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Modeling effects of abiotic factors on the abundances of eight woody species in the Harana forest using artificial networks,random forest,and generalized linear models

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Ecological Processes 2023年第1期12卷 151-164页

作者： Girma Ayele Bedane Gudina Legese Feyisa Feyera Senbeta Wakjira center for environmental science College of Computational and Natural ScienceAddis Ababa UniversityP.O.Box 1176Addis AbabaEthiopia Centre for Environment and Development College of Development StudiesAddis Ababa UniversityAddis AbabaEthiopia

Background Abiotic factors exert different impacts on the abundance of individual tree species in the forest but little has been known about the impact of abiotic factors on the individual plant,particularly,in a tropical *** study identified the impact of abiotic factors on the abundances of Podocarpus falcatus,Croton macrostachyus,Celtis africana,Syzygium guineense,Olea capensis,Diospyros abyssinica,Feliucium decipenses,and Coffea arabica.A systematic sample design was used in the Harana forest,where 1122 plots were established to collect the abundance of *** forest(RF),artificial neural network(ANN),and generalized linear model(GLM)models were used to examine the impacts of topographic,climatic,and edaphic factors on the log abundances of woody *** RF model was used to predict the spatial distribution maps of the log abundances of each *** The RF model achieved a better prediction accuracy with R^(2)=71%and a mean squared error(MSE)of 0.28 for Feliucium *** RF model differentiated elevation,temperature,precipitation,clay,and potassium were the top variables that influenced the abundance of *** ANN model showed that elevation induced a nega-tive impact on the log abundances of all woody *** GLM model reaffirmed the negative impact of elevation on all woody species except the log abundances of Syzygium guineense and Olea *** ANN model indicated that soil organic matter(SOM)could positively affect the log abundances of all woody *** GLM showed a similar positive impact of SOM,except for a negative impact on the log abundance of Celtis africana at p<*** spatial distributions of the log abundances of Coffee arabica,Filicium decipenses,and Celtis africana were confined to the eastern parts,while the log abundance of Olea capensis was limited to the western *** The impacts of abiotic factors on the abundance of woody species may vary with *** ecological underst

关键词： Species distribution model Random forest Artificial neural network Generalized linear model Species abundance Woody species environmental variable

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Vulnerability analysis of smallholder farmers to climate variability and change: an agroecological system-based approach in the Fincha’a sub-basin of the upper Blue Nile Basin of Ethiopia

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Ecological Processes 2019年第1期8卷 49-66页

作者： Israel Tessema Belay Simane center for Environment and Development College of Development StudiesAddis Ababa UniversityAddis AbabaEthiopia environmental Engineering College of Biological and Chemical EngineeringAddis Ababa Science and Technology UniversityAddis AbabaEthiopia

Background:Ethiopia is frequently cited as a country that is highly vulnerable to climate variability and *** country’s high vulnerability arises mostly from climate-sensitive agricultural sector that suffers a lot from risks associated with rainfall *** vulnerability factors(exposure,sensitivity,and adaptive capacity)of the agricultural livelihoods to climate variability and change differ across agro-ecological systems(AESs).Therefore,the aim of this study was to analyze AES-specific vulnerability of smallholder farmers to climate variability and change in the Fincha’a *** surveyed 380 respondents from 4 AESs(highland,midland,wetland,and lowland)randomly ***,focus group discussion and key informant interviews were also performed to supplement and substantiate the quantitative *** vulnerability index was employed to analyze the levels of smallholders’agriculture vulnerability to climate variability and *** on socioeconomic and biophysical attribute were collected and combined into the indices and vulnerability score was calculated for each agro-ecological ***:Considerable variation was observed across the agro-ecological systems in profile,indicator,and the three livelihood vulnerability indices-Intergovernmental Panel on Climate Change dimensions(exposure,sensitivity,and adaptive capacity)of *** lowland AES exhibited higher exposure,low adaptive capacity,and high vulnerability,while the midland AES demonstrated lower exposure,higher adaptive capacity,and lower *** wetland and highland AESs scored intermediate ***:Our results suggest that resilience-building adaptation strategies are vital to reduce the vulnerability of smallholder *** measures taken should consider site-specific agro-ecological system requirements to reduce the vulnerability of smallholder mixed crop-livestock agriculture *** the approach based on the long-term rea

关键词： Vulnerability index Exposure Sensitivity Adaptation capacity Fincha’a sub-basin

Allometric equations for aboveground biomass estimation of Olea europaea *** in Mana Angetu Forest

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Ecosystem Health and Sustainability 2018年第1期4卷 1-13页

