Differential Impact of Wildfire and Rice Straw Ash on the Skin Microbiota of Rana dybowskii Adults and Tadpoles

Abstract

Global warming has intensified severe weather conditions and increased the frequency of wildfires, posing significant threats to ecosystems. Moreover, rice straw ash, a byproduct of human agricultural activities, represents an environmental stressor that can further impact these vulnerable ecosystems. These changes particularly impact sensitive species and microorganisms, yet limited research has explored the effects of wildfire ash and agricultural byproducts, such as rice straw ash, on amphibians. This study aims to investigate the effects of both wildfire and rice straw ashes on the skin microbiota of Rana dybowskii tadpoles and adult frogs, using ash aqueous extracts (AEAs). While alpha diversity showed significant variation among tadpoles, it remained stable in adult frogs. Beta diversity analyses revealed distinct microbiota compositions, especially between control and wildfire ash-treated tadpoles. Linear discriminant analysis (LDA) Effect Size (LEfSe) analysis indicated that different ash treatments led to the enrichment of specific microbiota, reflecting the complex effects of environmental changes on amphibian skin microbiota. Specific bacterial enrichments were associated with each treatment group, and phenotypic analysis highlighted bacterial traits, including Aerobic, Anaerobic, Potentially_Pathogenic, and Stress_Tolerant, providing insights into ecological adaptations. Therefore, contrasts wildfire and rice straw ash treatments distinctly influence amphibian skin microbiota and associated bacterial traits. Our findings emphasize the impact of agricultural and wildfire ash on amphibian skin microbiota, offering key ecological insights into the challenges posed by global environmental changes.