Response of emergent macrophytes to hydrological changes in a shallow lake, with special reference to nutrient cycling

Abstract

The effect of water level reduction on nutrient concentrations and productivity of emergent macrophytes was analyzed in a shallow, polymictic lake, located in Central-Western Poland. The water level was regulated for irrigation purposes from 1974 to 2002, with an average amplitude of 0.85 m. In 2002, the water level was reduced by 0.60 m during winter time and by 0.40 m in summer time. Nutrient concentrations, nitrogen, phosphorus, and potassium standing stocks and aboveground biomass production were compared among four vegetation types along with a moisture gradient in the littoral zone. This study was conducted in the littoral zone of Lake Niepruszewskie during the growing seasons in 1999-2001 (1st period with high water level) and [2005][2006][2007][2008] (2nd period with low water level). The reduction of water level resulted in a negative effect on biomass production and nutrient concentrations. Stoichiometric indexes, like N:P and N:K ratios, indicate that the shift in nutrient limitation due to changes in hydrological conditions caused a reduction of the nutrient uptake by vegetation and affected productivity. The decrease in the aboveground biomass production was more marked at sites that were less affected by drainage, i.e., permanently flooded. However, in drawdown areas, plant growth decreased. Species including Phragmites australis and Carex acutiformis coped better with the reduction of water levels than Typha angustifolia and Glyceria maxima.

A shallow lake remediation regime with Phragmites australis : Incorporating nutrient removal and water evapotranspiration

“…Tian et al (2009) analyzed the reed nutrient uptake in Taihu Lake, China, and found that both plant species and soil substrates could influence nutrient concentrations of water body. Lawniczak et al (2010) studied the effect of water level reduction on nutrient concentrations and productivity of reeds in Niepruszewskie Lake of Poland, and presented that the decrease of water level resulted in a negative effect on reed biomass production and its nutrient concentrations.…”

Sedimentary response of lake El Tobar, Spain, to climate: lake level changes after the Maunder Minimum

“…However, it can be found in shore habitats as well. By contrast, T. angustifolia is usually found in the flooded littoral (average 60 and maximum 130 cm water depth) (Lawniczak et al ., ) because of the high capacity for oxidation in its rhizosphere (Armstrong et al ., ). These results also support the idea of depositional changes in the shore of El Tobar, establishing differences between levels in the bottom (MZ1a dominated by Juncus ) and the uppermost part of the sequence (MZ2b, dominated by Typha ).…”

Indicator Values of Emergent Vegetation in Overgrowing Lakes in Relation to Water and Sediment Chemistry

“…This approach makes it possible to evaluate the directionality of changes occurring in natural lakes of the temperate zone in which there are natural fluctuations of water levels. In lakes with significant water level variations, the development of vegetation will depend on their resistance to prolonged periods of drought or flooding [44].…”