Abstract:
An incubation test on the yellow and alpine meadow soils collected from the tea plantations in the subtropical region was conducted at 10, 20, and 30℃ to examine the response of the soil organic carbon (SOC) mineralization due to the temperature changes. The results showed that, in a 47 d incubation, both soil type and temperature significantly affected the SOC mineralization with significant interactions between the two factors. At a same incubation temperature, the SOC mineralization accumulation and mineralization constant (
k) were significantly higher in the alpine meadow than the yellow soil, but not on the mineralization rate. The cumulative SOC mineralization increased with increasing temperature by 20.90%-91.88% on the yellow soil, and 48.52%-113.88% on the alpine meadow soil. The temperature sensitivity,
Q10, on SOC of the alpine meadow soil was significantly higher than that of the yellow soil, suggesting a greater effect of climate warming on SOC mineralization for tea plantations at higher altitudes. In addition,
Q10 were higher at lower temperatures (<20℃) than higher temperatures (>20℃), indicating that the mineralization was more sensitive to temperature rise at low temperatures. And, when the temperature was lower than 20℃, the sensitivity of the alpine meadow soil was significant higher than that of its counterpart. Whereas, as the temperature raised beyond 25℃, no significant difference was found between them. The dynamics of SOC mineralization appeared to fit a first-order kinetics function, while the SOC mineralization potential (
Co) increased with increasing incubation temperature.