Regeneration Status, Population Structure and Floristic Composition of Woody Plant Species in Sheleko Medicinal Natural Forest, South Gondar Zone, North West Ethiopia

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.

Structure and regeneration status of woody species in the Munessa Forest,Southern Ethiopia

This study evaluates the structure and regeneration status of woody species in the Munessa Forest,a dry Afromontane forest in southern Ethiopia.Vegetation data were collected using a systematic sampling method.Density and distribution of seedlings,saplings and mature trees were assessed along an altitudinal gradient using quadrats of different sizes.The number of individuals,frequencies,heights and DBH of species>1 m and DBH>2.5 cm were recorded in altitudinal bands of 100 m.Analysis of the vegetation structure shows that the density of woody species decreases as DBH and height class increases.Basal area of stems with DBH>2.5 cm was 53.4 m^(2)ha^(−1).Population structure and regeneration patterns indicate a significant degradation of the forest due to anthropogenic disturbances.Regeneration was better for less valuable woody species than for species with economic and ecological value.This suggests a discontinuous recruitment of these species due to selective cutting of middle and higher diameter classes.Therefore,enrichment planting of high value,endangered species is necessary to maintain them as part of this forest.There is a need to develop and implement an effective forest management plan for sustainable use of these forest resources.

Woody plant diversity,structure and regeneration in the Ambo State Forest,South Gondar Zone,Northwest Ethiopia

For this study in the Ambo State Forest on woody plant diversity, structure and regeneration, 70 quadrats, each 25 m by 25 m, were selected using a systematic random sampling technique and intervals of 100 m along a transect line. For assessing seedlings and saplings, two 2 × 10 m sub quadrats were set upon opposite sides of each main quadrat. Data on species diversity, abundance, structure, basal area, density, frequency and regeneration status were collected and analyzed using standard procedures and programs. Of 58 woody plant species identified, 69 % were trees, 16 % were shrubs, 12 % were tree/shrubs and 4 % were climbers. Fabaceae was the most speciesrich family comprising 17 species. The Shannon-Weiner diversity index was 2.73, and evenness was 0.67. The population structure in the cumulative diameter class frequency distribution revealed an interrupted and inverted J-shape with a very high decrease in higher diameter class. Acacia lahai （49 %） was the most important woody species with the highest importance value index. To maintain balanced structure, enhanced regeneration and protecting the forest from selective cutting are recommended.

Effect of exclosure ages on woody plant structure,diversity and regeneration potential in the western Tigray region of Ethiopia

Exclosure is a method of rehabilitating degraded lands by protecting them from the interference of animals and from human encroachment, and is used to regenerate native vegetation as a way to reduce soil erosion, increase rain water infiltration and provide fodder and woody biomass in degraded grazing lands. Therefore, we studied woody plant structure, diversity and regeneration potentials in 5-and 10-year grazing exclosures in comparison with open grazed sites in a semi-arid environment. Data on species diversity, abundance, structure, basal area, frequency, density, and regeneration status were collected from 270 sample plots. Forty-one woody species representing 20 families were identified, with 18, 28 and 38 species found in open grazed areas, and in 5-and 10-year grazing exclosures, respectively. The 10-year grazing exclosures had a higher(P <0.05) species richness and plant densities compared to the 5-year grazing exclosures and the open grazed areas. The population structure and regeneration status of woody species in both grazing exclosures showed an inverted J-shape, indicating a healthy regeneration status, whereas hampered regeneration was observed in open grazed areas. The establishment of grazing exclosures had positive effects in restoring woody plant diversity and improving vegetation structure and regeneration potentials of degraded grazing lands.

Effect of exclosure on dryland woody species restoration in northeastern Amhara,Ethiopia

In Ethiopia,among many restoration efforts to reverse deforestation and land degradation,area exclosure is one of the most common practices to restore secondary forests with assisted natural regeneration.The present study in the S ekota district,northeastern Amhara region,Ethiopia evaluated the influence of areas exclosures on woody species diversity,population structure and regeneration status.A total of 36 and 27 quadrats,each 20 m×20 m,were used to collect data in exclosures and non-exclosures,respectively.Within quadrats,four 5 m×5 m and 2 m×2 m quadrats at the corners were used to sample saplings and seedlings,respectively.In exclosures,35 woody species representing21 families and 29 genera were recorded;19 woody species representing 13 families and 13 genera were recorded in the non-exclosure.Acacia etbaica was the most dominant species in the two land-uses.The Shannon diversity index was1.77±0.46 in exclosures and 1.39±0.46 in non-exclosures.Shannon and Simpson diversity indices showed a significant difference between the two land-uses(p<0.01).The regeneration status of all wood species in exclosures was good,only fair in non-exclosures.Area exclosures have thus played a great role in the restoration of degraded lands by improving vegetation diversity and regeneration status.The least dominant woody species should be maintained through active restoration.Continuous follow-up,maintenance of soil water conservation structure to improve soil fertility will further help enhance the woody species diversity and abundance.

