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The aim of this study was to determine the floristic composition, diversity, density of soil seed bank, and relationship of soil seed bank and above ground vegetation in forest patch, riverine and grazing lands of Arsi-Bale Massifs of Southeast Ethiopia. Soil samples were collected from 56 plots of 10 cm x 10 cm quadrats size from four layers (litter layer, 0–3 cm, 3–6 cm and 6–9 cm). Regarding above ground vegetation, 30 m x 30 m for trees, 5 m x 5 m for shrubs and 1 m x 1 m quadrat sizes for herbaceous were used for sampling from the same 56 plots. Shannon-Weiner diversity index was used for soil seed bank and above ground vegetation. Similarities among the land use types, soil seed bank and above ground vegetation were analyzed using Jaccard coefficient of similarity (JCS). Variance analysis of species abundance in each soil layer and land use types was done by ANOVA using SAS software (Version 9.0). A total of 292 vascular plant species from standing vegetation and 107 species from soil seed bank were identified. A total of 10,828.57 seedlings per m2 with mean density of 34.27 ± 7.79 individuals/m2 was recorded. The mean density of soil seed bank among the soil seed bank layers did not show significant difference (one-way ANOVA, (F3, 316) = 0.13, P

Bamboos provide a number of ecosystem services, including the provision of a permanent carbon (C) sink. The present study was undertaken in the Sheka forest, currently recognized as a UNESCO Biosphere Reserve. The objectives of this study were to: (1) develop species- and site-specific allometric models for biomass estimation and (2) quantify the carbon storage capacity of highland bamboo stands. A total of 12 plots each measuring 10 m x 10 m were established at a distance of 200 m in the forest. 96 culms were harvested for the development of biomass estimation equations. Litter samples were collected in 1 m x 1 m subplots, while soil samples were collected at 0–10, 10–20, 20–40, and 40–60 cm soil depths for determination of soil organic carbon (SOC) contents. The estimated mean DBH, basal area and plant height were 7.0 cm, 53.2 m2 ha−1 and 12.9 m, respectively. The study has established allometric scaling of plant height with stem diameter in highland bamboo. It has also established that the allometric model is superior to commonly used non-linear H-DBH models. Aboveground biomass was estimated at 93 Mg ha−1 with mean C stocks of 43.7 Mg ha−1. The estimated below-ground biomass was 18.6 Mg ha−1 with C stocks of 8.7 Mg ha−1. The C stocks in the litter layer were estimated at 1.57 Mg ha−1. Average soil C storage was estimated at 388.12 Mg ha−1 within the 0–60 cm soil depth. In total, the natural highland bamboo stands store approximately 442.1 Mg C ha−1. The estimated C stocks were comparable with values reported for bamboos in Ethiopia and elsewhere. It is concluded that natural highland bamboo stands play a significant role as carbon sinks. The insights gained in this study are expected to be applicable to Afromontane ecosystems where highland bamboo occurs in Africa. Highland bamboo (Oldeania alpina) is a conspicuous element of Afromontane vegetation in Africa We developed models for estimating biomass carbon (C) stocks in highland bamboo stands We estimated biomass C stock of highland bamboo stands at 52.5 Mg ha−1 and litter C at 1.6 Mg ha−1 Soil organic C stock of highland bamboo stands was 388.1 Mg ha−1 Total system C in highland bamboo stands was over 442 Mg ha−1

While top-down control plays an important role in shaping both natural and agricultural food webs, we lack insights into how top-down control effects vary across spatial scales. We used a multi-scale survey of top-down control of coffee pests and diseases by arboreal ants to examine if colony location creates a small-scale mosaic in top-down control around trees and if the strength of that control varies between sites at the landscape scale. We investigated pest and disease levels on coffee shrubs at different distances from shade trees with and without a Crematogaster spp. ant colony in 59 sites along a coffee management intensity gradient in southwestern Ethiopia. Within sites, ants significantly suppressed herbivory and coffee leaf rust at distances less than 10 m from nesting trees. Top-down control varied between sites, with stronger top-down control of free-feeding herbivory near ant colonies at sites with lower management intensity and stronger top-down control of a skeletonizer at sites with higher canopy cover. We conclude that the strength of top-down control by ants is highly heterogeneous across spatial scales, as a consequence of the biology of the predator at the small scale and herbivore density or changes in herbivore-ant interactions at the landscape scale.

Research Highlights: Hagenia abyssinica is geographically localized, poor regenerated and endangered species in Ethiopia. Ethiopia has been experiencing variability of rainfall and rise in temperature due to the climate change. This study has hypothesized that the suitable areas for the species will be narrowed by the year 2070. Background and Objective The prediction of species distribution models help to implement appropriate conservation actions. The aim of this research was to identify the current and likely future distribution range and suitable areas for the species, and to determine the presence of H. absyssinica in risk in a short-term future. Material and method: To this end, occurrence data, bioclim variables, soil, elevation, and land cover map of Ethiopia were used. MaxEnt was used to predict distribution. Climate change impacts on the distribution of the species was performed using bioclimatic variables of the future climate data, 2070 (average for 2061-2080) was obtained from IPPC5 (CMIP5) at 30 seconds (1km) spatial resolution. The climate data was projected from GCMs, downscaled and calibrated using rcp4.5. Results: Both current and likely future distribution models were excellent and significantly better than random performance. This study has computed 59987 km2 to be the low impact area for the species under current conditions and will remain habitat under future climates and 39025 km2 area has been identified as the possible high impact areas or declining habitat. The model has also determined that 1238724 km2 of the areas are unsuitable at present and for future climates. The current study found that 15751 km2 of the area will be modified as a new suitable area for H. abyssinica due to climate change. Conclusion: Species distribution modeling is essential for the implementation of conservation actions that are compatible with the inevitable changing climatic conditions of the country.

