Temporal dynamics of bacterioplankton community in response to excessive nitrate loading in the oligotrophic coastal water

Coastal ecosystems are receiving elevated inputs of nitrogen (N), primarily as nitrate, from anthropogenic sources. Bacterioplankton play important roles in marine N-cycle. Understanding how excessive N-loading affects marine bacterioplankton communities is critical for the insight into the biodiversity of marine ecosystems under the condition of eutrophic disturbance. In this study, the oligotrophic coastal water microcosms were perturbed with a certain nitrate level of 1.0 mg L-1 in two loading modes: 1) one-off loading (OL) with the level of 1.0 mg L-1 at the beginning; 2) periodic loading (PL) with the level of 0.125 mg L-1 every two days during 16 days.

滨海生态系统正承受着来自人为源的氮（N）输入的增加，其中主要是以硝酸盐的形式。细菌浮游生物在海洋氮循环中扮演着至关重要的角色。探讨过量氮负荷对海洋细菌浮游生物群落的影响，对于深入了解富营养化扰动条件下海洋生态系统的生物多样性至关重要。在本研究中，对寡营养型滨海水微生态系统进行了扰动，施加了1.0 mg L-1的特定硝酸盐浓度，采用两种负荷模式：1）一次性负荷（OL），初始浓度为1.0 mg L-1；2）周期性负荷（PL），每两天施加0.125 mg L-1，持续16天。