Embed Size (px)
DESCRIPTION
Plant communities in coffee forests of South-Western Ethiopia along a fragmentation and degradation gradient. * Kitessa Hundera 1 , 2 , Raf Aerts 2 , Olivier Honnay 3 & Bart Muys 2 1 Department of Biology, Jimma University, Ethiopia; 2 Division Forest, Nature and Landscape, KU Leuven, - PowerPoint PPT Presentation
Citation preview
.
4. Result: 78 woody species were recorded in the fragments. The most frequent species were Croton macrostachyus Hochst. ex Delile and Syzygium guineense DC. occurring in 50 and 44 % of the plots respectively. Dominance of Croton macrostachyus indicates high level of forest disturbance.Six plant communities were identified from the Indicator Species Analysis (ISA), i.e. Croton macrostachyus, Albzia schimperiana, Albizia gummifera, Syzygium-Olea welwitischii, Prunus-Polyscias and Schefflera-Rhus.Diversity indices for each community given in table 1.
From NMS two main groups were identified: (i) the Croton, Albzia schimperiana and Albizia gummifera communities in the semi-forest coffee plantations at Geruke and Fetche and (ii) the Syzygium-Olea welwitischii, Prunus-Polyscias and Schefflera-Rhus communities in the forest and semi-forest coffee in the continuous forest at Gera (Fig 1a&b). Management intensity and distance from Jimma explained the major differences in species composition in the two groups (Fig.2).
3. METHODOLOGY: 91 sample plots of 20 m x 20 m were laid in coffee forest fragments in Geruke, Feche and Gera, (Jima Zone) with different size and varying level of coffee management practices. Data on vegetation, edaphic and anthropogenic disturbances were collected from each plots. Indicator species analysis was used to determine the optimal number of groups in the cluster analysis. Diversity indices were calculated for each community. NMDS was used to investigate indirect gradients influencing species distribution.
Plant communities in coffee forests of South-Western Ethiopia along a fragmentation and degradation gradient
*Kitessa Hundera1,2, Raf Aerts2, Olivier Honnay3 & Bart Muys2
1Department of Biology, Jimma University, Ethiopia; 2Division Forest, Nature and Landscape, KU Leuven, 3Department of Biology, Laboratory of plant ecology KU Leuven, Belgium
1. INTRODUCTION: The SW E forests are believed to be home to wild
coffee arabica and are the reservoirs for it’s genetic diversity. Traditionally the people living in and around these forests manage the forests for coffee production. Coffee management varies from simple collection of coffee berries from the wild coffee shrubs to altering the composition and structure of the forest to reduce shade on coffee shrubs (Feyera Senbeta, 2006). Even though there are some reports on the effect of coffee management in the relatively large and undisturbed Afromontane forests in the south west, no study has been conducted in small fragmented coffee forests in Jimma area.
Diversityindices
Croton Albizia gummifera
Albizia schimperiana
Syzygium-Olea welwetschii
Prunus-Polyscias
Schefflera-Rhus
All plots
α 4.82 3.71 4.15 7.70 11.18 9.22 6.52
β 6.84 6.73 5.06 6.23 6.73 4.12 10.58
γ 33 25 21 48 41 38 69
H’ 1.03 0.78 0.83 1.08 1.40 1.01 1.02
D 0.54 0.44 0.46 0.53 0.66 0.49 0.52
Hill’s N1 3.22 2.41 2.39 3.30 4.36 3.05 2.76
Hill’s N2 2.19 3.29 2.94 5.66 1.58 4.06 1.93
Hill’s E1 0.73 0.73 0.61 0.50 0.42 0.34 0.04
Nr of plots 17 14 13 20 11 9 84
Table 1. Diversity indices for each community and for all plots together
5. Conclusion: In the Geruke and Feche fragments, the original understorey is almost completely removed and replaced by even-aged coffee stands and sparse old, mature shade trees. Devising mechanisms for regeneration of the shade trees is recommended before they reach post-reproductive stage and die, which strongly affects the coffee production.
2. Objective: to assess the vegetation composition, community types and structure of the forest fragments and the anthropogenic and environmental variables that might cause the variations.
This PhD work was done in the context of the IUC-JU project. Contacts: [email protected]; Supervisor: [email protected]
Fig 1a. Profile of Croton community Fig 1b. Profile of Prunus- Polyscis community
Veg
eta
tion
data
collecti
on
Fig 2. NMS graph of the communities
Charcoal making in Charcoal making in coffee forestscoffee forestsCoffee forest fragment in GerukeCoffee forest fragment in Geruke
References: References: Feyera Senbeta, 2006. Biodiversity and ecology of Afromontane rainforests with wild Coffea arabica L. populations in Ethiopia. Ecology and Development Series No. 38
