Sediment Production in French Alpine Rivers

The characteristics of stream and river ecosystems in arctic and alpine areas are determined mainly by the relative contribution of glacial meltwater, snowmelt, rainfall and groundwater. Each source generates a particular seasonal hydrological signature, affecting physical and chemical properties, and hence biological communities. The relative contribution of each source is sensitive to climate change. The study was concentrated on the glacial River W-Jökulsá and some non-glacial rivers in the central highlands of Iceland. The water in the glacial river was entirely glacial meltwater at the glacier margin, but the glacial contribution was about 20% 40 km downstream. However, its tributaries and non-glacial reference rivers were mainly springfed. The invertebrate fauna was confined to Chironomidae of the genus Diamesa close to the glacier, but other taxa (species and groups of species) occupied the river further downstream, where their diversity was close to that found in the reference rivers.

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Particulate light absorption and the prediction of phytoplankton biomass and planktonic metabolism in northeastern Spanish aquatic ecosystems

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f99-184 ◽

2000 ◽

Vol 57 (1) ◽

pp. 25-33 ◽

Cited By ~ 2

Author(s):

C M Duarte ◽

S Agustí ◽

J Kalff

Keyword(s):

Absorption Coefficient ◽

Light Absorption ◽

Aquatic Ecosystems ◽

Coastal Lagoons ◽

Strong Relationship ◽

Community Respiration ◽

Chl A ◽

Light Absorption Coefficient ◽

Alpine Rivers ◽

Detrital Particles

Examination of particulate light absorption and microplankton metabolism in 36 northeastern Spanish aquatic ecosystems, ranging from alpine rivers to inland saline lakes and the open Mediterranean Sea, revealed the existence of general relationships between particulate light absorption and the biomass of phytoplankton and microplankton metabolism. The particulate absorption spectra reflected a dominance of nonphotosynthetic, likely detrital, particles in rivers and a dominance of phytoplankton in coastal lagoons. There was a strong relationship between the light absorbed by phytoplankton and the chlorophyll a (Chl a) concentration of the systems, which indicated an average (±SE) Chl a specific absorption coefficient of 0.0233 ± 0.0020 m2·mg Chl a-1 for these widely diverse systems. Chl a concentration was a weaker predictor of the total particulate light absorption coefficient, pointing to an important role of nonphytoplanktonic particles in light absorption. Gross production was very closely related to the light absorption coefficient of phytoplankton, whereas community respiration was strongly correlated with the total particulate light absorption coefficient, indicating the optical signatures of sestonic particles to be reliable predictors of planktonic biomass and metabolism in aquatic ecosystems.

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Seasonal ice nucleation activity of water samples from alpine rivers and lakes in Obergurgl, Austria

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.149442 ◽

2021 ◽

pp. 149442

Author(s):

Philipp Baloh ◽

Regina Hanlon ◽

Christopher Anderson ◽

Eoin Dolan ◽

Gernot Pacholik ◽

...

Keyword(s):

Water Samples ◽

Ice Nucleation ◽

Rivers And Lakes ◽

Nucleation Activity ◽

Alpine Rivers ◽

Ice Nucleation Activity

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The risk reduction effect of sediment production rate by understory coverage rate in granite area mountain forest

Scientific Reports ◽

10.1038/s41598-021-93906-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Toshiaki Mizuno ◽

Nagahiro Kojima ◽

Satoshi Asano

Keyword(s):

Climate Change ◽

Risk Reduction ◽

Production Rate ◽

Meta Analysis ◽

Coverage Rate ◽

Sustainable Land Use ◽

Mountain Forest ◽

Evidence Based ◽

Sediment Production ◽

Reduction Effect

AbstractEcosystem-based disaster risk reduction (Eco-DRR) is an important concept to the adaption of climate change for a sustainable life. In Japan, it is anticipated that damages caused by sediment production will be increased as the intensity and amount of rainfall are increased by climate change. Thus, we need to know the Eco-DRR effect of the forest for planning sustainable land use by evidence-based data. In this study, we focused on the relationship between sediment production rate and the understory coverage rate of a low mountain forest in the granite area. From the results of the field survey and statistical meta-analysis, the sediment production rate was reduced by 97% in granite area mountain forest when the understory coverage rate was 60% or more compared to when less than 30% by evidence-based data. Accordingly, we found that it will be necessary to keep forests with an understory coverage rate of 60% or more when considering the risk-reducing effect of sediment disaster in granite area mountain forests for the adaption of climate change.

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Discharge of debris from ice at the margin of the Greenland ice sheet

Journal of Glaciology ◽

10.3189/172756502781831359 ◽

2002 ◽

Vol 48 (161) ◽

pp. 192-198 ◽

Cited By ~ 21

Author(s):

Peter G. Knight ◽

Richard I. Waller ◽

Carrie J. Patterson ◽

Alison P. Jones ◽

Zoe P. Robinson

Keyword(s):

Ice Sheet ◽

Greenland Ice Sheet ◽

High Rate ◽

Outlet Glacier ◽

Tidewater Glaciers ◽

Sediment Production ◽

Basal Ice ◽

Order Of Magnitude ◽

Sediment Transfer ◽

A Minor

AbstractSediment production at a terrestrial section of the ice-sheet margin in West Greenland is dominated by debris released through the basal ice layer. The debris flux through the basal ice at the margin is estimated to be 12–45 m3 m−1 a−1. This is three orders of magnitude higher than that previously reported for East Antarctica, an order of magnitude higher than sites reported from in Norway, Iceland and Switzerland, but an order of magnitude lower than values previously reported from tidewater glaciers in Alaska and other high-rate environments such as surging glaciers. At our site, only negligible amounts of debris are released through englacial, supraglacial or subglacial sediment transfer. Glaciofluvial sediment production is highly localized, and long sections of the ice-sheet margin receive no sediment from glaciofluvial sources. These findings differ from those of studies at more temperate glacial settings where glaciofluvial routes are dominant and basal ice contributes only a minor percentage of the debris released at the margin. These data on debris flux through the terrestrial margin of an outlet glacier contribute to our limited knowledge of debris production from the Greenland ice sheet.

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