AM 
EN 
የኢትዮጵያ የብዝሀ ሕይወት ጆርናል
Vol 4 - No 2
Research Articles
The study was undertaken with the general objective of investigating the composition, diversity and structure of six forest patches in northwestern Ethiopia. Vegetation data were collected from 154 sampling plots of each 400 m2 (20 m × 20 m). Species frequency, density, basal area, dominance, importance value index and population structure of the forest patches were analyzed using descriptive statistical tools. Floristic diversity and evenness were computed using Shannon diversity and evenness indices, respectively. The variations of floristic richness, density and basal area among the forest patches was tested using One-Way ANOVA in PAST software Package. The results of the study revealed that the study area harbored 212 species (122 woody and 90 herbaceous) belonging to 169 genera and 79 families. The Shannon diversity index and evenness values of the study area were 3.7 and 0.8, respectively. The highest number of species were recorded in Khatasa forest, followed by Bradi, Askunabo, Ambiki, Kidamaja and Degera forests. The density, basal area and dominance of woody species were 2172.1 stems ha-1, 41.2 m2 ha-1 and 23.1 m2 ha-1, respectively. There were no significant variations of floristic richness, density and basal area among the forest patches. A number of tree species showed unhealthy population structure and were found to be at conservation risk. To reverse these changes, among other measures, undertaking restoration activities using locally threatened woody species is highly recommended.
Keywords: Basal area, Density, Diversity index, Importance value index, Population.
Parthenium hysterophorus L. has become a major environmental, social, and economic threat in Ethiopia. Therefore, examining its impacts on soil chemical properties is vital to designing future management strategies. A total of 36 soil samples were collected from P. hysterophorus invaded and non-invaded sites. A simple t-test was conducted to examine the impacts of P. hysterophorus’s invasion on soil chemical properties between invaded and non-invaded sites per depth. Significant pairwise differences (p<0.05) were observed among means of soil pH, calcium, electrical conductivity, phosphorus, and magnesium between invaded and non-invaded sites. The threats of this species on native biodiversity, soil chemical properties, and the economy will be high in the future unless management action is undertaken. This study suggests that all relevant stakeholders should be organized to combat the expansion of the species to new areas.
Keywords: Biological invasion, Impact of invasion; Parthenium hysterophorus, Soil