177Ziziphus mucronata178Balanites aegyptiaca478Acacia seyal378Acacia senegal378Acacia polyacantha278Acacia tortilis378Acacia oerfota278Tamarindus indica178Flueggea virosa178Capparis tomentosa179Balanites aegyptiaca579Acacia seyal479Acacia senegal379Acacia polyacantha279Acacia tortilis279Acacia oerfota280Balanites aegyptiaca580Acacia seyal380Acacia Senegal380Acacia polyacantha280Acacia tortilis280Acacia oerfota280Tamarindus indica180Flueggea virosa180Ziziphus mucronata180Capparis tomentosa1Source: vegetation raw data for Ph.D. thesis, Gatluak [24].The maximum indicator values for group 1 species were observed forCombretum collinum (49%), Combretum molle (47%), Terminalia brownii (40%), and Terminalia laxiflora (32%). This group had formed the vegetation community known as Combretum collinum-Terminalia brownii community. The maximum indicator values for group 2 species were observed for Hyparrhenia rufa (26%), Oryza barthii (23%), and Oryza longistaminata (25%). This group formed Hyparrhenia rufa-Oryza longistaminata community (Table 2), while Cyprerus castaneus (48%) and Perpyrnuo cypress (40%) were species in group 3 with maximum indicator values. These species formed Cyprerus castaneus-Perpyrnuo cypress community.The maximum indicator values for group 4 species were observed forZiziphus mucronata (33%), Acacia senegal (32%), Acacia polyacantha (22%), Acacia nilotica (20%), and Hyparrhenia rufa (22%). These species formed Ziziphus mucronata-Acacia senegal-Hyparrhenia rufa community. Group 5 was named Acacia nilotica-Acacia bussei community because the maximum indicator values were observed in the Acacia nilotica (30%) and Acacia bussei (25%). The maximum indicator values for group 6 were observed in the Balanites aegyptiaca (32%), Acacia nilotica (22%), and Acacia asak (21%). These species formed vegetation community known as Balanites aegyptiaca-Acacia nilotica.


### 4.3. Habitat Types of Gambella National Park

The Rapid Eye image classified the Gambella National Park into five major habitat types which included woodland, wooded grassland, savanna, grassland, and wetlands (Figure3). Other minor habitat types classified on the map were temporary burned, water body, and rivers.Figure 3
Habitat types of Gambella National Park.The woodland comprised three vegetation community types. These wereCombretum collinum-Terminalia brownii, Acacia nilotica-Acacia bussei, and Balanites aegyptiaca-Acacia nilotica communities while Ziziphus mucronata-Acacia senegal-Hyparrhenia rufa community was found in wooded grassland habitat of the park. Hyparrhenia rufa-Oryza longistaminata and Cyperus castaneus-Perpyrnuo cypress community was found in open grassland and wetland, respectively.The classification of habitats for Gambella National Park had also shown that woodland in Gambella National Park cover an area of 1,716.50 square kilometers (37.92%) of the land cover of the park followed by wooded grassland which had an area coverage of 1,650.04 square kilometer (36.45%) of the land coverage of the park (Table4). The wetland had also relative large share of the area of the park, 645.99 square kilometer (14.27%) of the area coverage as compared with grassland and savannah, comprising 8.74% and 1.52% of the land coverage, respectively.Table 4
Area covered by each habitat type.