作者： Birhanu Kebede Teshome Soromessa center for environmental science College of Natural and Computational SciencesAddis Ababa UniversityAddis AbabaEthiopia

Introduction:African wild olive,Olea europaea ***(*** ***)Cif.,L‘Olivicoltore is widely distributed in dry forest and forest margins,often with Juniperus procera,in east Africa and *** reaches southern Africa,also India and China,ranging from tall trees to stunted *** best in good forest soil,but hardy and drought resistant once established,even in poor *** is used for firewood,charcoal,poles,posts,timber(furniture,carving,floors,and paneling),medicine(stem,bark,and leaves),bee forage,milk flavoring(smoking wood),toothbrushes(twigs),and walking *** the species has many economic and ecological functions,its environmental uses like carbon storage and climate change mitigation are less ***,the objective of the study was to develop species-specific allometric equations for *** *** using semi-destructive method and evaluate allometric models for estimating the aboveground biomass(AGB).Results and Discussions:After all the necessary biomass calculations were done,seven AGB equations were *** regression equations relate AGB with diameter at breast height(DBH),height(H),and density(ρ)individually and in *** of seven,four allometric equations were chosen based on goodness-of-fit statistics and three were *** selected models were tested for accuracy based on observed *** best models selected have higher R2-adj and lower residual standard error and Akaike information criterion than rejected *** relations for all selectedmodels are significant(p<0.000),which showed strong correlation of AGB with selected dendrometric ***,the AGB was strongly correlated with DBH and was not significantly correlated with wood density and height individually in *** *** allometric equation *** combination,AGB was strongly correlated with DBH and height;DBH and wood density;and the combination of DBH,height,and wood

关键词： AGB allometricequation biomass estimation Mana Angetu Forest Olea europaea subsp.cuspidata

Species composition,structure,regeneration and management status of Jorgo-Wato Forest in west Wollega,Ethiopia

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Journal of Forestry Research 2022年第1期33卷 136-144页

作者： Kebu Balemi Zemede Asfaw Sebsebe Demissew Gemedo Dalle Department of Plant Biology and Biodiversity Management Addis Ababa UniversityP.O.Box 34Addis AbabaEthiopia center of environmental science Addis Ababa UniversityAddis AbabaEthiopia Ethiopian Biodiversity Institute P.O.Box 30726Addis AbabaEthiopia

Species composition,structure,regeneration,and management status of Jorgo-Wato Forest(JWF)was *** of individuals,diameter at breast height(dbh)and height of woody species(dbh≥2.5 cm)were counted and measured in each *** discussions with local farmers residing around JWF were carried out to understand the management of the *** structural attributes were computed using descriptive statistics;correlation was used to assess relationships between the structural variables.A total of 4313 individuals(dbh≥2.5 cm)with a density of 1477 ha-1 were recorded,the number of species and individuals decreasing with increasing dbh *** with the highest Importance Value Index(IVI)were Pouteria adolfifriedericii(37.7),Syzygium guineense ***(23.6),Dracaena afromontana(20.5),Chionanthus mildbraedii(15.9),and Croton macrostachyus(12.3).Overall distribution of woody plants across size classes exhibited a reverse J-pattern,suggesting a healthy population structure and good ***,some species were not represented in smaller diameter classes,including juvenile phases,which indicate a lack of *** these species,monitoring and enrichment planting would be necessary,along with curbing illegal cutting and coffee farming in the natural *** interventions in the JWF need to consider livelihood options and to respect the rights of local communities.

关键词： Species composition Structure Regeneration Participatory Forest Management

Spatial distribution of above ground carbondensity in Harana Forest,Ethiopia

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Ecological Processes 2022年第1期11卷 14-26页

作者： Girma Ayele Bedane Gudina Legese Feyisa Feyera Senbeta center for environmental science College of Computational and Natural ScienceAddis Ababa UniversityP.O.Box No.1176Addis AbabaEthiopia Centre for Environment and Development College of Development StudiesAddis Ababa UniversityAddis AbabaEthiopia

