USDA-ARS, Wind Erosion &Water Conservation Research Unit, Lubbock, TX 79415, USA.
J Environ Qual. 2012 May-Jun;41(3):744-53. doi: 10.2134/jeq2011.0347.
Little is known about the microbial communities carried in wind-eroded sediments from various soil types and land management systems. The novel technique of pyrosequencing promises to expand our understanding of the microbial diversity of soils and eroded sediments because it can sequence 10 to 100 times more DNA fragments than previous techniques, providing enhanced exploration into what microbes are being lost from soil due to wind erosion. Our study evaluated the bacterial diversity of two types of wind-eroded sediments collected from three different organic-rich soils in Michigan using a portable field wind tunnel. The wind-eroded sediments evaluated were a coarse sized fraction with 66% of particles >106 μm (coarse eroded sediment) and a finer eroded sediment with 72% of particles <106 μm. Our findings suggested that (i) bacteria carried in the coarser sediment and fine dust were effective fingerprints of the source soil, although their distribution may vary depending on the soil characteristics because certain bacteria may be more protected in soil surfaces than others; (ii) coarser wind-eroded sediment showed higher bacterial diversity than fine dust in two of the three soils evaluated; and (iii) certain bacteria were more predominant in fine dust (, , and ) than coarse sediment ( and ), revealing different locations and niches of bacteria in soil, which, depending on wind erosion processes, can have important implications on the soil sustainability and functioning. Infrared spectroscopy showed that wind erosion preferentially removes particular kinds of C from the soil that are lost via fine dust. Our study shows that eroded sediments remove the active labile organic soil particulates containing key microorganisms involved in soil biogeochemical processes, which can have a negative impact on the quality and functioning of the source soil.
关于不同土壤类型和土地管理系统中风蚀沉积物中携带的微生物群落，我们知之甚少。焦磷酸测序技术是一种新颖的技术，有望扩展我们对土壤和侵蚀沉积物中微生物多样性的理解，因为它可以比以前的技术多测序 10 到 100 倍的 DNA 片段，从而更深入地了解由于风蚀而从土壤中流失的微生物。我们的研究使用便携式野外风洞评估了从密歇根州三个不同富含有机质土壤中收集的两种风蚀沉积物的细菌多样性。评估的风蚀沉积物有一个粗粒部分，其中 66%的颗粒>106 μm（粗侵蚀沉积物）和一个更细的侵蚀沉积物，其中 72%的颗粒<106 μm。我们的研究结果表明：(i) 粗粒沉积物和细尘中携带的细菌是源土壤的有效指纹，但由于某些细菌可能比其他细菌更能在土壤表面得到保护，它们的分布可能因土壤特征而异；(ii) 在评估的三种土壤中的两种中，较粗的风蚀沉积物比细尘具有更高的细菌多样性；(iii) 某些细菌在细尘（、、和）中比粗沉积物（和）更为优势，揭示了土壤中细菌的不同位置和生态位，这些细菌取决于风蚀过程，对土壤的可持续性和功能有重要影响。红外光谱表明，风蚀优先从土壤中去除特定类型的 C，这些 C 通过细尘流失。我们的研究表明，风蚀会带走土壤中含有参与土壤生物地球化学过程的关键微生物的活跃的易分解有机土壤颗粒，这可能对源土壤的质量和功能产生负面影响。
