The relationships of meteorological factors and nutrient levels with phytoplankton biomass in a shallow eutrophic lake dominated by cyanobacteria, Lake Dianchi from 1991 to 2013

Abstract

Long-term interannual and monthly (1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013) data were analyzed to elucidate the effects of meteorological factors and nutrient levels on phytoplankton biomass in the cyanobacteria-dominated Waihai basin of Lake Dianchi. The interannual ln(chl. a) exhibited positive correlations with the mean air temperature, mean minimum air temperature, and mean maximum air temperature; in addition, a positive relationship between Δln(chl. a) and ΔTP was observed throughout the period. Additionally, ln(chl. a) exhibited a positive correlation with the TP concentration, negative correlations with the sunshine hours and wind speed during the dry season, and positive correlations with the TN and TP concentrations during the rainy season. Furthermore, TP was the most influential factor affecting cyanobacterial bloom dynamics throughout the entire period and during the dry season, and TN and TP were the most important factors during the rainy season, as determined by relative importance analysis. The results of this study based on interannual analysis demonstrated that both meteorological factors and nutrient levels have important roles in controlling cyanobacterial bloom dynamics. The relative importance of these factors may change according to precipitation patterns. Thus, climate change regulation and eutrophication management should be considered in strategies for bloom control. Decreasing the TP load should be prioritized throughout the entire period and during the dry season, and decreasing the TN and TP loads should be considered initially during the rainy season. In addition, further studies of more frequent and complete data acquired over a longer period of time should be conducted in the future.

MODIS-Satellite-Based Analysis of Long-Term Temporal-Spatial Dynamics and Drivers of Algal Blooms in a Plateau Lake Dianchi, China

“…This result is consistent with existing findings [5,13,22]. Additionally, the solar radiation in the low latitude plateau of Lake Dianchi is sufficient for cyanobacteria growth, while the low self-shading and high-intensity light inhibit the growth of cyanobacteria [27].…”

“…In this plateau Lake Dianchi, the annual T mean is approximately 20°C and does not change considerably, the WT can be greater than 20°C from May to August [5], which provides suitable conditions for the growth of algal blooms. Also, high summer temperature is conducive to the occurrence of algal blooms, which confirms the phenomena observed in Caohai or the entire Lake Dianchi [5,27,74].…”

“…The influence of single water quality parameters on algal blooms is greater than that of meteorological factors, among which, TN and TP are the most commonly used in studies [5,27,71,72]. But in our research, we found out that the meteorological factors were expressed as the first principal component, while water quality parameters were identified as the second component in monthly…”

“…The longer the projection length, the stronger the correlation. The nutrient levels in the lake are affected by the dry and rainy seasons [27]. Except for heavy rain, snow melting, and other sudden water pollution and ecological events, the daily changes in water quality are not significant.…”

N2O Fluxes and Rates of Nitrification and Denitrification at the Sediment–Water Interface in Taihu Lake, China

“…As most allochthonous nutrient comes from the north of the Taihu Basin with most cities and the major inflow rivers [72], high nutrient concentrations in water can be observed at Meiliang Bay As most allochthonous nutrient comes from the north of the Taihu Basin with most cities and the major inflow rivers [72], high nutrient concentrations in water can be observed at Meiliang Bay (S1) in the beginning of rainy season (June), further releasing more N 2 O. However, water nutrient concentration would be diluted due to much rainfall during monsoon season (August and September) [32] and due to continuous nutrient consumption by enlarging algae [73], reducing nitrification and denitrification rates and N 2 O flux (Figures 2 and 3). This is likely the main reason that the nitrification and denitrification rates and N 2 O flux peaked in June 2015 at S1 (Figures 2 and 3).…”