In the central and northern highlands of Ethiopia, native forest and forest biodiversity is almost confined to sacred groves associated with churches. Local communities rely on these 'church forests' for essential ecosystem services including shade and fresh water but little is known about their region-wide distribution and conservation value. We (1) performed the first large-scale spatially-explicit assessment of church forests, combining remote-sensing and field data, to assess the number of forests, their size, shape, isolation and woody plant species composition, (2) determined their plant communities and related these to environmental variables and potential natural vegetation, (3) identified the main challenges to biodiversity conservation in view of plant population dynamics and anthropogenic disturbances, and (4) present guidelines for management and policy. The 394 forests identified in satellite images were on average ~2 ha in size and generally separated by ~2 km from the nearest neighboring forest. Shape complexity, not size, decreased from the northern to the central highlands. Overall, 148 indigenous tree, shrub and liana species were recorded across the 78 surveyed forests. Patch α-diversity increased with mean annual precipitation, but typically only 25 woody species occurred per patch. The combined results showed that >50% of tree species present in tropical northeast Africa were still present in the 78 studied church forests, even though individual forests were small and relatively species-poor. Tree species composition of church forests varied with elevation and precipitation, and resembled the potential natural vegetation. With a wide distribution over the landscape, these church forests have high conservation value. However, long-term conservation of biodiversity of individual patches and evolutionary potential of species may be threatened by isolation, small sizes of tree species populations and disturbance, especially when considering climate change. Forest management interventions are essential and should be supported by environmental education and other forms of public engagement.

Reubens B., Moeremans C., Poesen J., Nyssen J., Tewoldeberhan S., Franzel S., Deckers J., Orwa C., Muys B., 2011. Tree species selection for land rehabilitation in Ethiopia: from fragmented knowledge to an integrated multi-criteria decision approach. Agroforestry Systems, 82: 303-330. planted when both ecological suitability for the targeted area or preferences of local stakeholders are 6 not properly taken into account during selection. To develop a decision support tool for multi-purpose 7 species selection, first information needs to be pooled on species-specific ranges, characteristics and 8 functions for a set of potentially valuable species. In this study such database has been developed for 9 the highly degraded northern Ethiopian highlands, using a unique combination of information sources, 2

In the north Ethiopian highlands, gully erosion is a significant land degradation process. Although the protective role of vegetation has been demonstrated in many studies, efforts previously made in using woody species for erosion control in the research area are limited, and when applied, survival of the planted seedlings was very low. Lack of experience and fundamental knowledge on species autecology and traits are two important bottlenecks. This study therefore aims at better understanding seedling establishment and growth in a context of tree plantings, with the view to further control gully erosion in a semi-arid environment. To this end survival, growth and development of seedlings of Acacia etbaica Schweinf., Sesbania sesban (L.) Merr. and Dodonaea angustifolia L.f. were monitored during 26 months in a field trial under different site conditions and treatments. The experiment was established at two sites characterized by topographic and edaphic conditions (Vertisol and sandy colluvium) representative for the study area. At each site, seedlings were subjected to different treatments of watering, sheltering and planting position (gully floor, sidewall and shoulder), and a large set of plant growth variables was regularly monitored. Height and biomass growth was fastest for Sesbania, even if affected by different pests. Regardless of the species, plants growing in the (nutrient-rich) Vertisol site had a higher survival rate and an overall better development. Shelter protection significantly increased survival and resulted in taller seedlings. Notwithstanding these general trends, treatment effects were often varying over time and strongly influenced by specific edaphic conditions. Generally, Acacia performed best on gully shoulder and wall, Sesbania on the gully floor and Dodonaea on shoulder positions. Recommendations for planting practice and follow-up research are discussed.Plant Soil (2009) 324:131-156

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