An Ecological Analysis of the Vegetation Along the Eastern Escarpment of Wello, Ethiopia
No Thumbnail Available
Date
2005-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa Universty
Abstract
Woody vegetation analysis was made along eastern Rift Valley escarpment in Wello. The study
was earned out based on preferential sampling of the vegetation by establishing seventy 20 X 20 m
releves. A total of 216 species belonging to 62 families were identified and described. Out of
these, 104 woody species and succulents were used for vegetation classification. Two-way
Indicator Species Analysis (TWINSPAN ) classified the vegetation into seven woody vegetation
types , These are: Dodonaea angustifolia Type (I), Enclea schimperi ssp. racemosa-Acacia lahai-
Dichrostachys cinerea Type (II), Cadia purpurea-Euclea schimperi ssp, racemosa-Enphorbia
candelabrum Type (III), Acacia asak-Grewia bicolor-Sansevieria ehrenbergii Type (IV), Ximenia
americana-Acacia asak Type ( V), Acacia mellifera-A. oerfota Type (VI), and Prosopis julijlora
Type (VII). Woody species were counted and later the relative density and importance value index
of the dominant woody species was calculated. Endemic and invasive species were identified.
The diversity and evenness of each community was compared using Shannon-Weiner diversity and
evenness index. Correlation of different environmental factors with the community types was
made using Pearson 's coefficient and Tukey's HSD family error test. The interrelationships among
environmental variables were analyzed. The results of species diversity showed that communities
at the high altitudes are species rich while richness decreases down elevation gradient. Altitude
and slope were found to be the most important environmental factors in determining the
distribution and composition of species along communities. Most of the vegetation was found
highly disturbed except along inaccessible steep slopes, few protected and privately owned areas
indicating some implications of conservation and management .
Keywords: Environmental variables , Plant communities, Releves, TWINSPAN
Description
Keywords
Environmental variables, Plant communities, Releves, TWINSPAN