| 1. |
- Beche, Dinkissa, et al.
(author)
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Prevalence of major pests and diseases in wild and cultivated coffee in Ethiopia
- 2023
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In: Basic and Applied Ecology. - 1439-1791 .- 1618-0089. ; 73, s. 3-9
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Journal article (peer-reviewed)abstract
- The study of pests and diseases on crops and crop relatives in the wild is valuable from both a theoretical and an applied point of view. Few studies have addressed multiple pests and diseases in such ecosystems. Our objectives were to (1) compare the prevalence of multiple pests and diseases on coffee in forests and more managed landscapes and (2) assess how spatial, environmental, host density and management factors affect the incidence and severity of coffee pests and diseases across forests.To achieve these objectives we studied different pests, diseases and one hyperparasite on wild and semi-wild coffee from 84 plots of 20 × 20 m across a forested landscape in southwest Ethiopia and compared the results to previous studies of more intensively managed adjacent landscapes.The prevalence of all surveyed coffee leaf pests and diseases was high (>71% of investigated plots) and very similar to the levels in more intensively managed landscapes reported in the literature. The incidence rates of all pests, diseases and the hyperparasite showed a high variation among the plots, and correlation with each other in some cases. However, this variation was weakly related to the measured environmental and management variables, but coffee pests and diseases were often positively related to high coffee density.One possible explanation for the similar prevalence is that, although the landscapes are different, the local environmental conditions have much in common since coffee is also grown under indigenous shade trees in more intensively managed landscapes. However, the variability in pest and disease levels among sites was large and it is difficult to predict where they attain high levels. There is a need of detailed investigations on drivers of spatio-temporal population dynamics of these species, including their natural enemies, to be able to provide advice for development of sustainable coffee disease management.
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| 2. |
- Beche, Dinkissa, et al.
(author)
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Spatial variation in human disturbances and their effects on forest structure and biodiversity across an Afromontane forest
- 2022
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In: Landscape Ecology. - : Springer Science and Business Media LLC. - 0921-2973 .- 1572-9761. ; 37:2, s. 493-510
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Journal article (peer-reviewed)abstract
- Context Human disturbances can have large impacts on forest structure and biodiversity, and thereby result in forest degradation, a property difficult to detect by remote sensing.Objectives To investigate spatial variation in anthropogenic disturbances and their effects on forest structure and biodiversity.Methods In 144 plots of 20 x 20 m distributed across a forest area of 750 km2 in Southwest Ethiopia, we recorded: landscape variables (e.g., distance to forest edge), different human disturbances, forest structure variables, and species composition of trees and epiphyllous bryophytes. We then first assessed if landscape variables could explain the spatial distribution of disturbances. Second, we analysed how forest structure and biodiversity were influenced by disturbances.Results Human disturbances, such as coffee management and grazing declined with distance to forest edges, and penetrated at least a kilometer into the forest. Slope was not related to disturbance levels, but several types of disturbances were less common at higher elevations. Among human disturbance types, coffee management reduced liana cover and was associated with altered species composition of trees. The presence of large trees and basal area were not related to any of the disturbance gradients.Conclusions Although most anthropogenic disturbances displayed clear edge effects, surprisingly the variation in the chosen forest degradation indices were only weakly related to these disturbances. We suggest that the intersection between edge effects and forest degradation is very context specific and relies much on how particular societies use the forests. For example, in this landscape coffee management seems to be a key driver.
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| 4. |
- Gove, Aaron D., et al.
(author)
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Structurally complex farms support high avian functional diversity in tropical montane Ethiopia
- 2013
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In: Journal of Tropical Ecology. - 0266-4674 .- 1469-7831. ; 29, s. 87-97
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Journal article (peer-reviewed)abstract
- Of all feeding guilds, understorey insectivores are thought to be most sensitive to disturbance and forest conversion. We compared the composition of bird feeding guilds in tropical forest fragments with adjacent agro-ecosystems in a montane region of south-west Ethiopia. We used a series of point counts to survey birds in 19 agriculture and 19 forest sites and recorded tree species within each farm across an area of 40 x 35 km. Insectivores (similar to 17 spp. per plot), frugivores (similar to 3 spp. per plot) and omnivores (similar to 5 spp. per plot) maintained species density across habitats, while granivores and nectarivores increased in the agricultural sites by factors of 7 and 3 respectively. Species accumulation curves of each guild were equal or steeper in agriculture, suggesting that agricultural and forest landscapes were equally heterogeneous for all bird guilds. Counter to most published studies, we found no decline in insectivore species richness with forest conversion. However, species composition differed between the two habitats, with certain forest specialists replaced by other species within each feeding guild. We suggest that the lack of difference in insectivorous species numbers between forest and agriculture in this region is due to the benign nature of the agricultural habitat, but also due to a regional species pool which contains many bird species which are adapted to open habitats.
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| 6. |
- Hailu, Beyene Zewdie, et al.
