Study of Vegetation Composition of Magada Forest, Borana Zone, Oromia, Ethiopia

Universal Journal of Plant Science 3(5): 87-96, 2015 http://www.hrpub.org DOI: 10.13189/ujps.2015.030501 Study of Vegetation Composition of Magada Forest, Borana Zone, Oromia, Ethiopia Genene Bekele Tura1,*, P. Ramachandra Reddy2 1Department of Biology, Madawalabu University, Ethiopia 2Plant Anatomy and Taxonomy Laboratory, Department of Botany, Osmania University, India Copyright © 2015 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract The Magada forest is one of the National Forest forest or woodland of approximately the same species Priority Areas (NFPAs), which is located in the southern part composition as that of the remaining areas with closed forest of the country in the Borana Zone of Oromia National indicates the extent to which Ethiopian highlands were once 0 Regional State. It lies approximately between longitudes 38 forested [17]. There is no accurate or reliable information 0 0 0 15’ E and 38 20’ E and latitude 5 27 N and 5 32’ N (EMA, about the extent and location of the past and present natural 1987) in between Bule-Hora and Dugda Dawa districts. The forests and woody vegetation cover in Ethiopia. However, objective of this work was to provide a list of plant species historical sources indicate that, on the basis of potential found in the forest and to recommend solutions for climatic climax high forests might have once covered about management and conservation problems. The vegetation 35 – 40 % of the total land area of the country. If the compositions of the Magada forest were described based on savannah woodlands are included, 66 % of the country has the vegetation data collected between February 2013 and been believed to be covered with forests and woodlands [3]. October 2013. Releves of 30 m x 30 m were taken for the The country’s forest and woodland resources have been woody species and 2 m x 2 m for field layers. A total of 66 declining both in size (deforestation) and quality releves were analyzed at altitude between 1750 and 2100 m (degradation) and the current annual loss of high forests is a.s.l. Data on the species list was collected. A total of 197 estimated to about 150,000 – 200,000 ha. The main reasons species of vascular plants belonging to 64 families were of deforestation are agricultural expansion, uncontrolled identified. Out of these [100 (50.8 %)] are woody species and exploitation for various purposes, notably for fuel wood [97 (49.2 %)] are non-woody species (field layers). 84.3 % of the families are dicots while 12.5 % are monocots and charcoal, construction materials, etc, shifting cultivation and gymnosperms and pteridophytes comprise 1.6 % each. forest fire [3] which are closely linked with the vicious cycle Asteraceae is the largest family with [18 (9.1%)] followed by of mutually reinforcing factors, i.e. poverty, population Acanthaceae [16 (8.1%)], Lamiaceae and Rubiaceae each growth and the state of the environment. The other reason is with [14 (7.1%)] and Fabaceae [13 (6.6%)] species. The inadequate standard of forest management. vegetation of the Magada forest is disturbed through grazing The depletion of the natural vegetation in many parts of and browsing by domestic livestock, cultivation and other the country has led to the threat and decline in number and human uses. This further retard regeneration processes of the area of distribution of many plant species, and surprisingly, trees and shrubs. Pressure on the resources from human 120 threatened endemic plant species are known from population could intensify and impose more rapid and more Ethiopia [5]. Unless the present trend of exploiting the degenerative changes. Recognizing these issues as possible remaining spare forest resources, every piece of relict forest future scenario underlines the need for management remaining will be gone in the very near future [15]. The trend intervention to increase quality of regeneration being can only be reversed if appropriate measures taken to halt recruited and accelerate the growth of the young plants them. already present. In order to maintain the ecological equilibrium and to Keywords Vegetation Composition, Magada Forest, meet the forest resources requirement of the population, Borana Zone scientific information is the basis. Several ecological studies have been made in Ethiopia with emphasis on plant community analysis, viz., [11,21,17,13,18,10,19,1,9,7,8,16] Despite these, studies on the ecology and flora of the Magada forest vegetation are lacking. 