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Partitioning the net ecosystem carbon balance of a semiarid steppe into biological and geological components
Language
English
Obiettivo Specifico
7A. Geofisica di esplorazione
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Title of the book
Issue/vol(year)
/118 (2014)
ISSN
0168-2563
Electronic ISSN
1573-515X
Publisher
Springer Science+Business Media B.V.
Pages (printed)
83-101
Issued date
2014
Keywords
Abstract
Recent studies have highlighted the need
to consider geological carbon sources when estimating
the net ecosystem carbon balance (NECB) of terrestrial
ecosystems located in areas potentially affected
by geofluid circulation. We propose a new methodology
using physical parameters of the atmospheric
boundary layer to quantify the CO2 coming from deep
ground origin in a steppe ecosystem located in the SE
of Spain. Then, we compared published NECB
estimates at the site with seasonal patterns of soil
CO2 efflux and biological activity measured by
satellite images over a 2-year period (2007/2008).
The alpha grass ecosystem was a net carbon source
(93.8 and 145.1 g C m-2 year-1, in 2007 and 2008,
respectively), particularly as a result of large amounts
of carbon released over the dry period that were not
related to biological activity. While the highest
ecosystem CO2 emission rates were measured over
the dry period (reaching up to 15 lmol m-2 s-1), soil
CO2 efflux rates (ca. 0.5 lmol m-2 s-1) and plant
productivity were minimal during this period. After
using a linear relationship between NECB and wind
speed for different stability conditions and wind
sectors, we estimated the geological flux FGEO
(217.9 and 244.0 g C m-2 in 2007 and 2008, respectively)
and subtracted it from the NECB to obtain the
biological flux FBIO (-124.0 and -98.9 g C m-2 in
2007 and 2008, respectively). We then partitioned
FBIO into gross primary productivity and ecosystem
respiration and proved that, after removing FGEO,
ecosystem respiration and soil CO2 efflux followed similar seasonal patterns. The annual contribution of
the geological component to NECB was 49.6 and
46.7 % for the year 2007 and 2008, respectively.
Therefore, it is clear that geological carbon sources
should be quantified in those ecosystems located in
areas with potential natural emission of geological
gases to the surface.
to consider geological carbon sources when estimating
the net ecosystem carbon balance (NECB) of terrestrial
ecosystems located in areas potentially affected
by geofluid circulation. We propose a new methodology
using physical parameters of the atmospheric
boundary layer to quantify the CO2 coming from deep
ground origin in a steppe ecosystem located in the SE
of Spain. Then, we compared published NECB
estimates at the site with seasonal patterns of soil
CO2 efflux and biological activity measured by
satellite images over a 2-year period (2007/2008).
The alpha grass ecosystem was a net carbon source
(93.8 and 145.1 g C m-2 year-1, in 2007 and 2008,
respectively), particularly as a result of large amounts
of carbon released over the dry period that were not
related to biological activity. While the highest
ecosystem CO2 emission rates were measured over
the dry period (reaching up to 15 lmol m-2 s-1), soil
CO2 efflux rates (ca. 0.5 lmol m-2 s-1) and plant
productivity were minimal during this period. After
using a linear relationship between NECB and wind
speed for different stability conditions and wind
sectors, we estimated the geological flux FGEO
(217.9 and 244.0 g C m-2 in 2007 and 2008, respectively)
and subtracted it from the NECB to obtain the
biological flux FBIO (-124.0 and -98.9 g C m-2 in
2007 and 2008, respectively). We then partitioned
FBIO into gross primary productivity and ecosystem
respiration and proved that, after removing FGEO,
ecosystem respiration and soil CO2 efflux followed similar seasonal patterns. The annual contribution of
the geological component to NECB was 49.6 and
46.7 % for the year 2007 and 2008, respectively.
Therefore, it is clear that geological carbon sources
should be quantified in those ecosystems located in
areas with potential natural emission of geological
gases to the surface.
Type
article
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Rey et al 2013- biogeochem.pdf
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