Resilience of Pelagic and Benthic Microbial Communities to Sediment Resuspension in a Coastal Ecosystem, Knebel Vig, Denmark
Resilience of Pelagic and Benthic Microbial Communities to Sediment Resuspension in a Coastal Ecosystem, Knebel Vig, Denmark
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沿海生态系统中上层和底栖微生物群落对沉积物再悬浮的适应能力，Knebel Vig，丹麦
DOI：
10.1006/ecss.1996.0027
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发表时间：
1996
影响因子：
2.8
通讯作者：
T. Blackburn
中科院分区：
文献类型：
--
作者：
N. Sloth;B. Riemann;L. Nielsen;T. Blackburn
摘要 在丹麦沿海水系统中研究了再悬浮对底栖和中上层光合作用、细菌产生、反硝化以及碳和氮循环其他方面的影响。实验在两个 3·6–3·8 m 深的中层环境中进行，其中通过搅拌水产生再悬浮。六毫米的沉积物悬浮，导致上覆水中的塞西深度减少至 10 厘米。研究的系统是氮限制的，有相当数量的底栖硅藻和蓝藻种群，其光合活性与中上层相同或更大。藻类在沉积物表面形成了明显的垫层，有效控制了沉积物-水中溶解无机氮的通量。在再悬浮过程中，两个中环境中水中的O 2 含量下降了5%，水中的叶绿素a含量增加了28%，相当于仅2%的底栖藻类叶绿素运输到水相中。中上层的初级生产力和营养物质没有受到影响，但细菌产量增加了 1 天。重新悬浮后，平均底栖叶绿素没有变化，但分布更加不均匀。事件发生后1周内，底栖初级生产受到影响，主要是由于水体浑浊； N 物质的暗呼吸和通量没有变化。相对于未受干扰的对照，在重悬浮的中生态系统中反硝化速率受到刺激。研究的系统表现出显着的稳定性，对重新悬浮有一些短期反应，几乎所有测量参数在 1 周内恢复到现状。
Abstract The effects of resuspension on benthic and pelagic photosynthesis, bacterial production, denitrification and other aspects of C- and N-cycling were studied in a Danish coastal water system. Experiments were done in two 3·6–3·8 m deep mesocosms where resuspension was generated by stirring of the water. Six millimetres of the sediment was suspended, causing a reduction of Secci-depth in the overlying water to 10 cm. The system studied was N-limited and had considerable populations of benthic diatoms and cyanobacteria with photosynthetic activity of the same magnitude or larger than the pelagic.The algae created a distinct mat on the sediment surface and effectively controlled the sediment–water fluxes of dissolved inorganic nitrogen. During resuspension, the O 2 content of the water in the two mesocosms decreased by 5%, and chlorophyll a content in the water increased by 28%, corresponding to a transport of only 2% of the benthic algal chlorophyll to the water phase. Primary production and nutrients in the pelagic were not affected, but bacterial production increased for 1 day. After resuspension, the average benthic chlorophyll was unchanged, but was more unevenly distributed. Benthic primary production was affected for 1 week after the event, mostly due to water turbidity; dark respiration and fluxes of N-species were unchanged. Denitrification rates were stimulated in resuspended mesocosms relative to undisturbed controls. The system studied showed remarkable stability with some short-term responses to resuspension and almost all measured parameters returned to status quo within 1 week.