Table 2 The response rate (kilograms of Ceq hectare−1year−1 per 1 kg N ha−1year−1) of woody biomass carbon, soil carbon, and GWP of soil N2O and CH4 emission to nitrogen addition from 2013 to 2016 (means ± SD; n = 3).

ΔBC, woody biomass increment including above- and underground biomass. Different lowercase letters indicate significant differences among N addition rates for the same variable (P < 0.05).

Aboveground
biomass C
ΔBC
C
SOCNEP
C
GWPEcosystem
C
N2OCH4Subtotal
N3043.1 ± 7.6a84.1 ± 14.0a−28.7 ± 9.6a55.4 ± 12.5a6.5 ± 0.3a−0.17 ± 0.03b6.7 ± 0.3a48.7 ± 12.6a
N6026.5 ± 3.5b46.8 ± 7.4b−13.0 ± 6.2b33.8 ± 2.6b3.5 ± 0.5b−0.25 ± 0.03a3.8 ± 0.6b30.0 ± 2.9b
N9010.1 ± 2.4c19.1 ± 5.9c−5.5 ± 1.7b13.6 ± 4.9c1.2 ± 0.4c−0.18 ± 0.02b1.4 ± 0.4c12.2 ± 5.0c