Old Sacred Trees as Memories of the Cultural Landscapes of Southern Benin (West Africa)

Large old trees (LOTs) are emblematic elements of the cultural landscape and can live for hundreds of years. They represent an intermediate aspect of cultural heritage, linking spirits and humans. They can also provide a range of ecosystem services. In spite of their importance, declining numbers have been reported. This study examined the diversity of LOTs and the impact of anthropogenic threats on their preservation in three districts of southern Benin: Ketou and Abomey, which represent historical districts with royal courts, and Lokossa, which does not have a tradition as a dynastic seat. Semi-structured interviews focused on ethnobotanical aspects and storytelling were conducted with a total of 150 community leaders and traditional practitioners; these were coupled with an inventory of LOTs to demonstrate their importance in maintaining the heritage and providing ecosystem services in cultural landscapes. Diversity, cultural importance, and ethnobotanical indices were calculated to compare positive and negative attitudes towards LOTs by the local people of the study areas. A total of 270 LOT individuals belonging to 14 species were recorded. The most common species was Adansonia digitata (70 individuals), followed by Milicia excelsa (47 individuals), Ceiba pentandra (37 individuals), and Blighia sapida (25 individuals). Sacred forests and the royal palaces (ten for Abomey and three for Kétou), which are protected by a traditional veto, had the highest number of LOTs (145 individuals) belonging to nine species. Details of 79 specific uses were documented for each plant part of LOTs. The most frequently reported were related to medicinal (80.64%), cultic (16.65%), and craft uses (2.6%). Based on a standard area of 100 km2, mean Shannon diversity (H’) and evenness (J) were lower in the cultural landscape of Ketou (H′ = 0.26 ± 0.42; J = 0.23 ± 0.37) compared to Lokossa (H′ = 0.27 ± 0.32; J = 0.21 ± 0.24) and Abomey (H′ = 0.42 ± 0.37; J = 0.35 ± 0.31). The threat patterns suggest that, irrespective of the species involved, certain determining factors (urbanization (35%), the timber trade (18%), and decisions made during the Marxist–Leninist revolution in Benin in 1972 (11%)) have affected and continue to affect LOT abundance and diversity. For better management of LOTs, there is a need to promote decision-making strategies that better align human cultural values and ecological objectives.