This presentation by Naomi Rea of Mulga Data Services discusses the question "Is the role of fire in restoring and maintaining ecosystems overstated?"

1. the role of fire in ecological restoration:
unanswered questions
naomi rea, mulga.data@westnet.com.au

2. This presentation:
 arose from the use of fire for ecological restoration having
brought many different groups or sectors together in a space
where fire promotion overshadows discussion about risks
 highlights research areas to inform a judicious role of fire in
ecological restoration
Research that:
 resolves uncertainty
 clarifies assumptions
 leads to unambiguous language

3.  key feature of fire - generally easy to start
 training/expertise not required
 but shouldn’t detract from fire’s serious nature and impact
 whole ecosystems are effected
 fire for ecological restoration and Indigenous cultural
burning involves knowledge and understanding (why,
when, where) … … but fire is still a risky business
 fine line between destructive and restorative impact
 fires are often hard to put out
 more country is burnt than often intended

4. In this situation
 critically important that evidence underpins practise
 without informed fire management, there may be
counterproductive outcomes
 knowledge base is developing
 noticeable gaps
 opportunity to frame research questions

5. Observation 1. Using fire as a management tool involves
underlying tensions between:
 Bushfire is an EPBC listed ecologically threatening process
versus used as an ecological restoration tool
 National policy to decrease Carbon emission versus burning that
accelerates emissions (caveat: small burns can limit larger burns)
 Use of fire to control fire
 National policy to restore and increase Soil Carbon versus
burning that overall reduces Soil Carbon
 Adverse respiratory health problems from smoke versus
accepting health consequences of bushfire
 Land managers interest in fire for ecosystem management versus
emergency services interest in fire for fire suppression

6. Issue 1
As an environmental factor, fire is relatively uncommon -
lightning ignition (albeit more common in lightning prone regions).
Fire has become very much a human activity and
has become relatively common.
Prior to human evolution, fire along with
other stochastic forces (unexpected
disturbances: ie flood, drought, tsunami,
cyclone), was uncommon.
Fire as a human activity is a relatively
recent driver on the evolutionary clock.

7. As a human activity, fire is now used (or avoided) not so much
to reinstate ‘natural’ fire regimes but:
a) as a management tool and
b) to reinstate Indigenous burning practises
This presentation focusses on a subset of (a) fire as a
management tool: ie
(c) fire as a management tool in ecological restoration:
questions and research that could inform the role and merit
of fire in this situation

8. Fire as a human activity
Black Friday, January 13, 1939. There were multiple sources of ignition:
Lightning kindled some fires, but most emanated from a register of casual
incendiarists that reads like a roster of rural Australia: settlers, graziers,
prospectors, splitters, mine workers, arsonists, loggers and mill bushmen, hunters
looking to drive game, fishermen hoping to open up the scrub around streams,
foresters unable to contain controlled burns, bush residents seeking to ward off
wildfire by protective fire, travellers and transients of all kinds. Honey gatherers lit
smoking fires. Campers burned to facilitate travel through thick scrub.
Locomotives threw out sparks along their tracks. A jackeroo tossed lighted
matches alongside a track so that his boss would know where he was. Residents
hoping to be hired to fight fires set fires. Possibly a third of the documented fires
had no known cause. A self styled bushman shrugged off the multiple sources by
explaining to a royal commission that “the whole of the Australian race have a
weakness for burning.”
Pyne,S. Burning Bush. A Fire History of Australia. 1991, pg31.

9. Research Q1:
Background:
There is a great deal of both consistent and contradictory
evidence from paleoecology, palynology, archaeology,
anthropology about the extent and nature of fire in Australia
prior to human records, across recorded Aboriginal occupation
and over 200+ years of European colonization.
Objective:
 Collate and summarize the major theories supported by
evidence as a benchmark at this time, and
 to inform reasoned debate, action and research needs.

10. Issue 2
What shapes vegetation types?
 vegetation types are shaped by topography, climate,
soil (many references)
 these drivers underpin a plant’s essential requirements
(water, light, O2, CO2, nutrients, space)
seasonal variation in essential requirements is a stress that limits
productivity and performance
 stochastic or unexpected disturbances are not essential
(fire, flood, drought, cyclone, tsunami, human activity)
not necessary for plants to grow and reproduce; major disturbances
can  plant death, species loss or ecosystem change

11. Plant growth and survival
Essential and Non-essential Factors
 Some plants may have some traits that allow them to withstand some
disturbance some of the time, but this does not mean a plant needs fire
(or other stochastic disturbances) to survive.
 Ecosystem change post fire depends on fire timing, intensity,
frequency.
 one shift is from fire sensitive to fire prone vegetation
(caveat: careful judicious use of fire can protect fire sensitive vegetation)
 Non-essential forces or disturbances can leach a landscape of
essential elements and ‘take an ecosystem back to the starting line’
from where it has to re-establish and recover. This is a difficult
challenge where weeds are present and where the climate has
become less favourable.

12. Research Q2:
Background:
Fire has become part of some of the Australian landscape
as a result of human activity past and present. With regard
to this situation, there are many generalisations with
underlying assumptions that are open to interpretation.
Objective:
Investigate possible merit, fallacies or risks of
generalizations such as ‘fire is part of the Australian
landscape’ and the ‘bush needs a burn’ and develop
accurate defensible descriptions of specific aspects
of fire and Australia’s environment.

