Future wood productivity ofPinus radiatainNewZealand under expected climatic changes

Abstract

The physiologically based growth model CenW was used to simulate wood‐productivity responses of Pinus radiata forests to climate change in New Zealand. The model was tested under current climatic conditions against a comprehensive set of observations from growth plots located throughout the country. Climate change simulations were based on monthly climate change fields of 12 GCMs forced by the SRES B1, A1B and A2 emission scenarios for 2040 and 2090. Simulations used either constant or increasing CO2 concentrations corresponding to the different emission scenarios. With constant CO2, there were only slight growth responses to climate change across the country as a whole. More specifically, there were slight growth reductions in the warmer north but gains in the cooler south, especially at higher altitudes. For sites where P. radiata is currently grown, and across the full suite of GCMs and emission scenarios, changes in wood productivity averaged +3% for both 2040 and 2090. When increasing CO2 concentration was also included, responses of wood productivity were generally positive, with average increases of 19% by 2040 and 37% by 2090. These responses varied regionally, ranging from relatively minor changes in the north of the country to very significant increases in the south, where the beneficial effect of increasing CO2 combined with the beneficial effect of increasing temperatures. These relatively large responses to CO2 depend on maintenance of the current adequate fertility levels in most commercial plantations. Productivity enhancements came at the expense of some soil‐carbon losses. Average losses for the country were simulated to average 3.5% under constant CO2 and 1.5% with increasing CO2 concentration. Again, there were regional differences, with larger losses for regions with lesser growth enhancements, and lesser reductions in regions where greater productivity enhancements could partly balance the effect of faster decomposition activity.

Climate change impacts and adaptation in forest management: a review

“…Incorporating the effects of rising CO 2 in models of future tree growth continues to be a major challenge. The sensitivity of projected productivity to assumptions regarding increased CO 2 was high in modelling studies of climate change impacts in commercial timber plantations in the Southern Hemisphere (Kirschbaum et al 2012;Battaglia et al 2009), and a recent analysis indicated a general convergence of different model predictions for future tree species distribution in Europe, with most of the difference between models due to the way in which this effect is incorporated (Cheaib et al 2012). Increased CO 2 has been shown to increase the water-use efficiency of trees, but this is unlikely to entirely offset the effects of increased water stress on tree growth in drying climates (Leuzinger et al 2011;Booth 2013).…”

Potential impacts of regional climate change on site productivity of Larix olgensis plantations in northeast China

“…In the context of global warming, the effect of rising temperatures on site productivity have been examined and both positive and negative impacts have been reported (Loustau et al 2005, Ollinger et al 2008, Kellomäki et al 2008, Chiang et al 2008, Latta et al 2009, Coops et al 2010, Kirschabum et al 2012. Quantifying such effect is still challenging, because the temperature simultaneously affects ecosystem processes (photosynthesis, respiration, transpiration, allocation, decomposition, etc.).…”

Growth, biomass, leaf area and water-use efficiency of juvenile Pinus radiata in response to water deficits

“…Therefore possible changes in water availability due to changes in weather with increasingly erratic seasonal rainfall and more frequent and severe drought events, coupled with increased evaporative demand brought about by higher temperatures have the potential to alter forest growth and reduce primary production (Kirschbaum and Fischlin 1996). At present, soil water deficits are common across many eastern regions of New Zealand during summer (Palmer et al 2009) and many of these areas are predicted to receive less rainfall in the future (Mullen et al 2005;Kirschbaum et al 2012).…”