Linking N2O flux to abiotic and biotic factors
under nitrogen addition and altered precipitation
N2O flux was positively correlated with soil
NO3−-N (R 2 =
0.38, P < 0.05) and belowground biomass
(R 2 = 0.13, P < 0.05) but was
negatively correlated with soil pH (R 2 = 0.17P < 0.05) and soil temperature
(R 2 = 0.16, P < 0.05) (Figure
4). Soil moisture (P = 0.77),
NH4+-N (P = 0.18), and
aboveground biomass
(P= 0.15) were not correlated with N2O flux (Figure 4). In
addition, N2O emissions were also affected by multiple
biological factors (Table 3). N2O flux was negatively
correlated with AOA (r = -0.435, P < 0.05) andnosZ (r = -0.484, P < 0.01) and positively
correlated with AOB (r = -0.428, P < 0.05). Although
N2O flux did not significantly affect nirS andnirK , it was nonetheless positively correlated with the ratio of
(nirS+ nirK )/nosZ (r = 0.484, P < 0.05).