Context
In Burkina Faso, Sudanian savannas are important ecosystems for conservation of plant diversity. Due to desertification and insecurity, population migration from the North has increased human density and anthropogenic pressure on southern savannas. This study aims to investigate knowledge of local populations on ecosystem services (ES) and perception of their conservation.

Method
Individual semi-structured interviews about knowledge on ES and ecosystem conservation issues were conducted. Informants were selected according to sociocultural groups and sex in three areas of different land use intensity: the communal area of Dano (CAD), the Total Wildlife Reserve of Bontioli (TWRB) and the Game Ranch of Nazinga (GRN). The use value and vulnerability index of each plant species were determined. A cluster analysis and a principal component analysis were carried out to identify the particular knowledge of different ethnic groups.

Results
Overall, 163 plant species were cited for fifteen ES. Provisioning services were most frequently cited (100%), regulating services second most frequently (92.47%). Entire plants were exclusively used for ES with non-material benefits (protection against wind, for shading, soil fertility, erosion prevention, tourism and religion). The ten species contributing most to ES provision were Vitellaria paradoxa, Parkia biglobosa, Diospyros mespiliformis, Adansonia digitata, Lannea microcarpa, Faidherbia albida, Khaya senegalensis, Afzelia africana, Ficus sycomorus, Pterocarpus erinaceus. Seven of them were identified as highly vulnerable. Around GRN, migrants and natives shared the same knowledge, while migrants in TWRB used the ES only to a small extent due to restricted contact with the native population. Migrants and natives of GRN had more knowledge on tourism and crafts services while the natives of CAD and TWRB made use of the services that sustain the quality of the agricultural land and meet their primary needs. To reduce further degradation, different communities suggested unanimously raising awareness of the importance of biodiversity and ecosystem conservation. The most quoted motivations to preserve ecosystems were vegetation sustainability and village development.

Conclusion
This study documented important local knowledge-based information to guide cultivation of local multipurpose species and initiation of communities to practice best management strategies for sustainable conservation of biodiversity.

Indigenous knowledge, Land use, Plant vulnerability, Sustainable management, Sociocultural groups