Woody Species Composition, Structure, and Status of Regeneration in Pugnido Forest, Gambella Region, Western Ethiopia

Wabero forest is one of the very few remnant moist evergreen montane forests in Southeast Ethiopia. However, basic data on vegetation structure and composition of the forest that could provide valuable information for possible conservation measures is lacking. The main objective of this study, therefore, was to investigate the woody species composition, vegetation structure and regeneration status of the forest. In the study 30 quadrants of 20 m by 20 m were used for woody species data and 5 m by 5 m for sapling and seedling in a nested form. The sample quadrants were laid down along transects at a distance of 300 m from each other. Diameters at breast height (DBH), basal area, frequency and importance value index were used for analysis of vegetation structure. In the study, a total of 47 woody plant species belonging to 43 genera and 33 families were recorded. The major families were Rubiaceae and Rutaceae each represented by four species followed by Sapindaceae, Moraceae and Oleaceae each represented by three species. The rest of the 28 families were represented by one or two species, only. The mean density of all the woody species recorded in the study site was 21,737 ha-1. Diospyros abyssinica, Podocarpus falcatus, Strychnos mitis, Celtis africana and Coffea arabica were found to be the most dominant and frequent species with the highest importance value index. Results of regeneration status of the forest, which was analyzed by comparing number of seedling and sapling with mature trees, revealed that the forest is under good regeneration status. Therefore, based on the results of the study, awareness creation and implementation of participatory forest management strategy is recommended in order to sustain the forest. Key words: Basal area, diameters at breast height (DBH), importance value index, Montane forest, woody species composition.

The study was conducted on Gemechis natural forest, West Hararghe, Oromia Regional state, Ethiopia with the objective of determining the floristic composition, structural analysis and regeneration of wood plant species. Systematic sampling was used to collect vegetation data. Accordingly,50 sampling quadrats of 20 m x 20 m were laid along six line transects at every 50 m interval within which five 5 m x 5 m small quadrats were laied to sample woody species with <2cm DBH (diameter at breast height). In each quadrat, all live woody species were recorded with their number counted and DBH measured for those with DBH>2cm. Fifty one (51) woody species belonging to 50 genera and 34 families were recorded in the forest. The collected specimens were composed of 64.7% of tree, 31.3% shrubs and 3.9% of lianas. The most species rich families were Rosaceae, Lamiaceae and Myrsinaceae. Shannon diversity index and evenness of woody species of the Gemechis natural forest were 3.04 and 0.77, respectively. The total density of woody species recorded in Gemechis forest was 3430 individuals ha -1 . . Total basal area of woody species in the study area was 31.12 m 2 h -1 . The dominant and ecologically most important tree species in Gemechis Forest on the basis of their importance value index( IVI) values were Maesa lanceolata (19.2), Rytigna neglecta (16.9), Maytenus sp. (15.9), Bersama abyssinica (14.2), Argomuellera macrophyllab (11.7), Dovyalis caffra (10.9), Teclea nobilis (9.24) and Vernonia amygdalina (7.3). Cummulative DBH class distribution showed that large number of individuals fall in lower DBH class, which shows that this vegetations is in a good regeneration status. However, as some species are of irregular population structure and low IVI further study should be conducted to identify factors that negatively affect them. In general, the data from this study showed that the forest had high species diversity. From the cummulative DBH class distribution of the study area, the number of individuals that fall in lower DBH classes were higher than their number at higher DBH classes which indicate that seedlings and sapling were more in number than the mature/older woody species which suggesting that vegetation of Gemechis forest was generally in a good regeneration status. Keywords : Basal area, Diameter at breast highest, Gemechis forest, Important value index, Woody species DOI : 10.7176/JBAH/9-1-07

