Coastal wetlands store large amounts of carbon in their soils, helping to slow climate change. Microorganisms in the soil play a key role in controlling how much carbon is released or stored. In this study, we examined how soil bacteria interact with each other and how these interactions affect carbon cycling under seasonal climate changes. We conducted a field experiment in the Yellow River Delta wetland in China, simulating winter-spring warming and summer-autumn drought. We found that when bacterial networks became less connected, more carbon was lost from the soil, and less was stored. This pattern was especially evident under warming and drought. We also found that specific groups of bacteria were associated with carbon loss or carbon storage, and their presence was influenced by how well-connected the microbial community was. Our results suggest that the way microbes interact with each other can help ecosystems resist the effects of climate change. Managing microbial communities in wetlands may be an effective way to protect soil carbon and enhance climate resilience.