Fire and carbon dynamicsin grazed rangelands of northern AustraliaLeigh Hunt, Adam Liedloff and Robert Eager20th February ...
What this talk is about                   Can land managers increase aboveground carbon                   stocks through i...
Key questions                                                 vs.                             ?                  • Can a c...
Kidman Springs fire experiment   Savanna grassland-open shrubland                           Open eucalypt savanna woodland...
Experimental details                                                                       2.6 ha plots                   ...
Aboveground carbon – open woodland                24                      Fire freq P=0.01                      Fire seaso...
Aboveground carbon – grassland/shrubland                24                      Fire freq P>0.05                      Fire...
Carbon trajectory – Eucalypt woodlandPast to future                                                                       ...
Current carbon stock* (t/ha)     *includes aboveground carbon and root carbon but not soil carbon9 | Fire and carbon | Hun...
If fire excludedChange in carbon stock* (t/ha) over 50 years      *includes aboveground carbon and root carbon but not soi...
Conclusions• Changing fire management has a relatively small effect on  carbon stocks (per unit area)• Reducing fire can i...
Thank you• Aust. Centre Ecological Analysis & Synthesis         • Robyn Cowley• Dept of Agriculture, Fisheries & Forestry ...
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Leigh Hunt_Modelling above- and below-ground carbon dynamics of different fire regimes in extensive grazing systems in northern Australia

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Leigh Hunt_Modelling above- and below-ground carbon dynamics of different fire regimes in extensive grazing systems in northern Australia

  1. 1. Fire and carbon dynamicsin grazed rangelands of northern AustraliaLeigh Hunt, Adam Liedloff and Robert Eager20th February 2013CSIRO SUSTAINABLE AGRICULTURE FLAGSHIP
  2. 2. What this talk is about Can land managers increase aboveground carbon stocks through improved fire management? Two approaches: • Experimental (field) studies • Modelling2 | Fire and carbon | Hunt, Liedloff and Eager
  3. 3. Key questions vs. ? • Can a change in fire regime increase carbon stocks? • What fire regime can increase carbon stocks? • How much additional carbon can be stored in the landscape? • Is there likely to be an effect on livestock production?3 | Fire and carbon | Hunt, Liedloff and Eager
  4. 4. Kidman Springs fire experiment Savanna grassland-open shrubland Open eucalypt savanna woodland on grey Vertosol soil on red Calcarosol soil Trees/Shrubs: Terminalia, Bauhinia Eucalyptus, Hakea, Carissa Perennial grasses: Heteropogon, Dichanthium Chrysopogon, Dichanthium + Enneapogon, Brachyachne Annual rainfall ≈ 680 mm; grazed at 5 cattle/sq. km4 | Fire and carbon | Hunt, Liedloff and Eager
  5. 5. Experimental details 2.6 ha plots Three fire frequencies • every 2, 4 or 6 years (and no fire) Two times of fire • early or late dry season Two randomised blocks per vegetation type Determined biomass in • grass • litter May 2011 • coarse woody debris (twigs) (18 years) • heavy ground fuels (logs) • trees and shrub and converted to carbon5 | Fire and carbon | Hunt, Liedloff and Eager
  6. 6. Aboveground carbon – open woodland 24 Fire freq P=0.01 Fire season P>0.05 No effect of fire season 20 Freq x season P=0.023 Variable effect of fire frequency 16 Exclosure = 16.2 t C/haCarbon (t/ha) 12 Grass 8 Litter Coarse woody debris 4 Heavy ground fuels Shrub Tree 0 Early 2 Early 4 Early 6 Late 2 Late 4 Late 6 Not burnt Open Eucalypt woodland 6 | Fire and carbon | Hunt, Liedloff and Eager
  7. 7. Aboveground carbon – grassland/shrubland 24 Fire freq P>0.05 Fire season P>0.05 No effect of fire 20 Freq x season P>0.05 frequency or intensity on C stock 16 Exclosure = 5.0 t C/haCarbon (t/ha) 12 Grass 8 Litter Coarse woody debris 4 Heavy ground fuels Shrub Tree 0 Early 2 Early 4 Early 6 Late 2 Late 4 Late 6 Not burnt Open grassland/shrubland 7 | Fire and carbon | Hunt, Liedloff and Eager
  8. 8. Carbon trajectory – Eucalypt woodlandPast to future Total C Soil C (30 cm) Aboveground C Pastoralism starts Fire experiment starts8 | Fire and carbon | Hunt, Liedloff and Eager
  9. 9. Current carbon stock* (t/ha) *includes aboveground carbon and root carbon but not soil carbon9 | Fire and carbon | Hunt, Liedloff and Eager
  10. 10. If fire excludedChange in carbon stock* (t/ha) over 50 years *includes aboveground carbon and root carbon but not soil carbon10 | Fire and carbon | Hunt, Liedloff and Eager
  11. 11. Conclusions• Changing fire management has a relatively small effect on carbon stocks (per unit area)• Reducing fire can increase C, but many areas already have a low fire frequency• Changing the vegetation state (e.g. increase woody density) may be the key to getting a measurable effect on carbon stocks• Increasing carbon stocks may be the expense of pasture and livestock production11 | Fire and carbon | Hunt, Liedloff and Eager
  12. 12. Thank you• Aust. Centre Ecological Analysis & Synthesis • Robyn Cowley• Dept of Agriculture, Fisheries & Forestry • Tony Moran• Qld Dept of Agriculture, Fisheries & Forestry • Alison Haines•Aust. Collaborative Rangeland Information System • Dionne Walsh• NT Department of Resources • John Carter• Casey Collier • Bill Parton• Jodie Ward • Gary Bastin• Beverley HenryContact:Leigh HuntCSIRO Ecosystem SciencesDarwinT (08) 8944 8485e Leigh.Hunt@csiro.auSUSTAINABLE AGRICULTURE & CLIMATE ADAPTION FLAGSHIPS

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