Field temperature dominantly affected soil organic carbon stability along an altitudinal gradient in Changbai Mountain, Northeast China

Abstract

An improved understanding of how soil organic carbon (SOC) stability varied with temperature and forest type was required to evaluate the global warming effects on SOC dynamics and the potential feedback of forest ecosystems to the climate change. Here, SOC stability along an altitudinal gradient in Changbai Mountain was investigated with a 180-day incubation experiment at the field temperature of 15°C. Soil respirations were determined dynamically to quantify the decomposition rate and the stability of SOC. The respiration rate declined at the first 30days and became relatively constant within the latter days. After fitting two-pool C decomposition model, the rate constant of stable C pool increased with the increase of mean growing season temperature except soil from Picea and Abies forest which had weaker physical protection than other soils. In conclusion, SOC stability increased with mean growing season temperature, while forest type had little effect on SOC stability.