Introducing N2-fixing tree species into Eucalyptus plantations promotes soil organic carbon sequestration in aggregates by increasing microbial carbon use efficiency
Introducing N2-fixing tree species into Eucalyptus plantations promotes soil organic carbon sequestration in aggregates by increasing microbial carbon use efficiency
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DOI：
10.1016/j.catena.2023.107321
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发表时间：
2023-10
期刊：
影响因子：
6.2
通讯作者：
Wen Zhang;Ye-ming You;Xiaoyan Su;Jinliu Yan;Guannv Gao;Angang Ming;Weijun Shen;Xueman Huang
中科院分区：
文献类型：
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作者：
Wen Zhang;Ye-ming You;Xiaoyan Su;Jinliu Yan;Guannv Gao;Angang Ming;Weijun Shen;Xueman Huang
单作混交林可以改善土壤性质，增加土壤有机碳（SOC）的固存。然而，在桉树人工林中引入固氮树种对有机碳组成和转化的影响，以及与之相关的微生物特性的变化仍然知之甚少。本文研究了15年纯尾叶桉（PP）和混合尾叶桉人工林不同团聚体（>2.0 mm、1-2 mm、0.25 - 1 mm和<0.25 mm）的有机碳组分（LPI-C、LPI-C和RP-C）。尾叶相思（一种固氮树种）（MP）结果表明：土壤有机碳组分含量和团聚体中固定性碳库（fRP-C）比例显著高于土壤有机质（P< 0.05）， Pearson相关分析表明凋落物性质、土壤性质和微生物性质之间存在较强的相关性。固氮物种增加了土壤团聚体稳定性和氮有效性，同时改变了凋落物的质量和数量；所有这些因素都强烈影响微生物特性。氮有效性和微生物特性（如碳利用效率）的变化是土壤有机碳组分变化的驱动因素。我们的研究结果强调了引入固氮物种对调节土壤微生物特性的重要性，从而增加了桉树人工林的有机碳固存和稳定性，从提高生态系统的碳效益的角度来看，这应该是未来造林项目的一个相对较好的选择。
The conversion of a monoculture plantation into a mixed forest can improve soil properties and increase soil organic carbon (SOC) sequestration. However, the impacts of introducing N2-fixing tree species intoEucalyptusplantations on SOC composition and transformation, as well as the associated changes in microbial properties remain poorly understood. Here, we examined the SOC fractions (LPI-C, LPII-C, and RP-C) in different aggregates (>2.0 mm, 1–2 mm, 0.25–1 mm, and <0.25 mm) from 15-year-old plantations of pureEucalyptus urophylla(PP) and mixedE. urophyllaandAcacia mangium(an N2-fixing tree species) (MP). The results showed that the contents of SOC fractions and the proportion of recalcitrant C pool (fRP-C) in aggregates were significantly higher (P< 0.05) in MP than those in PP. Pearson correlation analysis indicated strong correlations among litter properties, soil properties, and microbial properties. N2-fixing species increased soil aggregate stability and N availability while altering litter quality and quantity; all of these factors strongly impacted microbial properties. Changes in nitrogen availability and microbial properties (e.g. carbon use efficiency) were the drivers of changes in SOC fractions. Our findings highlight the importance of introducing N2-fixing species in regulating soil microbial properties thereby increased SOC sequestration and stability inEucalyptusplantations, which should be a relatively good option for future afforestation projects in the view of improving the carbon benefits of the ecosystem.