Early growth of jarrah (Eucalyptus marginataDonn ex Smith) on rehabilitated bauxite minesites in south-west Australia

Summary The development of jarrah (Eucalyptus marginata Donn ex Smith) from direct seeding and the growth of jarrah planted as seedlings, in response to a number of rehabilitation treatments, were investigated on bauxite minesites in south-west Australia. Seedlings in these experiments grew faster than young jarrah in unmined forest. Sixty three percent of the jarrah established from seed had developed into saplings with a mean height of 3.28m after 55 months. Sixty six percent of the jarrah planted as seedlings had developed into saplings with a mean height of 3.07m after 47 months. Most of the jarrah displayed good form with 58% of seeded jarrah and 44% of planted jarrah, which were 3m or taller, having only one stem to a height of 2m. Tree heights, the proportion of plants that developed into saplings, and the proportion of trees with more than one stem increased in treatments which increased the amount of resources available to the trees or decreased competition, such as applying diammonium phosphate, reducing tree density, or planting a less vigorous understorey. Both direct seeding and planting seedlings are suitable methods for establishing jarrah on bauxite minesites. With the present emphasis of restoring conservation values on rehabilitated mines, direct seeding is the preferred method of jarrah establishment as it creates a more natural distribution of trees.