Effects of climate variability and change on groundwater impacts of forestry plantations

Quantifying water use of various water consumers is an essential part of sustainable water management. Annual evapotranspiration (ET) of plantation forests often exceeds that of dryland agriculture, which in South Africa and South Australia has resulted in restrictions on plantation development. In the latter case, water licences are issued to commercial forestry plantations to account for higher ET compared to dryland pasture. Unlike irrigated crops, it is not practicable to measure water use of plantations directly and so in South Australia a set of ‘deemed’ average water use rates has been applied since 2013, based on species and depth to groundwater. Since South Australia's ‘deemed’ rates were calculated, additional plot‐scale measurements of annual ET from plantations