Plant community and ecological analysis of woodland vegetation in Metema Area,Amhara National Regional State,Northwestern Ethiopia

We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia to determine plant community types and species distribution patterns and their relationships with environmental variables, including altitude, pH, cation exchange capacity, electrical conductivity （EC）, and moisture. We used a selective approach with a systematic sampling design. A total of 74 quadrats, each 25m × 25m at intervals of 150-200 m were sampled along the established transect lines. For herbaceous vegetation and soil data collection, five subquadrats each lm x lm were established at the four corners and the center of each quadrat. Three community types were identified using TWINSPAN analysis. All three community types showed high diversity （Shannon-Weiner index）, the highest in community type II at 3.55. The highest similarity coefficient was 0.49 （49%） between community types II and III, reflecting 0.51 （51%） dissimilarity in their species richness. The canonical correspondence ordination diagram revealed that the distribution pattern of community type I was explained by moisture while that of community types III and II was explained by EC and altitude and moisture, respectively. Altitude was the most statistically significant environmental variable, followed by moisture and EC in determining the total variation in species composition and distribution patterns while pH and cation exchange capacity were non significant. In conclusion, we recommend that any intervention should take into account these three discrete community types and their environmental settings to make the intervention more successful.

Floristic diversity, regeneration status, and vegetation structure of woodlands in Metema Area, Amhara National Regional State, North-western Ethiopia

We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia Our objective was to describe plant species composition, diversity, re- generation status, and population structure by a selective approach with a systematic sampling design. A total of 74 quadrats （each for 25 m x 25 m, spaced at intervals of 150--200 m） were sampled along established tran- sect lines following the homogeneity of the vegetation. Vegetation data including cover-abundance, height, diameter at breast height （DBH）, and numbers of seedlings and saplings of woody species were analyzed using Excel spreadsheet, Shannon Weiner diversity index, and PAST version 1.62. A total of 87 vascular plant species of 74 genera and 36 families were recorded. The dominant family was Fabaceae represented by 16 （18.39 %） species of 13 genera. Shannon Weiner diversity and evenness were 3.67 and 0.82, respectively, which showed that the area was en- dowed with rich floral diversity evenly distributed. The vegetation structure, as quantified by cumulative diameter class frequency distribution, plotted as an interrupted inverted-J- shape pattern with a sharp decrease in the 2nd diameter class. This indicated poor vegetation structure. The diameter classes frequency distributions of selected species plotted in four general patterns i.e., interrupted Inverted-J-shape, J-shape, Bell-shape and Irregular-shape. In conclusion, although the area showed high floral diversity and evenness, woody species including Sterculea setigera, Boswellia papyrifera, and Pterocarpus lucens showed lowest recruitment of seedlings and saplings.

Anthropogenic effects on floristic composition, diversity and regeneration potential of the Debrelibanos Monastery forest patch, central Ethiopia

This study assesses the effects of human disturbance on:(1)floristic composition,diversity,and plant community types;and,(2)the regeneration potential of woody species in the Debrelibanos Monastery forest patch in the North Showa zone of Oromia National Regional State,Ethiopia.Fifty sample quadrats were placed on parallel transect lines along altitudes in the forest using a systematic sampling design.Quadrats of 1 m^2,100 m^2 and 400 m^2 were used for recording herbaceous/seedling,sapling and tree species,respectively,with symptoms of different human disturbance effects.One hundred and thirteen species belonging to 52 families were recorded in the forest patch.The results show 459.5 stems ha^-1 of tree/shrub species present.Four community types,namely Juniperus procera–Acacia lahai,Carissa spinarum–Acacia abyssinica,Olea europaea subsp.cuspidata–Euphorbia abyssinica and Ficus sur–Allophylus abyssinicus were identified.The overall Shannon–Wiener diversity index was 3.3.The regeneration patterns of some species were poor.Slope,altitude and human activities had significant effects on vegetation patterns and imply that current management practices are not satisfactory to sustain the forest.Unless improved management interventions are made,the sustainability of forest services will be at stake.

The arbuscular mycorrhizal fungi status of selected tree nurseries in the Ethiopian highlands

We investigated the arbuscular mycorrhizal fungi(AMF)status of ten nurseries suitable for restoration of dry evergreen Afromontane forests in Ethiopia.We quantified AMF root colonization(RC)and spore abundance(SA)in seedlings of nine native tree species namely Acacia abyssinica Hochst.ex Benth.,Cordia africana Lam.,Dovyalis abyssinica(A.Rich.)Warb.,H agenia abyssinica J.F.Gmel.,Juniperus procera Hochst.ex Endl.,Millettia ferruginea(Hochst.)Baker,Olea europaea L.subsp.c uspidata(Wall.ex G.Don)Cif.,Podocarpus falcatus(Thunb.)R.Br.ex Mirb.and Prunus africana(Hook.f.)Kalkman.We used the ink and vinegar method to stain AMF in roots.RC levels ranged from 8.00 to 99.67%and were generally higher than the RC levels reported from other similar nurseries in Ethiopia.SA levels ranged from 1 to 25 spores g~(-1)and werecomparable with some reports from the field in Ethiopia but they were lower than levels reported by another similar study.RC was more affected by host species than nursery location,while the reverse was true for SA.The results also showed that nursery management could improve AMF status among seedlings.When all nursery tree species were considered,RC and SA levels were unrelated.No strong correlation existed between the nursery management variables considered and RC or SA.However,considering C.africana,J.procera and P.falcatus separately,RC-age(r_(s)=0.829,P=0.042)correlation for O.europaea and RC-pot diameter(r_(s)=0.820,P=0.046),RC-pot volume(r_(s)=0.928,P=0.008)and SA-age(r_(s)=0.943,P=0.005)correlations for C.africana,were significant,strong and positive.Generally,most of the tree species and particularly,early-mid successional tree species had sufficient AMF inoculum.Hence,only the mid-late successional tree species;J.procera,P.falcatus,and P.africana may require AMF inoculation,preferably,during filed planting.Based on our results,age and pot volume were identified to be important variables potentially affecting RC and SA.To better understand the effects of these and other nursery management variables,additional study is required.We demonstrated for the first time that black Hero ink is suitable for staining root AMF and can be used in future AMF research.