No.Habitat classificationArea in km2Percentage1Grassland395.508.742Savannah68.631.525Wet land645.9914.274Wooded grassland1650.0436.453Woodland1716.5037.926Others6.1Settlements/roads0.160.006.2Temporary burned23.150.506.3Water body27.150.60Total4,527.12100


## 4.1. Cluster Classification of Plant Species of Gambella National Park

Six vegetation groups were identified using cluster analysis in combination with multiresponse permutation procedure (MRPP) and the cutoff for this classification was 50% (Figure2).Figure 2
Dendrogram of cluster analysis results of species abundance data of the studied plant species of Gambella National Park. Plots forming the same cluster have similar symbols.From 80 sample plots, 4 plots were considered as outliers and thus were excluded from the cluster analysis.The T value statistic for six groups was −1.28 (P<0.001) which indicated the significant different at P value, while the statistic chance-corrected within group agreement was 0.1. The T statistic is based on Pearson type III distribution. The P value associated with T is determined by numerical integration of type III distribution (Table 1). A statistic is descriptor within a group homogeneity falling between 0 and 1 (Table 1). When the items are identical, A = 1. Therefore, A statistic is equal to 1 when all items are identical within groups while the delta is equal to 0. A = 0 when heterogeneity within groups equals expectation by chance.Table 1
Chance within group agreement.
Chance corrected within group agreement,A = 0.07734179A = 1—(observed delta/expected delta)Amax = 1 when all items are identical within groups (delta = 0)A statistic is descriptor within a group homogeneity falling between 0 and 1A = 0 when heterogeneity within groups equals expectation by chanceA < 0 with more heterogeneity within groups than expected by chanceProbability of a smaller or equal delta,P = 0.00143541Skewness of delta = Pearson type II distributionSource, 2017 source: result of vegetation analysis, Gatluak, [24]


## 4.2. Naming of Vegetation Communities by Indicator Species of Study Plant of Gambella National Park

The 6 vegetation communities were named based on indicator values indicated by percent prefect indication value (combining relative abundance and relative frequency) (Tables2 and 3). The species in bold for each group is one with the maximum indicator values for combining relative abundance and relative frequency.Table 2
Indicator values (% of perfect indication based on combining values for relative abundance and relative frequency).
GroupSequence123456Identifier156879Number of items301111888Species MaxGrpCombretum collinum14907940Combretum molle14710000Cyperus castaneus30048000Hyparrhenia rufa202602200Oryza barthii20230100Oryza longistaminata20250000Perpyrnuo cypress32840000Terminalia brownii14000000Terminalia laxiflora13200000Ziziphus mucronata46363300MaxGrp = maximum indicator value in group.Table 3
Data for vegetation abundance of Gambella National Park.
Plot no.Species nameAbundance1Combretum aculeatum21Combretum collinum41Combretum molle41Terminalia brownie51Terminalia laxiflora41Terminalia macroptera Guill. & Perr.11Terminalia schimperiana Hochst.11Commiphora africana11Commiphora habessinica11Albizia malacophylla11Sterculia africana11Securidaca longipedunculata12Combretum collinum42Combretum molle42Terminalia brownie52Terminalia laxiflora42Terminalia schimperiana Hochst12Commiphora africana12Commiphora habessinica12Cordia africana12Sterculia africana12Securidaca longipedunculata13Combretum