Underground Explorers

Okinawa, Japan's southernmost and only subtropical prefecture, comprises numerous islands that form a natural laboratory for testing how dispersal limitation and island-specific soil chemistry shape mycorrhizal fungal communities. Some islands are derived from coral limestone, whereas others are volcanic in origin, creating strong contrasts in soil properties and nutrient availability. We will survey multiple islands and collect standardized soil samples alongside plant-community, soil-biogeochemical, and airborne fungal-spore data. Fungal communities will be characterized using metabarcoding of fungal DNA markers. We hypothesize that geographic isolation limits fungi with poor long-distance dispersal, while contrasting soil conditions select for fungi with distinct nutrient-acquisition capacities. By integrating community composition, dispersal potential, and soil nutrient data, we will identify mechanisms governing fungal community assembly across islands. The findings will support the conservation of plant–fungal partnerships and inform land management to protect biodiversity, enhance carbon sequestration, and reduce nutrient loss to coastal waters.

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