Relationship between basal soil respiration and the temperature sensitivity of soil respiration and their key controlling factors across terrestrial ecosystems.

Purpose: The purposes of this study are to characterize the relationship between basal soil respiration at 0 °C (R₀) and the temperature sensitivity (Q₁₀) of soil respiration and climate, soil, and vegetation factors and to establish R₀ and Q₁₀ models. Materials and methods: We compiled R₀ and Q₁₀ and variables (i.e., climate factors, soil properties, and vegetation characteristics) that were measured in various terrestrial ecosystems. Results and discussion: The results showed that both R₀ and Q₁₀ could generally be fitted by a normal distribution curve across various ecosystems, but they varied greatly among the different ecosystems. The lowest median R₀ and Q₁₀ appeared in the desert, while the highest median R₀ and Q₁₀ appeared in the deciduous broad-leaf forest and deciduous needle-leaf forest ecosystems, respectively. The relationship between R₀ and Q₁₀ across different soil depths varied among the different ecosystems, with the highest and lowest R² occurring in the cropland (R² = 0.701) and evergreen needle-leaf forest (R² = 0.095), respectively. A model that included Q₁₀, fine root production and the ratio of soil organic carbon to total nitrogen (TN) explained 75.0% (R² = 0.750) of the variation in R₀, with a P value less than 0.001. Q₁₀ was further expressed as a model (R² = 0.663, P < 0.001) including annual precipitation, mean air temperature, TN, bulk density, and leaf area index. Conclusions: Our R₀ models can potentially be used to improve terrestrial carbon cycle models by considering the comprehensive effects of Q₁₀ and soil and vegetation factors. [ABSTRACT FROM AUTHOR]