Australia used eucalyptus to fight soil salinity but the geology prevented it

Eucalyptus cladocalyx ‘nana’. Image Credit: ERA Nurseries Australia planted eucalyptus trees to fight rising soil salinity, hoping that thirsty, deep-rooted vegetation could help control the groundwater processes behind the problem. A long-running experiment in south-western Australia later showed that the effects of such plantations were more complicated than simply planting trees and waiting for the land to recover. Researchers established a mixed eucalyptus plantation above a saline seep in 1976 and monitored how the trees affected groundwater levels and salt movement for 15 years. The study found clear signs that the plantation used more water than nearby crops and pasture, while groundwater conditions also changed over time. Yet the trees did not stop the saline seep as researchers had hoped. Published in ‘Agricultural Water Management,’ the research offers a revealing look at why tree planting can influence groundwater and salinity without necessarily solving the underlying problem everywhere it is tried.How did eucalyptus plantations change groundwater and soil salinity in AustraliaThe study examined a plantation established on about 12% of a small farm catchment. The trees ...