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Increased temperature sensitivity of net DOC production from ombrotrophic peat due to water table draw-down.

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Increased temperature sensitivity of net DOC production from ombrotrophic peat due to water table draw-down. / Clark, J. M.; Ashley, D.; Wagner, D. M. et al.
In: Global Change Biology, Vol. 15, No. 4, 04.2009, p. 794-807.

Research output: Contribution to Journal/MagazineJournal articlepeer-review

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Clark JM, Ashley D, Wagner DM, Chapman PJ, Lane SN, Evans CJ et al. Increased temperature sensitivity of net DOC production from ombrotrophic peat due to water table draw-down. Global Change Biology. 2009 Apr;15(4):794-807. doi: 10.1111/j.1365-2486.2008.01683.x

Author

Clark, J. M. ; Ashley, D. ; Wagner, D. M. et al. / Increased temperature sensitivity of net DOC production from ombrotrophic peat due to water table draw-down. In: Global Change Biology. 2009 ; Vol. 15, No. 4. pp. 794-807.

Bibtex

@article{2c046140dd24446c956168950978ac0e,
title = "Increased temperature sensitivity of net DOC production from ombrotrophic peat due to water table draw-down.",
abstract = "The production and release of dissolved organic carbon (DOC) from peat soils is thought to be sensitive to changes in climate, specifically changes in temperature and rainfall. However, little is known about the actual rates of net DOC production in response to temperature and water table draw-down, particularly in comparison to carbon dioxide (CO2) fluxes. To explore these relationships, we carried out a laboratory experiment on intact peat soil cores under controlled temperature and water table conditions to determine the impact and interaction of each of these climatic factors on net DOC production. We found a significant interaction (P < 0.001) between temperature, water table draw-down and net DOC production across the whole soil core (0 to −55 cm depth). This corresponded to an increase in the Q10 (i.e. rise in the rate of net DOC production over a 10 °C range) from 1.84 under high water tables and anaerobic conditions to 3.53 under water table draw-down and aerobic conditions between −10 and − 40 cm depth. However, increases in net DOC production were only seen after water tables recovered to the surface as secondary changes in soil water chemistry driven by sulphur redox reactions decreased DOC solubility, and therefore DOC concentrations, during periods of water table draw-down. Furthermore, net microbial consumption of DOC was also apparent at − 1 cm depth and was an additional cause of declining DOC concentrations during dry periods. Therefore, although increased temperature and decreased rainfall could have a significant effect on net DOC release from peatlands, these climatic effects could be masked by other factors controlling the biological consumption of DOC in addition to soil water chemistry and DOC solubility. These findings highlight both the sensitivity of DOC release from ombrotrophic peat to episodic changes in water table draw-down, and the need to disentangle complex and interacting controls on DOC dynamics to fully understand the impact of environmental change on this system.",
keywords = "climate change • DOC • drought • Moor House • organic carbon • peat • Q 10 • temperature • water table",
author = "Clark, {J. M.} and D. Ashley and Wagner, {D. M.} and Chapman, {P. J.} and Lane, {S. N.} and Evans, {C. J.} and Heathwaite, {A. Louise}",
year = "2009",
month = apr,
doi = "10.1111/j.1365-2486.2008.01683.x",
language = "English",
volume = "15",
pages = "794--807",
journal = "Global Change Biology",
issn = "1354-1013",
publisher = "Blackwell Publishing Ltd",
number = "4",

}

RIS

TY - JOUR

T1 - Increased temperature sensitivity of net DOC production from ombrotrophic peat due to water table draw-down.

AU - Clark, J. M.

AU - Ashley, D.

AU - Wagner, D. M.

AU - Chapman, P. J.

AU - Lane, S. N.

AU - Evans, C. J.

AU - Heathwaite, A. Louise

PY - 2009/4

Y1 - 2009/4

N2 - The production and release of dissolved organic carbon (DOC) from peat soils is thought to be sensitive to changes in climate, specifically changes in temperature and rainfall. However, little is known about the actual rates of net DOC production in response to temperature and water table draw-down, particularly in comparison to carbon dioxide (CO2) fluxes. To explore these relationships, we carried out a laboratory experiment on intact peat soil cores under controlled temperature and water table conditions to determine the impact and interaction of each of these climatic factors on net DOC production. We found a significant interaction (P < 0.001) between temperature, water table draw-down and net DOC production across the whole soil core (0 to −55 cm depth). This corresponded to an increase in the Q10 (i.e. rise in the rate of net DOC production over a 10 °C range) from 1.84 under high water tables and anaerobic conditions to 3.53 under water table draw-down and aerobic conditions between −10 and − 40 cm depth. However, increases in net DOC production were only seen after water tables recovered to the surface as secondary changes in soil water chemistry driven by sulphur redox reactions decreased DOC solubility, and therefore DOC concentrations, during periods of water table draw-down. Furthermore, net microbial consumption of DOC was also apparent at − 1 cm depth and was an additional cause of declining DOC concentrations during dry periods. Therefore, although increased temperature and decreased rainfall could have a significant effect on net DOC release from peatlands, these climatic effects could be masked by other factors controlling the biological consumption of DOC in addition to soil water chemistry and DOC solubility. These findings highlight both the sensitivity of DOC release from ombrotrophic peat to episodic changes in water table draw-down, and the need to disentangle complex and interacting controls on DOC dynamics to fully understand the impact of environmental change on this system.

AB - The production and release of dissolved organic carbon (DOC) from peat soils is thought to be sensitive to changes in climate, specifically changes in temperature and rainfall. However, little is known about the actual rates of net DOC production in response to temperature and water table draw-down, particularly in comparison to carbon dioxide (CO2) fluxes. To explore these relationships, we carried out a laboratory experiment on intact peat soil cores under controlled temperature and water table conditions to determine the impact and interaction of each of these climatic factors on net DOC production. We found a significant interaction (P < 0.001) between temperature, water table draw-down and net DOC production across the whole soil core (0 to −55 cm depth). This corresponded to an increase in the Q10 (i.e. rise in the rate of net DOC production over a 10 °C range) from 1.84 under high water tables and anaerobic conditions to 3.53 under water table draw-down and aerobic conditions between −10 and − 40 cm depth. However, increases in net DOC production were only seen after water tables recovered to the surface as secondary changes in soil water chemistry driven by sulphur redox reactions decreased DOC solubility, and therefore DOC concentrations, during periods of water table draw-down. Furthermore, net microbial consumption of DOC was also apparent at − 1 cm depth and was an additional cause of declining DOC concentrations during dry periods. Therefore, although increased temperature and decreased rainfall could have a significant effect on net DOC release from peatlands, these climatic effects could be masked by other factors controlling the biological consumption of DOC in addition to soil water chemistry and DOC solubility. These findings highlight both the sensitivity of DOC release from ombrotrophic peat to episodic changes in water table draw-down, and the need to disentangle complex and interacting controls on DOC dynamics to fully understand the impact of environmental change on this system.

KW - climate change • DOC • drought • Moor House • organic carbon • peat • Q 10 • temperature • water table

UR - http://www.scopus.com/inward/record.url?scp=61449151145&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2486.2008.01683.x

DO - 10.1111/j.1365-2486.2008.01683.x

M3 - Journal article

VL - 15

SP - 794

EP - 807

JO - Global Change Biology

JF - Global Change Biology

SN - 1354-1013

IS - 4

ER -