collinum43Combretum molle43Terminalia brownie53Terminalia laxiflora43Terminalia macroptera Guill. & Perr.13Terminalia schimperiana Hochst.13Commiphora africana133Diospyros mespiliformis113Celtis toka13Securidaca longipedunculata14Combretum collinum44Combretum molle54Terminalia brownie44Terminalia laxiflora34Terminalia macroptera Guill. & Perr.14Diospyros mespiliformis14Sarcocephalus latifolius14Sterculia africana15Combretum aculeatum25Combretum collinum45Combretum molle45Terminalia brownie55Terminalia laxiflora45Terminalia macroptera Guill. & Perr.15Terminalia schimperiana Hochst.15Commiphora africana15Diospyros mespiliformis15Sarcocephalus latifolius15Sterculia africana15Securidaca longipedunculata16Combretum collinum46Combretum molle46Terminalia brownie56Terminalia laxiflora46Terminalia schimperiana Hochst.16Commiphora africana16Commiphora habessinica16Sarcocephalus latifolius16Sterculia africana16Securidaca longipedunculata17Combretum collinum47Combretum molle47Terminalia brownie57Terminalia laxiflora47Terminalia macroptera Guill. & Perr.17Terminalia schimperiana Hochst.17Commiphora africana17Commiphora habessinica17Sarcocephalus latifolius17Securidaca longipedunculata18Combretum collinum48Combretum molle58Terminalia brownie48Terminalia laxiflora38Terminalia macroptera Guill. & Perr.18Commiphora africana18Sarcocephalus latifolius18Ficus sycomorus19Combretum aculeatum29Combretum collinum49Combretum molle49Terminalia brownie59Terminalia laxiflora49Terminalia macroptera Guill. & Perr.19Terminalia schimperiana Hochst.19Commiphora africana19Sclerocarya birrea19Ficus sycomorus19Sterculia africana19Securidaca longipedunculata110Combretum aculeatum310Combretum collinum310Combretum molle510Terminalia brownie410Terminalia laxiflora410Terminalia macroptera Guill. & Perr.110Terminalia schimperiana Hochst.110Commiphora africana110Commiphora habessinica110Sarcocephalus latifolius110Sterculia africana110Sclerocarya birrea111Combretum collinum411Combretum molle411Terminalia brownie511Terminalia laxiflora411Terminalia schimperiana Hochst.111Commiphora africana111Commiphora habessinica111Sclerocarya birrea111Sterculia africana111Ficus sycomorus112Combretum collinum412Combretum molle412Terminalia brownie512Terminalia laxiflora412Terminalia macroptera Guill. & Perr.112Terminalia schimperiana Hochst.112Commiphora africana112Sclerocarya birrea112Sarcocephalus latifolius112Securidaca longipedunculata113Combretum collinum413Combretum molle513Terminalia brownie413Terminalia laxiflora313Terminalia macroptera Guill. & Perr.113Commiphora africana113Sarcocephalus latifolius113Sclerocarya birrea114Combretum aculeatum214Combretum collinum414Combretum molle414Terminalia brownie514Terminalia laxiflora414Terminalia macroptera Guill. & Perr.114Terminalia schimperiana Hochst.114Commiphora africana114Ceiba pentandra114Ficus vasta Forssk.114Sterculia africana114Sclerocarya birrea115Combretum aculeatum315Combretum collinum315Combretum molle515Terminalia brownie415Terminalia laxiflora415Terminalia macroptera Guill. & Perr.115Sclerocarya birrea115Commiphora africana115Commiphora habessinica115Sarcocephalus latifolius115Sterculia africana115Securidaca longipedunculata116Combretum collinum416Combretum molle416Terminalia brownie516Terminalia laxiflora416Terminalia schimperiana Hochst116Commiphora africana116Commiphora habessinica116Salvadora persica116Sterculia africana116Ficus vasta Forssk.117Combretum collinum417Combretum molle417Terminalia brownie517Terminalia laxiflora417Salvadora persica117Terminalia schimperiana