Seasonal variation in functional phytoplankton groups in Xiangxi Bay, Three Gorges Reservoir

Abstract

We describe the phytoplankton dynamics and structure in Xiangxi Bay, Three Gorges Reservoir. Samples were collected monthly in the surface waters between August 2007 and July 2008. We identified 10 principle functional groups. C-strategists and S/R-strategists with a wide range of tolerance dominated the phytoplankton assemblage. Seasonal variation was related to water column stability because of changes in hydraulic operation in October, January, and May. Functional group C (Asterionella formosa) and P (Aulacoseria granulata) dominated in August and September, whereas group Lo (Peridiniopsis niei) was the most abundant between February and April, forming a dinoflagellate bloom. Group B (Stephanodiscus hantzschii), X2 (Komma acudata), and Y (Cryptomonas erosa) were present throughout most of the year but were most abundant in late spring. A cyanobacterial bloom occurred from June to July, during which group M (Microcystis aeruginosa, M. wesenbergii) and H 1 (Anabaena flos-aquae) were dominant. Green algae, characterized by group G (Eudorina sp., Pandorina sp., Pyramidomonas sp.) and J (Pediastrum spp., Coelastrum spp., Scenedesums spp.), were abundant after the bloom degraded. This sequence was corroborated by canonical correspondence analysis (CCA). The summary sequence of functional groups resulting from CCA was: C/P → Lo → H1/M/J/G. The dynamics of the phytoplankton community may be explained by the stability of water column, irradiance, water temperature, and nutrient structure.

Warming Effects on Periphyton Community and Abundance in Different Seasons Are Influenced by Nutrient State and Plant Type: A Shallow Lake Mesocosm Study

“…Moreover, the periphyton community, which prefers warm water, exhibited higher relative abundances in spring/summer, such as functional groups B, J, and F (Jiang et al, 2013), whereas functional group D which prefers cold water (Jiang et al, 2013), showed higher proportions of periphyton in winter. Our results, therefore, support the view that functional group can be used as an approach to analyze the seasonal variability in algal community (Yang et al, 2011;Yu et al, 2012). Except for winter, the periphyton functional composition responded strongly to nutrient addition and temperature increase, which is consistent with the responses of periphyton genus composition to nutrient and temperature in spring, summer and winter.…”

“…In our study, the functional group composition of periphyton also showed a noticeable seasonal change. The functional groups MP and L O exhibited the highest densities and relative abundances in spring and summer, which can be linked to high light and high nutrient conditions (Bovo-Scomparin and Train, 2008;Yang et al, 2011). Functional group T, which is tolerant to light deficiencies (Reynolds et al, 2002), dominated the periphyton community in winter.…”

Responses of phytoplankton functional groups to the hydrologic regime in the Daning River, a tributary of Three Gorges Reservoir, China

“…Moreover, the competitiveness of this group is enhanced by the possession of flagella, which allow vertical migration through the water layers to reach optimal light conditions and nutrient concentrations (Bovo-Scomparin and Train, 2008;Jansson et al, 1996). Members of the Lo group, mainly represented by motile Peridiniopsis niei and Peridinium spp., can obtain nutrients easily from the hypolimnion and grow well in a wide range of nutrient concentration (Liu et al, 2008;Xiao et al, 2011;Yang et al, 2011). Furthermore, high water temperature (20-27°C) is favorable for reproduction in this genus (Grigorszky et al, 2006).…”

Seasonal pattern of cyanobacteria community and its relationship with environmental factors: a case study in Luoma Lake, East China

“…We believe the rising temperature was the main reason for the increase of cyanobacteria abundance. Besides, the species richness could be influenced by water velocity and fluctuating water level [39,40]. The water level in Luoma Lake experienced conspicuous fluctuation in warm months, which was unfavorable for nutrient accumulation and the maintenance of a stable water column.…”