Fig 1.
Map of Ethiopia showing Wonchi District and sample plots along the Walga River in Southwest Shewa Administrative Zone.
Table 1.
Endemic species with their level of threat and distribution in the present community and Flora.
Fig 2.
Dendrogram of hierarchical clustering using similarity ratio showing four community types in different sites (plot 1–50) of the study area (Ward's method, Euclidean distance).
The vertical axis of the dendrogram represents the distance or dissimilarity between labeled clusters and the horizontal axis represents the sampled sitesclusteringinfour branches.
Table 2.
Similarity between the four plant community types a(C1-C4) in Walga riparian vegetation.
Table 3.
Species richness, evenness and diversity in the four plant community types.
Fig 3.
Scatter plots with least squares regression line showing relationship between patterns of species richness per plot and altitude.
Equation of least square regression line:Species richness per plot = 34.387 − 0.00771558 Altitude (m a.s.l.). Correlation coefficient, r = -0.648, coefficient of determination, r2 = 0.420, and the best estimate for the slope is -0.00771558 +/-0.00262944 at a 95% of confidence level. The standard error of the regression slope is 0.0013, p<0.001.
Table 4.
Top 13 most frequently occurring riparian woody species out of fifty quadrats.
Fig 4.
Four representative patterns of frequency distribution of tree density values against DBH classes in the riparian vegetation.
Species represented by (a) Allophylus abysinicus (b) Croton macrostachyus, (c) Erythrina brucei, (d) Podocarpus falcatus. Class 1 = 2.5–10.0 cm, 2 = 10.1–20.0 cm, 3 = 20.1–30.0 cm, 4 = 30.1–40.0 cm, 5 = ≥ 40.1 cm.
Fig 5.
Canonical correspondence analysis diagram showing the ordination of community typesrepresented by plot numbers (1–50) and their correlation with environmental variables (altitude, grazing, human impacts).
The direction and length of arrows shows the degree of correlation between plant community typesand the variables.
Table 5.
Comparison of the riparian vegetation of Walga with others studies in Ethiopia.