Low Pore Connectivity Increases Bacterial Diversity in Soil
Low Pore Connectivity Increases Bacterial Diversity in Soil
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DOI：
10.1128/aem.03085-09
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发表时间：
2010-06-01
影响因子：
4.4
通讯作者：
Gleeson, Deirdre B.
中科院分区：
文献类型：
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作者：
Carson, Jennifer K.;Gonzalez-Quinones, Vanesa;Gleeson, Deirdre B.
土壤微生物学最有趣的难题之一是，当竞争理论预测竞争力较弱的物种会减少并最终消失时，如此多的不同细菌物种如何能够在小体积的土壤中共存。我们提供的证据支持这一理论，即低水势（因此低含水量）导致的低孔隙连通性增加了土壤中复杂细菌群落的多样性。我们通过降低水势和增加淤泥和粘土大小颗粒的含量来改变土壤的孔隙连通性。通过将淤泥和粘土大小的石英颗粒以 0%（沙子）或 10%（淤泥 + 粘土）添加到石英基沙土中，在不改变土壤化学性质或矿物成分的情况下创建了两种纹理。两种纹理均在多个水势下孵育，并使用细菌 16S rRNA 的末端限制性片段长度多态性 (TRFLP) 测量对活性细菌群落的影响。随着水势降低和土壤变干，细菌丰富度和多样性增加（P < 0.012），但不受质地影响（P > 0.553）。水势增加时细菌多样性增加
One of soil microbiology's most intriguing puzzles is how so many different bacterial species can coexist in small volumes of soil when competition theory predicts that less competitive species should decline and eventually disappear. We provide evidence supporting the theory that low pore connectivity caused by low water potential (and therefore low water content) increases the diversity of a complex bacterial community in soil. We altered the pore connectivity of a soil by decreasing water potential and increasing the content of silt- and clay-sized particles. Two textures were created, without altering the chemical properties or mineral composition of the soil, by adding silt- and clay-sized particles of quartz to a quartz-based sandy soil at rates of 0% (sand) or 10% (silt + clay). Both textures were incubated at several water potentials, and the effect on the active bacterial communities was measured using terminal restriction fragment length polymorphism (TRFLP) of bacterial 16S rRNA. Bacterial richness and diversity increased as water potential decreased and soil became drier (P < 0.012), but they were not affected by texture (P > 0.553). Bacterial diversity increased at water potentials of