Totems and sacred groves in southeast Nigeria: indigenous nature-based solutions for climate change mitigation and biodiversity conservation

Introduction This research investigated the profound influence of indigenous religious and cultural practices among the Igbo communities in Southeast Nigeria on biodiversity conservation, particularly focusing on the role of totems and groves as traditional ecological knowledge systems. Methods Using a mixed-methods approach, the study combines descriptive assessments through interviews and quantitative ethnographic fieldwork and ecological assessment of selected groves. Twenty-seven (27) communities in Enugu State served as case studies. Results Out of the 21 totemic plants reported, Cola acuminata (RFC = 0.89; frequency = 452; UV = 4), Elaeis guineensis (RFC = 0.89; frequency = 452), Milicia excelsa (RFC = 0.83; frequency = 424), and Newbouldia laevis (RFC = 0.72; frequency = 368) were found to have high cultural salience in the ethnographic evaluation. Dracaena arborea (94.44%), Ficus thonningii (92.42%), and Cola acuminata (71.24%) had the highest fidelity scores, demonstrating substantial informant agreement on their distinct cultural significance. With values of 96.90% and 95.58%, respectively, ancestral link and symbolism dominated the cultural dimensions, demonstrating the crucial significance that plants play as cultural pillars. The combination of high species richness (133–179 species), high Shannon diversity (4.18–4.62), near-maximal Simpson’s index (0.97–0.99), and strong evenness (0.86–0.91) across the studied groves clearly demonstrates that these sacred forests function as ecological strongholds within the landscape while preserving their carbon sequestration potential. Importantly, groves with fewer individuals did not necessarily show reduced diversity, emphasizing that cultural protection rather than forest size alone is a key driver of biodiversity conservation. Moreover, the findings suggest that groves harbor a range of flora, often untouched by deforestation, and that totemic systems guide sustainable behavior toward the environment. Discussion This research contributes to a growing discourse on the value of indigenous knowledge in global sustainability efforts and offers a localized framework for implementing culturally relevant, low-cost, and community-led environmental solutions in Nigeria and beyond.