Developing, implementing and evaluating fire management for the Gulf region

Part of FIREPLAN and Dynamic Savannas projects

Project leader: Jim Kernot, Qld Dept Primary Industries & Fisheries, Mareeba

Dense stands of breadfruit grow above the grass of the paddock

Thickening trees targeted During the early consultation phase it was decided that the project should focus primarily on two species, breadfruit (Gardenia vilhelmii Rubiaceae) and gutta percha (Excoecaria parvifolia, Euphorbiaceae). These species are most widely regarded as being problematic in the Gulf savannas. Breadfruit is a small straggly tree that grows to about 7m high and is found on gravelly soils and red earths. Gutta percha is a straggly shrub growing to 6m high and preferring heavier (clay) soils. The two species tend not to occur together. Data were also collected on the other species present at each site.

Background | Northern gulf savannas l Potential Industry Benefit | Objectives | Progress | Major achievements since mid-2002 |

Background

Many parts of the Gulf region have experienced increases in woody vegetation cover in recent decades. This thickening in the cover of trees (e.g. eucalyptus) and shrubs (e.g. gardenias, and acacias) has reduced pasture production and made cattle management more difficult. These changes have probably resulted from a combination of the effects of grazing, changes in fire regimes and climatic conditions. The strategic use of fire has the potential to reduce woody vegetation cover and allow pasture production to increase.

This project is tackling this issue by bringing together graziers from the gulf region of Queensland with fire and woodland ecologists under the umbrella of the Tropical Savannas Management CRC. It is devising, implementing and evaluating fire regimes that are appropriate for the management of Gulf savanna grazing lands.

Northern Gulf savannas

The Northern Gulf Savannas occupy an extensive area in north Queensland stretching from the south-western part of Cape York Peninsula along the southern coast of the Gulf of Carpentaria. Across this region, the increase of native trees and shrubs is a significant issue for pastoral industries. Several species have apparently increased in density sufficiently to impair livestock production and husbandry. This is a problem common to rangelands elsewhere in Australia and in other parts of the world.

An approach that has been used to counter large-scale deleterious increases in the density of woody species, whether natives or exotics, involves prescribed burning. This project is testing the use of fire to manage woody species in the Gulf savannas. It involves establishing sites in the region in collaboration with landholders, imposing prescribed fires, documenting the responses of woody species, and interpreting and communicating the results. The work commenced in 2002.

The Northern Gulf Savannas is an extensive and reasonably diverse area with variation in geology, soils and climate. These factors mean that there are many different plant communities in the Northern Gulf Region, variety that is reflected in the species of shrubs and trees that have been increasing. The project has had to focus on some of these species. The species that were targeted by this project, gutta percha and breadfruit, was decided in consultation with landholders.

Potential industry benefit

The fire project will enable beef producers in the Gulf Region to evaluate the ability of fire to manage woody vegetation thickening. The current exponential increase in woody thickening is dramatically reducing carrying capacity, animal performance and biodiversity. If the fire strategies are successful the benefits will be significant both in terms of increased productivity and profitability at the property level and also for the long term sustainability of the Gulf savannah.

The protocols developed in the Gulf region will have benefits to other regions that will be captured by collaboration with the FIREPLAN and Dynamic Savannas projects of the Tropical Savanna Management CRC.

Objectives

This project aims to develop and test recommendations for the use of fire for management of woody vegetation in the gulf savannas through a collaborative effort between landholders and woodland ecologists.

By September 2006 this project aims to:

1. Devise management guidelines and practices for the use of fire for the management of the woody vegetation and pastures of the Gulf savannas.
2. Ensure that 50% of graziers in the northern and southern Gulf savannas of Queensland are aware of these guidelines and practices for the use of fire.

Progress

Since the project began in 2002, five core sites and 12 satellite sites have been established and prescribed fires implemented at five of the core sites and seven of the satellite sites.

The possibility of burning and the fire intensities that could be achieved were affected by the fact that rainfall and consequent grass growth in 2002–03 was below average throughout much of the region.

Breadfruit and gutta percha were the two main target species at the core sites and these species showed somewhat contrasting responses to fire. Breadfruit showed a strong tendency to sprout after burning whereas gutta percha experienced significant mortality. The satellite sites encompassed a greater range of species and conditions and indicated a strong interest in the use of fire as a management tool for pastoral lands of the Gulf savannas. It is important to build an understanding of shrub responses to longer-term fire regimes rather than single fires, and of the overall population biology of woody species in these northern tropical savannas.

Major achievements since mid-2002

• Community consultative group established to guide the project and help communicate information and recommendations that arise from it.
• Sites selected in collaboration with the community consultative group and individual landholders.
• Baseline information collected including photographic records of each site.
• Treatments begun, that is, burning of sites.
• Immediate (short-term) responses to fire documented.
• Discussion with consultative group and individual landholders regarding directions and progress on the project.

This part of the paddock was left as an unburnt control. The photo opposite shows the burnt part of the paddock, and the successful reduction of breadfruit.

For information on results and recommendations click here , or on the Continuing page at the top of this page.