Background

The Burnett Mary region is located in overlapping climate zones with tropical influences to the north, predominantly subtropical lowlands in the south, and temperate climatic conditions in the Bunya Mountains to the south west of the region.  The area also spans two biogeographic regions: the Southeast Queensland Bioregion in the east, and the Brigalow Bioregion in the west.  See map.  The region’s variety of climates, soils, vegetation, topography, and historical management by indigenous peoples and others make it a region of great ecological diversity.

Remnant vegetation covers about 45% of the region, with most of this existing in public estate lands and a large proportion in State forest.  Areas with very high biodiversity values within the region include the Fraser Island / Cooloola Coast, Cania Gorge, Bunya Mountains, Kinkuna / Woodgate, Bustard Bay, Bulburin, Conondale / Kilkivan range and the Burrum-Cherwell catchments.  These areas have large tracts of relatively intact remnant vegetation, providing habitat for numerous threatened species and serving as major bastions for biodiversity.

The Burnett Mary region contains the State’s highest number of priority species requiring urgent attention through improved conservation practices.  Communities under threat include semi-evergreen vine thicket, Brigalow, and littoral rainforest.  Key threatening processes to biodiversity in the region are a result of ongoing reduction in the extent and condition of native habitat.  Clearing for agriculture and the continuing demand for land for urban growth, particularly along the coast, continue to place pressure on an already fragmented natural environment.

The intrusion of threatening processes6 further threatens the condition and extent of terrestrial ecosystems.  Unchecked threatening process6 incursions adversely alter ecosystem function, reduce primary industry productivity and profitability, and seriously limit the long-term sustainability of natural systems.  They can increase the risk of fire, change the structure of vegetation, increase costs for infrastructure maintenance and reduce the amenity of recreation areas.  The coupling of effective threatening process6 control with appropriate land management is critical to maintaining or improving terrestrial ecosystem function.

Altered fire regimes have also been identified as a significant threat to priority native flora and fauna in the Burnett Mary Region.  Examples include grassland decline in the Bunya Mountains associated with low fire frequency, and declining condition of rainforest boundaries caused by too frequent fire associated with invasive pasture grasses.  Projected climate change scenarios raise the spectre of a more intense “fire weather future”, posing an overarching threat to the structural integrity of many of the region’s terrestrial ecosystems.  Extended drought periods, reduced Spring rainfall and more frequent “fire weather” periods, overlain on the inherent temperature tolerances of species and ecosystems, will challenge the current extent, structure and integrity of terrestrial ecosystems.

Improving the condition and relative connectivity of our native vegetation and freshwater ecosystems is the best way to increase their resilience to long and short term environmental changes.

Asset Description

Terrestrial ecosystems of the region were delineated using 1:1 Million Broad Vegetation Group (BVG) Classification. Further delineation by geographic area for several Broad Vegetation Groups was necessary to capture the discrete differences in Asset sensitivity and adaptive capacity in the region.

The following table identifies collections of like BVG’s, a detailed description of the constituent assets in Background paper – Plants and Animals.

Asset Codes BVG Collection
TE 2a, TE 3a1, TE 3a2, TE 4a1, TE 4a2, TE 4b, TE 5a1, TE 5a2, TE 7a Rainforests, Scrubs
TE 8a, TE 8b1, TE 8b2 Wet Eucalypt Open Forests
TE 9a, TE 9f, TE 9g1, TE 9g2, TE 9h1, TE 9h2, TE 10a, TE 10b, TE 11a, TE 12a, TE 13c1, TE 13c2, TE 13d Eastern Eucalypt Woodlands to Open Forests
TE 16a1, TE 16a2, TE 16c Eucalypt Open Forests To Woodlands on Floodplains
TE 17a, TE 17b, TE 18a, TE 18b Eucalypt Dry Woodlands on Inland Depositional Plains
TE 20a Callitris Woodlands – Open Forests
TE 21ab, TE 22a Melaleuca Open Woodlands on Depositional Plains
TE 24a, TE 25a Other Acacia Dominated Open Forests, Woodlands and Shrublands
TE 28a, TE 28d, TE 28e, TE 29a, TE 29b, TE 32b Other Coastal Communities or Heaths

Potential Climate Futures

The vulnerability of each BVG (terrestrial ecosystem asset) to relevant climate change exposure indicators – temperature increases, increasing lengths of dry periods, decrease in Spring rainfall and more frequent and intense fires – was assessed by an expert panel.  The Background paper – Plants and Animals details the vulnerability assessment method.  An order of the ten most climate change vulnerable TE assets, under the RCP8.5 2090 scenario, was identified.  The map, Plants and Animals displays these vulnerable communities, as well as all other mapped BVGs.  In general, the assessment revealed that elevated closed rainforests and scrubs, associated wet sclerophyll forests, Brigalow communities on clay substrates and some floodplain woodlands were most vulnerable.  A further meeting of vegetation/ecosystem experts considered the nature of threats and protection of each of these assets.  Recommendations regarding their future management were made and factored into refinement of the vision and targets for this theme, along with implementing actions to help deliver the 2020 targets.

Note – the provisions derived from analysis of vegetation communities in this section have not considered Land Zone 2 vegetation types, those found on coastal dunes.  Such systems are considered in the plan’s Coastal and Marine asset section.

Strategic Direction

Healthy vegetation communities (terrestrial and aquatic), associated landscape processes and habitat values are maintained across the region.

2020 Target (Extent)

PA1. The extent of the region’s vegetation communities will be maintained at the 2013 baseline.

Desired Outcome

Opportunities for linking and enlarging vegetation community fragments with larger habitat patches are pursued, to increase the extent of vegetation communities.

2020 Target (Diversity)

PA2. The diversity of vegetation communities will be maintained at 20134 levels and opportunities for sustaining species’ populations, particularly those that are threatened5, will be improved.

Desired Outcome

  • No loss of regional biodiversity
  • Survival prospects for threatened species and communities are improved
  • Regeneration of “regrowth” areas to “remnant” status.

2020 Target (Landscape function)

PA3. Landscape function is enhanced through activities that address threatening processes6.

Desired Outcome

On-ground activities are implemented that address threats to the “health” of vegetation communities, including:

  • fragmentation and small patch size of vegetation communities
  • inappropriate fire regimes
  • invasive, exotic species
  • inappropriate land management systems.
4 Most recent version of BVG coverage to be released by the Herbarium and pertinent species spatial data, including biodiversity planning assessments
5 Listed under NCA / EPBC or Regional Ecosystems scheduled as endangered or of concern under VMA
6 A process that threatens, or may threaten, the survival, abundance or evolutionary development of a native species or ecological community