施肥对杉木林不同土层温室气体排放的影响OA北大核心CSTPCD

To investigate the migration and transformation of greenhouse gases across soil layers,we examined the impact of fertilization on greenhouse gas emissions from the 0 to 40 cm soil layers in a subtropical Chinese fir plantation.Additionally,we identified the dominant factors regulating greenhouse gas emissions from various soil layers.Our findings revealed that forest soil acted as both a source of CO2 and N2 O and a sink for CH4.As soil depth increased,both CO2 and N2 O emissions decreased,along with CH4 absorption.Specifically,the CO2 and N2 O emissions and CH4 absorption from the 0 to 10 cm soil layer were 1.3-,2.5-,and 3.3-fold greater than those from the 30 to 40 cm layer,respectively.Fertilization significantly reduced soil CO2 emissions and CH4 uptake in each layer(P＜0.05).Compared with those of the unfertilized treatment,fertilization led to a substantial decrease in soil CO2 emissions(approximately 56.7%-77.5%)and CH4 absorption(approximately 30.4%-57.8%).Notably,the inhibitory effect of fertilization on these gases was most pronounced in the 30-40 cm and 20-40 cm soil layers.Furthermore,N2 O emissions decreased significantly in the 10-30 cm soil layers due to fertilization(P＜0.05),with the most obvious effect observed in the 10-20 cm layer.Overall,fertilization primarily reduced soil CO2 and N2O emissions and CH4 uptake by increasing soil moisture content.