Relationship between Prosopis juliflora invasion and livelihood diversification in the South Afar region,Northeast Ethiopia

This study assessed the effects of Prosopis juliflora invasion on livelihood diversification and evaluated the determinants of livelihood diversification in two districts in the South Afar region of Northeast Ethiopia.Using random sampling method,154 households and 2 focus groups composed of 10 individuals were selected from four sites in the two districts.The relationship between P.juliflora invasion and incomes obtained from P.juliflora varied across the study sites.In Awash Fentale District and Amibara District,11.0%and 3.2%of households,respectively,earned income from P.juliflora charcoal production.In total,14.3%of households were involved in charcoal production.In addition,19.9%of households earned income from selling P.juliflora pods and wood materials in the two districts.With the exception of income from P.juliflora charcoal production,the sex of households did not affect incomes from other livelihood activities.Moreover,household educational attainment significantly affected income obtained from vegetables,fruits,and cereal crops.Male householders were engaged in more diverse livelihood activities than female householders.Reversing the severe invasion of P.juliflora on grazing and woodlands in the region is advisable through integrated natural resources,pastoralist participation,and multidisciplinary research strategies.

牧豆树(Prosopis juliflora)入侵对埃塞俄比亚东北部阿法尔民族地区国家牧场本地物种多样性和木本植物更新的影响

调查牧豆树(Prosopis juliflora)的入侵及其对本土植物物种的影响和控制该物种入侵具有重要意义。本研究旨在评估:(1)牧豆树入侵对Awash Fentale和Amibara Woredas两地植物物种多样性的影响;(2)牧豆树入侵对本地木本植物更新潜力的影响。样品采集是在牧豆树灌丛、牧豆树与本地物种混生群落、未入侵林地和开阔放牧场进行的。植被调查按照牧豆树的入侵状况分类,然后在不同入侵状况生境中采用随机抽样技术进行数据收集。在植物种类组成中,非入侵林地记录的物种比例最高,为87个(占27.4%),而开阔放牧地记录的物种比例最低,为70个(占22%)。牧豆树的入侵降低了植物的香农多样性指数,香农多样性指数(H’)和物种丰富度(R)的平均值在牧豆树与本地物种混生群落(H’=2.22,R=14)和未入侵林地(H’=2.23,R=13)显著高于牧豆树灌丛(H′=1.96,R=12)和开阔放牧场(H′=1.84,R=10)。在牧豆树与本地物种混生的群落下,本地植物更新苗总密度最高,为358株ha-1,而在牧豆树灌丛下更新幼苗密度最低,为153株ha-1。此外,本地木本植物更新苗密度在牧豆树灌丛下仅为102株ha-1,而在未入侵林地下却高达1252株ha-1。如果牧豆树入侵及其对本地物种多样性的影响继续,外加气候干旱,阿法尔植物区系的植物多样性将受到严重影响,其生态系统服务的变化存在着不确定性。因此,所有利益相关方应参与,并采取多学科研究应用于研究区的牧豆树管理和牧场恢复。

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.

Invasion of Prosopis juliflora and its effects on soil physicochemical properties in Afar region,Northeast Ethiopia

Woody species within pastures and savannas are often associated with‘resource islands’characterized by higher fertility under canopies trees.The aims of this study were to evaluate(1)the effects of Prosopis juliflora on some soil physicochemical properties and(2)the impacts of Prosopis invasion on soil salinity.For soil physicochemical analysis,a total of 104 soil samples from Teru and Yalo Districts were collected.The soil samples were collected from soil depths of 0-15 cm and 15-30 cm in Prosopis invaded and non-invaded open grazing lands.Invasion of Prosopis had significantly affected soil pH,exchangeable Na^(+),water soluble Ca^(2+)+Mg^(2+),water soluble Na^(+),and exchangeable sodium percentage in Teru and Yalo Districts(p<0.05).The invasion of Prosopis significantly increased soil pH(1.5%),but decreased exchangeable Na^(+)(24.2%),exchangeable sodium percentage(21.6%),and water soluble Ca^(2+)+Mg^(2+)(39.9%)than non-invaded lands.Clay content of Prosopis invaded lands was higher by 19%than non-invaded lands.However,sand content of soil was higher under non-invaded lands by 5.6%than Prosopis invaded lands.Most results indicated that invasion of Prosopis had positive effects on physicochemical properties and thus conducive for cereal crops and forages.