Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/9841
AuthorsRey, A. 
Belelli-Marchesini, L. 
Etiope, G. 
Papale, D. 
Canfora, E. 
Valentini, R. 
Pegoraro, E. 
TitlePartitioning the net ecosystem carbon balance of a semiarid steppe into biological and geological components
Issue Date2014
Series/Report no./118 (2014)
DOI10.1007/s10533-013-9907-4
URIhttp://hdl.handle.net/2122/9841
Keywordscarbon emission, soil, dry land
Subject Classification03. Hydrosphere::03.04. Chemical and biological::03.04.05. Gases 
AbstractRecent 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.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
Rey et al 2013- biogeochem.pdf1.06 MBAdobe PDFView/Open
Show full item record

Page view(s)

178
Last Week
0
Last month
checked on Jun 26, 2017

Download(s)

75
checked on Jun 26, 2017

Google ScholarTM

Check

Altmetric