bushfireconf 2015 - 5. where has all the fire gone? quantifying the spatial and temporal extent of...
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WHERE HAS ALL THE FIRE GONE?
Quantifying the spatial and temporal extent of fire exclusion in
Byron Shire NSW
Andy BakerWildsite Ecological Services
Overview
Fire Exclusion & Vegetation Change
GIS Analysis Methods
Results - Fire exclusion in Byron Shire
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3 Key Messages
1. Nearly half of Byron Shire’s biodiversity needs regular fire to maintain suitable habitat
Click icon to add picture2. Without regular fire,
habitats can change rapidly 3. If habitat becomes unsuitable,
localised extinctions follow
Fire Exclusion & Vegetation Change
• Worldwide phenomenon
• Two main processes:
1. Treeless ecosystems forests2. Open forest rainforest
Wet Tropics Bioregion
• 25% (>100 000 ha.) open forest/woodland rainforest since 1950’s
• 2014 study mapped 2 million ha.(Stanton et al. 2014)
Major open forest types
Time
Rainforest
Climatic Potential
Fire
Why is Change Happening?
5 years
Grassland
Time
Fire interval governs structure
20 years
Dry Sclerophyll
Forest
Time
Fire interval governs structure
100+ yearsor
No fire
Rainforest
Time
Fire interval governs structure
HeathlandGrassland
Wet Sclerophyll
ForestDry Sclerophyll
Forest
Fire-dependent vegetation
• Most species need fire for recruitment
Click icon to add pictureTreeless Ecosystems Forests
Click icon to add pictureTreeless Ecosystems Forests
Click icon to add pictureTreeless Ecosystems Forests
Click icon to add pictureTreeless Ecosystems Forests
Click icon to add pictureTreeless Ecosystems Forests
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19842012
Open Forests Rainforests
Fire-resistance threshold
• Rainforest trees not removed by fire (manual removal?)• Rainforest regrowth quickly resumes transition process after fire
Fire-suppression threshold
• Understorey unlikely to carry fire (prescribed or wildfire)• Loss of understorey diversity
Is fire-exclusion a problem in Byron Shire?
METHODS - GIS Analysis
Native Vegetation
Endangered Ecological
Communities
Coastal Wetlands
Coastal Koala Habitat
Time since last known fire
Fire Exclusion Status
Fire-intervals guidelines for
vegetation types
Mapping Time Since Last Known Fire
Step 1: Combine fire records
1974 - 2014
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Mapping Recommended Fire Intervals
Step 1: Combine vegetation datasets
Click icon to add pictureStep 2: Exclude exoticvegetation
Click icon to add pictureStep 3: Assign to vegetation formations
after Walker & Hopkins 1984; Beadle & Costin 1952
Click icon to add pictureStep 4: Determine fire relationships
Click icon to add pictureStep 5: Assign recommended fire intervals
• Specific to the region
• Recommended by Northern Rivers Regional Biodiversity Management Plan (DECC 2010)
• Factor in risk of vegetation change resulting from fire exclusion
Fire Interval Guidelines - NSW North Coast and SE Queensland
compiled from Watson 2001, Watson 2006 and Tierney & Watson 2009
Step 5: Assign fire intervals
Results
RESULTS
Fire-dependent Native Vegetation
Long-term Fire Exclusion across
Key Conservation Values
RESULTSEndangered Ecological
Communities(Fire-dependent)
Long-term Fire Exclusion across
Key Conservation Values
RESULTS Coastal Wetlands
Long-term Fire Exclusion across
Key Conservation Values
RESULTS Coastal Koala Habitat
All koala feed trees require fire for widespread recruitment
So what is their relative importance in Byron Shire?
High vs Low Frequency Fire
High Frequency Fireo listed as Key Threatening Process (TSC Act)o routinely listed as a threat in ecological assessments
Low Frequency Fireo Not listed as KTPo Rarely considered in ecological assessments
Inappropriate Fire Frequency
What about high frequency fire?
Fire-exclusion is spatialy extensive…
but by how long are thresholds exceeded?
Temporal Extent
?
No Data
species & habitat decline
10 yrs
Temporal Extent - formations
Total for Byron Shire
942Fire-dependent communities430 (46%)
Impact on Floristic Diversity
Flora species by height class
0-2m
2-5m
5-50m
600 20 40
Fire-dependent Species (%)
Hei
ght C
lass
(m)
6%
100
initial shading zone
84%
6%
10%
80
Regional Patterns:OEH analysis
What about the broader region?
ConclusionFire exclusion:• major threatening process affecting Byron Shire’s biodiversity• potentially widespread in similar regions along east coast Restoration complicated by:• encroaching trees that have become fire resistant, and • loss of flammable understorey to carry ecological burns
Further research:• What is the extent of fire-exclusion in other regions?• How quickly are critical thresholds reached in diff. ecosystems?
ReferencesBeadle, N.C.W. and Costin, A.B. (1952) Ecological classification and nomenclature. Proceedings of
the Linnean Society of New South Wales 77: 61-82.
Stanton, P., Stanton, D., Stott, M. & Parsons, M. (2014) Fire exclusion and the changing landscape of Queensland’s Wet Tropics Bioregion 1. The extent and pattern of transition. Australian Forestry, 77, 51–57.
Tierney, D., & Watson, P. (2009). Fire and the Vegetation of the Namoi CMA. Nature Conservation Council of NSW, Newtown.
Walker,J. & Hopkins,M.S.(1984). Vegetation. In R.C.McDonald, R.F.Isbell, J.G.Speight, J.Walker & M.S.Hopkins(eds). Australian Soil and Land Survey Field Handbook. pp44-67. Inkata Press, Melbourne.
Watson, P. (2001). The role and use of fire for biodiversity conservation in south-east Queensland: Fire management guidelines derived from ecological research. Nature Conservation Council of NSW, Newtown.
Watson, P. (2006). Fire frequency guidelines and the vegetation of the Northern Rivers region. Nature Conservation Council of NSW, Newtown.
Read more...
Baker, A and Catterall, C. (2015) Where has all the fire gone? Quantifying the spatial and temporal extent of fire exclusion in Byron Shire, Australia. Ecological Management & Restoration 16. doi: 10.1111/emr.12161
Ecological Management & RestorationVolume 16, Issue 2, May 2015
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Questions