On allowing for transient variation in end-member δ13C values in partitioning soil C fluxes from net ecosystem respiration
| dc.contributor.author | McCloskey, Christopher S. | |
| dc.contributor.author | Otten, Wilfred | |
| dc.contributor.author | Paterson, Eric | |
| dc.contributor.author | Kirk, Guy J. D. | |
| dc.date.accessioned | 2021-11-18T13:40:51Z | |
| dc.date.available | 2021-11-18T13:40:51Z | |
| dc.date.issued | 2021-09-24 | |
| dc.description.abstract | The use of stable isotope analysis to resolve ecosystem respiration into its plant and soil components rests on how well the end-member isotope signatures (δ13C) are characterised. In general, it is assumed that end-member values are constant over time. However, there are necessarily diurnal and other transient variations in end-members with environmental conditions. We analyse diurnal and seasonal patterns of ecosystem respiration and its δ13C in a C4 grass growing in a C3 soil using fixed and diurnally varying plant and soil δ13C end-members. We measure the end-members independently, and we assess the effects of expected variation in values. We show that variation in end-members within realistic ranges, particularly diurnal changes in the plant end-member, can cause partitioning errors of 40% during periods of high plant growth. The effect depends on how close the end-member is to the measured net respiration δ13C, that is, the proportion of the respiration due to that end-member. We show light-driven variation in plant end-members can cause substantial distortion of partitioned soil organic matter (SOM) flux patterns on a diurnal scale and cause underestimation of daily to annual SOM turnover of approximately 25%. We conclude that, while it is not practicable to independently measure the full temporal variation in end-member values over a growing season, this error may be adjusted for by using a diurnally varying δ13Cplant. | en_UK |
| dc.identifier.citation | McCloskey CS, Otten W, Paterson E, Kirk GJ. (2021) On allowing for transient variation in end member δ13C values in partitioning soil C fluxes from net ecosystem respiration. European Journal of Soil Science, Volume 72, Issue 6, November 2021, pp. 2343-2355 | en_UK |
| dc.identifier.issn | 1351-0754 | |
| dc.identifier.uri | https://doi.org/10.1111/ejss.13177 | |
| dc.identifier.uri | http://dspace.lib.cranfield.ac.uk/handle/1826/17277 | |
| dc.language.iso | en | en_UK |
| dc.publisher | Wiley | en_UK |
| dc.rights | Attribution 4.0 International | * |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | * |
| dc.subject | C3 and C4 photosynthesis | en_UK |
| dc.subject | ecosystem respiration | en_UK |
| dc.subject | isotopic flux partitioning | en_UK |
| dc.subject | natural abundance | en_UK |
| dc.subject | rhizosphere priming effect | en_UK |
| dc.subject | soil carbon | en_UK |
| dc.title | On allowing for transient variation in end-member δ13C values in partitioning soil C fluxes from net ecosystem respiration | en_UK |
| dc.type | Article | en_UK |