Ethiopia is one of the countries in the world endowed with rich biological resources. However, due to human impacts, the forest cover in Ethiopia has been decreasing rapidly. The study was carried out with the purpose of finding out the Regeneration Status, Population Structure and Floristic composition of Woody Plant Species in Sheleko Medihanialem Natural Forest in Gondar, North West Ethiopia, from October 2019 to September 2020. The systematic vegetation sampling method was used to collect data from Fifty plots of 20 m × 20 m (400 m2) along five line transects. In addition, five, 5 m × 5 m subplots were laid within the main plot to sample seedlings and saplings. The floristic composition and population structure of woody individuals of trees and shrubs with a diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 2 m were measured. DBH ≤ 2.5 cm and less than 1 m height were considered as seedlings and DBH ≥ 2.5 cm and height of 1 - 2 m as saplings. Vegetation data of density, frequency, basal area, and importance value index were computed. A total of 65 woody plant species in 54 genera and 34 plant families were recorded. Fabaceae, Moraceae and Euphorbiaceae were the dominant families in terms of species richness. Woody species densities for mature individuals were 2202.5 stems∙ha−1, seedling 2419.2 stems∙ha−1 and sapling 1737.6 stems∙ha−1. The forest was dominated by small-sized/young trees and shrubs, indicating the status of secondary growth and/or regeneration.

Protected areas are the most commonly used tool for in situ conservation of biodiversity. Selective removal of species proposed by the local communities living surrounding the national park and grazing pressure negatively affect the composition, structure, and regeneration of woody species. Assessment of vegetation structure and regeneration status of woody species is essential for orienting management activities. The purpose of this study was to investigate the floristic composition, population structure, and regeneration status of woody species in the Loka Abaya National Park, to design conservation strategies. A total of 99, 20 m × 20 m quadrats were systematically laid along an established line transect to collect a list of woody species, abundance, height, and diameter at breast height (DBH), while five 3 m × 3 m subquadrats within the main quadrats were established to assess the regeneration status of woody species. In each quadrat, all woody species were identified, counted, and recorded. In each quadrat, all tree and shrub species higher than ≥2 m in height and ≥2 cm in diameter at breast height were measured by a calibrated wooden stick and by a caliper, respectively. Density, frequency, basal area, importance value index (IVI), height, and diameter at breast height (DBH) were used for description of vegetation structure, while the density of mature trees, saplings, and seedlings was used for assessment of regeneration status of woody species. A total of 101 woody plant species representing 40 families in 69 genera were collected, identified, and documented. Fabaceae was the most diverse family representing 16 (15.84%) species, followed by Euphorbiaceae 9 species (8.91%) and Anacardiaceae with 6 species (5.94%). Four families including Combretaceae, Moraceae, Olacaceae, and Tiliaceae were represented by 4 species each. 4 families were also represented by 3 species each, 12 families were represented by two species each, and 18 families were represented by one species. The density of trees was 831.31 individuals ha−1, while the total basal area was 73.18 m2·ha−1. D. angustifolia, C. molle, E. schimperi, R. natalensis, O. europaea L. subsp. cuspidataD. cinerea, A. brevispica, I. mitis, and E. tirucalli were ecologically important woody species. The majority (75%) of woody plant species had a less than 5% importance value index (IVI). The diameter class distribution of selected tree species demonstrated various patterns of population structure, implying the existence of different population dynamics among ecologically important tree species. The regeneration assessment results demonstrate that 32.35% had poor regeneration, 19.12% had good regeneration, 16.17% had fair regeneration, 8.82% lacked regeneration, and 14.08% appeared as newly regenerated species in the national park. The majority of woody species had a small population size, and some of them were found in specific habitats which need attention for conservation, and those woody species lack regeneration study soil seed bank and propagation methods for sustainable conservation.

Information on species composition, structure, and diversity is essential to introduce and select different management activities to improve the forest productivity. Accordingly, species composition, structure, diversity, and regeneration status of trees were assessed in the Dindin natural forest. In this forest, trees or shrubs having ≥2.5 cm diameter at breast height and height &gt;1.5 m were identified and measured in 35 quadrats of 20 m × 20 m. Regeneration status was assessed in 5 m × 5 m subplots that were laid within each main plot to sample seedling and sapling. Woody species diversity, density, basal area, and importance value index were calculated. To prioritize conservation efforts, the study utilized factors such as the importance value index, seedling and sapling densities, and population structure. A total of 42 woody tree species representing 30 families were recorded in the forest. The diversity and evenness of woody species in the Dindin forest were 2.66 and 0.70, respectively. Woody species density was 1403 individual ha−1, and the total basal area was 35.54 m2ha−1. About 480 seedlings per hectare were recorded in the Dindin forest. The research yielded practical insights into the dominance, population structure, importance value, and regeneration status of tree species. The analysis of population structure indicates that certain dominant species are experiencing inadequate regeneration. In addition, multiple nondominant shrubs and tree species within the forest are also at risk of extinction due to insufficient regeneration. Therefore, these important findings play a crucial role in the formulation and implementation of effective strategies to restore and rehabilitate the studied forest.

