Negative interactions between bacteria and fungi modulate life history strategies of soil bacterial communities in temperate shrublands under precipitation gradients

Abstract Understanding organisms' life history strategies is crucial for predicting biodiversity patterns and ecological responses to environmental disturbances. Amid global climate change, alterations in precipitation patterns significantly impact microbial community structure and diversity. However, our knowledge of how precipitation affects microbial life history strategies, particularly in rainfall‐sensitive shrub ecosystems, remains limited. This study examined soil microbial communities beneath temperate shrubs in Inner Mongolia along a natural rainfall gradient and analysed soil bacterial life strategy responses to rainfall variations. Our results showing that 16S rRNA gene copy numbers significantly decreased with increasing rainfall, indicating a shift from r‐strategists to K‐strategists. Interestingly, the proportion of negative correlations between bacteria and fungi was positively correlated with 16S rRNA gene copy numbers, suggesting that negative interactions between bacteria and fungi may shift soil bacterial life history strategies towards r‐strategists. Further analysis identified mean annual precipitation and total nitrogen as the most critical abiotic factors predicting bacterial life history strategies, while negative interactions between bacteria and fungi were key biotic factors. This study is the first to confirm the role of bacterial‐fungal interactions in regulating microbial life history strategies under rainfall variation, offering insights into soil ecosystem responses to climate change. Read the free Plain Language Summary for this article on the Journal blog.