Asynchronous seasonal patterns of soil microorganisms and plants across biomes: A global synthesis

Seasonal changes in climates, plant phenology, and soil properties alter soil microbial biomass and composition. In this study, we synthesized the seasonal patterns in soil microbial biomass and their associations with plant gross primary productivity (GPP) with 335 seasonal cases from nine types of biomes in the world (133 publi-cations). We found that seasonal dynamics in microbial biomass changed with biome types. Microbial biomass peaked in winter in tundra, dry season in savanna and tropical monsoon forest, spring in Mediterranean, autumn in temperate forest, and summer in subtropical forest. Negative relationships between monthly microbial biomass and GPP were detected in tundra, tropical monsoon forest, savanna, and desert, suggesting seasonal asynchrony between plants and microorganisms. This asynchronous pattern was advanced by low temperature and dry climate. In addition, seasonal microbial biomass and GPP were decoupled in temperate forest, sub-tropical forest, tropical rain forest, and grassland. Overall, our findings suggested that seasonal dynamics differentiate microorganism and plant growth, especially in biomes with cold or (seasonal) dry climates, and such asynchronous growth between plants and microorganisms has implications for nutrient conservation and plant-soil-microbe interactions.