1. Introduction Therefore, ecological assessment of the existing forests is The numerous isolated mature forest trees or patches of the basis for meaningful planning to rationally utilize the 88 Study of Vegetation Composition of Magada Forest, Borana Zone, Oromia, Ethiopia remaining forest resources. Thus, the present study has the Magada forest is distinctive in that Podocarpus is following objectives (a) to provide a list of plant species dominant and mapped by Reference [2] as Podocarpus found in the forest and (b) to recommend solutions for dominated coniferous forest. The altitude of the forest ranges management and conservation problems. between 1750 – 2100 m a.s.l. The southern and south-eastern parts of the country including the Magada forest area experience a bimodal rainfall pattern from September to 2. Materials and Methods November and from March to May. The most reliable rainy months are April and May. The nearest weather station to Magada forest is Bule-Hora town in about 10 km north of the 2.1. Description of the Study Area forest edge. From metrological data for 2003 – 2012 the The Magada forest is one of the National Forest Priority mean annual rainfall in Bule-Hora was 809 mm, and there Areas (NFPAs), which is located in the southern part of the are two peaks (April and October). The mean annual country in the Borana Zone of Oromia National Regional maximum temperature and the mean annual minimum State. It lies approximately between longitudes 380 15’ E and temperature were 24.5 and 11.56 respectively. The mean 380 20’ E and latitude 50 27 N and 50 32’ N (EMA 1987) in maximum temperature for the hottest month was 28.3 in February and mean minimum℃ temperature℃ for coldest month Bule-Hora district (Fig. 1). The forest covers about 25,012 ha ℃ of land [14] and comprises essentially a single compact was 8.8 in December. The mean annual temperature was 18.03 . According to FAO (1990) mean annual rainfall and block of forest, roughly four sided and divided into two ℃ unequal sized areas by the main road running north south mean temperature were 18.6 and 973 mm respectively. The recent℃ data indicated lower precipitation rather than from Addis Ababa to Nairobi and it is about 485 km away ℃ from Addis Ababa. before. Figure 1. Location Map of Magada Forest in Borana Zone Universal Journal of Plant Science 3(5): 87-96, 2015 89 2.2. Data Collection A total of 197 species of vascular plants representing 64 A reconnaissance survey was made across the Magada families were recorded from the tree, shrubs, and field layers. forest on 10 -12 February 2013 in order to obtain an Of these, 52 (26.4 %) species were trees, 38 (19.3 %) species impression of the site conditions and variation in shrubs, 16 (8.1 %) species climbers including one epiphyte physiognomy of the vegetation. Field data were collected and one semi-parasite, 91 (46.2 %) species were herbs during February 2013 to October 2013. During sampling including 3 graminoids and one fern species (Fig. 2). 83.61 visually checked homogenous representative stands were per cent of the families were dicots, while 13.11 % monocots, subjectively selected (subjective sampling) in such a way 1.64 % pteridophytes and 1.64 % gymnosperms. The that the various conditions encountered were represented by families with the highest number of species were Asteraceae at least one sample. [18 (9.1%)], Acanthaceae [16 (8.1%)], Rubiaceae [14 Sixty six sampling sites 900 m2 (30 m x 30 m)in size were (7.1%)], Lamiaceae [14 (7.1%)] and Fabaceae [13 (6.6%)]. considered to sample trees and shrubs. Floristic analysis of Fourteen species of climbers belonging to 11 families were herbaceous and graminoid species was made on a 2 m x 2 m recorded from the plots. Three species to Asclepiadaceae, (4 m2) sub plots laid within the larger plot where the and two Vitaceae, whereas the rest belong to Apocynaceae, vegetation was assumed to be representative. At each Asparagaceae, Celastraceae, Cucurbotaceae, Fabaceae, sampling site altitude was measured using Pretzel digital Oleaceae, Ranunculaceae, Rhamnaceae and Rubiaceae. altimeter and aspect and / or position using Magellan GPS. The Magada forest is a home for 11 endemic species of From each plot a complete list of trees, shrubs and herbs plants (Tesfaye Hawas, unpublished database) and 13 was made. indicator species of plants for forest disturbance were Additional plant species out of the plot, but in the forest, identified [12]. The endemic plant species of the Magada including the edaphic grasslands were recorded. forest include Ceropegia microgaster, Cynoglossum Regeneration status, dead standing trees, stumps and logs in coeruleum, Justicia bizuneshiae, Echinops longisetus, the plots were noted. Identification of plant specimens was Maytennus addat, Millettia ferruginea, Phylanthus mooney, conducted in the National Herbarium (ETH), Addis Ababa Saturegia paradoxa, Senecio ochrocarpus, Solanecio gigas, University and nomenclature follows that of the published Thunbergia ruspolii and Vernonia leopoldi. volumes of the Flora of Ethiopia and Eritrea. The indicator species for disturbance of the forest include Achyranthus aspera, Asparagus Africana, Biden biternata, 3. Result and Discussion Croton macrostachyus, Cyathula polycephala, Dodonia angustifolia, Galinsoga parviflora, Girardinia bullosa, 3.1.

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