Hochst.117Commiphora africana117Ficus vasta Forssk117Sarcocephalus latifolius118Securidaca longipedunculata118Combretum collinum418Combretum molle518Terminalia brownie418Terminalia laxiflora318Terminalia macroptera Guill. & Perr.118Commiphora africana118Sarcocephalus latifolius118Sterculia africana119Terminalia brownie519Capparis erythrocarpus119Terminalia laxiflora419Salvadora persica119Tamarindus indica219Acacia oerfota119Maytenus senegalensis119Ziziphus mucronata220Terminalia brownie420Capparis erythrocarpus120Terminalia laxiflora420Boswellia rivae120Tamarindus indica220Acacia oerfota120Maytenus senegalensis120Grewia bicolor220Terminalia brownie520Capparis erythrocarpus120Terminalia laxiflora420Boswellia rivae120Tamarindus indica220Acacia oerfota120Grewia bicolor120Ziziphus mucronata121Terminalia brownie421Capparis erythrocarpus121Terminalia laxiflora421Boswellia rivae121Tamarindus indica221Grewia bicolor121Maytenus senegalensis121Ziziphus mucronata123Terminalia brownie523Terminalia laxiflora523Boswellia rivae123Tamarindus indica123Maytenus senegalensis123Ziziphus mucronata124Terminalia brownie524Capparis erythrocarpus124Terminalia laxiflora424Boswellia rivae124Tamarindus indica224Acacia oerfota124Maytenus senegalensis124Ziziphus mucronata225Terminalia brownie425Capparis erythrocarpus125Terminalia laxiflora425Boswellia rivae125Tamarindus indica225Acacia oerfota125Maytenus senegalensis125Ziziphus mucronata226Terminalia brownie526Capparis erythrocarpus126Terminalia laxiflora426Boswellia rivae126Tamarindus indica226Acacia oerfota126Maytenus senegalensis126Ziziphus mucronata127Terminalia brownie427Capparis erythrocarpus127Terminalia laxiflora427Boswellia rivae127Tamarindus indica227Acacia oerfota127Maytenus senegalensis127Ziziphus mucronata128Terminalia brownie528Terminalia laxiflora528Boswellia rivae128Tamarindus indica128Maytenus senegalensis128Ziziphus mucronata129Terminalia brownie429Terminalia laxiflora529Boswellia rivae129Tamarindus indica229Maytenus senegalensis129Ziziphus mucronata130Terminalia brownie530Terminalia laxiflora530Boswellia rivae130Tamarindus indica130Ricinus communis130Ziziphus mucronata131Terminalia brownie531Terminalia laxiflora531Boswellia rivae131Tamarindus indica131Maytenus senegalensis131Ricinus communis132Tamarindus indica532Terminalia brownie432Terminalia laxiflora332Steganotaenia araliacea132Strychnos innocua132Sterculia africana232Vitellaria paradoxa233Tamarindus indica533Terminalia brownie433Terminalia laxiflora433Ricinus communis133Strychnos innocua133Sterculia africana133Vitellaria paradoxa234Tamarindus indica434Terminalia brownie434Terminalia laxiflora334Steganotaenia araliacea134Ricinus communis134Sterculia africana134Vitellaria paradoxa135Tamarindus indica535Terminalia brownie435Terminalia laxiflora435Steganotaenia araliacea135Strychnos innocua135Sterculia africana135Vitellaria paradoxa236Tamarindus indica536Terminalia brownie436Terminalia laxiflora436Steganotaenia araliacea136Grewia mollis A.Juss.136Sterculia africana236Vitellaria paradoxa137Tamarindus indica537Terminalia brownie437Terminalia laxiflora437Steganotaenia araliacea137Strychnos innocua137Sterculia africana137Vitellaria paradoxa238Tamarindus indica438Terminalia brownie438Terminalia laxiflora338Grewia mollis A.Juss.138Strychnos innocua138Sterculia africana138Vitellaria paradoxa139Tamarindus indica539Terminalia brownie439Terminalia laxiflora439Steganotaenia araliacea139Strychnos innocua139Sterculia africana239Vitellaria paradoxa140Balanites aegyptiaca540Acacia seyal340Acacia senegal340Acacia