Project leaders: Prof Dave Gillieson, James Cook University, Cairns

Dr Garry Cook, CSIRO Sustainable Ecosystems, Darwin

Full title: The Dynamic Savanna: Assessing and managing structural change in woody vegetation in northern Australian savannas

Project 2.4.1

Rationale | Objectives | Outputs | Project team | Contact information |

Rationale

Recent legislative changes restricting tree clearing in Queensland have highlighted the need for better information about the extent and nature of woody vegetation change, and about how to manage woody vegetation structure in pastoral landscapes.

Conversely, in depopulated savanna regions, such as parts of the Kimberley in Western Australia, there is concern about the extent of detrimental thinning of woody vegetation that may be caused by the increasing frequency and extent of wildfire.

Changes have also been noted in the density of seedling trees and shrubs in the Barkly Tableland region of the Northern Territory.

Limited case studies to date have demonstrated that woody change is differential over broad regions, with thickening in some areas and thinning or no change in others. This spatial variability needs to be assessed using a set of tools that are applied consistently across the tropical north of Australia.

Each state has its own monitoring system for pastoral land, relying heavily on on-ground measurements of vegetation structure, biomass and composition. But these vary substantially in detail.

This project will attempt to survey a widespread ecological phenomenon in tropical Australia using a consistent and comparable methodology. It will also bring together a widely separated group of people interested in the ecology and productivity of woodlands, creating synergies and lasting collaborations between individuals.

Objectives

The overall objective of the project is to increase the ability of land managers and policy makers to make informed decisions regarding the management of woody vegetation dynamics in the savannas of north Australia in a series of related activities with the following individual objectives.

1. Develop a communication conduit for land managers, scientists, policy makers and other stakeholders in Queensland, the Northern Territory and Western Australia to exchange views and consider the evidence of historic changes in vegetation structure collected during the project.
   
   
2. Create a data dictionary of existing information and resources (literature, maps, photographic archives) and use this to (a) analyse spatial patterns of woody vegetation change across regions, landscapes and management regimes; and (b) identify knowledge gaps in concepts, spatial information and data across WA, NT and Qld.
   
   
3. Develop a robust tool for interpreting structural change in vegetation using aerial photography.
   
   
4. Assess woody vegetation change within case study regions in Qld, NT and WA identified in activity 2, using landscape and aerial photography. These regions will include areas in the Northern Gulf region of Qld, and the Kimberley region of WA.
   
   
5. Record local people’s experience and perceptions of woody change, in conjunction with the Northern Gulf and Kimberley case studies undertaken in activity 4.
   
   
6. Determine the production and biodiversity costs and benefits of tree thickening and mechanical thinning, using the Desert Uplands of Qld as a case study, to indicate possible costs and benefits in other tropical savanna regions, and improve trend forecasts of pastoral productivity.
7. Use ecological and economic modelling to predict and communicate the potential effectiveness of management interventions aimed at modifying woody vegetation structure, using data from regional case studies and relevant TRAPS sites in Qld.

Outputs

1. A website providing a forum for documenting evidence of change and interpretation of change from diverse perspectives.
   
2. A protocol for interpreting vegetation change from historic and recent aerial photographs
   
3. A synthesis of existing information and an analysis of gaps in knowledge of woody vegetation change across northern Australia
   
4. A photo-library (georeferenced) illustrating woody vegetation change in selected case study regions across northern Australia (including the Northern Gulf of Queensland) using photographic and oral history sources
   
5. Scientific papers and reports describing change in woody vegetation structure in terms of historical events, biodiversity and production costs and benefits, and likely responses to and costs of management options.
   
6. A protocol for interpreting historic and future trends from current vegetation structure developed using TRAPS data and Flames model of tree dynamics.
   
7. Development of a state-and-transition model describing patterns and processes underlying change in woody vegetation structure across northern Australia.
   
8. The “Dynamic Savanna”: A manuscript integrating the output from all activities and illustrated with historical landscape photographs, aerial photographs, scientific and oral history information collated for the case study regions. This will complement the book Slower than the eye can see written by Daryl Lewis for the VRD.
   
9. “Structural Changes in Savanna Vegetation” symposium presented by team members at the International Geographical Union conference in Brisbane in July 2006, to be published in a special journal issue.

Project team

Dave Gillieson, JCU
Garry Cook, CSIRO SE

Adam Liedloff, CSIRO
Rod Fensham, QEPA
Alex Kutt, QEPA
Marnie McCullough, QDPI&F
Bill Holmes, QDIP&F
Jim Kernot, QDPI&F
Steven Bray, QDPI&F
Madonna Hoffman, QDPI&F
Peta Standley, JCU
Val Speedie, Northern Gulf Resource Management Group
Michael Digby, Northern Gulf Resource Management Group
Peter Jacklyn, TS–CRC
Andrew Craig, AgWA