Contributions of microbial biofilms to ecosystem processes in stream mesocosms
Contributions of microbial biofilms to ecosystem processes in stream mesocosms
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DOI：
10.1038/nature02152
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发表时间：
2003-11-27
期刊：
影响因子：
64.8
通讯作者：
Hansen, CME
中科院分区：
文献类型：
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作者：
Battin, TJ;Kaplan, LA;Hansen, CME
在许多水生生态系统中，大多数微生物生活在基质封闭的生物膜中(1-3)，并对能量流动和养分循环做出重大贡献。然而，对这些生物膜的结构和动力学与生态系统功能的耦合知之甚少(2)。在这里，我们表明，微生物生物膜改变了物理和化学微生境，并在30米长的河流中促进了生态系统的进程。生物膜的生长增加了水动力暂态存储-滞留在静止区的溪水，这是溪流(4，5)生态过程的主要物理模板-增加了300%，悬浮物的滞留增加了120%。此外，生物膜微结构和传质的相互作用通过提高生物利用度较低的有机分子的相对吸收，改变了它们的下游联系。生物膜作为暂态储存的生命区，将水动力滞留和生化过程紧密地联系在一起，影响着河流的生物地球化学过程和模式。因此，生物膜是高效和成功的生态群落，也可通过当地生物地球化学和水动力过程的纵向联系，促进源头溪流对河流、河口甚至海洋(6，7)的影响。
In many aquatic ecosystems, most microbes live in matrix-enclosed biofilms(1-3) and contribute substantially to energy flow and nutrient cycling. Little is known, however, about the coupling of structure and dynamics of these biofilms to ecosystem function(2). Here we show that microbial biofilms changed the physical and chemical microhabitat and contributed to ecosystem processes in 30-m-long stream mesocosms. Biofilm growth increased hydrodynamic transient storage-streamwater detained in quiescent zones, which is a major physical template for ecological processes in streams(4,5) - by 300% and the retention of suspended particles by 120%. In addition, by enhancing the relative uptake of organic molecules of lower bioavailability, the interplay of biofilm microarchitecture and mass transfer changed their downstream linkage. As living zones of transient storage, biofilms bring hydrodynamic retention and biochemical processing into close spatial proximity and influence biogeochemical processes and patterns in streams. Thus, biofilms are highly efficient and successful ecological communities that may also contribute to the influence that headwater streams have on rivers, estuaries and even oceans(6,7) through longitudinal linkages of local biogeochemical and hydrodynamic processes.