Underutilized non timber forest products in Ethiopia; socioeconomic, status and yield potential

Zusammenfassung

Ethiopia is rich in biodiversity; however, the diversity of plants is highly threatened. Consequently, many of the Non-Timber Forest Products (NTFPs) with significant potential for rural livelihood improvement are unvalued, underutilized, and threatened. Moreover, the NTFPs are neglected and not included in Ethiopia's forest management plans and strategies. Then again, location based specific studies related to the NTFPs production are scarce in the country. They would be key to assist the rural communities in their food security and income generation through the sustainable management, use and conservation of valuable species strategies in their natural habitat. Thus, in this doctoral thesis, we aimed to generate information on the socioeconomic, population status, and yield potential of underutilized NTFP producing tree species and wild edible mushrooms in Ethiopia. For this purpose, we targeted the valuable but underutilized NTFP such as wild mushrooms, Tamarindus indica fruits and Senegalia senegal gums. In this study, we did the ethnomycological socioeconomic, vegetation inventory and yield estimation studies . The socio- economic survey was conducted to collect information related to wild mushrooms by using semi-structured interviews with members of the Amhara, Agew, and Sidama ethnic groups. Forest inventories were also undertaken to investigate mushroom growing habitat and to identify useful wild mushroom species in each study area. In total, 300 households were surveyed. In the vegetation survey of the T. indica, we evaluated the stand status, dendrometric variables, and fruit production of Tamarind trees growing in bushland- and farmland- use ty pes in dryland areas of Dello Menna district, Ethiopia. In this case, we used the point -centered quarter method and the tree density per ha and the fruit yield were evaluated. Predictive models were used for Tamarind fruit yield estimations. Furthermore, we also evaluated the population status and potential gum yield of Senegalia senegal growing in the dryland areas of South Omo Zone, Ethiopia. Forty -five sample plots, each measuring 20 × 20 m, were established at 500 m intervals along transects, with 1 m 2 subplot located within the main plots to determine regeneration. A linear model of dendrometric variables was used to estimate gum production from individual S. senegal. From the results of the socio-economic survey, we found that the Sidama ethnic groups have the most extensive ethnomycological knowledge of mushrooms as compared to the Amhara and Agew ethnic groups. A total of 24 useful wild mushrooms were identified. In the Amhara and Agew ethnic groups, wild mushrooms consumption is not common. However, they indicated that their ancestors were used to eating wild mushrooms, which could eventually represent a loss of mycological knowledge in these two ethnic groups. On the other hand, such inconsistency between ethnic groups in terms of their knowledge and perception may also be linked to the social valuation of mushroom resources, which could easily be mitigated by raising awareness. Similarly, the vegetation survey of Tamarind revealed that there was a significant difference in Tamarind tree density between the two land- use types (p = 0.01). The mean fruit yield of farmland trees was significantly higher than that of bushland trees. However, Tamarind has an unsustainable stand/age structure in the farmlands. Differences in the dendrometric characteristics of trees were also observed between the two land- use types. Although higher Tamarind fruit yields were obtained from trees growing on farmland than in bushland in the Dello Menna district, the majority of farmland trees produced <5000 fruit per tree, and t heir yield can be improved through deliberate selection of higher fruit yielder trees . This strategy might also lead to the development of a sustainable fruit supply in rural areas for commercialization or subsistence use. Similarly, the vegetation survey of Senegalia senegal indicated the presence of forty-two tree species, of which 16 were gum - and resin- producing tree species. Senegalia senegal comprised approximately 35% of regenerating trees. The maximum gum arabic yield obtained was 3948 g tree −1. Linear models of dendrometric variables indicated that gum arabic yield is better predicted by tree diameter than by height. The information obtained through the socioeconomic study could be useful for further investigations, and for promoting ethnomycological benefits to different ethnic groups in countries with similar settings. The information generated from the vegetation survey of the Tamarindus trees could also help rural communities in areas that are facing similar challenges for valuable trees due to land- use change as well as for the development of management plans to establish stands that have a more balanced diameter structure and thereby ensure continuity of population and fruit yields. Similarly, the information gathered from S. senegal study could help to safeguard the longevity and the proliferation of valuable NTFP - producing tree species in lowland areas, as well as the livelihoods supported by these resources, both in the study area and country -wide. Generally, the findings in the three s tudies could provide management support to conserve the forests resources in Ethiopia through adding economic value from the NTFPs production and utilization while enhancing the livelihood of local communities.