The University of Southampton
University of Southampton Institutional Repository

Predicting the yield and water-use of poplar short rotation coppice under a future climate

Predicting the yield and water-use of poplar short rotation coppice under a future climate
Predicting the yield and water-use of poplar short rotation coppice under a future climate
Under the current climate there is significant spatial variation in the yield and water-use of
bioenergy crops such as poplar short rotation coppice (SRC). Marked changes in patterns
of precipitation and temperature are predicted globally as a result of anthropogenic climate
change. This is likely to significantly impact on the yield and transpiration of poplar SRC.
The response of poplar SRC to future climate change is unknown and represents a
significant knowledge gap in the path to a sustainable future.
This thesis used a land-surface scheme, JULES, to investigate the response of poplar SRC
yield and transpiration to the interaction between changes in atmospheric CO2
concentration and changes in climate. Empirical work generated poplar SRC specific
parameter values for use JULES. It was found that Vmax, a key model photosynthetic
parameter, was significantly lower when estimated under the assumption of infinite leaf
internal conductance to CO2. This invalidated the assumption that internal CO2 transfer has
a negligible impact on the drawdown of CO2 from ci to cc. The photosynthesis model in
JULES is based on this assumption; however, inclusion of this additional CO2 transfer
pathway in the model did not impact on the accuracy of the simulated carbon assimilation,
because the value of Vmax used in the model compensated for the presence/absence of this
pathway. It was concluded that, given the model’s high sensitivity to Vmax, it is essential to
calibrate the model with a parameter value estimated under assumptions appropriate for the
model. Further modification, calibration and validation enabled JULES to simulate the
dynamic growth and water-use of poplar under a managed SRC cycle, which is a novel
application for the model. Changes in climate were simulated using an ensemble of GCM
anomalies and atmospheric CO2 concentration was simulated using the SRES A1B
emissions scenario. Results of this work highlighted the influence of climate in modifying
the yield and transpiration responses to elevated concentrations of atmospheric CO2.
Additionally, for a future climate scenario, these simulations indicated higher yields but
also higher water-use of poplar SRC, although the magnitude and direction of response
was highly spatially variable.
Oliver, Rebecca Joy
a27fa9c1-3d89-4b9b-a0d7-6f2293fe84bc
Oliver, Rebecca Joy
a27fa9c1-3d89-4b9b-a0d7-6f2293fe84bc
Finch, J.W.
00d68dba-a397-4bcb-b841-eb688760f243
Taylor, Gail

Oliver, Rebecca Joy (2010) Predicting the yield and water-use of poplar short rotation coppice under a future climate. University of Southampton, School of Biological Sciences, Doctoral Thesis, 268pp.

Record type: Thesis (Doctoral)

Abstract

Under the current climate there is significant spatial variation in the yield and water-use of
bioenergy crops such as poplar short rotation coppice (SRC). Marked changes in patterns
of precipitation and temperature are predicted globally as a result of anthropogenic climate
change. This is likely to significantly impact on the yield and transpiration of poplar SRC.
The response of poplar SRC to future climate change is unknown and represents a
significant knowledge gap in the path to a sustainable future.
This thesis used a land-surface scheme, JULES, to investigate the response of poplar SRC
yield and transpiration to the interaction between changes in atmospheric CO2
concentration and changes in climate. Empirical work generated poplar SRC specific
parameter values for use JULES. It was found that Vmax, a key model photosynthetic
parameter, was significantly lower when estimated under the assumption of infinite leaf
internal conductance to CO2. This invalidated the assumption that internal CO2 transfer has
a negligible impact on the drawdown of CO2 from ci to cc. The photosynthesis model in
JULES is based on this assumption; however, inclusion of this additional CO2 transfer
pathway in the model did not impact on the accuracy of the simulated carbon assimilation,
because the value of Vmax used in the model compensated for the presence/absence of this
pathway. It was concluded that, given the model’s high sensitivity to Vmax, it is essential to
calibrate the model with a parameter value estimated under assumptions appropriate for the
model. Further modification, calibration and validation enabled JULES to simulate the
dynamic growth and water-use of poplar under a managed SRC cycle, which is a novel
application for the model. Changes in climate were simulated using an ensemble of GCM
anomalies and atmospheric CO2 concentration was simulated using the SRES A1B
emissions scenario. Results of this work highlighted the influence of climate in modifying
the yield and transpiration responses to elevated concentrations of atmospheric CO2.
Additionally, for a future climate scenario, these simulations indicated higher yields but
also higher water-use of poplar SRC, although the magnitude and direction of response
was highly spatially variable.

Text
Rebecca_Oliver_-_final_thesis.pdf - Other
Download (5MB)

More information

Published date: 30 September 2010
Organisations: University of Southampton

Identifiers

Local EPrints ID: 188255
URI: http://eprints.soton.ac.uk/id/eprint/188255
PURE UUID: 6ddcd660-fc90-4e4f-ba97-6c61d5b3546f

Catalogue record

Date deposited: 24 May 2011 11:45
Last modified: 14 Mar 2024 03:30

Export record

Contributors

Author: Rebecca Joy Oliver
Thesis advisor: J.W. Finch
Thesis advisor: Gail Taylor

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 http://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.

×