The impact of climate change on areas suitable for growing fruit tree crops in Australia

Fruit from tree crops such as avocados, apples, citrus and grapes are a major Australian export, generating over $1 billion in 2023. Fruit trees require specific climatic conditions for growth and fruit production, including an optimal temperature range to allow the accumulation of energy, and a winter chilling period during dormancy to encourage blossom. We examine how Australia's climate has changed over the past 80 years and is predicted to change in the future and how these changes effect areas under tree crop cultivation. This will enable farmers to make informed choices about future land use to maintain production levels and income.

We used the ERA5-Land climate reanalysis dataset to calculate the mean, minimum and maximum annual temperatures, the occurrence of extreme heat (> 35°C), and to derive agroclimatic indices relevant to some tree crops such as growing degree days and winter chill hours. Decreases in winter chill hours and increases in growing degree days are evident along the southeastern coastline around Sydney and Melbourne, and in Tasmania. Using the current and projected climatic and agroclimatic indices, we develop crop suitability maps for five major tree crops which are assessed in relation to a Western Australia tree crop map derived using Sentinel-2 data.