Environmental Engineering Reference
In-Depth Information
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Figure 12.6 Total water content (mm) in the top 3 m of soil. Measured, solid symbols (control) and open symbols (rainfall
manipulation). Modelled, solid line (control) and dotted line (rainfall manipulation). Error bars are standard errors (n
4). The
vertical arrows indicate the beginning of the rainfall manipulation (Reproduced with permission from Fisher et al . 2007, Global
Change Biology. Permission Pending. Fisher, R.A., Williams, M., Lola da Costa, A. et al . (2007) The response of an Eastern
Amazonian rain forest to drought stress: results and modelling analyses from a through-fall exclusion experiment. Global Change
Biology , 13, 1-18).
=
a clear framework in which to approach the problem of
modelling the biosphere' and Moorcroft (2006) ask the
question 'How close are we to a predictive science of the
biosphere?' in the title of their paper. In the next decade,
as the various optimal approaches described here are
meshed together into a coherent whole, we may approach
something analogous to a fundamental theory of how
to model the ecology of plants, and predict their role in
shaping both the climate system and the land surface on
which we depend.
12.5 Conclusions
The challenge of predicting the future behaviour of all
global living systems, under a changing climate and
atmosphere, is immense, and our ability to make these
kinds of predictions is at an early stage. Nevertheless,
in this chapter I have attempted to demonstrate the
pervasive role of optimality approaches in deriving the
emergent behaviour of ecosystems, and their usefulness in
simplifying a problem of extreme complexity (see Cowan,
1977, Makela et al ., 1996 and van Wijk and Bouten, 2001
for additional examples). Other issues remain to be solved,
notably the fundamental interrelationship between differ-
ent plant traits, and the influence of apparently random
genetic and environmental conditions on the ability of
different plant strategies to co-exist in the same location.
Slingo et al . (2009: 825) note that 'we do not yet have
12.6 Acknowledgements
I would like to thank Drew Purves, Ian Woodward, Mark
Lomas, Nate McDowell, Mat Williams, Peter Cox, Paul
Moorcroft, Stephen Sitch and Colin Prentice for interest-
ing discussions on the topics covered in this chapter.
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