ABSTRACT

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 CO₂ 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 N₂O 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 CO₂ flux (2.21 t C·hm⁻²) in summer but have no significantly effects on N₂O 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 CO₂ 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.

摘要

简介：管理措施对于在病虫害不断增加的情况下维持森林生态功能至关重要。研究了松材线虫（Bursaphelenchus xylophilus）感染的马尾松（Pinus massoniana）人工林的氮肥和净土对土壤微生物群落结构和温室气体排放的影响。

结果：相对于对照（CK），CC增加了土壤微生物量碳（SMBC）和土壤微生物量氮（SMBN）的含量。NF增加了SMBN，但对SMBC含量没有显着影响。与CK相比，CC处理的总真菌和细菌丰度增加，但NF和CK之间没有显着差异。夏季土壤累积CO ₂排放量（2.35 t C·hm ^-2）高于CK（1.65 t C·hm ^-2），累积年N ₂ O排放量（16.90 kg N·hm ^-2 yr）NF ^-1）约为CK的47倍（0.36 t N·hm ^-2 ·yr ^-1）。CC增加了CO夏季为₂通量（2.21 t C·hm ^-2），但对N ₂ O排放没有明显影响。

结论：这些结果表明，NF和CC的做法改变了森林土壤微生物群落结构并影响了松材线虫感染的马森松人工林土壤温室气体的排放。在NF和CC处理中，CO ₂排放速率增加，这降低了森林的固碳功能，并对气候变化产生了负面影响。