Compound Effects of Warming and Wetting Enhance Soil Respiration on the Earth's Third Pole

Abstract

The temperature sensitivity ( Q ₁₀ ) of soil respiration ( Rs ) is one of the major determinants of carbon emissions from Rs . Identifying the controlling factors of Q ₁₀ can contribute to quantifying the response of Rs to climate change and assessing potential carbon emission risks. The Tibetan Plateau (TP), known as the Earth's third pole, plays a pivotal role in the global climate and carbon cycle system. However, the controlling factors of Q ₁₀ and its responses to future climate change in this region are not well understood. Here, we introduce a method for calculating Q ₁₀ from cumulative carbon emission data on Rs , which allows substantially expanding the available data set. Building on this, we integrate various statistical analyses with explainable machine learning techniques to examine the controlling factors regulating Q ₁₀ on the TP. Our analyses consistently show that precipitation and soil potential of Hydrogen are the two most important factors regulating Q ₁₀ . Precipitation is the dominant factor regulating Q ₁₀ across nearly 70% of the plateau, while pH's dominance is about 30%, highlighting the primary role of precipitation as a regulator of Q ₁₀ on the TP. Future precipitation increases (wetting) on the TP are predicted to markedly boost the warming‐induced increase in Rs , with this effect being particularly pronounced in arid areas. Our findings clearly demonstrate that under future warming and wetting on the TP, the compound effects of precipitation and temperature would enhance Rs , consequently accelerating the soil organic carbon release.