polyacantha240Acacia tortilis240Acacia oerfota240Tamarindus indica140Flueggea virosa140Ziziphus mucronata140Piliostigma thonningii141Balanites aegyptiaca541Acacia seyal341Acacia senegal341Acacia polyacantha241Acacia tortilis241Acacia oerfota241Tamarindus indica141Flueggea virosa141Saba Florida (Benth.) Bullock142Balanites aegyptiaca542Acacia seyal442Acacia senegal342Acacia polyacantha242Acacia tortilis242Acacia oerfota242Flueggea virosa142Grewia mollis A.Juss.142Piliostigma thonningii143Balanites aegyptiaca543Acacia seyal343Acacia senegal343Acacia polyacantha243Acacia tortilis243Acacia oerfota243Tamarindus indica143Flueggea virosa143Ziziphus mucronata143Saba Florida (Benth.) Bullock144Balanites aegyptiaca544Acacia seyal344Acacia senegal344Acacia polyacantha244Acacia tortilis244Acacia oerfota244Tamarindus indica144Piliostigma thonningii144Saba Florida (Benth.) Bullock145Balanites aegyptiaca445Acacia seyal445Acacia senegal345Acacia polyacantha245Acacia tortilis345Acacia oerfota245Tamarindus indica145Grewia mollis A.Juss.145Capparis tomentosa146Balanites aegyptiaca546Acacia seyal446Acacia senegal346Acacia polyacantha246Acacia tortilis246Piliostigma thonningii246Flueggea virosa146Ziziphus mucronata146Capparis tomentosa147Balanites aegyptiaca547Acacia seyal347Acacia senegal347Acacia polyacantha247Acacia tortilis247Piliostigma thonningii247Tamarindus indica147Flueggea virosa147Ziziphus mucronata148Balanites aegyptiaca448Acacia seyal448Acacia senegal348Acacia polyacantha248Acacia tortilis348Acacia oerfota248Tamarindus indica148Flueggea virosa148Grewia tenax (Forssk.) Fiori149Balanites aegyptiaca549Acacia seyal449Acacia senegal349Acacia polyacantha249Acacia tortilis249Acacia oerfota249Flueggea virosa149Grewia tenax (Forssk.) Fiori149Capparis tomentosa150Balanites aegyptiaca550Acacia seyal350Acacia senegal350Acacia polyacantha250Acacia tortilis250Acacia oerfota250Grewia tenax (Forssk.) Fiori150Flueggea virosa150Ziziphus mucronata150Balanites aegyptiaca450Acacia seyal350Acacia senegal350Acacia polyacantha250Acacia tortilis350Acacia oerfota250Tamarindus indica150Flueggea virosa150Capparis tomentosa151Balanites aegyptiaca551Acacia seyal451Acacia senegal351Acacia polyacantha251Acacia tortilis251Acacia oerfota251Flueggea virosa151Ziziphus mucronata151Capparis tomentosa152Balanites aegyptiaca552Acacia seyal352Acacia senegal352Acacia polyacantha252Acacia tortilis252Acacia oerfota252Tamarindus indica152Flueggea virosa152Ziziphus mucronata152Capparis tomentosa153Balanites aegyptiaca553Acacia seyal353Acacia senegal353Acacia polyacantha253Acacia tortilis253Acacia oerfota253Tamarindus indica153Flueggea virosa153Ziziphus mucronata154Balanites aegyptiaca454Acacia seyal454Acacia senegal254Acacia polyacantha254Acacia tortilis354Acacia oerfota254Tamarindus indica154Flueggea virosa154Capparis tomentosa155Balanites aegyptiaca555Acacia seyal455Acacia senegal355Acacia polyacantha255Acacia tortilis255Acacia oerfota255Flueggea virosa155Ziziphus mucronata155Capparis tomentosa156Balanites aegyptiaca556Acacia seyal356Acacia senegal356Acacia polyacantha256Acacia tortilis256Acacia oerfota256Tamarindus indica156Flueggea virosa156Ziziphus mucronata156Capparis tomentosa157Balanites aegyptiaca557Acacia seyal357Acacia senegal357Acacia polyacantha257Acacia tortilis257Acacia oerfota257Tamarindus indica157Flueggea virosa157Ziziphus mucronata158Balanites aegyptiaca458Acacia seyal458Acacia senegal358Acacia polyacantha258Acacia tortilis358Acacia oerfota258Tamarindus indica158Flueggea virosa158Capparis tomentosa159Balanites