Woody species composition,structure and environmental determinants in a moist evergreen Afromontane forest,southern Ethiopia

Ethiopian moist evergreen Afromontane forests are vital for the conservation of plant diversity,including genetic pools of Coffea arabica L.However,these forests are continuously shrinking and need empirical scientific studies for their effective conservation and sustainable management.This study was,therefore,conducted to assess woody species composition,diversity,endemicity,structure,plant communities,and environmental determinants in Sirso moist evergreen Afromontane forest of southern Ethiopia.Environmental variables such as altitude,slope,aspect,disturbance levels,and geographical location were recorded for each main plots.Vegetation structure and importance value index(IVI),diversity,vegetation classification,and correlation with environmental factors were analyzed.A total of 74 woody species representing 70 genera and 34 families were identified.Seven species were endemic.Rhus glutinosa A.Rich subsp.glutinosa and Prunus africana(Hook.f.)Kalkm.were species categorized as vulnerable according to the IUCN red list category.The highest number of species was recorded for the Rubiaceae family(8),followed by Euphorbiaceae(6),and Asteraceae(6).Five plant communities were identified:Maesa lanceolata-Dombeya torrida,Galiniera saxifraga-Cyathea manniana,Vepris dainellii-Triumfetta tomentosa,Dracaena fragrans-Rytigynia neglecta,and Arundinaria alpina.The distribution of these communities depends on altitude,slope,and disturbance factors.Syzygium guineense(Wild.)DC.,Schefflera abyssinica(Hochst.ex A.Rich.)Harms,and Galiniera saxifraga(Hochst.)Bridson were species with the highest IVI,while P.africana,Cordia africana Lam.,Hagenia abyssinica(Bruce)J.F.Gmelin,Bridelia micrantha(Hochst.)Baill.,and C.arabica had the lowest.Population structure of woody species showed an inverted J-shape,a J-shape,a bell-shape,and an irregular shaped pattern.These latter three population structure revealed signs of disturbances,and were negatively correlated with altitude and slope.The study showed that the Sirso moist evergreen Afromontane forest is species rich and should be given conservation priority to maintain endemic and native species.

The Potential Contribution of Wildlife Sanctuary to Forest Conservation: A Case Study from Binsar Wildlife Sanctuary

Forest vegetation of a protected area （Binsar Wildlife Sanctuary） in Kumaun region （west Himalaya） was analysed for structure, composition and representativeness across three different altitudinal belts, lower （1,6oo-1,8oo m a.s.1.）, middle （1,900-2,100 m a.s.1.） and upper （2,200-2,400 m a.s.1.） during 2oo9-2011 using standard phytosociological methods. Four aspects （east, west, north and south） in each altitudinal belt were chosen for sampling to depict maximum representation of vegetation in the sanctuary. Population structure and regeneration behaviour was analysed seasonally for two years to show the establishment and growth of tree species. A total of 147 plant species were recorded from the entire region of which 27 tree species were selected for detailed study. Highest number was recorded at upper （18 species）, and lowest at lower altitudinal belt （15 species）. The relative proportion of species richness showed higher contribution of tree layer at each altitudinal belt. The population structure, based on the number of individuals, revealed a greater proportion of seedling layer at each altitudinal belt. The relative proportion of seedlings increases significantly along altitudinal belts （p〈0.05） while opposite trends were observed in sapling and tree layers. The density of sapling and seedling species varied non-significantly across seasons （p〉0.05）. The density values decreased in summer and increased during rainy season. As far as the regeneration status is concerned, middle and upper altitudinal belts showed maximum number of species with fair regeneration as compared to lower altitudinal belt. Overall density diameter distribution of tree species showed highest species density and richness in the smallest girth class and decreased in the succeeding girth classes. This study suggests that patterns of regeneration behaviour would determine future structural and compositional changes in the forest communities. It is suggested that the compositional changes vis-a-vis role of ＇New＇ and ＇Not regenerating＇ species need priority attention while initiating conservation activities in the sanctuary. This study calls for exploring other less explored Wildlife Sanctuaries in the Himalaya and across the world, to achieve overall biodiversity status in these protected areas and thus to justify their role in conserving biodiversity in the region.

Ecological and floristic study of Hirmi woodland vegetation in Tigray Region,Northern Ethiopia

The dryland area in Ethiopia covers a substantial region endowed with diverse plant resources.However,the landmass has received less attention even if it has high ecological,environmental,and economic uses.The present study was conducted in Hirmi woodland vegetation,which is one of the dryland areas in Ethiopia,with the objective of investigating the floristic composition,plant community types,vegetation structure,communityenvironment relations and its regeneration status.Vegetation and environmental data were collected from 80 sampling plots with a size of 25 m×25 m designated as the main plots.Diameter at breast height(DBH),height,basal area,density,vertical structure,importance value index(IVI),and frequency were computed.Species diversity and evenness were analyzed using Shannon diversity and evenness indices.The plant community types and vegetation-environment relationships were analyzed using classification and ordination tools,respectively.A total of 171 vascular plant species belonging to 135 genera and 56 families were recorded.About 5.3%of the species were endemic and near-endemic to Ethiopia.The highest number of species was recorded in families Fabaceae(16.4%)and Poaceae(11.7%)followed by Asteraceae(7.0%),Combretaceae,Lamiaceae,and Moraceae(3.5%each).Five plant communities were identified.According to the results from ordination analysis,the floristic composition of these plant communities was significantly affected by altitude,slope,sand,silt,soil organic matter,total nitrogen,and disturbance.The vegetation structure reveals that a large number of individual species was categorized in the lower DBH,frequency,and height classes.The highest Shannon diversity index and evenness values of the study area were 4.21 and 0.95,respectively.Anogeissus leiocarpa,Combretum hartmannianum,Ziziphus mucronata,Terminalia macroptera,and Acacia polyacantha were the species with high IVI.Some endemic plants were in the IUCN red list categories of Ethiopia and Eritrea.The overall regeneration status of the study area was poor because of anthropogenic disturbances and grazing pressures.Although the study area is endowed with high plant species diversity including endemism,it is under poor regeneration status due to various disturbances.To overcome this challenge,integrated management measures including monitoring and application of restoration techniques by taking into consideration the significant environmental factors associated with species diversity as well as observed regeneration status and IUCN threat level of the species are highly recommended.