Nutritive values of seven high priority indigenous fodder tree species in pastoral and agro-pastoral areas in Eastern Ethiopia

Abstract Background Indigenous tree and shrub species are critical feed resources for the pastoralist and agro-pastoralist areas in Ethiopia. Nutritional and mineral composition of seven high priority leguminous indigenous tree species, (Acacia nilotica, Acacia tortilis and Tamarindus indica) and non-leguminous species (Berchemia discolour, Cordia sinensis, Dobera glabra and Ziziphus spina-christi) were characterized to inform decisions on the species utilization and domestication. Method Data on a total of 17 nutritional factors were generated on leaf samples from 10 to 12 trees per species following standard lab procedures. Descriptive statistics, one-way analysis of variance among species and types, and Spearman correlations between the nutritional factors were conducted. Results Result showed that there were significant differences among the species for all chemical compositions and mineral contents except for iron. The leguminous species had significantly higher mean dry matter, organic matter, lignin and in vitro digestible organic matter in dry matter, whereas the non-leguminous species had significantly higher mean total ash, neutral detergent fibre, acid detergent fibre and hemi-cellulose. Similarly, the leguminous species had significantly higher mean iron, whereas the non-leguminous species had significantly higher mean macro-minerals, Mn and Zn. Across all the species and samples analysed, the majority (69%) of the paired comparisons revealed significant associations among the chemical compositions and digestibility, whereas nearly 54% of the comparisons were significant among the mineral contents. Conclusions We conclude that the tree species investigated are important sources of protein, energy and minerals, and utilization and domestication should target both the leguminous and non-leguminous types

Maintenance of genetic diversity in Cordia africana Lam., a declining forest tree species in Ethiopia

We assessed genetic variation in a total of 22 populations of the tree species Cordia africana Lam. in Ethiopia and analyzed the country-wide impact of population history, forest disturbance and alteration of land use on extant intraspecific diversity. Amplified Fragment Length Polymorphisms (AFLPs) and chloroplast microsatellite markers were investigated. The analyses of the AFLP data revealed high diversity in all investigated populations: the percentage of polymorphic loci (PPL) ranged from 62.2% to 92.2% and Nei\u27s gene diversity from 0.220 to 0.320 within the populations. The mean PPL and the mean diversity within populations were 85.7% and 0.287, respectively. The analysis of molecular variance revealed a moderate level of differentiation (ΦST = 0.07, p \u3c 0.001) among the populations. The Mantel test proved a significant but low correlation (r = 0.31, p \u3c 0.001) between the geographic distance and the genetic differentiation matrices. Only three different cpDNA haplotypes were observed; no more than two haplotypes were found in any population. The dominant haplotype with an overall frequency of 81% was observed in all populations. The level of differentiation among the populations was comparatively low at chloroplast DNA (GST = 0.18, RST, NST = 0.22). The observed patterns and levels of genetic variation within and among the populations indicate that efficient gene flow via pollen and seed is likely to be the main factor contributing to the maintenance of genetic diversity in natural and disturbed conditions. © 2010 The Author(s)

Assessment of tree species diversity patterns and socioeconomic uses on agricultural landscapes a case of Western Oromia, Ethiopia

This dataset was moved to: https://doi.org/10.34725/DVN/Q7W3JEDeforestation is one of the prominent problems in developing countries. Forest destruction, land degradation and loss of biodiversity are major environmental problems in Ethiopia. A study was conducted to assess study was to characterize on-farm tree diversity, their patterns and socioeconomic uses in the study area. Four sites representing drier and moist agroecology in the sub-humid agroecology were selected. A total of 100 households, 25 from each sites, were randomly selected and assess tree and shrub species diversity and understand their socioeconomic importance. Data on tree species diversity in the homestead, crop fields and grazing/pasture land use system were collected from 100, 18 and 11 households, respectively. The result showed that a total of 82 tree species were recorded from crop fields, homegardens and grazing/pasture land use system in the study sites. The total number of tree species in the homegardens, crop fields and grazing land was 67, 52 and 29 respectively. The Shannon diversity index in the entire land use system varied from 2.11 at Uke Badiya to 2.28 at Ongobo Bakanisa, and species evenness of the entire land use system varied from 0.565 at Oda Haro to 0.593 at Ongobo Bakanisa. The Shannon diversity index in the homestead land use system varied from 1.80 at Wayu Kumba to 2.13 at Oda Haro, and species evenness of the homestead land use system varied from 0.519 at Wayu Kumba to 0.596 at Oda Haro. The Shannon diversity index in the crop fields use system varied from 1.06 at at Oda Haro to 2.44 at Ongobo Bakanisa, and species evenness of the crop fields land use system varied from 0.450 at Wayu Kumba to 0.879 at Ongobo Bakanisa. The Shannon diversity index in the grazing land use system varied from 1.53 at Ongobo Bakanisa to 1.82 at Oda Haro, and species evenness of the grazing land use system varied from 0.487 at Ongobo Bakanisa to 0.709 at Oda Haro. The density of woody species recoreded in entire land use system varied from 133 at Oda Haro to 476 at Wayu Kumba. Structurally, Eucalyptus camaldulensis was the most important tree species among the common species to the three land use system in the study sites. Homestead size area influenced the species diversity, and coversly wealth status did not influence it. From the total surveyed of tree species abundance in the study sites 85.6% estabilished through plantation and 18.4% established through natural regenerated (retention). The purposes of tree retaining/planting were 38% for live fence, 30% for firewood, 13% for income, 13% for fodder, 4% for timber and 2% for fruit production. Generally, the study showed that agricultural landscapes harbour high diversity of trees and shrubs, to which farmers attach various values to the different utilities acrued from the system