In this study, Floristic composition, diversity, population structure and regeneration status of woody plant species of Yegof Forest in South Wollo Zone, Amhara Regional State, Ethiopia were analyzed. Data were collected from 72 quadrants, each of which was 20 m × 20 m area. Sorensen‟s similarity coefficient was used to detect similarities and differences among different forests of Ethiopia. Shannon -Wiener diversity index was applied to quantify species diversity and richness. A total of 123 vascular plant species, representing 109 genera and 63 families were recorded. One hundred and twelve of the species collected from sample plots were used for floristic and structural analysis. The rest 11 were collected out of the sample plots but from the same forest and were used to describe the complete floristic list. Out of the total plant species which have been included in the preliminary list assessed for IUCN Red data List, 9 were found to be endemic to Ethiopia. The family Fabaceae had the highest number of species (8) followed by Asteraceae (7 species), Poaceae (6 species), Lamiaceae and Solanaceae (5 species each). The five most abundant woody plant species in the forest were Dodonaea angustifolia, Myrsine africana, Olea europaea subsp cuspidata, Juniperus procera and Erica arborea. In the forest, the overall Shannon-Wiener diversity was 3.73 and evenness of woody species was 0.79, indicating that the diversity and evenness of woody species in the forest is relatively high. Woody species density for mature individuals was 1685 stems ha-1, density of saplings was 1800 stems ha-1 and the density of seedlings was 2089 stems ha-1. Density decreased with increasing tree height and DBH classes. The basal area of the forest was 25.4 m2/ha. We prioritized tree species for conservation using criteria such as species population structure, important value index and regeneration status. The population structure in the forest revealed that there is a need for conservation priority of woody plant with poor regeneration status. Based on the result of the study, research on the soil seed bank, population dynamics and ethno botany are recommended. Keywords: Floristic composition, Endemic species, IUCN Red list Phytogeographical Comparison, Population Structure, Yegof Forest

Dry evergreen Afromontane forests are severely threatened due to the expansion of agriculture and overgrazing by livestock. The objective of this study was to investigate the composition of woody species, structure, regeneration status and plant communities in Seqela forest, as well as the relationship between plant community types and environmental variables. Systematic sampling was used to collect vegetation and environmental data from 52 (20 m x 20 m) (400 m2) plots. Density, Diameter at Breast Height (DBH), basal area, frequency, and importance value index (IVI) of woody species were computed to characterize the vegetation structure of the forest. Agglomerative hierarchical cluster analysis and Canonical Correspondence Analysis (CCA) with R software were used to identify plant communities and analyse the relationship between plant community types and environmental variables, respectively. A total of 68 woody plant species belonging to 63 genera and 44 families were identified. The Shannon diversity index and evenness values of the study area were 2.12 and 0.92, respectively. The total basal area and density of woody species were 27.4 m2 ha-1 and 1079.3 individual ha-1, respectively. The most frequent woody species in the Seqela forest included Albizia gummifera (51.92%), Croton macrostachyus (44.23%), Olinia rochetiana and Teclea nobilis (36.54%). Additionally, the most dominant species, as indicated by their importance value index (IVI), were Erythrina brucei (IVI = 11.24), Prunus africana (IVI=8.68), and Croton macrostachyus (IVI=7.38). Four plant community types were identified: Albizia gummifera - Ekebergia capensis, Prunus africana - Croton macrostachyus, Vachellia abyssinica - Dombeya torrida and Schefflera abyssinica - Teclea nobilis. The CCA results showed that the variation of species distribution and plant community formation were significantly (P < 0.05) related to altitude, organic matter, aspect, slope and soil available phosphorus. The regeneration status assessment of the forest revealed a good regeneration status, which was linked to diverse and abundant seed bank in the soil can ensure a continuous supply of seeds for regeneration; therefore, it is recommended to implement periodic soil seed bank assessments to monitor seed diversity and abundance and inform targeted conservation actions.

