Macadamia
Macadamia growing regions in NSW will continue to experience high to very high climate suitability under a changing climate.
Macadamia in NSW
Macadamias are a significant Australian horticultural export and the first Australian native plant to have been developed as an international food crop. In 2021-22, the NSW macadamia harvest produced over 22,000 tonnes of nuts worth $135 million. In NSW, macadamias are predominantly grown around the Northern Rivers and mid-north coast regions. Macadamias in NSW are not irrigated, except at a trial site in Dareton in south-western NSW. The map shows macadamia growing regions in NSW. Darker colours represent high production of nuts.
The key macadamia phenophases assessed in this project are flower bud initiation, flowering, nut set and size, oil accumulation and harvest. This model assumes that the crop is not irrigated and depends only on rainfall.
What is the NSW DPIRD Climate Vulnerability Assessment? ⏷
Climate change is altering the growing conditions for many agricultural commodities across NSW. Primary producers need evidence-based information about the changing climate, and the risks and opportunities it may bring.
The NSW DPIRD Climate Vulnerability Assessments are enhancing the resilience of our primary industries by providing information and data to help the sector better plan for, and respond to, climate change. They have assessed climate change impacts for extensive livestock, broadacre and irrigated cropping, marine fisheries, forestry, horticulture and viticulture, and important biosecurity risks associated with these industries to inform sound planning, risk management and adaptation decisions.
How we assessed climate suitability ⏷
Climate projections were sourced from Climate Change in Australia’s ‘Application Ready Data’. This dataset is comprised of projections from an ensemble of 8 global climate models, each presenting a plausible future climate. The models differ in their projections, giving rise to uncertainty which is reflected in the confidence statements given in brackets. Care should be taken when interpreting these results.
The Climate Vulnerability Assessment is intended to highlight potential industry- or regional-level changes. Intermediate and high emissions scenarios were used in the assessments (RCP4.5 and RCP8.5), but these are not the only future scenarios possible. The inclusion of climate variables important to the commodities production was based on published research, expert knowledge and data quality and availability.
Learn more in the Climate Vulnerability Assessment Project Framework.
Climate impacts: what to expect
Macadamia-growing regions in NSW are expected to continue to have high to very high climate suitability for growing macadamias by 2050 under both emissions scenarios.
Macadamia vulnerabilities
- During nut set and sizing there is likely to be an increase in the number of days with temperatures over 40°C in Dunoon, Clarenza, Nambucca and Bunyah (moderate to high confidence). This is likely to decrease the suitability from very high to between moderately suitable and highly suitable.
- Dareton is an irrigated trial site that is likely to be vulnerable to heat impacts in the future. Dareton is likely to have increased temperatures during oil accumulation and harvest, which will decrease suitability from suitable to sub-optimal (moderate to high confidence).
Macadamia opportunities
- The reduction in the number of days with temperatures below 10°C during nut set and size and below 15°C during oil accumulation is likely to increase suitability around the Bunyah and Herons Creek regions from highly suitable to very highly suitable during these phenophases (high confidence).
- All growing regions, except Dareton, are likely to remain highly suitable for the flower bud initiation, flowering and oil accumulation phenophases (moderate to high confidence).
Macadamia rainfall
- The macadamia model also considered potential impacts due to a reduction in rainfall. Seasonal rainfall for current growing sites will remain similar to what has been experienced in the past (moderate confidence).
Adapting to the changing climate
Adapting to extreme heat
- An increase in the number of hot days is expected to affect nut set and size phenophase. Implementing supplementary irrigation systems and increasing soil organic matter through the regular application of compost and mulch may help to alleviate the impacts during hotter periods. A transition to growing macadamias as an irrigated crop in NSW may need to be considered to offset heat impacts on this phenophase.
Where can I find the climate suitability maps?
Maps of historical and future climate suitability for horticultural commodities were produced to demonstrate where in the state a commodity is likely to thrive or else be limited by future climatic conditions. The maps are not provided on these webpages but can be found in the Climate Vulnerability Assessment Summary Report (PDF, 41425.92 KB).
Macadamia Factsheet
(PDF, 297.97 KB)
Summary Report
(PDF, 41425.92 KB)
