Tree Physiology Advance Access originally published online on July 17, 2009
Tree Physiology 2009 29(9):1081-1093; doi:10.1093/treephys/tpp049
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The carbon budget of Pinus radiata plantations in south-western Australia under four climate change scenarios
1 Forest Products Commission, Locked Bag 888, Perth Business Centre, Western Australia 6849, Australia
2 CRC for Greenhouse Accounting, Australian National University, G.P.O. Box 475, Canberra ACT 2601, Australia
3 Corresponding author (guillaume.simioni{at}avignon.inra.fr)
4 Landcare Research, Private Bag 11052, Palmerston North 4442, New Zealand
5 Forest Products Commission, P.O. Box 236, Bunbury WA 6231, Australia
 |
Abstract |
|---|
We conducted a comprehensive modelling study to estimate future stem wood production and net ecosystem production (NEP) of Pinus radiata D. Don plantations in south-western Australia, a region that is predicted to undergo severe rainfall reduction in future decades. The process-based model CenW was applied to four locations where it had previously been tested. Climate change scenarios under four emission scenarios for the period from 2005 to 2066 were considered, in addition to simulations under the current climate. Results showed that stem wood production and NEP were little affected by moderate climate change. However, under the most pessimistic climate change scenario (Special Report on Emission Scenarios A2), stem wood production and NEP decreased strongly. These results could be explained by the trade-off between the positive effect of rising atmospheric CO2 on plant water use efficiency and the negative effects of decreasing rainfall and increasing temperatures. Because changes in heterotrophic respiration (RH) lagged behind changes in plant growth, and because RH rates were increased by higher temperatures, NEP was more negatively affected than stem wood production. Stem wood production and NEP also strongly interacted with location, with the site currently having the wettest climate being least affected by climatic change. These results suggest that realistic predictions of forest production and carbon sequestration potential in the context of climate change require (1) the use of modelling tools that describe the important feedbacks between environmental variables, plant physiology and soil organic matter decomposition, (2) consideration of a range of climate change scenarios and (3) simulations that account for a gradual climate change to capture transient effects.
Keywords: carbon sequestration, CenW, modelling, net ecosystem exchange, net primary production
Received November 12, 2008; Accepted June 11, 2009
* Present address: INRA, Unité Ecologie des Forêts Méditerranéennes, UR626, Domaine Saint Paul, Site Agroparc, 84914 Avignon Cedex 9, France.