THE INTERACTION BETWEEN BENTHIC DIATOM FILMS AND SEDIMENT TRANSPORT
THE INTERACTION BETWEEN BENTHIC DIATOM FILMS AND SEDIMENT TRANSPORT
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DOI：
10.1016/0272-7714(86)90056-9
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发表时间：
1986-08-01
影响因子：
2.8
通讯作者：
MILLS, EL
中科院分区：
文献类型：
--
作者：
GRANT, J;BATHMANN, UV;MILLS, EL
现场和实验室水槽研究用于检查硅藻粘液膜对潮间沙的稳定性。通过分析胶体碳水化合物、叶绿素以及通过扫描电子显微镜对完整的沉积物样品描绘薄膜。在现场，硅藻膜呈厘米级的斑片状，与沙波纹的结构相对应。平静天气后，沉积物表面会出现薄膜，暴风雨后则消失。胞外多糖最多占微藻碳的20%。水槽中完整核心的侵蚀表明，尽管薄膜稳定了河床的局部区域，但部分薄膜也被冲走或掩埋。当床形“穿过”薄膜时，床的稳定区域被转移到新的波纹位置。这一观察结果解释了薄膜在现场波纹形貌方面的不均匀分布。扫描电镜显示硅藻细胞附着在带有粘液链的沙粒之间，特别是在薄膜样品中。还观察到原生动物、真菌和其他生物体引起的粘液附着。在水槽中，硅藻细胞被冲走，留下粘液丝。在相似的侵蚀阶段下，具有硅藻膜的水槽核心比没有硅藻膜的水槽核心损失的叶绿素量要少。在最高流量下，许多谷物的粘液涂层被清除；这些谷物似乎来自田间主动运输地点（波峰）。我们的结论是，生物膜对沉积物的稳定作用必须在厘米的空间尺度和几天到几周的时间尺度上进行研究。微生物对沉积物的结合最重要的影响可能是它们在沉积物和水体之间有机物转移中的作用。
Field and laboratory flume studies were used to examine the stabilization of intertidal sands by diatom mucus films. Films were delineated by analyzing colloid carbohydrates, chlorophyll, and by scanning electron microscopy on intact sediment samples. In the field, diatom films were patchy on a scale of centimeters, corresponding to the structure of sand ripples. Films were present on the sediment surface after calm weather and absent after storms. Extracellular polysaccharides accounted for a maximum of 20% of microalgal carbon. Erosion of intact cores in the flume showed that although films stabilized local areas of bed, portions of the film were also washed away or buried. Stabilized areas of the bed were transposed to new ripple locations as the bedform move ''through'' the film. This observation explained the heterogeneous distribution of films with respect to ripple topography in the field. SEM showed diatom cells attached between sand grains with mucus strands, particularly in samples from the films. Mucus attachment due to protozoa, fungi, and other organisms was also observed. In the flume, diatom cells were washed away leaving mucus strands behind. A flume core with diatom films lost smaller amounts of chlorophyll than a core without films, under similar stages of erosion. At the highest flow, many grains were cleaned of mucus coatings; the grains appeared to those from sites of active transport (crests) in the field. We conclude that sediment stabilization by biofilms must be studied on a spatial scale of centimeters, and a temporal scale of days to weeks. The most important effect of microbial binding of sediments may be their role in the transfer of organic matter between the sediment and the water column.