Nematodes and microbial community affect the sizes and turnover rates of organic carbon pools in soil aggregates
Nematodes and microbial community affect the sizes and turnover rates of organic carbon pools in soil aggregates
复制标题
线虫和微生物群落影响土壤团聚体中有机碳库的大小和周转率
DOI：
10.1016/j.soilbio.2018.01.001
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发表时间：
2018-04-01
影响因子：
9.7
通讯作者：
Sun, Bo
中科院分区：
文献类型：
--
作者：
Jiang, Yuji;Qian, Haiyan;Sun, Bo
土壤团聚体为线虫和微生物提供了微生境，但线虫和微生物群落如何交互驱动土壤有机碳库的动态变化尚不清楚。在这里，我们研究了在4种施肥制度下的红壤中的食菌线虫，微生物群落，和3个SOC库的大小和周转率之间的关系。线虫和细菌群落的丰度和群落组成进行了检查内的聚集体组分，包括大的大聚集体（LMA），小的大聚集体（SMA），和微聚集体（MA）。土壤团聚体中有机碳库的大小随团聚体大小的减小而增大，而有机碳库的周转速率则随团聚体大小的减小而减小。MA组分中细菌与真菌的比值（B/F）和革兰氏阳性菌与革兰氏阴性菌的比值（GP/GN）高于SMA和LMA组分。在LMA馏分中的食菌线虫的组合显着不同的MA和SMA馏分中，主要是因为较高的丰度的优势属原小杆线虫。结构方程模型的结果表明，与LMA相比，MA组分的B/F和GP/GN比值与SOC库的大小和周转率呈更强的正相关。相反，噬菌体表现出间接的关系，SOC池的大小和周转率通过B/F比在SMA和LMA馏分。总之，这些结果突出了线虫和微生物群落在控制SOC池动态在总规模的功能作用。
Soil aggregates provide microhabitats for nematodes and microorganisms, but how nematodes and microbial community interactively drive the dynamics of soil organic carbon (SOC) pool remains unclear. Here, we examined the relationships between bacterivorous nematodes, microbial community, and the sizes and turnover rates of three SOC pools in a red soil under four fertilization regimes. The abundance and community composition of nematode and bacterial communities were examined within aggregate fractions, including large macroaggregates (LMA), small macroaggregates (SMA), and microaggregates (MA). The sizes of SOC pools in soil aggregates increased with decreasing aggregate size, while the turnover rates of SOC pools followed the opposite trend. The ratios of bacteria to fungi (B/F) and Gram-positive to Gram-negative bacteria (GP/GN) were higher in the MA fraction than in the SMA and LMA fractions. The assemblages of bacterivorous nematodes in the LMA fraction were significantly different from those in the MA and SMA fractions, primarily because of the higher abundance of the dominant genus Protorhabditis. Results of structural equation modelling indicated that the ratios of B/F and GP/GN showed stronger positive correlations with the sizes and turnover rates of SOC pools in the MA fraction compared with the LMA fraction. Conversely, bacterivores exhibited indirect relationships with the sizes and turnover rates of SOC pools through the B/F ratio in the SMA and LMA fractions. Taken together, these results highlight the functional role of nematodes and microbial community in controlling SOC pool dynamics at the aggregate scale.