Temperature Sensitivity of Soil Nitrous Oxide Emissions in Tea Plantations at Different Elevations

Abstract

To solve the problems that the response of nitrous oxide （N2O） emissions to warming may be different in different biological communities and the uncertainty of its response to warming may be aggravated by the high heterogeneity of tea plantation soils, an incubation experiment at five elevations of tea plantation soils [537 m（E1）, 433 m（E2）, 350 m（E3）, 308 m（E4）, and 238 m（E5）] and three temperatures （15, 25, and 30 ℃） was conducted for 35 days to explore the temperature sensitivity of N2O in different tea plantation soils and the driving factors. The results showed that elevated temperature could promote soil N2O emissions at different elevations, but the effect was inconsistent at different elevations. Specifically, elevated temperature decreased the cumulative N2O emissions in the E1 treatment, but the difference was not significant. At the same time, the cumulative N2O emissions in the E2-E5 treatments were increased, especially in the E3-E5 treatments. The Q10 values of N2O in the tea plantation soils at different elevations were significantly different, ranging from 0.90 to 4.98, with E4 > E5 > E3 > E2 > E1. The multiple regression model analysis showed that 97.4% of the variation in N2O temperature sensitivity was explained by soil physicochemistry and microorganisms, and N2O temperature sensitivity was significantly positively correlated with bacterial beta diversity PCoA1. In conclusion, increasing temperature can promote the N2O emissions in tea plantation soils at different elevations, but there is no consistent change rule between elevation and N2O temperature sensitivity, and N2O temperature sensitivity is mainly affected by the bacterial beta diversity.