Effectiveness of exclosures to control soil erosion and local communities perception on soil erosion

The study investigated how effective exclosures are in the fight against soil erosion and how they are perceived as a means to control soil erosion by the local community (farmers and local experts). The universal soil loss equation (USLE) used to estimate potential soil erosion. Data on local community perception obtained from a survey of 62 farm households and five local experts. In-depth interview, group discussion and non-participant field observation also carried out to obtain additional information. The USLE results agreed with the farmers' (67%) and local experts' opinion that erosion at study area is severe and affect the quality of lives of residents. Insignificant difference (p > 0.05) was observed in the estimated soil loss among treatments. However, the estimated soil loss from free grazing lands was higher by 47% than soil loss from exclosures which illustrated that exclosures are effective to control soil erosion. The majority of farmers (70%) also rated exclosures effectiveness to control soil erosion as high. Local communities were optimistic about the chances to rehabilitate degraded lands and make them productive. The majority of farmers (60%) did not consider population growth as a cause of soil erosion. For the majority of interviewed farmers, poor land management is more important. Efforts to create awareness within the rural communities should focus on the link between high population growth, environmental degradation and poverty. The optimistic view of local communities can be considered as an asset for the planning and development of degraded lands rehabilitation efforts

Tree species selection for land rehabilitation in Ethiopia: from fragmented knowledge to an integrated multi-criteria decision approach

Dryland regions worldwide are increasingly suffering from losses of soil and biodiversity as a consequence of land degradation. Integrated conservation, rehabilitation and community-based management of natural resources are therefore of vital importance. Local planting efforts should focus on species performing a wide range of functions. Too often however, unsuitable tree species are planted when both ecological suitability for the targeted area or preferences of local stakeholders are not properly taken into account during selection. To develop a decision support tool for multi-purpose species selection, first information needs to be pooled on species-specific ranges, characteristics and functions for a set of potentially valuable species. In this study such database has been developed for the highly degraded northern Ethiopian highlands, using a unique combination of information sources, and with particular attention for local ecological knowledge and preferences. A set of candidate tree species and potentially relevant criteria, a flexible input database with species performance scores upon these criteria, and a ready-to-use multi-criteria decision support tool are presented. Two examples of species selection under different scenarios have been worked out in detail, with highest scores obtained for Cordia africana and Dodonaea angustifolia, as well as Eucalyptus spp., Acacia abyssinica, Acacia saligna, Olea europaea and Faidherbia albida. Sensitivity to criteria weights, and reliability and lack of knowledge on particular species attributes remain constraints towards applicability, particularly when many species are jointly evaluated. Nonetheless, the amount and diversity of the knowledge pooled in the presented database is high, covering 91 species and 45 attributes

Effects of biodiversity loss and restoration scenarios on tree-related ecosystem services

In landscapes worldwide, trees in forests and agricultural lands have important ecological functions. Their loss may have important consequences for the delivery of ecosystem services (ES) to local communities, even if individual trees have low conservation values. This study explores the effect of land use and land use change on the provisioning of tree-related ES in a mixed Afromontane landscape in Ethiopia. First, we mapped the current distribution of tree-related ES using indicator ES, which represent the most characteristic ES for different land use types. More ES were characteristic for indigenous forest and agroforest, compared to exotic forest, cropland, and rangeland. A scenario analysis was conducted on the effect of tree species loss and restoration (RES) on ES. Two ES indices, ES diversity and ES multifunctionality, were used to evaluate the ES supply. The different behavior of the two ES indices in the species loss scenarios suggests that rare species have distinct traits that provide specific ES, which could not be compensated by the remaining common species. In tree species-poor landscapes, local communities prefer multifunctional tree species and these keep the diversity of ES supply high. Overall, our findings demonstrate that future conservation and restoration programs in mixed landscapes should both protect a large diversity of tree species, including rare tree species, and promote multifunctional keyston species to ensure a long-term and diverse ES supply.EDITED BY Edmundo Barrio