Investigating the feasibility of growing <i>Quercus</i> species in Tasmania
Creators: name: Saunders, Luke
Publisher: name: University of Tasmania
Year: 2024

description: Growing <i>Quercus</i> trees for oak barrel production would provide significant cost and marketing benefits to the rapidly growing Tasmanian whisky industry. It would also offer significant long-term environmental benefits to Tasmania into the future. This study investigates the feasibility of growing the right oak trees in Tasmania. <br>The three main species used for barrel production, <i>Quercus alba</i>, <i>Quercus robur</i>, and <i>Quercus petraea</i>, are predominately grown and coopered in the USA and Europe. Growing oak trees in Tasmania would allow the Tasmanian whisky industry to produce barrels locally, rather than sourcing them internationally or interstate. This would reduce supply risks, ensure the industry’s net carbon emissions are reduced by verifiable amounts, and enable the whisky product to be marketed as “sustainable” and entirely Tasmanian. <br>In detail, this study addresses what <i>Quercus</i> growth rates can be expected in Tasmania, over time and relative to different rainfalls. This was done by first estimating the biomass for <i>Quercus</i> trees, with a range of ages and locations, that were already growing in Tasmania. The estimates were based on a general allometric equation using tree diameter and height measurements, which were collected from field work across the state. An analogous data set was then collated from <i>Quercus</i> trees in the USA. This second data set was much larger and enabled a richer model of biomass accumulation. Using these biomass estimates, regression predictions were made to assess the effects of species, rainfall, and age on biomass accumulation. While these estimates have significant limitations, they provide a reasonable guide to the Tasmanian whisky industry about where to begin trialling <i>Quercus</i> plantings and what to expect regarding biomass. <br>After 50 years, approximately 2500kg more biomass is expected in a 1000mm rainfall zone compared to a 500mm rainfall zone, and at 100 years a difference of approximately 7000kg in biomass could be expected. This study also presents data that suggests it is reasonable to expect a diameter of approximately 75cm at 50 years, and 100cm at 100 years, though formal modelling of diameters is remains an area of future research. The study was limited by using non-localised biomass equations, urban <i>Quercus</i> trees rather than plantation forests, and a limited set of observations for the target species <i>Quercus alba</i> at different rainfalls. These limitations can be all be addressed in future research. <br>This study concludes that the three main <i>Quercus</i> species can grow well in Tasmania (they are all currently growing in Tasmania, just in small numbers) and that the local cooperage industry would be capable of producing oak barrels. By giving information on where to best locate <i>Quercus</i> trees in Tasmania, how much biomass to expect, and what limitations need to be addressed along the way, this study provides the Tasmanian whisky industry with a scientific foundation for establishing a strategic plan for oak plantation trials. The study concludes that industry can proceed with the next practical steps in their plans to trial Tasmanian oaks.