Dissolved Silica Retention and Its Impact on Eutrophication in a Complex of Mountain Reservoirs

Koszelnik, Piotr; Tomaszek, J. A.

doi:10.1007/s11270-007-9567-x

Cited by 28 publications

(24 citation statements)

References 38 publications

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“…3.5 kT Si year − 1 . Presently, it has been accepted that the "artificial lake effect" caused by the dam construction, should be responsible for the silicon retention, which has been observed in impounded rivers worldwide, such as Danube , Changjiang (Li et al, 2007;Wang et al, 2007), Seine (Jossette et al, 1999), San River (Koszelnik and Tomaszek 2007), Columbia River in Canada (Matzinger et al, 2007), as well as some smaller rivers (Humborg et al, 2002) . However, reservoirs in this study showed the reverse effects on DSi, that is, only WJD is the sink for Si, and other three are sources.…”

Section: Discussionmentioning

confidence: 99%

“…As a macronutrients required by certain groups of plants, e.g. diatom, DSi plays an important role in sustaining river, coastal and oceanic ecosystems (Jossette et al, 1999;Neal et al 2005;Koszelnik and Tomaszek 2007). Diatoms, contributing 25% of the world's entire net primary production (Willén, 1991), are the most important group of planktonic algae in marine ecosystem .…”

Section: Introductionmentioning

confidence: 99%

“…However, in the last few decades, human activities have caused enormous changes both in the nature and quantity of nutrient fluxes to oceans , of which the rapid increases of phosphate and nitrate inputs was well documented (Meybeck 1998;Yan et al, 1999;Liu et al, 2003;Yan et al, 2003;Biggs et al, 2004;Gächter et al, 2004;Duan et al, 2007), but the fluvial flux of DSi was found continuously decreasing in rivers worldwide (Justić et al, 1995;Conley et al, 2000;Humborg et al, 2000;Vörösmarty and Sahagian, 2000;Paul, 2003;Vörösmarty et al, 2003;Neal et al, 2005;Humborg et al, 2006;Duan et al, 2007;Li et al, 2007;Koszelnik and Tomaszek 2007;Roubeix et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

“…As the source, transport and sink characteristics of silicate are distinct from those of nitrogen and phosphorus , scientists gradually relate the "silicate retention" with the extensive river impounding (Humborg et al, 1997;Conley et al, 2000;Humborg et al, 2000;Kelly 2001;Humborg et al, 2002;Teodoru and Wehrli 2005;Teodoru et al, 2006a, b;Koszelnik and Tomaszek 2007). In the study of Jossette et al (1999), 50% of incoming silica flux was observed lost in the reservoirs (Jossette et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

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Dissolved silicate retention and transport in cascade reservoirs in Karst area, Southwest China

Wang

Liu

et al. 2010

Science of The Total Environment

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Presently, the fluvial fluxes of Dissolved silicate (DSi) by many famous rivers in the world have been reported significantly decreased in the past several decades. DSi retention by river damming hence becomes a great concern. In this study, the impact on DSi retention and transport by cascade reservoirs in the Karst area were investigated. Based on the monitoring data for four seasons, budget of DSi in these reservoirs were calculated. Results showed that, only the downstream eutrophic Wujiangdu reservoir (WJD) was the sink for DSi, with a value of ca. 3.5 kT DSi trapped annually. The new Hongjiadu reservoir (HJD) in the headwater area revealed to be an important source for DSi. Both Dongfeng (DF) and Suofengyin (SFY) reservoirs also released more DSi to the downstream than entering them. The great discrepancy of DSi source and sink effects among these reservoirs indicates that, (i) DSi was obviously taken up in summer and spring, and the concentration of DSi could be dropped down to below 30 μΜ; (ii) during the period of thermal stratification, the concentration stratification of DSi is also developed along the water column. Possibly DSi releasing from inundation soil and bottom sediment was the important compensation for the silicon depletion in the epilimnion. In the newly constructed reservoirs (e.g. HJD and SFY), the releasing flux of DSi can significantly exceed the assimilating flux by diatom; and (iii) due to the hypolimnion introducing for hydropower operation, water leaving the dam generally had high DSi content, and then masked the DSi taking up in the epilimnion. This process also decreased the ratio of DIN to DSi, mitigating the silicon limiting situation in the downstream.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Dissolved silicate retention and transport in cascade reservoirs in Karst area, Southwest China