Dry evergreen Afromontane forests are severely threatened due to the expansion of agriculture and overgrazing by livestock. The objective of this study was to investigate the composition of woody species, structure, regeneration status and plant communities in Seqela forest, as well as the relationship between plant community types and environmental variables. Systematic sampling was used to collect vegetation and environmental data from 52 (20 m x 20 m) (400 m2) plots. Density, Diameter at Breast Height (DBH), basal area, frequency, and importance value index (IVI) of woody species were computed to characterize the vegetation structure of the forest. Agglomerative hierarchical cluster analysis and Canonical Correspondence Analysis (CCA) with R software were used to identify plant communities and analyse the relationship between plant community types and environmental variables, respectively. A total of 68 woody plant species belonging to 63 genera and 44 families were identified. The Shannon diversity index and evenness values of the study area were 2.12 and 0.92, respectively. The total basal area and density of woody species were 27.4 m2 ha−1 and 1079.3 individual ha−1, respectively. The most frequent woody species in the Seqela forest included Albizia gummifera (51.92%), Croton macrostachyus (44.23%), Olinia rochetiana and Teclea nobilis (36.54%). Additionally, the most dominant species, as indicated by their importance value index (IVI), were Erythrina brucei (IVI = 11.24), Prunus africana (IVI=8.68), and Croton macrostachyus (IVI=7.38). Four plant community types were identified: Albizia gummifera - Ekebergia capensis, Prunus africana - Croton macrostachyus, Vachellia abyssinica - Dombeya torrida and Schefflera abyssinica - Teclea nobilis. The CCA results showed that the variation of species distribution and plant community formation were significantly (P < 0.05) related to altitude, organic matter, aspect, slope and soil available phosphorus. The regeneration status assessment of the forest revealed a good regeneration status, which was linked to diverse and abundant seed bank in the soil can ensure a continuous supply of seeds for regeneration; therefore, it is recommended to implement periodic soil seed bank assessments to monitor seed diversity and abundance and inform targeted conservation actions.

Floristic composition, structure and regeneration status of woody plant species in Northwest Ethiopia

Deforestation and habitat fragmentation are the major environmental concerns in southwest Ethiopia.Understanding woody species diversity and socio-economic factors causing destruction of natural forests is crucial in the management of the remnant forest ecosystems.However, the forest in south west Ethiopia is poorly studied.This paper examines the diversity, regeneration status, socio-economic importance of the forests in Kaja Araba and Tula forests, southwestern Ethiopia.A systematic sampling strategy was used to collect vegetation data from the natural forests, while Participatory Rural Appraisal (PRA) method was employed to generate the socioeconomic data.A total of 60 square plots (30 for each forests measuring 10 m × 10 m) were established along line transects laid across the forests.Primary data were collected by field observation, semi-structured interview with key informants and discussion with relevant stakeholders.A total 51 woody species representing 25 families were found in the study area and of all the species 30 (59%) were trees, 18 (35%) trees/shrubs, and 3 (6%) shrubs.The most species rich families were Rubiaceae, Fabaceae, Euphorbiaceae and Moraceae.The Shannon diversity and evenness of woody species in Keja Araba forest are 2.81 and 0.79, respectively and in Tula forest they are 3.14 and 0.86, respectively.Millettia ferruginea is the most frequent and abundant species at Keja Araba natural forest, while Vepris dainellii and Phoenix reclinata are the most frequent and abundant woody species at Tula natural forest, respectively.The total basal area of woody species in Keja Araba forest is 2612 m 2 •ha -1 and in Tula forest the value is 3751 m 2 •ha -1 .In Keja Araba forest, the species with the highest IVI value are Sapium ellipticum, and in Tula forest it is Schefflera abyssinica.The results on the importance value index (IVI) and DBH class distributions show that the species with low IVI value and poor regeneration status need to be prioritized for conservation.Data collected from the key informants reveal that the forest is the major sources of fuel wood (94%), forest coffee and spices (80%), construction material (78%), timber (60%) and farm implements (58%).The forests are also sources of medicines, animal fodder, bee forage, handles tools and household utensils.Anthropogenic factors such as expansion of agricultural land, fuel wood collection, charcoal making, land use change by investors and settlements of people are responsible for destruction of natural forest in the study area, in descending order of severity.Thus,

