The growing demand for nuts and the required diversification of supply are urging to identify additional zones
for hazelnut tree cultivation around the world. Given the long-term nature of the investment needed to establish
new orchards, an ex-ante evaluation of the future production trends due to global changes is critical to support
stakeholders and decision makers. With this motivation, we investigate the physiological response and the
attainable yield of hazelnut in Australia, using a process-based model. Simulations examined phenological
development, hazelnut growth processes and yield in recent past and near-future climate conditions, using an
ensemble of regional climate models bounded by four global climate models (GCMs). While the entire domain of
analysis will warm up in the next twenty years, the precipitation patterns are rather erratic across GCMs. The
effect of climate change on hazelnut farming is variable across agro-climatic zones, except in the southeast
ernmost part of Australia, where all simulations agree in predicting a yield increase ranging from 18 to 52%.
Elsewhere the hazelnut production potential varies, with some GCMs projecting yield increase and others esti
mating reductions or no significant changes. Yield increase is associated mainly with higher gross assimilation
rates, whereas decrease is related to a delay in chilling requirements fulfilment, caused by the projected increase
in minimum temperatures and to sub-optimal conditions for the photosynthetic process. Despite the need of
additional field trials to further validate the model, these results may be used by private and public bodies to
support new investment plans, and promote legislative measures aimed at encouraging hazelnut cultivation in
Figure 4. The box plots show yield in future (2020–2039) and recent past (1990–2009) climate for different agro-climatic zones. The quadrants show changes in
hazelnut yield (future – present climate) according to the climate input projected by various GCMs (marked by numbers 1, 2, 3 and 4) in different agro-climatic zones.
The diameter of the spheres represents the magnitude of increase (shown by green color) or decrease (shown by red color) in yield. The position of the spheres in X
and Y axes represent their relative position with respect to the change in temperature and precipitation.
This page is maintained by Jason Evans |
Last updated 23 January 2018