Wang

Liu

et al. 2010

Science of The Total Environment

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“…Koszelnik and Tomaszek (2008) discussed the role of the N:P:Si ratio not only in marine environments but also in freshwater ecosystems such as natural lakes. The regular monitoring of the DSi or N:P:Si ratio is thus important, especially in lakes and estuaries subjected to intense human activities.…”

Section: Introductionmentioning

confidence: 99%

Impacts of long-term increase in silicon concentration on diatom blooms in Lake Kasumigaura, Japan

Arai

Fukushima

2014

Ann. Limnol. - Int. J. Lim.

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-In the eutrophic Lake Kasumigaura in Japan, a trend of dissolved Si (DSi) concentration was detected over the last three decades, probably caused by the DSi release enhanced by an increase in sediment resuspension for the same period (Arai et al., Limnol., 13, 81-95, 2012). The present study described the long-term trends of the magnitude and seasonality of diatom blooms in the lake during 1981-2010 using the database and assessed the influencing factors for the trends by the numerical simulation of DSi and diatoms. The box model was developed based on the lake budgets (inflow, outflow, release and sedimentation) and the simple diatom growth model depending on DSi, temperature and light condition. As results, database analysis detected a long-term trend of increasing diatom abundance and a shift of blooming season from spring and autumn to the winter-spring period. Si could be regarded as a main nutrient factor limiting diatom growth by analyzing N:P:Si ratios. Our model simulation relatively well-reproduced the increasing trend and the shift of seasonality of DSi and diatoms, even though peaks of diatom blooms were underestimated in some years. Among input variables, the concentration of resuspended sediments radically increased. The model simulation with the input variables or parameters changed suggested as follows: (1) the recent DSi release from resuspended sediments enhanced diatom abundance and (2) the degradation of light condition caused by resuspension affected the shift of blooming season. These findings implicate the significance of the interactions between sediments and water to phytoplankton blooms.

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Natural and human influences on dissolved silica export from watershed to coast in Southeast China

Chen

et al. 2014

J. Geophys. Res. Biogeosci.

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Natural and human factors controlling dissolved silica (DSi) export from the watershed were investigated for the Jiulong River watershed in Southeast China, which is a subtropical region where tectonic activity and high runoff combine to create a global hot spot for DSi flux. Results showed that river DSi was fairly high (246 ± 76 μmol L À1 ) due to granite lithology and increased human perturbation. The percentage of granite, paddy soil, arable land, and forest land each explain 47-69% of the spatial variation in DSi level at the subwatershed scale. Land use change (deforestation for agriculture) and soil erosion increased DSi transfer from terrestrial systems towards the river. Discharge explains over 95% of the variation in DSi fluxes, and a discrepancy of up to 16% of watershed DSi export was observed between low and high flow conditions. DSi retention is more significant in the dry season, likely due to biological uptake by diatoms in reservoirs under low flow conditions and higher residence time. However, this may be offset by high runoff flush in the wet season, which might cause unfavorable conditions for diatom growth and DSi depletion. There has been little overall change in DSi in estuarine water in recent decades. However, seasonal variation and occasionally fluctuation of DSi during extreme hydrological events (rainstorms) does exist, with important implications for the coastal ecosystem. This research confirmed that human activities and land use change have substantially altered Si delivery, cycling and riverine export to the coast in this region.

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Dissolved Silica Retention and Its Impact on Eutrophication in a Complex of Mountain Reservoirs

Cited by 28 publications

References 38 publications

Dissolved silicate retention and transport in cascade reservoirs in Karst area, Southwest China

Dissolved silicate retention and transport in cascade reservoirs in Karst area, Southwest China

Impacts of long-term increase in silicon concentration on diatom blooms in Lake Kasumigaura, Japan

Natural and human influences on dissolved silica export from watershed to coast in Southeast China

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