An Ecological Study of The Vegetation of the Ravenna Forest
No Thumbnail Available
Date
1987-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
An ecological study of the vegetation of the Harenna
forest was performed from April 1986 to October 1986. Data
on the vegetation and environmental factos were collected,
i.e. enumeration of tree and shrub species, an estimate of
cover abundance value for herbs, epiphytes and lianes, alti~
tude, edaphic factors and topography.
The program GROUPAGE \'las used to summarlze -the vef,eta-tion
data. The program CHECK \'las employed to analyse species
diversity. Five homogeneous clusters of vegetation were re~
cognized using the presence-absence and quantitative data.
The clusters obtained were compared for the mean values of
the environmental factors using the statistic t-test.
The highest number of significant contrasts among the
clusters were observed to result from variation in altitude.
Analysis of species diversity showed that with increasing
al ti tude, tree and shUl'b species decrease \>I11ile herbaceous
species, epiphytes and lianes increase in number. As a result,
in the area of the Harenna forest, the main vegetation
gradient is caused by differences in altitude associated \'lith
variation in moisture. The moisture gradient is accompanied
by gradients in soil physical and chemical properties and
topography.
Description
Keywords
Biology