13. Issue 3
Tolerance vs adaptation
 a fire tolerant plant does not necessarily equate with a fire
adapted plant, nor a plant that needs fire
 traits may have been selected for, but that may not equate with
saying that a plant needs fire to survive, nor that an ecosystem
needs fire to function
 diet analogy – people can tolerate being starved to a certain
extent, but most people do not need to go on a diet
 Huon Pine forests (1in 2000 year fire regime) are not adapted to a
very low fire regime they just not able to tolerate fire

14. Research Q3a:
Background
Plant traits that have enabled a plant to withstand an impact
are not necessarily traits that are adaptations
Objective:
With regard to fire, distinguish between:
– what a plant needs and what it can tolerate
– a plant adaptation versus a plant trait (that enables
tolerance of a stress or disturbance)
– the impact of fire on plant species versus plant
communities versus the whole ecosystem

15. Epicormic growth
 epicormic buds are not necessarily an ‘adaptation’
 they are a trait that is a response to any serious stress
 its what eucalypts do
Seed Dormancy
 is fire or chemicals in smoke necessary to break seed
dormancy or emergence from underground structures?
 it is one cue, but there are many other cues for breaking
dormancy of seeds with hard coats:
• alternating temperatures (diurnal variation)
• frost, ice, saturation
• microorganisms causing seed coat decay
• animal or bird foraging, break seed coat

16. Research Q3b:
Background
Epicormic buds are often regarded as an adaptation to fire.
Some plants are referred to as being adapted to fire because
heat/smoke can break their seed dormancy
Objective:
1) Explore the difference between adaptation and tolerance
using epicormic shooting in eucalypts.
2) Investigate factors that break dormancy in different species
relative importance of fire or smoke as a cue
relative frequency of different factors
frequency of factors vs seed bank viability
consequences of flushing seed bank, possible exhaustion

17. Issue 4
Terminology
The term ‘adaptation’ illustrates the ambiguity of language and underlying
assumptions and how terms can be misinterpreted.
Fuel
Litter
Both refer to ‘dead and decomposing plant and organic matter’ in
natural environments. Opportunity for new language.

18. Research Q4:
Background
• Issues around language; misunderstanding, misinterpretation
• Many Indigenous languages, as compared to English, are
more diverse and better describe complexities of the
environment.
Objective
Need to clarify and define terms
Opportunity for new vocab to explain nuances

19. Issue 5
Coarse particulate organic matter
(colloquially known as fuel or litter)
 ameliorates ecosystem temperature
extremes; warm in winter, cool in summer
 water retention, carbon and nutrient storage and cycling
 prevents leaching and run-off of water, nutrients, carbon
 litter load (dwt g m2) is often less than it appears
 habitat for micro-organisms, fungi, bacteria, animals and birds

20. Coarse particulate organic matter - role of biota
Native animals and birds -
reduce litter load through:
 foraging and scratching by bush hens, bandicoots, echidna,
wombats, scrub fowl, lyre birds etc that also turns over the soil
 facilitating decomposition and recycling of nutrients for plants and
animals to use again
 controlling weeds and weed seeds by eating, scratching, trampling
 likely break seed dormancy, and facilitate seed germination and
establishment of native plants
 wallaby/kangaroo also graze grasses making some places look
like a lawn

21. Research Q5:
Background
Loss and decline of native animals in Australia.
Dead and decomposing plant material (fuel, litter) generates
concerns and mitigating actions.
Objective
Does absence of biota result in higher litter loads?
What is the role of native animals and birds in terms of:
a) litter loads
b) nutrient cycling
c) seed germination
d) weeds
Could reintroducing native wildlife reduce risk of wildfire?

22. Issue 6
Soil Carbon
 global soil carbon is twice global atmospheric C
 small changes in soil carbon flux could impact atmospheric CO2
(Zhaosheng Fan & Chao Liang 2015)
 microbial populations in soil and litter drive carbon cycle
todays litter (‘fuel’) will be tomorrows soil
 maintaining and increasing soil carbon is a major Government
policy and investment
 fire results in carbon emissions and limits carbon entering the soil
 if litter can be allowed to decompose, a cooler world

23. Research Q6:
Background
Fire results in carbon emissions and limits carbon entering
the soil. Todays litter (‘fuel’) will be tomorrows soil … if
allowed to decompose. This promotes a more resilient
healthy ecosystem and a cooler world.
Objective
What are the impacts on soil carbon from burning for
ecological restoration and how is the whole
ecosystem effected?

24. Summary - risks of using fire in ecological restoration
 managing for single species can be problematic as fire does not
discriminate, it is a blunt tool
 what helps one species may be detrimental to another
 whole ecosystems effected; large ±error  possible extinctions
 possible counterproductive outcome – weeds proliferate and
environment becomes more flammable, increasing risk of wildfire
 fire and inappropriate frequency and intensity can deplete soil
fertility, decrease infiltration and protective plant cover, increase
surface runoff, erosion ecosystem degradation, species loss, more
fire prone environment
 the more stress and disturbance from fire, the less chance an
ecosystem can recover slow process of desertification, amplified
by warmer drier climate
 eg in dry sclerophyll forest, bark took 15-25yrs to recover to pre-
burn conditions (Tolhurst 1994); tree canopy never fully recovers
(pers.obs.)

25. Summary - fire for ecological restoration
fire is all about vegetation, however there is a scarcity of plant
ecologists working in this space
Although Australia’s vegetation is shaped by topography, soil,
and climate … fire as a human activity and management tool, has
influenced vegetation in many places and has potential to
become major driver of vegetation change (desirable or
otherwise)
fire as a powerful and blunt instrument with far reaching
consequences could be ‘up the back’ as an option, ‘up front’ or
somewhere between

26. Summary - Research topics
 Test generalisations and underlying assumptions through
rigorous analysis of the literature
 Discriminate between essential vs non-essential plant
requirements
 Discriminate between adaptation vs tolerance
 Fire management to help soil carbon capture and
storage
 Expand terminology and articulate accurately