Vascular Plants Diversity and Ethnobotany with Emphasis to Traditional Medicinal and Wild Edible Plants in Dugda Dawa District of Borana Zone, Oromia Regional State, Ethiopia
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Date
2017-04
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Addis Ababa Universty
Abstract
This research is aimed at documentation and analysis of plant diversity in Dugda Dawa District along with the
ethnobotanical knowledge associated with traditional medicinal and wild edible plants used by the local people.
Vegetation data were collected from 60 plots laid preferentially, 20 m x 20 m for trees and shrubs and 1m x 1m
subplots for herbs. Woody species with a diameter at breast height (DBH) > 3 cm were counted and cover
abundance values estimated. Shannon-Wiener diversity index was used to assess species richness and evenness.
Both Sorensen's similarity coefficient and Jaccardʼs index of similarity were used to measure similarities among
communities in Dugda Dawa District vegetation, and only Sorensen's similarity coefficient to measure between this
and other woodland vegetations types in Ethiopia. A hierarchical cluster analysis with PC-ORD was used to identify
plant communities and synoptic values for detection of the dominant species for naming each plant community type.
Frequency, density, DBH, basal area and importance value indices (IVI) of woody species were also computed.
Ethnobotanical data were collected by interviewing 392 informants (290 males and 102 females). Guided field walk
and discussion (group or individual discussion) were used in collecting the data.Quantitative approaches were used
to determine informant consensus factor (ICF), fidelity level (FL), and use value (UV). Ethnomedicinal knowledge
apprehended by different informant categories was compared using t-tests with R- software. The study area yielded
343 vascular plant species of which 12 were endemic and four were new records for the floristic region belonging to
227 genera and 81 families. The vegetation was classified into four community types, namely Prunus africana -
Calpurnia aurea, Ehretia cymosa - Juniperus procera, Boscia mossambicensis - Lannea schimperi and Celtis
africana - Podocarpus falcatus community types based on hierarchical cluster analysis. The overall Shannon-
Wiener diversity and evenness values of Dugda Dawa District vegetation were 4.87 and 0.54 respectively. The
percentage distribution of individual shrub and tree species across different DBH classes indicated relatively high
proportion (53.9%) of individuals in DBH class 3 - 10 cm. Four representative woody plant population structures
were identified. Results of the ethnobotanical study revealed 127 medicinal plant species in 123 genera and 82
fanilies; and 71 wild edible plant species belonging to 52 genera and 37 families in different vegetation formations
of the study area. The family Fabaceae with 10 (7.9%) species of medicinal and 7 (9.9%) species of wild edibles was
dominant followed by the Lamiaceae (7, 5.5%) species of medicinal plants and Anacardiaceae ( 7, 9.9%) species of
wild edibles were the families represented by more species in the district. Plants in which leaves are used as
medicine and fruits are used as wild food were more dominant (36.6% and 65.4% respectively) than other plant
parts in the district. Significant difference (P < 0.05) was seen in the mean number of medicinal plants reported by
informants in different age classes, education levels, and experiences. Similarly significant difference (P < 0.05)
was observed in the mean number of wild edible plants reported by informants in different age classes and
experiences. The highest ICF value (0.93) was recorded for human musculoskeletal and nervous system disease
category. The highest fidelity level values were recorded for Ocimum urticifolium (97%) and Cyphostema serpens
(97%). Dry evergreen afro-montane forest vegetation which encompasses community one, two and four in Dugda
Dawa District is under great anthropogenic pressure including selective cutting of big trees in community four,
medicinal plants (e.g. Prunus africana and Zanthoxylum chalybeum) as well as wild edible plants (e.g. Cordia
africana and Syzygium guineense) which need strict conservation measures. Thus, priority conservation action
should be given to the dry afromontane vegetation type which encompasses plant communities one, two, and four as
they contain high plant species number (295) and high useful species (214) though the other vegetation types are
also under threat and community - based conservation activities should be applied to create sustainable usage of
resources. Warburgia ugandensis and Psophocarpus grandiflorus should be given cultivation and chemical analysis
priority for their medicinal and food values respectively.
Key words: Dugda Dawa District, ethnobotany, medicinal plants, plant diversity, wild edible plants
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Keywords
Dugda Dawa District, Ethnobotany, Medicinal plants, Plant diversity, Wild edible plants