Our current study was conducted in Zijje Maryam Church Forest, Ethiopia, to explore woody species composition, structure, regeneration status, and anthropogenic disturbances inside the sacred groves. The aforementioned information for adequate conservation and management of the church forest is not well documented. Fifteen main quadrats each having an area of 625 m2 (25 m × 25 m) were used for vegetation and disturbance data collection. Determination of the sampled quadrats was based on the principle that minimum quadrats give the smallest possible area in which all species occurring in the church forest are present. All woody species with a diameter at breast height (DBH) ≥ 2.5 cm within the quadrat were identified, counted, and their height and DBH data were recorded. The criterion to start at DBH ≥ 2.5 cm was to exclude seedlings having DBH < 2.5 cm and height ≤0.6 m. Sapling and seedling data were collected using 45 saplings and 45 seedling quadrat that measured 4 m2 and 1 m2, respectively. Vegetation data analysis and ANOVA were used for statistical comparison. A total of 48 woody plant species belonging to 46 genera and 36 families were identified. Fabaceae was the dominant family containing 5 species followed by Rosaceae with 3 species. Total basal area of the church forest was 83.03 m2 ha−1. The density of seedlings, saplings, and matured woody species stem ha−1 were 15555, 3833, and 865, respectively. Talking these densities, the regeneration status of the forest was good. The Shannon diversity and evenness of woody plant species in the forest was high, 3.29 and 0.85, respectively. Juniperus procera 27.67 (9.22%) and Olea europaea were species with the highest IVI. Nearly, 22% of areas of the forest get disturbed and higher anthropogenic disturbances occurred near the edge of the forest. Gathering, clearing, and grazing are the major human disturbances that stakeholders need to tackle for conservation. Zijje Maryam Church Forest has heterogeneous species composition with varied seedlings and saplings. Therefore, local conservation policies recommended not only protect large forests, but also the small and valuable forests service to the needs of local people.

This study was conducted in Abbo Sacred Forest in Wonsho district, Sidama Zone of Southern Nations, Nationalities, and People's Region (SNNPR), southern Ethiopia, to investigate the woody species diversity, vegetation structure, and regeneration status of the forest. A systematic sampling design was employed to collect vegetation data. Sixty quadrats of 20 m × 20 m were laid at every 200 m interval between each quadrat and 400 m apart between each line transect following the altitudinal gradient. Quadrats of 20 m × 20 m were used to record DBH and the height of all woody plant species reaching a height of ≥2 m and a DBH of ≥2 cm. For the inventory of seedlings and saplings, five subplots of 2 m × 2 m, one at the center and the other four on each corner of the main quadrat, were used. DBH, height, seedling, and sapling density of woody species were recorded in each quadrat. The data were analyzed by using Shannon-Wiener diversity and equitability indices, and the structural analysis was carried out based on frequency, density, DBH, height, and basal area/ha-1. The importance value index was also computed. Regeneration status was computed by comparing the density data of saplings and seedlings with those of mature trees. A total of 63 woody species belonging to 56 genera and 35 families were identified. Three endemic species to Ethiopia were recorded. Analysis of selected woody species showed diverse population structures. The findings of this study revealed that small trees and shrubs dominated the forest, suggesting its status under a secondary stage of development. Some woody species require urgent conservation measures. Therefore, local and regional stakeholders should integrate and work together to develop and implement sound conservation and management strategies that encourage the sustainable utilization of forest resources.

