Soil warming increases soil temperature sensitivity in subtropical Forests of SW China

BACKGROUND: Soil respiration (R(S)) plays an important role in the concentration of atmospheric CO(2) and thus in global climate patterns. Due to the feedback between R(S) and climate, it is important to investigate R(S) responses to climate warming. METHODS: A soil warming experiment was conducted to explore R(S) responses and temperature sensitivity (Q(10)) to climate warming in subtropical forests in Southwestern China, and infrared radiators were used to simulate climate warming. RESULTS: Warming treatment increased the soil temperature and R(S) value by 1.4 °C and 7.3%, respectively, and decreased the soil water level by 4.2% (%/%). Both one- and two-factor regressions showed that warming increased the Q(10) values by 89.1% and 67.4%, respectively. The effects of water on Q(10)show a parabolic relationship to the soil water sensitivity coefficient. Both R(S) and Q(10) show no acclimation to climate warming, suggesting that global warming will accelerate soil carbon release.