-
Research Article
Population Dynamics and Ecological Patterns of Vitalaria paradoxa Nilotica Nilotica in the Gambella Region: Implications for Sustainable Management in South Western Ethiopia
Teshome Tamirat
,
Semegnew Tadesse*,
Tadesse Wolde Mariam Gole,
Aberu Tena,
Assefa Seyoum
Issue:
Volume 9, Issue 2, December 2025
Pages:
78-89
Received:
17 January 2025
Accepted:
2 July 2025
Published:
11 August 2025
DOI:
10.11648/j.ijaos.20250902.11
Downloads:
Views:
Abstract: Conservation and sustainable management practices are crucial for preservation of most threatened species of Vitalaria paradoxa Nilotica Nilotica for enhancing the socio-economic benefit in Ethiopia. This study employs quantitative methods to assess the population dynamics and regeneration status of Vitellaria paradoxa Nilotica (VPN) across three sites in the Gambella Regional State: Terkudi in Abobo district, Elia in Itang district, and Ateti in Gog district. Primary data were collected through transect walk and secondary data were gathered from existing documents. A forest inventory was conducted by establishing nine transect lines, with five sample quadrats per line, leading to an effective sampling area of 4.5 hectares. The results indicate a total tree population of 463, with the highest density in Ateti site (185 trees) and the lowest in Elia (131 trees). Sapling counts further favor Ateti, which recorded 76 saplings compared to Elia's 46. The average diameter at breast height (DBH) was 14.7cm, with Terkudi showing the largest mean DBH (15.10cm) and Elia the smallest (14.37cm). The average tree height across sites was 10.84 meters, reflecting generally healthy growth conditions, albeit impacted by anthropogenic activities. The findings of this study underscore the significant influence of environmental factors, specifically altitude and slope on height of the population dynamics of Vitalaria paradoxa Nilotica in the Gambella Region. The strong positive correlation coefficients across the three sites indicate that increased altitude is associated with heightened plant growth and the statistically significant P-values further validate these relationships. The study highlights the need for improved management strategies, including artificial plantations and agroforestry systems, to enhance food security and economic gains. The findings underscore the significant regeneration potential of VPN in Gog Woreda, while emphasizing the threats posed by agricultural expansion and human settlement. Effective management and community-based initiatives are essential for protecting and enhancing the ecological and economic value of VPN in the region.
Abstract: Conservation and sustainable management practices are crucial for preservation of most threatened species of Vitalaria paradoxa Nilotica Nilotica for enhancing the socio-economic benefit in Ethiopia. This study employs quantitative methods to assess the population dynamics and regeneration status of Vitellaria paradoxa Nilotica (VPN) across three s...
Show More
-
Research Article
Evaluation and Selection of the CMIP6 Climate Model over Ethiopia
Ajebush Gochaw Ayele*
Issue:
Volume 9, Issue 2, December 2025
Pages:
90-98
Received:
7 July 2025
Accepted:
23 July 2025
Published:
12 August 2025
DOI:
10.11648/j.ijaos.20250902.12
Downloads:
Views:
Abstract: Model simulation accuracy is essential for understanding climate change and its socioeconomic effects. Twenty global climate models that were a part of the Coupled Model Intercomparison Project Phase 6 (CMIP6) were assessed in this study. The main goal was to assess and determine which models performed best in capturing rainfall patterns over Ethiopia between 1981 and 2014. The Correlation Coefficient (CC), Root Mean Square Error (RMSE), and PBIAS were used to evaluate the performance of CMIP6-GCM. The findings showed that the majority of CMIP6 models mostly reproduced the features of the ENACTS climatology pattern for total rainfall. Furthermore, rainfall over the study area was underestimated in six out of twenty CMIP6 models. The models that overestimate rainfall the most are MRI-ESM2-0, INM-CM4-8, and CESM2_WACCM, whereas the models that underestimate rainfall the most are CNRM-ESM2-1, ACCESS-CM2, and MPI-ESM1-2-LR. Every model has a correlation coefficient that falls between 0.6 and 0.99. The top six models with greater correlation coefficient (CC) values and higher performance out of 20 are the MPI-ESM1-2-LR (0.99), BCC-CSM2-MR (0.98), MIROC-ES2L (0.96), NorESM2-MM (0.96), and EC_Earth3_CC (0.96). All models, except IITM-ESM and MRI-ESM2-0, have root mean square errors below 5mm, strong correlation with ENACTS values, PBIAS range -3.94-4.3, and RMSE and PBIAS values near optimal 0. The significance of determining the optimal performance models for extreme rainfall events over the study area, both now and in the future, is underscored by these findings.
Abstract: Model simulation accuracy is essential for understanding climate change and its socioeconomic effects. Twenty global climate models that were a part of the Coupled Model Intercomparison Project Phase 6 (CMIP6) were assessed in this study. The main goal was to assess and determine which models performed best in capturing rainfall patterns over Ethio...
Show More
-
Research Article
Evaluation of Coupled Model Intercomparison Project Phase 6 (CMIP6) Model Capability to Predict Rainfall over Ethiopia
Elias Fiseha Mekonnen*,
Endalamaw Wende Wasihun
Issue:
Volume 9, Issue 2, December 2025
Pages:
99-111
Received:
14 July 2025
Accepted:
28 July 2025
Published:
13 August 2025
DOI:
10.11648/j.ijaos.20250902.13
Downloads:
Views:
Abstract: There is a need for accurate climate model simulations to understand climate change and its socioeconomic implications. The main objective of this study was to evaluate the performance of twenty global climate models from Coupled Model Intercomparison Project Phase 6 (CMIP6) over Ethiopia. Enhancing National Climate Services (ENACTS) and Climate models rainfall data from 1981 to 2014 were utilized for model performance evaluation in this study. The performances of the models were evaluated with statistical metrics of Correlation Coefficient (CC), Root Mean Square Error (RMSE), and Percent Bias (PBIAS). The findings of this study indicated that most models had similar trends with the ENACTS. Among twenty climate models, six models such as ACCESS-ESM1-5, CanESM5, CNRM-ESM2-1, MPI-ESM1-2-LR, NorCPM1, and SAM0_UNICON underestimated the rainfall. Based on the statistical metrics values of correlation coefficient (CC), MPI-ESM1-2-LR (0.99), BCC-CSM2-MR (0.98), MIROC-ES2L (0.96), NorESM2-MM (0.96), and EC_Earth3_CC (0.96) are best performing models. For all models but IITM-ESM and MRI-ESM2-0, RMSE values were below 5 mm and PBIAS values were within a desirable range (-3.94 to 4.3). These results underscore the importance of selecting appropriate models for evaluating climate impacts, particularly for extreme rainfall events over Ethiopia.
Abstract: There is a need for accurate climate model simulations to understand climate change and its socioeconomic implications. The main objective of this study was to evaluate the performance of twenty global climate models from Coupled Model Intercomparison Project Phase 6 (CMIP6) over Ethiopia. Enhancing National Climate Services (ENACTS) and Climate mo...
Show More
