Three-dimensional structure and cyanobacterial activity within a desert biological soil crust.
Three-dimensional structure and cyanobacterial activity within a desert biological soil crust.
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沙漠生物土壤结皮内的三维结构和蓝藻活性
DOI：
10.1111/1462-2920.12859
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发表时间：
2015
影响因子：
5.1
通讯作者：
Kaplan
中科院分区：
文献类型：
--
作者：
Raanan;V.J.M.N.L;Drahorad;Ionescu;Eshkol;Treves;Felix-Henningsen;Berkowicz;Hagemann;Kaplan
沙漠生物土壤结皮(BSCs)是由丝状蓝藻分泌的多糖与土壤颗粒附着形成的，丝状蓝藻是沙漠生物土壤结皮的先驱和主要生产者。生物土壤结皮破坏是导致土地退化和荒漠化的中心因素。我们研究了BSC结构对蓝藻活性的影响。用X射线显微断层扫描进行的微观结构分析显示，在表面下1.5-2.5 mm处，靠近蓝藻的位置有一层水泡层。在1 mm的范围内，光剖面显示出表面光的1%-5%的深度衰减，但也显示出与水泡层重合的“光囊”的存在，那里的照度比相同深度的相邻地壳部分高10倍。从O2浓度分布来看，最大的光合作用活性出现在地表下1 mm处，另一个峰值与“光囊”有关。因此，目前使用的遥感技术可能看不到光合作用活动，这表明生物干细胞对陆地生产力的贡献被低估了。全光照度大于10%时，叶绿素荧光减弱，放氧和CO2吸收增加，表明荧光不能反映蓝藻的光合作用活性。我们的数据还表明，虽然生活在BSC中的蓝藻对高光照具有抵抗力，但它们的功能是‘适应弱光’的生物体。
Desert biological soil crusts (BSCs) are formed by adhesion of soil particles to polysaccharides excreted by filamentous cyanobacteria, the pioneers and main producers in this habitat. Biological soil crust destruction is a central factor leading to land degradation and desertification. We study the effect of BSC structure on cyanobacterial activity. Micro‐scale structural analysis using X‐ray microtomography revealed a vesiculated layer 1.5–2.5 mm beneath the surface in close proximity to the cyanobacterial location. Light profiles showed attenuation with depth of 1%–5% of surface light within 1 mm but also revealed the presence of ‘light pockets’, coinciding with the vesiculated layer, where the irradiance was 10‐fold higher than adjacent crust parts at the same depth. Maximal photosynthetic activity, examined by O2concentration profiles, was observed 1 mm beneath the surface and another peak in association with the ‘light pockets’. Thus, photosynthetic activity may not be visible to currently used remote sensing techniques, suggesting that BSCs' contribution to terrestrial productivity is underestimated. Exposure to irradiance higher than 10% full sunlight diminished chlorophyll fluorescence, whereas O2evolution and CO2uptake rose, indicating that fluorescence did not reflect cyanobacterial photosynthetic activity. Our data also indicate that although resistant to high illumination, the BSC‐inhabiting cyanobacteria function as ‘low‐light adapted’ organisms.
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影响因子：
2.7
作者：
Budel, B;Karsten, U;GarciaPichel, F
通讯作者：
GarciaPichel, F
影响因子：
2.9
作者：
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多孔土壤结构的形成机制及控制因素
影响因子：
6.2
作者：
M. Dietze;S. Bartel;M. Lindner;A. Kleber
通讯作者：
A. Kleber
影响因子：
3.4
作者：
Felde, Vincent John Martin Noah Linus;Peth, Stephan;Felix-Henningsen, Peter
通讯作者：
Felix-Henningsen, Peter
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影响因子：
2.5
作者：
Drahorad;Felix-Henningsen
通讯作者：
Felix-Henningsen