PROJECT NUMBER: 26/005

PROJECT TITLE: Increased Seedling Survival Rate in Ecosystem Restoration Projects on the Swan Coastal Plain

CLIENT: Rotary Club of Melville & Cottesloe Coastcare Assn

DISCIPLINE: Environmental Engineering

SUPERVISOR: Prof. Sally Thompson

PROJECT TYPE: Pro-Bono

STUDENTSHIP: $0

DEADLINE: Wednesday 16th July, via https://ceed.wa.edu.au/prospective-scholars/apply-now/

 

DESCRIPTION:

Increased Seedling Survival Rate in Ecosystem Restoration Projects on the Swan Coastal Plain.

Context

Volunteer groups, in cooperation with local government, are rehabilitating degraded natural areas by planting tube stock of a mix of locally adapted native species. Planting takes place in early winter and experience has indicated that survival of plantings can be greatly enhanced by summer watering to supplement summer rainfall, if it occurs. Plants that survive the first summer following establishment typically survive in the long-term without further intervention.

Summer watering is a resource intensive process so an irrigation strategy that ensures plant survival with the minimum irrigation frequency is highly desirable.  Currently, monthly watering has proven useful at some sites but not at others (greater frequency required) and there is uncertainty about when to commence watering following winter rains. Some understanding of soil water status through time has been established through the deployment soil water sensors in the planting zones.

A more systematic understand of irrigation requirements is needed to address the important operational decisions of:

  • when to commence watering following spring rains.
  • how much water to apply to seedling shrubs (l/plant in the locality of the Plant) and whether this varies with plant species and age.
  • how frequently to reapply in the absence of summer rainfall.
  • how long irrigation can be deferred following substantial summer rain.
  • the extent to with the watering strategy needs to be adjusted according to soil characteristics.

Given that all the sites being rehabilitated are both infertile and sandy with low water holding capability it would be advantageous to identify possible management interventions to improve conditions for plants and model whether they are likely to improve irrigation outcomes.