Seasonal Water Level Fluctuation and Concomitant Change of Nutrients Shift Microeukaryotic Communities in a Shallow Lake

Abstract

Seasonal water level fluctuations (WLFs) impose dramatic influences on lake ecosystems. The influences of WLFs have been well studied for many lake biotas but the microeukaryotic community remains one of the least-explored features. This study employed high-throughput 18S rRNA gene sequencing to investigate the spatiotemporal patterns of microeukaryotic communities in the dry and wet seasons with concomitant change of nutrients in Poyang Lake, which experiences huge seasonal WLFs. The results showed that the dry season and wet season had distinct microeukaryotic community compositions and structures. In the dry season, Ciliophora (13.86–40.98%) and Cryptomonas (3.69–18.64%) were the dominant taxa, and the relative abundance of these taxa were significant higher in the dry season than wet season. Ochrophyta (6.88–45.67%) and Chlorophyta (6.31–22.10%) was the dominant taxa of microeukaryotic communities in the wet season. The seasonal variation of microeukaryotic communities was strongly correlated to seasonal nutrient variations. Microeukaryotic communities responded significantly to dissolved organic carbon, total nitrogen, nitrate, and soluble reactive phosphorus in the dry season, and correlated to nitrate and total phosphorus in the wet season. The microeukaryotic community showed different modular structures in two seasons, and nutrient variations were the key factors influencing seasonal variations of the modular structures. Moreover, microeukaryotic community networks based on different seasons indicated that the microeukaryotic community co-occurrence patterns were not constant but varied largely associating with the nitrogen and phosphorus variations under the effects of WLFs. Our results are important for understanding how microeukaryotic communities respond to nutrient variation under seasonal water level fluctuation.

Spatiotemporal assembly and functional composition of planktonic microeukaryotic communities along productivity gradients in a subtropical lake

“…Water temperature, a key seasonal factor, may directly regulate microeukaryotic community composition (Liu et al, 2013). Prior investigations indicated that elevated water temperatures could enhance the proliferation of microeukaryotic species (Liu et al, 2020), partially explaining the higher species richness in the autumn compared to spring (Figure 1A). Nitrite (NO 2 -N) emerged as the sole nutrient significantly co-varied with microeukaryotic community structure during both seasons, as revealed by RDA ordination (Figures 9A,B).…”

Sedimentary microeukaryotes reveal more dispersal limitation and form networks with less connectivity than planktonic microeukaryotes in a highly regulated river

“…Thus, another reason for the lower diversity of planktonic microeukaryotes is the decreased suspended particle content and particle‐associated microbial species in river water. In contrast, the increased diversity in the downstream section may be explained by the higher NO 3 − and DSi concentrations in water, which could increase species diversity of planktonic microeukaryotes (Chen, Ren, et al, 2019; Liu et al., 2020; Zhang, Huang, et al, 2018).…”

Evaluación Del Estado Ecológico Del Río Ánimas Mediante Índices Multimétricos en Cerinza, Boyacá

“…Los macroinvertebrados tuvieron su mayor abundancia en la época de sequía, debido a que en la temporada húmeda las lluvias desestabilizan el sustrato y este es arrastrado por la corriente, mientras que en época seca el sustrato se estabiliza y hay una acumulación gradual de macroinvertebrados (Arimoro et al, 2021). A la vez, la reducción del nivel del agua en la fase de sequía provoca cambios en la concentración de nutrientes que favorecen a ciertas comunidades (Liu et al, 2020).…”