Roughness of biopores and cracks in Bt-horizons assessed by confocal laser scanning microscopy
Roughness of biopores and cracks in Bt-horizons assessed by confocal laser scanning microscopy
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通过共焦激光扫描显微镜评估 Bt 层中生物孔和裂缝的粗糙度
DOI：
10.1002/jpln.201600016
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发表时间：
2016
影响因子：
2.5
通讯作者：
中科院分区：
文献类型：
--
作者：
在结构性土壤中，水和活性溶质可以优先通过较大的集合体间孔隙、裂缝和生物孔。这种大孔隙的表面粗糙度对于描述微生物栖息地和大孔隙与土壤基质之间的水和溶质交换以及其他性质至关重要。本研究的目的是比较在黄土和冰川上发育的五个luvisol的Bt -层的完整结构表面的粗糙度，并测试共聚焦激光扫描显微镜的适用性。样品边缘长度为5至10厘米，结构表面完整，包括有或没有粘土有机涂层的裂缝、蚯蚓洞壁和根通道。用Keyence VK‐X100K型共聚焦激光扫描显微镜测定了这些结构的表面粗糙度。选取感兴趣的表面区域为0.342 mm2，高程分辨率为0.02µm，计算出根均方粗糙度（Rq）、曲率（Rcu）和表面积与基底面积之比（RA）。与未涂覆的裂缝和蚯蚓洞相比，涂覆层的粗糙度更小。这种通过粘土材料的照射而降低的粗糙度与质地较粗的土壤土- Bt和质地较细的黄土- Bt的结构表面相似。这种相似性表明，在Bt -层位中，土成作用对构造表面粗糙度的影响占主导地位，母物质对构造表面粗糙度的影响较小。在选定的空间尺度上，与未涂覆的裂缝相比，蚯蚓活动对洞壁表面的预期“平滑”效应并未反映在粗糙度值中。然而，对于一种黄土- Bt的根通道壁，与其他结构相比，粗糙度降低了。这些结果表明，在描述结构性土壤的优先流动和大孔基质交换或分析根系生长、微生物栖息地和胶体运输时，应单独考虑结构表面类型的表面粗糙度。共聚焦激光扫描显微技术被发现对表征完整结构表面的粗糙度是有用的。
In structured soils, water and reactive solutes can preferentially move through larger inter‐aggregate pores, cracks, and biopores. The surface roughness of such macropores is crucial for describing microbial habitats and the exchange of water and solutes between macropores and the soil matrix together with other properties. The objective of this study was to compare the roughness of intact structural surfaces from the Bt‐horizons of five Luvisols developed on loess and glacial till and to test the applicability of confocal laser scanning microscopy. Samples of 5 to 10 cm edge length with intact structural surfaces including cracks with and without clay‐organic coatings, earthworm burrow walls, and root channels were prepared manually. The surface roughness of these structures was determined with a confocal laser scanning microscope of the type Keyence VK‐X100K. The root‐mean‐squared roughness (Rq) the curvature (Rcu) and the ratio between surface area and base area (RA) were calculated from selected surface regions of interest of 0.342 mm2with an elevation resolution of 0.02 µm. The roughness was smaller for coated as compared to uncoated cracks and earthworm burrows of the Bt‐horizons. This reduction of roughness by the illuviation of clayey material was similar for the structural surfaces of the coarser textured till‐Bt and the finer‐textured loess‐Bt. This similarity suggested a dominant effect of pedogenesis and a minor effect of the parent material on the roughness levels of structural surfaces in the Bt‐horizons. An expected “smoothing” effect of burrow wall surfaces by earthworm activity was not reflected in the roughness values compared to those of uncoated cracks at the chosen spatial scale. However, for root channel walls from one loess‐Bt, the roughness was reduced as compared to that of other structures. These results suggest that the surface roughness of the structural surface types should separately be considered when describing preferential flow and macropore‐matrix exchange or analysing root growth, microbial habitats, and colloidal transport in structured soils. The confocal laser scanning microscopy technique was found useful for characterizing the roughness of intact structural surfaces.
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影响因子：
2.8
作者：
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通讯作者：
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影响因子：
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作者：
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影响因子：
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作者：
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DOI：
--
发表时间：
2002
期刊：
影响因子：
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