Abstract:
This study was conducted on the forest between Lake Abaya and hills of Dorie. Gama
Gofa zone. SNNPR. Southwest Ethiopia. The objective of the study was to determine
woody species composition and structure of the vegetation. assess the correlation of
plan! species with environmental parameters, determine regeneration status of the
forest and analyze the variation in species richness and dominance patterns along
attitudinal gradient. Systematic sampling method was used to collect the vegetation
data. Accordingly, 60 quadrats, each with 20mx20m were laid to sample the woody
species. In addition, seedlings and saplings were taken from the main plots. Altitude.
slope and aspect were also measured for each quadtat . Following modified Braun
Blanquet scale, cover abundance values of trees and shrubs were estimated. While
data on Height and DBH of frees and shrubs were collected to determine vegetation
structure. Shannon-Wiener diversity index, species richness, evenness and Sorensen
similarity index were determined for assessing the diversity and similarity of the
vegetation along the attitudinal gradient. In addition, Cluster analysis ,vas performed
using PC-ORD5 10 classify the vegetation i1110 communities. Fifty three plant species
belonging 45 genera and 30 families were identified in this study. Fabaceaefoliowed
by Anacaridiaceae were found to be the most abundant families. Structural data
analysis of the vegetation provided a density of 1026.2/ha and a total basal area of
15.61111
2
/lw.
In the three altitudinal zones of the study area (Lower. Middle, Upper),
small sized individuals shown 10 be prevalent. The 111os1 dominant tree species which
scored the highest importance values were Terminalia brownii, Ficus sur,
Euclea
divinorum, and Dodonaea angustifolia. The cluster analysis yielded four plant
/
community types that are named after one or two dominant species. The study 011 the
regeneration status of the woody species indicated poor regeneration status i11 the
forest. Generally, the forest
is
dominated by small sized trees and shrubs indicating
that ii is in the secondary stage of development. Besides low regeneration potential,
the vegetation
is
exposed to human-induced degradations and therefore, taking
appropriate conservation measures and also conducting a more detailed study is
recommended.
