This research examined beneficial soil bacteria called rhizobia that help legume plants grow by providing them with nitrogen. The study mapped these bacteria across the Hawaiian island of O’ahu and tested their ability to help grow native Hawaiian plants. The findings show these helpful bacteria are widespread but vary in their distribution and effectiveness with different plant species. This research has several practical implications: • Helps nurseries grow endangered native Hawaiian trees more effectively • Provides guidance for agricultural practices involving legume crops • Contributes to conservation efforts of native Hawaiian plants • Improves understanding of how beneficial soil microbes are distributed across islands • Demonstrates the importance of selecting specific bacterial strains for optimal plant growth