Background:The need for understanding spatial distribution of forest aboveground carbon density(ACD)hasincreased to improve management practices of forest *** study examined spatial distribution of theACD in the Harana Forest.A grid sampling technique was employed and three nested circular plots were establishedat each point where grids ***-related data were collected from 1122 plots while the ACD of each plotwas estimated using the established allometric *** variables in raster format were downloadedfrom open sources and resampled into a spatial resolution of 30 *** statistics were computed to summarize the ACD.A Random Forest classification model in the R-software package was used to select strong predictors,and to predict the spatial distribution of ***:The mean ACD was estimated at 131.505 ton per ha in this study *** spatial prediction showed thatthe high class of the ACD was confined to eastern and southwest parts of the Harana *** Moran’s statisticsdepicted similar observations showing the higher clustering of ACD in the eastern and southern parts of the *** higher ACD clustering was linked with the higher species richness,species diversity,tree density,tree height,clay content,and ***,the lower ACD clustering in the Harana Forest was associated with higher soilcation exchange capacity,silt content,and ***:The spatial distribution of ACD in this study area was mainly influenced by attributes of the forest standand edaphic factors in comparison to topographic and climatic *** findings could provide basis for bettermanagement and conservation of aboveground carbon storage in the Harana Forest,which may contribute to Ethiopia’s strategy of reducing carbon emission.

关键词： Aboveground carbon density Spatial modeling Prediction Random Forest Cluster Pattern

Valuing the water supply: ecosystem-based potable water supply management for the Legedadie-Dire catchments, Central Ethiopia

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Ecological Processes 2019年第1期8卷 104-127页

作者： Yilikal Anteneh Gete Zeleke Ephrem Gebremariam Water and Land Resource center(WLRC) Addis Ababa University3880 Addis AbabaEthiopia Chair of environmental Planning and Landscape Design Addis Ababa UniversityAddis AbabaEthiopia

Background:There is a substantial interest in the values that consumers place on drinking water quality and *** resources are crucial to improving the urban potable water supply in developing countries that are characterized by low-cost recovery rates and a high and rapidly growing demand for more reliable *** study examined households’willingness to pay(WTP)for the improvement of water services by identifying their water choice decisions and the mode of water supply that they prefer the water supply authority to use among several alternative water supply ***-preference data were collected from 322 randomly selected households in addis ababa,who were presented with three sets of choices(three alternative bundle choices,including the reference scenario).The data were analyzed using the mixed logit WTP space *** approaches to modeling the distribution of WTP(fixed,uncorrelated,and correlated)using mixed logit WTP space models were ***:Three-quarters of the households agreed to contribute money toward ecosystem-based water supply management(EBWSM)intervention programs on a monthly *** average contribution that the respondents were willing to pay was 150.5 Ethiopian Birr(ETB)as a one-off lump sum to kick off the EBWSM *** of the respondents chose a bundle of water supply options that provides risk-free and high-quality water with no months of shortages than moderate water quality that is safe to drink and palatable with 1 month shortages *** implies that households would need to be supplied with risk-free,high-quality water without interruption at an appropriate flow *** model with correlations fitted the data well with the highest simulated log-likelihoods at convergence and gave the best estimate of the households’WTP for water *** 46%of the sampled households were willing to pay more than 33 ETB per month,and 49%of the households were willing to pay between 21 E

关键词： Ecosystem service Water supply Mixed logit WTP-space model Catchment management Legedadie reservoir

A global view of regulatory ecosystem services:existed knowledge,trends,and research gaps

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Ecological Processes 2020年第1期9卷 461-474页

作者： Wondimagegn Mengist Teshome Soromessa Gudina Legese Feyisa Department of Natural Resource Management Debre Berhan UniversityDebre BerhanEthiopia center for environmental science Addis Ababa UniversityAddis AbabaEthiopia

Ecosystem services(ES)are growing fields of *** helps to provide an inherent way to understand the synergy and trade-offs between human beings and their natural *** ecosystem services(RES)are significantly important to maintaining the world in which people can live,and control the negative effects of flood,disasters,and *** can also provide regulatory services like ecosystem protection,human safety,and the provision of other ***,emerging ES decision-making agendas focus on ES that is tangible and has a direct link with human ***,the attention given to RES is low due to its less tangible benefits and complexity to measure the *** and lack of attention from policymakers and scientific community may lead to unintended risks to human well-being and significant influences on the provision of other *** study describes the research trends on RES,knowledge generated,and the major *** concluded that though there is an exponential growth of scientific publications on ES,no adequate studies were found on ***,the existed studies varied in their size and types of RES indicators covered,habitats/ecosystems,and geographic extent *** was also a lack of connecting knowledge generated on the benefits of RES with the national policy of natural resource management,inconsistency of ES classification,and methodological ***,scientific communities are promoted to link RES studies with human ***,the researcher should give priority for the least studied ecosystems and its services,developing robust methodology,and proposing management options to enhance the regulatory services of ecosystems.

