Functional Diversity of Arbuscular Mycorrhizal Fungi in Nigerian Agricultural Soils and Their Contribution to Ecosystem Services

This study characterises the functional diversity of arbuscular mycorrhizal fungi in Nigerian agricultural soils and quantifies their contribution to ecosystem services including phosphorus acquisition, drought tolerance, and soil aggregation across contrasting management systems and agro-ecological zones. AMF form mutualistic associations with the majority of crop species and provide critical ecosystem functions, yet their diversity and functional capacity in Nigerian soils are poorly understood. This represents a major gap in understanding the biological foundations of Nigerian soil fertility. This study collects AMF-associated soil samples from 48 sites spanning six agro-ecological zones and four management intensity levels, from indigenous forest analogues to intensively managed irrigated fields. Morphological spore identification and Illumina amplicon sequencing of the SSU rRNA gene characterise AMF community composition. Functional traits are assessed through trap culture experiments measuring hyphal production, phosphorus uptake efficiency, and stress tolerance attributes of dominant AMF taxa. Field experiments assess yield responses and ecosystem service provision from mycorrhizal inoculant addition across soil types. Findings reveal significant functional diversity in Nigerian AMF communities, with 68 taxa identified across the survey, showing strong agro-ecological zone specificity. Management intensity is the strongest driver of AMF community change, with intensively fertilised fields showing 54 percent lower AMF diversity than traditionally managed equivalents. Inoculant trials demonstrate significant yield responses of 18 to 34 percent on low-P soils. The study contributes an original AMF diversity database for Nigeria and recommends mycorrhizal inoculant product development based on identified high-performance taxa.

Keywords: arbuscular mycorrhizal fungi, functional diversity, ecosystem services, phosphorus acquisition, Nigeria.