aegyptiaca559Acacia seyal359Acacia senegal359Acacia polyacantha259Acacia tortilis259Acacia oerfota259Tamarindus indica159Flueggea virosa159Ziziphus mucronata159Capparis tomentosa160Balanites aegyptiaca560Acacia seyal360Acacia senegal360Acacia polyacantha260Acacia tortilis260Acacia oerfota260Tamarindus indica160Flueggea virosa160Ziziphus mucronata161Balanites aegyptiaca461Acacia seyal461Acacia senegal361Acacia polyacantha261Acacia tortilis361Acacia oerfota261Tamarindus indica161Flueggea virosa161Capparis tomentosa162Balanites aegyptiaca562Acacia seyal462Acacia senegal362Acacia polyacantha262Acacia tortilis262Acacia oerfota262Flueggea virosa162Ziziphus mucronata162Capparis tomentosa163Balanites aegyptiaca563Acacia seyal363Acacia senegal363Acacia polyacantha263Acacia tortilis263Acacia oerfota263Tamarindus indica163Flueggea virosa163Ziziphus mucronata163Capparis tomentosa164Balanites aegyptiaca564Acacia seyal364Acacia senegal364Acacia polyacantha264Acacia tortilis264Acacia oerfota264Tamarindus indica164Flueggea virosa164Ziziphus mucronata165Balanites aegyptiaca465Acacia seyal465Acacia senegal365Acacia polyacantha265Acacia tortilis365Acacia oerfota265Tamarindus indica165Flueggea virosa165Capparis tomentosa166Balanites aegyptiaca566Acacia seyal366Acacia senegal366Acacia polyacantha266Acacia tortilis266Acacia oerfota266Tamarindus indica166Flueggea virosa166Ziziphus mucronata166Capparis tomentosa167Balanites aegyptiaca567Acacia seyal367Acacia senegal367Acacia polyacantha267Acacia tortilis267Acacia oerfota267Tamarindus indica167Flueggea virosa167Ziziphus mucronata168Balanites aegyptiaca468Acacia seyal368Acacia senegal368Acacia polyacantha268Acacia tortilis368Acacia oerfota268Tamarindus indica168Flueggea virosa168Capparis tomentosa169Balanites aegyptiaca569Acacia seyal469Acacia senegal369Acacia polyacantha269Acacia tortilis269Acacia oerfota269Flueggea virosa169Ziziphus mucronata169Capparis tomentosa170Balanites aegyptiaca570Acacia seyal370Acacia senegal370Acacia polyacantha270Acacia tortilis270Acacia oerfota270Tamarindus indica170Flueggea virosa170Ziziphus mucronata171Balanites aegyptiaca471Acacia seyal471Acacia senegal371Acacia polyacantha271Acacia tortilis371Acacia oerfota271Tamarindus indica171Flueggea virosa171Capparis tomentosa172Balanites aegyptiaca572Acacia seyal472Acacia senegal372Acacia polyacantha272Acacia tortilis272Acacia oerfota272Flueggea virosa172Ziziphus mucronata172Capparis tomentosa173Balanites aegyptiaca573Acacia seyal373Acacia senegal373Acacia polyacantha273Acacia tortilis273Acacia oerfota273Tamarindus indica173Flueggea virosa173Ziziphus mucronata174Balanites aegyptiaca574Acacia seyal374Acacia senegal374Acacia polyacantha274Acacia tortilis274Acacia oerfota274Tamarindus indica174Flueggea virosa174Ziziphus mucronata175Balanites aegyptiaca475Acacia seyal375Acacia senegal375Acacia polyacantha275Acacia tortilis375Acacia oerfota275Tamarindus indica175Flueggea virosa175Capparis tomentosa176Balanites aegyptiaca576Acacia senegal376Acacia polyacantha276Acacia tortilis276Acacia oerfota276Flueggea virosa176Ziziphus mucronata177Balanites aegyptiaca577Acacia seyal377Acacia senegal377Acacia polyacantha277Acacia tortilis277Acacia oerfota277Tamarindus indica177Flueggea virosa177Ziziphus mucronata178Balanites aegyptiaca478Acacia seyal378Acacia senegal378Acacia polyacantha278Acacia tortilis378Acacia oerfota278Tamarindus indica178Flueggea virosa178Capparis tomentosa179Balanites aegyptiaca579Acacia seyal479Acacia senegal379Acacia polyacantha279Acacia tortilis279Acacia oerfota280Balanites aegyptiaca580Acacia