Floristic composition, population structure, and regeneration status of woody species of Dabal forest found in East Hararghe zone of Oromia Regional State, Ethiopia, were studied. Vegetation data were obtained from 52 main plots of 20 × 20 m for mature woody species and 5 subplots of 5 × 5 m for seedlings and saplings. Density and dbh of each live woody plant species found in each sample plot were recorded. Frequency, basal area, importance value, and Shannon-Wiener diversity indices were also computed. Totally 59 woody plant species distributed in 33 families were documented. Of these, 45.80, 44.10, and 5.08% were shrubs, trees, and lianas, respectively. Species diversity and evenness indices were 3.56 and 0.87, respectively. Stem count of all woody species was 3379 stems ha-1. Out of this, 44.6, 30.8, and 24.59% were seedlings (dbh <3.5 cm), saplings (dbh between 3.5 and 10 cm), and mature (dbh >10 cm) individuals, respectively. Total basal area of all individuals with dbh ≥3.5 cm was 29.88 m2 ha-1. Juniperus procera, Cupressus lusitanica, Eucalyptus globulus, Afrocarpus falcatus, Eucalyptus camaldulensis, Myrsine africana, Maytenus undata, Hagenia abyssinica, Ekebergia capensis, and Cordia africana were species with top ten IVI. Most of these species were top densest, dominant, and frequent. Analysis of population structure based on pooled densities of all species in each dbh class showed that density of seedling > sapling > mature individuals, signifying healthy population structure with good natural regeneration potential. On individual basis, however, 35.6 and 8.5% of species showed fair and poor regeneration statuses, respectively, that deserve attention for conservation.

Understanding population structure and regeneration status reflects the biological and ecological characteristics of the forest. The present study aims to know the population structure and regeneration status of Pinus-Quercus mixed forest in Bhardeu village of Lalitpur district, central Nepal. The study was carried out by laying down twenty-eight concentric circular plots of 8.92-meter radius randomly during 2021-2022. Altogether 28 tree species belonging to 24 genera and 17 families are recorded. Five species (Miliusa velutina, Cinnamomum camphora, Eriobotrya dubia, Maesa chisia and Saurauia napaulensis) were only recorded in adult form. The forest was found to be dominated by the species of Pinus and Quercus with the important value index (IVI) values ranging from 49.91 to 35.24. The average Simpson’s Diversity Index (1/D) is 2.88, Shannon Weiner’s Index is 0.85, species evenness is 0.57 and species richness is 1.07. The overall regeneration of the different species was seedlings 6484 individuals/ha., saplings 533 individuals/ha. and adults 1198 individuals/ha. showing fair regeneration. The majority of tree species show fair regeneration status (32.14%) followed by none regeneration (25%), new regeneration (17.85%), poor regeneration (14.28%) and good regeneration status (10.71%). The density diameter curve of the forest shows slightly flat reverse j-shaped structure indicating that majority of tree species were not in good regenerating status. The present analysis thus revealed that the population structure may get altered in future. Those species with none to poor regeneration status should be prioritized for the conservation and the proper management strategies need to be developed for sustainability of tree species in the forest.

The study was conducted at Ades Dry Afromontane Forest at 407 km Southeast of Addis Ababa to assess the diversity and composition of woody plant species. The sampling design was based on a US Forest Service model for the indigenous forests. A total of 60 circular plots each with an area of 0.017 ha were arranged in groups of four where a central plot is surrounded by three plots that are each at 36.6m from the central plot. In each plot, all woody plants that were ≥10cm in DBH were sampled for floristic diversity. Biodiversity analyses were accomplished using the Shannon-Weaver’s Index (H’) to assess the tree species diversity and Shannon Equitability (H’E) was calculated to assess the evenness values of species while the Importance Value Index (IVI) of each woody species was analyzed to see the Importance of individual tree and shrub species at the site. A total of 65 trees and shrub species belonging to 38 families had been recorded in this study. Rosaceae was a family with the highest number of species comprising about 9.23 % of the total number of species. The <i>H’</i> ranged between 0.004 to 0. 362 with the overall <i>H’</i> of 2.82. The H’E values ranged between 0.001 to 0.087 with a mean value of 0.01. A mean H’E value of 0.01 indicates that the relative homogeneity of woody plant species of the sampled plots was 1% of the maximum possible even population. The evenness values are not enough to justify uniformity in composition of tree species. The mean IVI value ranged between 0.36 to 49.06 with mean IVI value of 6.0. In this study only 15% of the recorded species were found with IVI values > 10 and the rest of 85% have IVI values < 10. The variation in survival mechanisms of species made some species to be dominant and most species to be lower in number in a given ecosystem. Tree species with high IVI were also found to have higher <i>H’</i> of diversity. The spatial distribution and dominance of species can be affected both by the properties of the species themselves and the environmental factors. The diversity of woody species observed in the Ades dry afromontane is encouraging since, among other reasons, it is useful for conservation strategy.