Arbuscular mycorrhizal fungi (AMF) are more widely distributed and can associate with a wide range of plant species. AMF are keystone organisms that form an interface between soils and plant roots. They are also sensitive to environmental changes. AMF are important microbial symbioses for plants under conditions of P-limitation. The AMF are crucial for the functioning of terrestrial ecosystems as they form symbiotic interactions with plants. Mycorrhizal fungi are known to influence plant diversity patterns in a variety of ecosystems globally. AMF hyphae form an extensive network in the soil. The length is a common parameter used to quantifying fungal hyphae. The mycelial network of AM fungi extends into the soil volume and greatly increases the surface area for the uptake of immobile nutrients. Also, AM symbioses improve plants tolerance to drought and enhance plants' tolerance of or resistance to root pathogens. Also, the networks of AM hyphae play a crucial role in the formation of stable soil aggregates and in the building up of a macroporous structure of soil that allows penetration of water and air and thereby prevents erosion. The functioning of AMF symbiosis is mediated by direct and indirect effects of biotic and abiotic factors of the surrounding rhizosphere, the community, and the ecosystem. AMF have great potential in the restoration of disturbed land and low fertility soil. However, despite the importance of AMF to terrestrial ecosystems, little is known about the effects of environmental changes on AMF abundance, activity and the impact of these changes on the ecosystem services. Therefore, it is important to gain a clearer understanding of the effects of environmental changes on the AM fungal species to guide conservation and restoration efforts.

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Banana (Musa spp.) production and diversity in the East African region, has been on the decline for the last 20 years due to both a biotic and biotic problems. There has been an ecological and socio-economic imbalance in the East African Highland banana (Musa AAA-EA) growing systems due to this decline. However, farmers have been growing these bananas in cultivar mixtures, a practice which ensures the continuous sustainability of the system. Cultivar mixtures, however, seem to be in specific proportions based on the strength and weakness of each cultivar and so affecting the clone sets to which cultivars belong, as well as providing predictions on the conservation status of each clone set. The primary objective of the study was to account for the farmers' perceptions behind cultivar proportions and to understand the scientific basis of these proportions in selected sites in East Africa. The study was carried out in Karagwe, Bushenyi and Masaka districts in East Africa, a region considered to be a secondary centre of diversity for bananas. Thirty farms were sampled in one selected parish/ ward in the three sites for ecological data. The quadrat method was used to record abundances of identified cultivars in order to determine the cultivar proportions. Ethno-botanical data collected on traditional knowledge was analysed for twenty-three identified traditional cultivar-selection criteria used in the participatory rural appraisal (PRA), as well as interviews from 15 key informants of each study area. A total of 105 cultivars were identified, 76% of which were the East African Highland bananas. Although fourteen cultivars were common to the three sites, Masaka had the highest proportion with Nfuuka cultivar leading the five clone sets. Cultivar diversity indices explained the proportions in terms of richness and evenness and Nfuuka was the richest clone set. Although all clone sets were represented at each site, they were not evenly distributed; a factor which is disadvantageous in the conservation status of the crop. While results indicated that the agro-ecological and traditional utilisation criteria formed the basis for cultivar proportions on farm for both Karagwe and Masaka, farmers were found to do so because of the high traditional values attached to the crop. However, knowing cultivar proportions in terms of richness and evenness can assist in predicting the stability or change in diversity of banana growing sites.Key Words: Highland, Musa spp., Tanzania, Uganda RÉSUMÉLa production et la diversité de la banane (Musa spp) dans cette région, a été sur le déclin pour le dernier 20 ans en raison des problèmes biotiques. Il y a eu un déséquilibre écologique et socio-économique dans la région montagneuse Africaine del 'Est (banane de montagne, Musa AAA-pièce) des systèmes de croissance en raison de ce déclin. Cependant, les agriculteurs ont grandi ces bananes dans les cultivars associés, une pratique qui garantit la durabilité continue du système d'association de cultivar, cependant, semble être dans les pr...

Attempts to structurally transform segments of the agri-food system inevitably involve trade-offs between the priorities of actors with different incentives, perspectives and values. Trade-offs are context-specific, reflecting different socio-economic and political realities. We investigate the potential of structured boundary objects to facilitate exposing and reconciling these trade-offs within the context of multistakeholder social learning processes with pastoral and mixed crop-livestock communities in Burkina Faso, Ethiopia and Tanzania. Building on boundary objects as items flexible enough to be understood by all without having one common definition, structured boundary objects visualize actors' input in a comparable format to facilitate knowledge sharing. Stakeholders in each country used a simulation tool and board game to explore the implications of changing livestock stocking and management practices for the environment and for actors' future socio-economic priorities. Using structured boundary objects elicited trade-offs between household food and animal feed, and between livestock for income, labour, and/ or cultural functions, reflecting the context-specific and subjective evaluations actors make when attempting to plan livelihood changes. Our findings suggest to policy and decision-makers that sustainable transition plans can be developed when stakeholders in local agri-food systems employ approaches that allow shared understandings of trade-offs inherent to sustainable agriculture to emerge.

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