Scaling of soil carbon, nitrogen, phosphorus and C:N:P ratio patterns in peatlands of China

Abstract

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, Zoig 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 (RH), 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