Balaton Limnological Research Institute, Eötvös Loránd Research Network, Klebelsberg Kuno str. 3, P.O. Box 35, H-8237 Tihany, Hungary.
Institute of Aquatic Ecology, Centre for Ecological Research, Eötvös Loránd Research Network, Karolina str. 29., H-1113 Budapest, Hungary.
Sci Total Environ. 2022 Jul 10;829:154576. doi: 10.1016/j.scitotenv.2022.154576. Epub 2022 Mar 15.
We intend to assess how macrophyte cover affects planktonic microbial communities by changing the physical and chemical environment, and how macrophyte-derived DOC affects the balance between autotrophy and heterotrophy/chemoorganotrophy in a shallow lake. The structure and production of phytoplankton and bacterioplankton in the open water of a large shallow lake and in the littoral zone were compared at two sampling stations with different macrophyte cover. According to the obtained results, uncoupling between bacterioplankton and phytoplankton was observed due to the high content of organic carbon of emergent macrophyte origin. While phytoplankton were regulated by TSS, bacterioplankton (in both heterotrophic and photoheterotrophic forms) were determined by dissolved organic carbon. As a result of these processes, the littoral and pelagic zones in the lake are completely separated from each other. In open water the autotrophic processes dominated, but at the sampling stations inside the reed belt, the metabolic processes shifted in the direction of chemoorganotrophy. Our results suggest that increase of macrophyte cover in shallow water bodies will increase the significance of microbe-based carbon pathways and weakens the efficiency of carbon transport from primary producers to higher trophic levels through the planktonic food chain.
我们旨在评估大型浅水湖泊开阔水域和沿岸带浮游植物和细菌浮游生物的结构和生产力，以了解大型浅水湖泊中大型水生植物覆盖如何通过改变物理和化学环境来影响浮游微生物群落，以及大型水生植物来源的 DOC 如何影响自养和异养/化能异养之间的平衡。在两个具有不同大型水生植物覆盖的采样点比较了两个采样点的浮游植物和细菌浮游生物的结构和生产力。根据获得的结果，由于源自挺水植物的有机碳含量高，观察到细菌浮游生物与浮游植物之间的解耦。而浮游植物受 TSS 调节，细菌浮游生物（包括异养和光异养形式）则由溶解有机碳决定。由于这些过程，湖中的沿岸带和深水区完全彼此分离。在开阔水域中，自养过程占主导地位，但在芦苇带内的采样点，代谢过程向化能异养方向转变。我们的结果表明，浅水体内大型水生植物覆盖的增加将增加基于微生物的碳途径的重要性，并削弱通过浮游食物链将碳从初级生产者输送到更高营养级的效率。
