Comparative Analysis of Functional Diversity and Ecosystem Health in Organic and Conventional Rice Paddies: A Trait-Based Assessment of Benthic Macroinvertebrate Communities

This study investigated the functional diversity of benthic macroinvertebrate communities in organic paddy and conventional paddy fields using biological trait analysis and assessed ecosystem health through the Korea Wetland Benthic Macroinvertebrate Index (KWBMI). Field surveys were conducted in Yangpyeong-gun, Korea, from June to July 2022, collecting benthic macroinvertebrate samples and environmental data. A total of 76 species, 17 orders, and 6797 individuals were identified, with biological traits analyzed among four categories: feeding habits, living types, food types, and voltinism. Community indices showed distinct differences between OP and CP. The dominance index was higher in OP, whereas CP had greater species diversity and evenness. However, functional diversity indices (FRic, FEve, FDiv, and FDis) were similar between the two fields. Despite this, OP exhibited greater taxonomic diversity within functional groups, whereas CP, despite its higher species diversity, contained functionally similar species. KWBMI scores were 84.4 for OP (Grade A: "very good") and 75.4 for CP (Grade B: "good"), suggesting the potential benefits of organic farming for ecosystem health. Although functional diversity indices remained similar, differences in taxonomic composition and trait distributions indicate that organic farming may promote taxonomic diversity within functional groups, contributing to ecological stability.