Battin Tom J, Kaplan Louis A, Denis Newbold J, Hansen Claude M E
Department of Limnology, IECB, University of Vienna, A-1090 Vienna, Austria.
Nature. 2003 Nov 27;426(6965):439-42. doi: 10.1038/nature02152.
In many aquatic ecosystems, most microbes live in matrix-enclosed biofilms 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. 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-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 through longitudinal linkages of local biogeochemical and hydrodynamic processes.
在许多水生生态系统中，大多数微生物生活在由基质包裹的生物膜中，并对能量流动和养分循环起着重要作用。然而，对于这些生物膜的结构与动态变化如何与生态系统功能相耦合，我们却知之甚少。在此，我们展示了微生物生物膜如何改变物理和化学微生境，并对30米长的溪流中宇宙进行生态系统过程产生影响。生物膜的生长使水动力瞬态存储（即滞留在静止区域的溪水，这是溪流生态过程的主要物理模板）增加了300%，悬浮颗粒的滞留量增加了120%。此外，通过增强对生物可利用性较低的有机分子的相对摄取，生物膜微结构与传质之间的相互作用改变了它们在下游的联系。作为瞬态存储的生活区域，生物膜使水动力滞留和生化处理在空间上紧密相邻，并影响溪流中的生物地球化学过程和模式。因此，生物膜是高效且成功的生态群落，它们还可能通过局部生物地球化学和水动力过程的纵向联系，对源头溪流对河流、河口甚至海洋的影响产生作用。
