Diversity and Ethnobotanical Use-Value of Trees Outside Forests in the Agricultural Landscape of the Mongala Province, Democratic Republic of the Congo

This study investigated the diversity and ethnobotanical use values of trees outside forests on agricultural lands (TOF-AL) in the Mongala province, Democratic Republic of Congo. To achieve this, inventories of TOF-AL, linked to surveys on ethnobotanical use values, were conducted in 45 villages across the three territories of this province (Bongandanga, Bumba and Lisala). The results identified 136 TOF-AL species, revealing significant species richness and diversity variations across three territories. Bongandanga and Lisala exhibited higher species diversity compared to Bumba. Five dominant species (Petersianthus macrocarpus (P.Beauv.) Liben., Pycnanthus angolensis (Welw.) Warb., Ricinodendron heudelotii (Baill.) Pierre ex Heckel., Erythrophleum suaveolens (Guill. & Perr.) Brenan., and Piptadeniastrum africanum (Hook.f.) Brenan.) accounted for over 50% of the total tree abundance and were widely cited for their ethnobotanical significance. P. macrocarpus, E. suaveolens, and R. heudelotii were universally recognised by local populations for their diverse uses, including medicine, food, and trade. Hierarchical clustering analysis revealed three distinct groups of preferred species based on their primary use values: (1) species valued for energy and construction, (2) species valued for crafts and trade, and (3) species valued for medicine, food, and trade. These results highlight the critical role of TOF-AL in supporting local livelihoods and underscores the importance of conserving these resources for sustainable agricultural landscapes.