Filamentous cyanobacteria have substantial niche overlap, and the causal mechanism behind their succession remains unclear. This has practical significance since several filamentous genera are the main producers of the musty odorant 2-methylisoborneol (MIB), which lead to odor problems in drinking water. This study investigates the relationships between two filamentous cyanobacteria, the MIB-producing genus Planktothrix and the non-MIB-producing genus Pseudanabaena, in a drinking water reservoir. We firstly identified their niche characteristics based on a monitoring dataset, combined this information with culture experiments and developed a niche-based model to clarify these processes. The results reveal that the optimal light requirements of Pseudanabaena (1.56 mol m⁻² d⁻¹) are lower than those of Planktothrix (3.67 mol m⁻² d⁻¹); their light niche differentiation led to a fundamental replacement of Planktothrix (2013) by Pseudanabaena (2015) along with MIB decreases in this reservoir during 2013 and 2015. This study suggests that light is a major driving force responsible for the succession between filamentous cyanobacteria, and that subtle niche differentiation may play an important role in shaping the filamentous cyanobacterial assemblages that drives the MIB odor problems in drinking water reservoirs.

丝状蓝藻具有大量生态位重叠，其演替背后的因果机制仍不清楚。这具有实际意义，因为几个丝状属是发霉气味剂 2-甲基异冰片 (MIB) 的主要生产者，这会导致饮用水中的气味问题。本研究调查了饮用水水库中两种丝状蓝细菌（产生 MIB 的Planktothrix 属和不产生 MIB 的Pseudanabaena属）之间的关系。我们首先根据监测数据集确定了它们的生态位特征，将这些信息与培养实验相结合，并开发了一个基于生态位的模型来阐明这些过程。结果表明，假单胞菌的最佳光照需求(1.56 mol m ^-2  d ^-1 )低于Planktothrix (3.67 mol m ^-2  d ^-1 )；在 2013 年和 2015 年期间，它们的光生态位分化导致Pseudanabaena (2015) 基本取代了Planktothrix (2013)，同时该水库中 MIB 减少。这项研究表明，光是负责丝状蓝藻之间演替的主要驱动力，和这种微妙的生态位分化可能在塑造导致饮用水水库中 MIB 气味问题的丝状蓝藻组合方面发挥重要作用。