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.

Enset (Ensete ventricosum (Welw.) Cheesman) is an endemic multipurpose Ethiopian crop with a potential for food security for it grows in areas where there is a high population pressure and scarce cultivable land. Studies indicate that pests and diseases are among the challenges to sustainability of enset agriculture. A survey on diversity, challenges and management of enset was conducted in Kambatta Tembaro Zone. Twelve farmscapes each with 15 sampling sites were randomly selected for the study. The identification of enset landraces and recording of data on criterion for landraces identification and selection, and cultural management practices were conducted with the help of farmers using interviews, questionnaire and group discussion. Shannon Index (H’) and multiple linear regression, and ANOVA were employed to analyze the data. Farmers’ characterization identified a total of 111 named enset landraces, of which 21 had medicinal value. There was high significant difference (P

A very long history of human interference and pressure from population growth has imparted different land use types in the Chilimo forest: shrub land, closed forest, Cupressus lusitanica plantation, Eucalyptus plantation, Juniperus procera dominated stand, Olea europaea subsp. cuspidata dominated stand, open forest, Podocarpus falcatus dominated stand, abandoned arable land, and grassland. A total of 100 plots (each 20 m x 20 m) were used in ten habitat types (10 plots in each) for the collection of data on the soil seed bank and standing vegetation. Soil samples were collected from within small quadrats (15 cm x 15 cm) from four successive soil layers. A total of 105 plant species were identified from the soil seed bank with total densities ranging between 4991 and 11017 seeds/m2. Of the total recorded species in the soil seed bank, herbaceous species were represented with the largest number (87.6%) whereas the contribution of woody species was low (11.4%). The highest number of species was recorded from the closed canopy stand while the highest density of seeds was found in the arable land. The overall vertical distribution of seeds showed the highest densities occurring in the upper 3 cm soil depth and gradually decreasing with increasing depth, except in the arable land. There was a significant difference among the habitat types in the density of soil seed bank suggesting different types, level and frequency of disturbance on different habitat types. The very low similarity between the soil seed bank and aboveground flora is reflective of both the current and past standing vegetation.Key words/phrases: Afromontane, Forest degradation, Restoration, Soil seed bank, Species diversity.

The expansion of pollinator-dependent crops, especially in the developing world, together with reports of worldwide pollinator declines, raises concern of possible yield gaps. Farmers directly reliant on pollination services for food supply often live in regions where our knowledge of pollination services is poor. In a manipulative experiment replicated at 23 sites across an Ethiopian agricultural landscape, we found poor pollination services and severe pollen limitation in a common oil crop. With supplementary pollination, the yield increased on average by 91%. Despite the heterogeneous agricultural matrix, we found a low bee abundance, which may explain poor pollination services. The variation in pollen limitation was unrelated to surrounding forest cover, local bee richness and bee abundance. While practices that commonly increase pollinators (restricted pesticide use, flower strips) are an integral part of the landscape, these elements are apparently insufficient. Management to increase pollination services is therefore in need of urgent investigation.

The mating system of Sesbania sesban was studied using one natural population and two cultivated populations. A large number of progeny (600) was assayed from each population for one polymorphic locus of Malate dehydrogenase (Mdh). The level of out-crossing in the studied populations ranged from 40–100%. The genotype frequencies were in agreement with those of the Hardy-Weinberg expected genotype proportions as in randomly mating populations at P < 0.05. The floral structure and the pollen shedding behaviour of the flowers of S. sesban could favour cross-pollination and/or self-pollination depending on the circumstances. Self-pollination usually occurs late in the flowering period when pollinators fail to visit the flowers. Such a “delayed selfing” facilitates out-crossing in the presence of appropriate pollinators under natural conditions, but confers a selective advantage where pollinators are limiting. The results indicated that S. sesban could be self-fertilized in the absence of pollinators or could out-cross with other heterozygous individuals in the neighboring population when suitable pollinators are available. S. sesban exhibits “facultative xenogamy” or “delayed selfing” and is a mixed mating species. Key words/phrases: Allozymes, delayed selfing, Hardy-Weinberg equilib rium, malate dehydrogenase, mixed mating system SINET: Ethiopian Journal of Science Vol.25(2) 2002: 177-190

Studies of early human settlement in alpine environments provide insights into human physiological, genetic, and cultural adaptation potentials. Although Late and even Middle Pleistocene human presence has been recently documented on the Tibetan Plateau, little is known regarding the nature and context of early persistent human settlement in high elevations. Here, we report the earliest evidence of a prehistoric high-altitude residential site. Located in Africa’s largest alpine ecosystem, the repeated occupation of Fincha Habera rock shelter is dated to 47 to 31 thousand years ago. The available resources in cold and glaciated environments included the exploitation of an endemic rodent as a key food source, and this played a pivotal role in facilitating the occupation of this site by Late Pleistocene hunter-gatherers.