Growth of tree species on ploughed mounds near a saline seep

The growth of nine tree species near a salt seep was evaluated over a six year period at Bakers Hill in south western Australia. The main criterion of growth was crown size on the assumption that large crowns and associated leaf area maximise rainfall interception and evapotranspiration, thus reducing groundwater level and secondary salinisation in the vicinity. Greatest height, crown volume and survival were achieved by Eucalyptus occidentalis grown near the surface seep area, and by E. sargentii and E. astringens grown on the seep. In all characteristics measured, the three species were significantly better ( P < 0.05) than the control ( E. wandoo), and they are recommended for plantations in similar environments of Western Australia. Differences in growth between species are discussed in relation to cool-wet and warm-dry seasons and in relation to waterlogging and salinity levels of the soil A horizon.