Fertilization and clear-cutting effects on greenhouse gas emissions of pinewood nematode damaged Masson pine plantation

Introduction:Management practices are essential for maintaining forest ecological functions under increasing diseases and pest disasters.The effects of nitrogen fertilization(NF)and clear-cutting(CC)on the soil microbial community structure and greenhouse gases emission were investigated of pinewood nematodes(Bursaphelenchus xylophilus)-infected Masson pine(Pinus massoniana)plantations.Outcomes:CC increased the soil microbial biomass carbon(SMBC)and soil microbial biomass nitrogen(SMBN)contents relative to the control(CK).NF increased the SMBN but had no significant effect on the SMBC content.The total fungal and bacterial abundances increased in the CC treatment compared with the CK,but there was no significant difference between the NF and CK.The cumulative soil CO_(2)emission(-2.35 t C·hm^(-2))was higher than that of CK(1.65 t C·hm^(-2))in summer,and the cumulative annual N_(2)O emission(16.90 kg N·hm^(-2)yr^(-1))of NF was approximately 47 times of CK(0.36 t N·hm^(-2)·yr^(-1)).CC increased the CO_(2)flux(-2.21 t C·hm^(-2))in summer but have no significantly effects on N_(2)O emission.Conclusion:These results indicated that NF and CC practices changed forest soil microbial community structure and affected soil greenhouse gas emissions in pinewood nematodes-infected Masson pine plantations.The CO_(2)emission rates increased in the NF and CC treatments,which reduced the carbon sequestration function of forests and had a negative impact on climate change.