The apparent temperature sensitivity (Q10) of peat soil respiration: A synthesis study

The temperature sensitivity (Q₁₀) of soil respiration is a critical parameter in modeling soil carbon dynamics; yet the regulating factors and the underlying mechanisms of Q₁₀ in peat soils remain unclear. To address this gap, we conducted a comprehensive synthesis data analysis from 87 peatland sites (361 observations) spanning boreal, temperate, and tropical zones, and investigated the spatial distribution pattern of Q₁₀ and its correlation with climate conditions, soil properties, and hydrology. Findings revealed distinct Q₁₀ values across climate zones: boreal peatlands exhibited the highest Q₁₀, trailed by temperate and then tropical peatlands. Latitude presented a positive correlation with Q₁₀, while mean annual air temperature and precipitation revealed a negative correlation. A noteworthy discovery was the pronounced negative relationship between the soil carbon-to-nitrogen ratio (C/N) and Q₁₀, echoing the carbon-quality temperature hypothesis that decomposition is more temperature-sensitive in low-quality than in high-quality carbon. However, the relationship between C/N and Q₁₀ varied significantly between peat types. Our data analyses also revealed that Q₁₀ was influenced by soil moisture levels, with significantly lower values observed for peat soils under wet than dry conditions. Essentially, boreal and temperate peatlands seem more vulnerable to global warming-induced soil organic carbon decomposition than tropical counterparts, with wet peatlands showing higher climate resilience.