Oral Presentation Australian Freshwater Sciences Society Conference 2018

Growth dynamics of restoration trees (#89)

Amy George 1 , Justin Stout 1 , Fran Sheldon 1 , Jon Olley 1 , Samantha Capon 1
  1. Australian Rivers Institute, Griffith University, Nathan, QLD, Australia

Active restoration techniques rely on the planting of trees to reinstate the ecological functions provided by overstory vegetation (riparian shading, erosion control, etc). Trees species are often selected based on their historical distribution rather than their capacity to deliver functionality, such as erosion control. Here we present the findings of a growth study which compared the relative growth rates of tree species used in river rehabilitation, primarily for erosion control, in south-east Queensland. Seedling Blue gum (Eucalyptus tereticornis), River she-oak (Casuarina cunninghamiana) and Bottle brush (Melaleuca viminalis), together with a native creeping grass (Ottochloa gracilis) were grown over a 30-week period and harvested at regular intervals. Comparisons of plant components (stems, leaf cover and roots) suggest that grass species are the most likely to contribute to erosion control in the short-term, while the trees are establishing and developing their complex root structure which will provide long-term erosion control. The study highlights the need for setting multi-stage restoration targets.