Diversity, Regeneration Status and Soclo-Econoi\Uc Importance of the Vegetation in the Islands of Lake Ziway, South-Central Ethiopia
No Thumbnail Available
Date
2004-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa Universty
Abstract
The study was conducted in the islands of Lake Ziway located in the Main Ethiopian Rift part
of the Ethiopian Rift Valley in south-central Ethiopia, The main objective of the study was to
investigate the diversity, regeneration status, socio-economic importance and the factors that
cause degradation of the plant resources in the islands, Vegetation and socio-economic data
were collected between 18 September and 7 November 2003, A total of 73 releves, measuring
20 m x 20 m (400 /1/), l\'ere established along line transects laid ,/i'om central part of each
island to the lake edge in eight aspects, Herbaceous species were sampled by using a 2 m x 2
m (4 m2
) sub-releve laid within each relet'!!, In each relev!!, the cover/abundance of each
species was estimated, 1\'oody species were counted, diameter at breast height of trees and
shrubs and environmental variables (altitude, slope, aspect and position) were measured,
Participat01J' Rural Appraisal method was employed to generate the socio-economic
information, A total of 141 species belonging to 113 genera and 55 families were identified, of
which 18.4% were trees, 21,3% trees/shrubs, ]2,1% shrubs, 3,5% lianas, 4,3% herbaceous
climbers and 40.4% herbs, The overall diversity and evenness of woody species in the islands
were 2,60 and 0,62, respectively, The number of species on the islands correlated with
island's size, degree of human disturbance as well as habitat diversity. The similarity in
species composition betlreen the islands was loll', indicating that each island has its own
unique flora, Nine plant communities were recognized and described. The total density and
basal area of the vegetation were 2979 individuals ha" and 191 n//w", respective~l', The
importance value index and the diameter class distribution revealed that some species are
threatened and need the highest priority for conservation, The socio-economic survey showed
that the island communities are high~)' dependent on the natural vegetation for various
Description
Keywords
Soclo-Econoi\Uc