Crop vs. tree : Can agronomic management reduce trade-offs in tree-crop interactions?

Scattered trees dominate smallholder agricultural landscapes in Ethiopia, as in large parts of sub-Saharan Africa (SSA). While the inclusion of scattered trees could provide a viable pathway for sustainable intensification of these farming systems, they also lead to trade-offs. We carried out a study to: 1) explore the rationale of farmers to maintain on-farm trees beyond crop yield; 2) quantify the impact of agronomic practices on the outcome of tree-crop interactions; and 3) analyse partial economic trade-offs for selected on-farm tree species at farm scale. We recorded agronomic practices within the fields of 135 randomly selected farms from seedbed preparation to harvesting. A multivariate analysis showed that farmers maintained on-farm trees because of their direct timber, fencing, fuelwood, and charcoal production values. Trees generally had a significant negative effect on maize yield. Mean grain yields of 1683, 1994 and 1752 kg ha−1 under the canopies of Cordia, Croton and Acacia, respectively, were significantly lower than in their paired open field with mean yields of 4063, 3415 and 2418 kg ha−1. Besides, more income from trees was accompanied by less income from maize, highlighting trade-offs. However, agronomic practices such as early planting, variety used, improved weed management, fine seedbed preparation and higher rates of nitrogen fertilizer significantly reduced yield penalties associated with trees. We found an inverse relationship between land size and on-farm tree density, implying that the importance of trees increases for land-constrained farms. Given the expected decline in per capita land size, scattered trees will likely remain an integral part of these systems. Thus, utilizing ‘good agronomic practices’ will be vital to minimize tree-crop trade-offs in the future

Conceptual Analysis: The Charcoal-Agriculture Nexus to Understand the Socio-Ecological Contexts Underlying Varied Sustainability Outcomes in African Landscapes

The production of charcoal is an important socio-economic activity in sub-Saharan Africa (SSA). Charcoal production is one of the leading drivers of rural land-use changes in SSA, although the intensity of impacts on the multi-functionality of landscapes varies considerably. Within a given landscape, charcoal production is closely interconnected to agriculture production both as major livelihoods, while both critically depend on the same ecosystem services. The interactions between charcoal and agricultural production systems can lead to positive synergies of impacts, but will more often result in trade-offs and even vicious cycles. Such sustainability outcomes vary from one site to another due to the heterogeneity of contexts, including agricultural production systems that affect the adoption of technologies and practices. Trade-offs or cases of vicious cycles occur when one-off resource exploitation of natural trees for charcoal production for short-term economic gains permanently impairs ecosystem functions. Given the fact that charcoal, as an important energy source for the growing urban populations and an essential livelihood for the rural populations, cannot be readily substituted in SSA, there must be policies to support charcoal production. Policies should encourage sustainable technologies and practices, either by establishing plantations or by encouraging regeneration, whichever is more suitable for the local environment. To guide context-specific interventions, this paper presents a new perspective—the charcoal-agriculture nexus—aimed at facilitating the understanding of the socio-economic and ecological interactions of charcoal and agricultural production. The nexus especially highlights two dimensions of the socio-ecological contexts: charcoal value chains and tenure systems. Combinations of the two are assumed to underlie varied socio-economic and ecological sustainability outcomes by conditioning incentive mechanisms to affect the adoption of technologies and practices in charcoal and agriculture productions. Contrasting sustainability outcomes from East Africa are presented and discussed through the lens of the charcoal-agriculture nexus. The paper then concludes by emphasizing the importance of taking into account the two-dimensional socio-ecological contexts into effective policy interventions to turn charcoal-agriculture interactions into synergies