Higher diversity, denser stands and greater biomass in peri-urban forests than in adjacent agroforestry systems in Western Burkina Faso: implications for urban sustainability.

Urban and peri-urban forests greatly contribute to the well-being of urban dwellers in West Africa. However, increasing urban densification and spatial expansion negatively affect the functioning of urban ecosystems. Therefore, highlighting the negative impacts of land use change on the ecological attributes of urban landscapes is fundamental for sustainable urban planning. This study aimed to assess the impacts of land use on woody species diversity, structure and carbon storage in peri-urban areas in Burkina Faso. Forest inventories were conducted in 167 plots across two peri-urban forests and their adjacent agroforestry systems. We found a total diversity of 91 woody species representing 69 genera and 26 families. Diversity indices were significantly higher (p-value < 0.0001) in the peri-urban forests than in the agroforestry systems, highlighting a negative impacts of land use on tree diversity. Besides, peri-urban forests had significantly lower tree diameter (15.749 ± 9.194 cm), but higher basal area (5.030 ± 4.407 m2. ha-1) and denser stands (317.308 ± 307.845 ind. ha-1) compared to the agroforestry systems. Tree aboveground biomass was significantly higher (p-value < 0.0001) in the peri-urban forests (18.198 ± 23.870 Mg. ha-1) than in the agroforestry systems (7.821 ± 6.544 Mg. ha-1). Multivariate analyses revealed that denser stands hold higher diversity in peri-urban areas, and that stand basal area mostly drives carbon storage than tree density and diversity. These findings highlight the potential of peri-urban forests to conserve plant biodiversity and mitigate climate change. The study advocates for a sustainable urban land use and planning.

Ethnobotany and conservation of the species Celtis toka (Forssk.) Hepper & J.R.I. wood: A way forward for sustainable use in Burkina Faso.

Celtis toka (C. toka), a critically endangered mystical plant, is a highly valued and overharvested multiuse tree species by local population in Burkina Faso. The ethnobotany of C. toka can lead to its sustainable use, therefore it is a great challenge because little information is available on this aspect concerning the species in Burkina Faso as well as in Africa. Thus, this study aims to assess the sustainable use and management of C. toka in Burkina Faso. The study was conducted along a climate gradient (Sudanian and Sudano-Sahelian climatic zones) in Burkina Faso. Data were collected randomly through selected semi-structured interviews with 405 informants (148 women and 257 men) randomly selected from 34 villages and 25 ethnolinguistic groups. Frequency of citation was computed. Kruskal-Wallis test, Mann-Whitney test and Generalized Linear Models analyses were performed to determine whatever information varied according to site and socio-demographic parameters. Among eight use categories, food (27.89%), livestock (18.97%), shade (16.23%), and pharmacopeia (14.92%) were the most recorded. Leaves (63.83%), roots (19.20%), and bark (17.11%) were the most valued plant parts. All plant parts were used to heal 29 ailments in 37 ways. The most common diseases treated by C. toka were vitamin deficiencies (FL = 8.84%), malaria (FL = 8.44%), cast (FL = 5.84%), madness (FL = 3.25%), eye ache (FL = 2.77%) and yellow fever (FL = 2.60%). Sacred forests (39%) and protected areas (27%) were the key biotopes of C. toka. Value of C. toka was well-treasured in the study sites. The frequency of citation of some use patterns and plant parts varied significantly across some ethnolinguistic groups, sex and generation levels (p < 0.05). Management such as sowing (0%), seedling transplantation (0%) and assisted natural regeneration (0%) were lacking. Sacred (37.99%), taboo (25.04%), mystic (11.62%), magic (10.28%) fetish (8.96%) and medico-magic (6.12%) characters of C. toka determined the traditional conservation strategies of the species in Burkina Faso. Our results recommend that the conservation policies and sustainable use of C. toka should be prioritized. Furthermore, studies should thus emphasize the domestication potential of C. toka for its plant parts.

Traditional knowledge and cultural importance of Gardenia erubescens Stapf & Hutch. in Sudanian savanna of Burkina Faso.

BACKGROUND: Traditional knowledge (TK) on the different uses of under-valued fruit tree species including Gardenia erubescens Stapf & Hutch.-a plant species of least concern (LC) based on International Union for Conservation of Nature (IUCN) classification yet considered threatened due to overharvesting by a National Assessment in addition to 59 other species in Burkina Faso. This study aimed to collect and synthesize information on traditional knowledge and cultural importance of G. erubescens. This information will contribute to document traditional knowledge systems that are fast eroding due to the lack of transmission of the knowledge and will also highlight G. erubescens as a priority species for conservation given that this species is widely used among householders in rural areas in Burkina Faso. METHODS: This study assesses TK on the uses and cultural importance (CI) of G. erubescens, among 514 randomly selected respondents across 15 villages bordering three community forest areas located in Eastern and Centre-Western Regions of Burkina Faso through face-to-face semi-structured interviews. Additionally, the uses and CI of G. erubescens were evaluated in relation to informant's gender, ethnicity, generation, and location. Ethnobotanical indices (relative frequency of citation, relative use value, and CI) were computed using generalized linear models, Kruskal-Wallis, and Mann-Whitney tests. RESULTS: Results indicated 30 specific uses of G. erubescens of which food values recorded the highest uses as reported by 58.97% respondents followed by medicine (17.22%) with a very low 0.23% for magical uses. Food and medicinal uses were the most important for women while men valued more the species for constructions, cultural, and magical uses. The fruit is the most preferred and marketable part of the plant while the leaves, fruits, roots, leafy twigs, and bark are mainly harvested for pharmacopeia and psycho-magical problems. CONCLUSIONS: Traditional knowledge on the uses of G. erubescens varied significantly in relation to gender, ethnicity, generations, and case study locations. Despite the importance of G. erubescens for food and other livelihood values, this specie is of LC to the IUCN; yet, a National Assessment considers it as threatened. The multiple uses of this specie based on TK systems for uses such as food, income, medicine, etc. is an indication that G. erubescens if sustainable managed could form an important safety net especially for rural households in Burkina Faso that are highly dependent on trees and forest resources.