CoBacFM: Core bacteria forecast model for global grassland pH dynamics under future climate warming scenarios

Soil microbes regulate various biogeochemical cycles on Earth and respond rapidly to climate change, which is accompanied by changes in soil pH. However, the long-term patterns of these changes under future climate scenarios remain unclear. We propose a core-bacteria-forecast model (CoBacFM) to model soil pH changes by shifts of core bacterial groups under future scenarios using a curated soil microbiota dataset of global grasslands. Our model estimates that soil pH will increase in 63.8%–67.0% of grassland regions and decrease in 10.1%–12.4% of regions. Approximately 32.5%–32.9% of regions will become more alkaline by 5.6%, and these areas expand in all future scenarios. These results were supported by 14 warming simulation experiments. Using bacterial responses as bioindicators of soil pH, the CoBacFM method can accurately forecast pH changes in future scenarios, and the changing global climate is likely to result in the alkalization of grasslands.