Structure and regeneration status of Komto Afromontane moist forest, East Wollega Zone, west Ethiopia

We conducted a study in Komto Forest in East WoUega Zone, Oromia National Regional State, West Ethiopia for determining vegetation structure and regeneration status in this forest. We systematically sampled 53 quadrats （20 m ×20 m） along line transects radiating from the peak of Komto Mountain in eight directions. Vegetation parameters such as DBH, height, seedling and sapling density of woody species, and location and altitude of each quadrat were recorded. In total, 103 woody plant species of 87 genera and 45 families were identified. Analysis of selected tree species revealed different population structures. Generally, the forest was dominated by small trees and shrubs characteristic of secondary regeneration. Observations on the regeneration of the forest indicated that there are woody species that require urgent conservation measures. Based on the results of this study, we recommend detailed ecological studies of various environmental factors such as soil type and properties, and ethnobotanical studies to explore indigenous knowledge on uses of plants.

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

Climate change is thought to have a greater impact on crops that require particular conditions for their productivity.Southwest Ethiopia is a region where important cash crops such as Coffea arabica and Aframomum corrorima(korerima)originate.These crops are known to require shade for their growth and productivity.This study was conducted to assess the impacts of climate change on an important but neglected cash crop of A.corrorima using GIS-based species distribution approaches.Local 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 Ethiopia.Moreover,96 key informants were interviewed and completed questionnaires to complement the distribution modeling.The key informants mapped the history and present occurrences of A.corrorima and based on this,ground-truthing survey was conducted.The 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 Analysis.Eleven best bioclimatic variables were selected and MaxEnt was used to model past,present and future distribution of A.corrorima.The output of our model was validated using Area Under the Curve(AUC)approach.Temperature 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 2050.On 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 2050.Our 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 2050.The findings from the key informants confirm the model results whereby 89.1%of the respondent replied korerima producing area has been shifted into the mountains over the last 30 years(by 150 m a.s.l.from 1988 to 2018)and thus expected to be pushing up in the next 32 years(by 133 m before 2050).The community claims that the length of the rainy season of the area has been shortening from 9 months in the past to an average of 5.5 months recently which also coincides with increasing temperature.We conclude that with the changing climatic condition,the suitable habitat of korerima has already shrank by 48.9%(from 1988 to 2018)and the trend may lead to a shrink by 84.38%before 2050(from 1988 to 2050).Therefore,it is important to develop site-specific climate adaptation strategies for the region such as promoting alternative livelihoods and avoiding further coffee forest degradation and deforestation.

Allometric equations for aboveground biomass estimation of Olea europaea L.subsp.cuspidata in Mana Angetu Forest

Introduction:African wild olive,Olea europaea L.subsp.cuspidata(Wall.ex G.Don)Cif.,L‘Olivicoltore is widely distributed in dry forest and forest margins,often with Juniperus procera,in east Africa and Ethiopia.It reaches southern Africa,also India and China,ranging from tall trees to stunted shrubs.Does best in good forest soil,but hardy and drought resistant once established,even in poor soils.It 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 sticks.Although the species has many economic and ecological functions,its environmental uses like carbon storage and climate change mitigation are less assessed.Therefore,the objective of the study was to develop species-specific allometric equations for O.europaea L.subsp.cuspidata 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 developed.These regression equations relate AGB with diameter at breast height(DBH),height(H),and density(ρ)individually and in combination.Out of seven,four allometric equations were chosen based on goodness-of-fit statistics and three were rejected.The selected models were tested for accuracy based on observed data.The best models selected have higher R2-adj and lower residual standard error and Akaike information criterion than rejected equations.The relations for all selectedmodels are significant(p<0.000),which showed strong correlation of AGB with selected dendrometric variables.Accordingly,the AGB was strongly correlated with DBH and was not significantly correlated with wood density and height individually in O.europaea L.subsp.cuspidata allometric equation development.In combination,AGB was strongly correlated with DBH and height;DBH and wood density;and the combination of DBH,height,and wood density.Species-specific equations are used for better carbon assessment than general equations.

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

Ecosystem services(ES)are growing fields of research.It helps to provide an inherent way to understand the synergy and trade-offs between human beings and their natural environment.Regulatory ecosystem services(RES)are significantly important to maintaining the world in which people can live,and control the negative effects of flood,disasters,and diseases.It can also provide regulatory services like ecosystem protection,human safety,and the provision of other ES.However,emerging ES decision-making agendas focus on ES that is tangible and has a direct link with human well-being.Thus,the attention given to RES is low due to its less tangible benefits and complexity to measure the benefits.Disregarding 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 ES.This study describes the research trends on RES,knowledge generated,and the major limitation.We concluded that though there is an exponential growth of scientific publications on ES,no adequate studies were found on RES.Also,the existed studies varied in their size and types of RES indicators covered,habitats/ecosystems,and geographic extent addressed.There 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 diversity.Therefore,scientific communities are promoted to link RES studies with human health.Besides,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.

Species composition, stand structure, and regeneration status of tree species in dry Afromontane forests of Awi Zone, northwestern Ethiopia

Species composition,structure,and regeneration status of trees were assessed in five dry Afromontane forests.In each of the forests,trees having≥5 cm diameter at breast height were identified and measured in 80 quadrats(20×20m^(2)).We compared tree species composition and similarities,stem densities,frequencies,basal area and importance value index of trees.Harvesting index was calculated to 13.3%in the least disturbed and 22.5%in highly disturbed forests.A total of 1,655 individuals representing 38 species and 28 families were recorded.The tree densities varied from 364.1 to 664.1stem ha^(−1) with an average basal area of 20.7m^(2) ha^(−1).The analysis showed significant differences in basal areas of tree species between the least and highly disturbed forests.Seedling densities ranged from 2000 to 8162.5 stem ha^(−1) and sapling densities ranged from 512.5 to 2562.5 stem ha^(−1).The anthropogenic disturbances revealed high degradation of population structure and regeneration statutes of the trees in the studied forest ecosystem.In conclusion,the study provided empirical results on the dominance,population structure,importance value and regeneration status of tree species,which would be instrumental for the development of successful rehabilitation strategies for the studied forests.

Allometric equations for aboveground biomass estimation of Diospyros abyssinica (Hiern) F. White tree species

Introduction:Quantifying forest biomass requires the application of allometric equations which is a fundamental step.Generalized allometric equations have been applied to quantify aboveground biomass(AGB)of forests.But,adopting generalized allometric equations to quantify AGB of different forests creates uncertainty.Therefore,developing species-and sitespecific allometric equations is essential to accurately quantify the biomass.The study was aimed to develop species-specific allometric equations for Diospyros abyssinica(Hiern)F.White in Yayu Coffee Forest Biosphere Reserve using the Semi-destructive method.The vegetation types of Yayu Coffee Forest Biosphere Reserve is categorized to Moist Evergreen Montane Rainforest of Ethiopia.Results and discussion:Evaluating statistical relationships of AGB against predictor variables,eight allometric equations were formulated.AGB was regressed against trunk diameter(D),total height(H),and wood density(ρ)individually and in combination.Selection of allometric equations was employed using model performance statistics.Equations with a higher coefficient of determination(adjusted R^(2)),lower residual standard error,and Akaike information criterion(AIC)values were found best-fitted.Relationships of AGB and independent variables were found statistically significant(p<0.000).Overall,formulating species-and site-specific allometric equations is significant for accurate estimation of forest biomass and carbon stock budget.