The University of Southampton
University of Southampton Institutional Repository

Persistent high temperature and low precipitation reduce peat carbon accumulation

Persistent high temperature and low precipitation reduce peat carbon accumulation
Persistent high temperature and low precipitation reduce peat carbon accumulation
Extreme climate events are predicted to become more frequent and intense. Their ecological impacts, particularly on carbon cycling, can differ in relation to ecosystem sensitivity. Peatlands, being characterized by peat accumulation under waterlogged conditions, can be particularly sensitive to climate extremes if the climate event increases soil oxygenation. However, a mechanistic understanding of peatland responses to persistent climate extremes is still lacking, particularly in terms of aboveground–belowground feedback. Here, we present the results of a transplantation experiment of peat mesocosms from high to low altitude in order to simulate, during 3 years, a mean annual temperature c. 5 °C higher and a mean annual precipitation c. 60% lower. Specifically, we aim at understanding the intensity of changes for a set of biogeochemical processes and their feedback on carbon accumulation. In the transplanted mesocosms, plant productivity showed a species-specific response depending on plant growth forms, with a significant decrease (c. 60%) in peat moss productivity. Soil respiration almost doubled and Q10 halved in the transplanted mesocosms in combination with an increase in activity of soil enzymes. Spectroscopic characterization of peat chemistry in the transplanted mesocosms confirmed the deepening of soil oxygenation which, in turn, stimulated microbial decomposition. After 3 years, soil carbon stock increased only in the control mesocosms whereas a reduction in mean annual carbon accumulation of c. 30% was observed in the transplanted mesocosms. Based on the above information, a structural equation model was built to provide a mechanistic understanding of the causal connections between peat moisture, vegetation response, soil respiration and carbon accumulation. This study identifies, in the feedback between plant and microbial responses, the primary pathways explaining the reduction in carbon accumulation in response to recurring climate extremes in peat soils.
carbon accumulation, climate extreme, drought, organic matter chemistry, plant productivity, Q, (10), soil enzymes, soil respiration
1354-1013
4114-4123
Bragazza, Luca
297b335a-0a17-4c30-afbb-dfc5267f6688
Buttler, Alexandre
df5e7c83-0729-4d2c-9534-0331eb8155c8
Robroek, Bjorn J.M.
06dcb269-687c-41db-ab73-f61899617f92
Albrecht, Remy
ec975943-875b-44c1-a2d9-a8988e1fbbf7
Zaccone, Claudio
e451a119-4e9a-48d9-b016-2630e3fd5918
Jassey, Vincent E.J.
f6f6f690-1b5e-4f7f-9cb3-b5cf325585b8
Signarbieux, Constant
8a752b84-cff1-4789-acd9-bda0d8c8c814
Bragazza, Luca
297b335a-0a17-4c30-afbb-dfc5267f6688
Buttler, Alexandre
df5e7c83-0729-4d2c-9534-0331eb8155c8
Robroek, Bjorn J.M.
06dcb269-687c-41db-ab73-f61899617f92
Albrecht, Remy
ec975943-875b-44c1-a2d9-a8988e1fbbf7
Zaccone, Claudio
e451a119-4e9a-48d9-b016-2630e3fd5918
Jassey, Vincent E.J.
f6f6f690-1b5e-4f7f-9cb3-b5cf325585b8
Signarbieux, Constant
8a752b84-cff1-4789-acd9-bda0d8c8c814

Bragazza, Luca, Buttler, Alexandre, Robroek, Bjorn J.M., Albrecht, Remy, Zaccone, Claudio, Jassey, Vincent E.J. and Signarbieux, Constant (2016) Persistent high temperature and low precipitation reduce peat carbon accumulation. Global Change Biology, 22 (12), 4114-4123. (doi:10.1111/gcb.13319).

Record type: Article

Abstract

Extreme climate events are predicted to become more frequent and intense. Their ecological impacts, particularly on carbon cycling, can differ in relation to ecosystem sensitivity. Peatlands, being characterized by peat accumulation under waterlogged conditions, can be particularly sensitive to climate extremes if the climate event increases soil oxygenation. However, a mechanistic understanding of peatland responses to persistent climate extremes is still lacking, particularly in terms of aboveground–belowground feedback. Here, we present the results of a transplantation experiment of peat mesocosms from high to low altitude in order to simulate, during 3 years, a mean annual temperature c. 5 °C higher and a mean annual precipitation c. 60% lower. Specifically, we aim at understanding the intensity of changes for a set of biogeochemical processes and their feedback on carbon accumulation. In the transplanted mesocosms, plant productivity showed a species-specific response depending on plant growth forms, with a significant decrease (c. 60%) in peat moss productivity. Soil respiration almost doubled and Q10 halved in the transplanted mesocosms in combination with an increase in activity of soil enzymes. Spectroscopic characterization of peat chemistry in the transplanted mesocosms confirmed the deepening of soil oxygenation which, in turn, stimulated microbial decomposition. After 3 years, soil carbon stock increased only in the control mesocosms whereas a reduction in mean annual carbon accumulation of c. 30% was observed in the transplanted mesocosms. Based on the above information, a structural equation model was built to provide a mechanistic understanding of the causal connections between peat moisture, vegetation response, soil respiration and carbon accumulation. This study identifies, in the feedback between plant and microbial responses, the primary pathways explaining the reduction in carbon accumulation in response to recurring climate extremes in peat soils.

Text
Bragazza_draft_v1_BJMR - Accepted Manuscript
Download (268kB)

More information

Accepted/In Press date: 4 April 2016
e-pub ahead of print date: 2 May 2016
Published date: December 2016
Keywords: carbon accumulation, climate extreme, drought, organic matter chemistry, plant productivity, Q, (10), soil enzymes, soil respiration
Organisations: Biomedicine

Identifiers

Local EPrints ID: 408480
URI: https://eprints.soton.ac.uk/id/eprint/408480
ISSN: 1354-1013
PURE UUID: b484549f-63aa-43ad-90a2-696318fb7a3d
ORCID for Bjorn J.M. Robroek: ORCID iD orcid.org/0000-0002-6714-0652

Catalogue record

Date deposited: 20 May 2017 04:05
Last modified: 20 Jul 2019 00:27

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×