seyal380Acacia Senegal380Acacia polyacantha280Acacia tortilis280Acacia oerfota280Tamarindus indica180Flueggea virosa180Ziziphus mucronata180Capparis tomentosa1Source: vegetation raw data for Ph.D. thesis, Gatluak [24].The maximum indicator values for group 1 species were observed forCombretum collinum (49%), Combretum molle (47%), Terminalia brownii (40%), and Terminalia laxiflora (32%). This group had formed the vegetation community known as Combretum collinum-Terminalia brownii community. The maximum indicator values for group 2 species were observed for Hyparrhenia rufa (26%), Oryza barthii (23%), and Oryza longistaminata (25%). This group formed Hyparrhenia rufa-Oryza longistaminata community (Table 2), while Cyprerus castaneus (48%) and Perpyrnuo cypress (40%) were species in group 3 with maximum indicator values. These species formed Cyprerus castaneus-Perpyrnuo cypress community.The maximum indicator values for group 4 species were observed forZiziphus mucronata (33%), Acacia senegal (32%), Acacia polyacantha (22%), Acacia nilotica (20%), and Hyparrhenia rufa (22%). These species formed Ziziphus mucronata-Acacia senegal-Hyparrhenia rufa community. Group 5 was named Acacia nilotica-Acacia bussei community because the maximum indicator values were observed in the Acacia nilotica (30%) and Acacia bussei (25%). The maximum indicator values for group 6 were observed in the Balanites aegyptiaca (32%), Acacia nilotica (22%), and Acacia asak (21%). These species formed vegetation community known as Balanites aegyptiaca-Acacia nilotica.


## 4.3. Habitat Types of Gambella National Park

The Rapid Eye image classified the Gambella National Park into five major habitat types which included woodland, wooded grassland, savanna, grassland, and wetlands (Figure3). Other minor habitat types classified on the map were temporary burned, water body, and rivers.Figure 3
Habitat types of Gambella National Park.The woodland comprised three vegetation community types. These wereCombretum collinum-Terminalia brownii, Acacia nilotica-Acacia bussei, and Balanites aegyptiaca-Acacia nilotica communities while Ziziphus mucronata-Acacia senegal-Hyparrhenia rufa community was found in wooded grassland habitat of the park. Hyparrhenia rufa-Oryza longistaminata and Cyperus castaneus-Perpyrnuo cypress community was found in open grassland and wetland, respectively.The classification of habitats for Gambella National Park had also shown that woodland in Gambella National Park cover an area of 1,716.50 square kilometers (37.92%) of the land cover of the park followed by wooded grassland which had an area coverage of 1,650.04 square kilometer (36.45%) of the land coverage of the park (Table4). The wetland had also relative large share of the area of the park, 645.99 square kilometer (14.27%) of the area coverage as compared with grassland and savannah, comprising 8.74% and 1.52% of the land coverage, respectively.Table 4
Area covered by each habitat type.
No.Habitat classificationArea in km2Percentage1Grassland395.508.742Savannah68.631.525Wet land645.9914.274Wooded grassland1650.0436.453Woodland1716.5037.926Others6.1Settlements/roads0.160.006.2Temporary burned23.150.506.3Water body27.150.60Total4,527.12100


## 5. Conclusion

It can be concluded that at microlevel the Gambella National Park is classified into 6 vegetation communities, whereas at a large level of the park, it was classified into 5 major habitat types.



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*Source: 8612593-2020-06-16.xml*