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Temporal dynamics of bio-available Si fluxes in a temperate forested catchment (Meerdaal forest, Belgium)

Clymans, Wim LU ; Govers, Gerard; Frot, Elisabeth; Ronchi, Benedicta; Van Wesemael, Bas and Struyf, Eric (2013) In Biogeochemistry 116(1-3). p.275-291
Abstract
Silicon (Si) is a key element in global biogeochemical cycling and recent research has shown that changes in the biological component of the Si cycle may lead to more rapid variations in the land-ocean Si transfer than previously thought. The objective of this paper is to better understand the controls on temporal Si dynamics in terrestrial ecosystems, by studying Si fluxes from a small forested catchment in central Belgium. An intensive monitoring program (2008-2010) of dissolved and amorphous silica (DSi and ASi) concentrations and load patterns show that DSi concentrations are significantly lower during winter-spring periods than during summer-autumn periods. In contrast to what was found in other studies, seasonal dynamics in Meerdaal... (More)
Silicon (Si) is a key element in global biogeochemical cycling and recent research has shown that changes in the biological component of the Si cycle may lead to more rapid variations in the land-ocean Si transfer than previously thought. The objective of this paper is to better understand the controls on temporal Si dynamics in terrestrial ecosystems, by studying Si fluxes from a small forested catchment in central Belgium. An intensive monitoring program (2008-2010) of dissolved and amorphous silica (DSi and ASi) concentrations and load patterns show that DSi concentrations are significantly lower during winter-spring periods than during summer-autumn periods. In contrast to what was found in other studies, seasonal dynamics in Meerdaal forest are not controlled by variations in biological uptake or temperature, but mainly by the more important supply of pore-water to the groundwater table in winter-spring periods. Analysis of seasonal and event fluctuations in stream water DSi concentrations showed that final stream water is a mixture of old, DSi rich water pushed out of the soil, and new, DSi poor water delivered by quick flow. The mixing of old and new water finally resulted in streamwater DSi concentrations responding only moderately to variations in discharge (near-chemostatic behaviour). We estimated the total DSi export from the system to be ca. 65.1 x 10(3) mol km(-2) year(-1). Because Si delivery is biologically regulated through an important Si cycle in the vegetation-soil continuum, an anthropogenic (e.g. agricultural expansion) or climatic disturbance of terrestrial ecosystems may alter both water residence times through shifts in hydrological regimes and the DSi chemical equilibrium concentration in soils. In turn, these perturbations will potentially alter long-term DSi and ASi inputs to aquatic systems. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Silica cycle, Dissolved silica, Amorphous silica, Chemostatic behaviour, Runoff, Hysteresis, Deforestation
in
Biogeochemistry
volume
116
issue
1-3
pages
275 - 291
publisher
Springer
external identifiers
  • wos:000328197800020
  • scopus:84889664892
ISSN
1573-515X
DOI
10.1007/s10533-013-9858-9
language
English
LU publication?
yes
id
a72d284f-8394-41a0-9b61-077a2fecd257 (old id 4272747)
date added to LUP
2014-02-11 14:08:12
date last changed
2019-02-20 01:37:14
@article{a72d284f-8394-41a0-9b61-077a2fecd257,
  abstract     = {Silicon (Si) is a key element in global biogeochemical cycling and recent research has shown that changes in the biological component of the Si cycle may lead to more rapid variations in the land-ocean Si transfer than previously thought. The objective of this paper is to better understand the controls on temporal Si dynamics in terrestrial ecosystems, by studying Si fluxes from a small forested catchment in central Belgium. An intensive monitoring program (2008-2010) of dissolved and amorphous silica (DSi and ASi) concentrations and load patterns show that DSi concentrations are significantly lower during winter-spring periods than during summer-autumn periods. In contrast to what was found in other studies, seasonal dynamics in Meerdaal forest are not controlled by variations in biological uptake or temperature, but mainly by the more important supply of pore-water to the groundwater table in winter-spring periods. Analysis of seasonal and event fluctuations in stream water DSi concentrations showed that final stream water is a mixture of old, DSi rich water pushed out of the soil, and new, DSi poor water delivered by quick flow. The mixing of old and new water finally resulted in streamwater DSi concentrations responding only moderately to variations in discharge (near-chemostatic behaviour). We estimated the total DSi export from the system to be ca. 65.1 x 10(3) mol km(-2) year(-1). Because Si delivery is biologically regulated through an important Si cycle in the vegetation-soil continuum, an anthropogenic (e.g. agricultural expansion) or climatic disturbance of terrestrial ecosystems may alter both water residence times through shifts in hydrological regimes and the DSi chemical equilibrium concentration in soils. In turn, these perturbations will potentially alter long-term DSi and ASi inputs to aquatic systems.},
  author       = {Clymans, Wim and Govers, Gerard and Frot, Elisabeth and Ronchi, Benedicta and Van Wesemael, Bas and Struyf, Eric},
  issn         = {1573-515X},
  keyword      = {Silica cycle,Dissolved silica,Amorphous silica,Chemostatic behaviour,Runoff,Hysteresis,Deforestation},
  language     = {eng},
  number       = {1-3},
  pages        = {275--291},
  publisher    = {Springer},
  series       = {Biogeochemistry},
  title        = {Temporal dynamics of bio-available Si fluxes in a temperate forested catchment (Meerdaal forest, Belgium)},
  url          = {http://dx.doi.org/10.1007/s10533-013-9858-9},
  volume       = {116},
  year         = {2013},
}