关键词： Ecosystem Ecosystem service indicators Less tangible benefits Regulatory ecosystem services Research trend Undervalued services

GIS-based assessment of climate change impacts on forest habitable Aframomum corrorima(Braun)in Southwest Ethiopia coffee forest

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Journal of Mountain science 2020年第10期17卷 2432-2446页

作者： Ayehu FEKADU Teshome SOROMESSA Bikila Warkineh DULLO center of environmental science Addis Ababa UniversityP.O.Box 1176Addis AbabaEthiopia Department of Plant Biology and Biodiversity Management Addis Ababa UniversityP.O.Box 1176Addis AbabaEthiopia

Climate change is thought to have a greater impact on crops that require particular conditions for their *** Ethiopia is a region where important cash crops such as Coffea arabica and Aframomum corrorima(korerima)*** crops are known to require shade for their growth and *** study was conducted to assess the impacts of climate change on an important but neglected cash crop of *** using GIS-based species distribution *** meteorological data and bioclimatic data from WorldClim were used to map past,present,and future distribution of the crop in the Coffee Forest System of Southwest ***,96 key informants were interviewed and completed questionnaires to complement the distribution *** key informants mapped the history and present occurrences of *** and based on this,ground-truthing survey was *** interpolation method of the Inverse Distance Weighted was used in ArcGIS 10.5 to develop bioclimatic variables for modeling past and present distribution while data from IPCC(AR4)Emissions Scenarios was used for the future occurrence prediction using Principal Component *** best bioclimatic variables were selected and MaxEnt was used to model past,present and future distribution of *** output of our model was validated using Area Under the Curve(AUC)*** and precipitation are the most important environmental variable,then temperature increased by 1.3°C in the past(from 1988 to 2018)while it is predicted to increase further by at least 1.4°C before *** the contrary,precipitation decreased by an average of 10.1 mm from the past while it is predicted to decrease further by 12.5 mm before *** model shows that the area suitable for korerima in 1988 was 20,638.2 ha and it was reduced by half and became 10,545.3 ha in 2018,similarly predicted to shrink into 3225.5 ha by *** findings from the key informants confirm the model res

关键词： Aframomum corrorima Coffee forest Bioclimatic variables Suitability GIS MaxEnt

Projecting future precipitation change across the semi-arid Borana lowland,southern Ethiopia

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Journal of Arid Land 2023年第9期15卷 1023-1036页

作者： Mitiku A WORKU Gudina L FEYISA Kassahun T BEKETIE Emmanuel GARBOLINO Department of Environment and Climate Change Management Ethiopian Civil Service UniversityAddis Ababa 1000Ethiopia center for environmental science Addis Ababa UniversityAddis Ababa 1000Ethiopia Climpact Data science Nova-Sophia 06904France

Climate change caused by past,current,and future greenhouse gas emissions has become a major concern for scientists in the field in many countries and regions of the *** study modelled future precipitation change by downscaling a set of large-scale climate predictor variables(predictors)from the second generation Canadian Earth System Model(CanESM2)under two Representative Concentration Pathway(RCP)emission scenarios(RCP4.5 and RCP8.5)in the semi-arid Borana lowland,southern *** Statistical DownScaling Model(SDSM)4.2.9 was employed to downscale and project future precipitation change in the middle(2036-2065;2050s)and far(2066-2095;2080s)future at the local *** precipitation observations from eight meteorological stations stretching from 1981 to 1995 and 1996 to 2005 were used for the model calibration and validation,respectively,and the time period of 1981-2018 was considered and used as the baseline period to analyze future precipitation *** results revealed that the surface-specific humidity and the geopotential height at 500 hPa were the preferred large-scale *** to the middle future(2050s),precipitation showed a much greater increase in the far future(2080s)under both RCP4.5 and RCP8.5 scenarios at all meteorological stations(except Teletele and Dillo stations).At Teltele station,the projected annual precipitation will decrease by 26.53%(2050s)and 39.45%(2080s)under RCP4.5 scenario,and 34.99%(2050s)and 60.62%(2080s)under RCP8.5 ***,the main rainy period would shift from spring(March to May)to autumn(September to November)at Dehas,Dire,Moyale,and Teltele stations,but for Arero and Yabelo stations,spring would consistently receive more precipitation than *** can be concluded that future precipitation in the semi-arid Borana lowland is predicted to differ under the two climate scenarios(RCP4.5 and RCP8.5),showing an increasing trend at most meteorological *** information could be he

关键词： future precipitation climate change second generation Canadian Earth System Model(CanESM2) Statistical DownScaling Model(SDSM) semi-arid Borana lowland southern Ethiopia