(author)
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Patterns and drivers of fungal disease communities on Arabica coffee along a management gradient
- 2020
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In: Basic and Applied Ecology. - : Elsevier BV. - 1439-1791 .- 1618-0089. ; 47, s. 95-106
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Journal article (peer-reviewed)abstract
- Plants, including those managed by humans, are often attacked by multiple diseases. Yet, most studies focus on single diseases, even if the disease dynamics of multiple species is more interesting from a farmers’ perspective. Moreover, most studies are from single management systems, although it is valuable to understand how diseases are distributed across broad management gradients, especially in cases where less intensive management also provides biodiversity values in the landscape. To understand the spatial dynamics and drivers of diseases across such a broad management gradient, we assessed the four major fungal diseases on Arabica coffee (Coffea arabica) at 60 sites in southwestern Ethiopia along a gradient from only little managed wild coffee in the forest understory to intensively managed coffee plantations. We found that environmental and management factors related to disease incidence and severity differed strongly among the four fungal diseases. Coffee leaf rust (Hemileia vastatrix) and Armillaria root rot (Armillaria mellea) were more severe in intensively managed sites, whereas coffee berry disease (Colletotrichum kahawae) and wilt disease (Gibberella xylarioides) were more severe in less managed sites. Among sites, incidence and severity of the four fungal diseases poorly correlated with each other. Within sites, however, shrubs that were severely attacked by coffee leaf rust also had high levels of berry disease symptoms. A better understanding of disease dynamics is important for providing management recommendations that benefit smallholder farmers, but also to evaluate possibilities for maintaining biodiversity values in the landscape related to shade cover complexity and wild coffee genetic variation.
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| 8. |
- Hylander, Kristoffer, et al.
(author)
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Effects of Coffee Management on Deforestation Rates and Forest Integrity
- 2013
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In: Conservation Biology. - : Wiley. - 0888-8892 .- 1523-1739. ; 27:5, s. 1031-1040
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Journal article (peer-reviewed)abstract
- Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest-agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973-2010) across elevations in 2 forest-agriculture mosaic landscapes (1100 km(2) around Bonga and 3000 km(2) in Goma-Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee-growing elevations compared with at higher elevations (-10/20% vs. -40/50% comparing relative rates at 1800 m asl and 2300-2500 m asl, respectively). Within the coffee-growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest-specialist species. Even if the presence of coffee slows down the conversion of forest to annual-crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administracion Cafetalera sobre las Tasas de Deforestacion y la Integridad de los Bosques Resumen El conocimiento sobre como se utilizan los margenes de los bosques puede ser crucial para el entendimiento general de los cambios en la cubierta boscosa, la estructura de los bosques y la biodiversidad en el paisaje. Estudiamos transiciones bosque-agricultura en el suroeste de Etiopia y partimos de la hipotesis de que la presencia del cafe (Coffea arabica) disminuye las tasas de deforestacion por la importancia del cafe para las economias locales y su ocurrencia extensa en los bosques y los margenes de estos. Usando imagenes de satelite e informacion de elevacion, comparamos los cambios en la cubierta boscosa a traves de 37 anos (1973-2010) a lo largo de elevaciones en 2 paisajes mosaico de bosque y sembradios (1100 km(2) alrededor de Bonga y 3000 km(2) en Goma-Gera). En el campo en el area de Bonga determinamos la cobertura de cafe y la estructura del bosque en 40 margenes de bosque que difirieron en el tiempo desde la deforestacion. Tanto la tasa absoluta como la relativa de deforestacion fueron mas bajas en las elevaciones donde se cultiva cafe comparadas con las de elevaciones mas altas (-10/20% vs. -40/50% comparando tasas relativas en 1800 msnm y 2300-2500 msnm, respectivamente). Dentro de la elevacion donde se cultiva cafe, la proporcion de sitios con una alta cobertura de cafe (>20%) fue significativamente mas alta en los margenes estables (42% de los sitios que habian estado en la misma localidad durante el periodo entero) que en los margenes con cambios recientes (0% de los sitios donde la expansion anual de cultivos habian alterado el margen). El nivel de perturbacion y de estructura del bosque no difirio entre los sitios con 30% o 3% de cafe. Sin embargo, un creciente cuerpo de literatura sobre los gradientes de administracion del cafe en Etiopia reportan los efectos negativos del cafe sobre la abundancia de especies especialistas de bosques. Aunque sea cierto que la presencia de cafe disminuye la conversion de bosque a sembradios de cosecha anual, existe el riesgo de que la intensificacion de la administracion de cafe todavia amenace la biodiversidad del bosque, incluyendo la diversidad genetica del cafe silvestre. La politica de conservacion para los bosques etiopes entonces debe desarrollar estrategias que reconozcan que los bosques sin produccion cafetalera pueden tener riesgos mayores de deforestacion que los bosques con produccion cafetalera y que los bosques con produccion cafetalera seguido tienen un valor bajo de biodiversidad.
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| 10. |
- Hylander, Kristoffer, et al.
(author)
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Liverworts of southwest Ethiopian montane forests : ecological and biogeographical notes
- 2010
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In: Journal of Bryology. - 0373-6687 .- 1743-2820. ; 32, s. 92-100
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Journal article (peer-reviewed)abstract
- Ethiopia has diverse topographic features and climatic conditions with a diverse flora. The liverwort flora of southwest Ethiopia is practically unknown, despite a favourable climate and the occurrence of suitable ecosystems such as montane rainforests. During an ecological study of diversity patterns of bryophytes and vascular plants in relation to land use, we recorded many bryophyte species. In this paper we report the finding of 89 species of liverworts, and give short ecological notes and describe the distribution (locally and in Africa) for each species. Of these, 51 species are newly reported from Ethiopia. It is thus obvious that Ethiopia is considerably richer in liverworts than might be expected from previous checklists.
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