Scaling of Soil Carbon, Nitrogen, Phosphorus and C:N:P Ratio Patterns in Peatlands of China

Inspired by the importance of Redfield-type C:N:P ratios in global soils, we looked for analogous patterns in peatlands and aimed at deciphering the potential affecting factors. By analyzing a suite of peatlands soil data (n = 1031), mean soil organic carbon (SOC), total nitrogen (TN) and total phosphorous (TP) contents were 50.51%, 1.45% and 0.13%, respectively, while average C:N, C:P and N:P ratios were 26.72, 1186.00 and 46.58, respectively. C:N ratios showed smaller variations across different vegetation coverage and had less spatial heterogeneity than C:P and N:P ratios. No consistent C:N:P ratio, though with a general value of 1245:47:1, was found for entire peatland soils in China. The Northeast China, Tibet, Zoigê Plateau and parts of Xinjiang had high soil SOC, TN, TP, and C:P ratio. Qinghai, parts of the lower reaches of the Yangtze River, and the coast zones have low TP and N:P ratio. Significant differences for SOC, TN, TP, C:N, C:P and N:P ratios were observed across groups categorized by predominant vegetation. Moisture, temperature and precipitation all closely related to SOC, TN, TP and their pairwise ratios. The hydrothermal coefficient (R_H), defined as annual average precipitation divided by temperature, positively and significantly related to C:N, C:P and N:P ratios, implying that ongoing climate change may prejudice peatlands as carbon sinks during the past 50 years in China.