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Department of Forest and Ecosystem Science Disturbance, degradation, and recovery: forest dynamics and climate change mitigation Professor Rod Keenan Acknowledgements to Colin Filer, Julian Fox, Cossey Yosi and the Australian Centre for International Agricultural Research
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Department of Forest and Ecosystem Science
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Fate of Anthropogenic CO 2 Emissions (2000-2007) Canadell et al. 2007, PNAS (updated) 1.5 Pg C y -1 + 7.5 Pg C y -1 Atmosphere 46% 4.2 Pg y -1 Land 29% 2.6 Pg y -1 Oceans 26% 2.3 Pg y -1 1 Petagram = 1000 Megatonnes Global C cycle
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Department of Forest and Ecosystem Science Canadell et al. 2007, PNAS (updated to 2007) Human Perturbation of the Global Carbon Budget Human perturbation of the global carbon cycle
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Department of Forest and Ecosystem Science After Bali Two parallel processes AWGKP –sets rules for post-2012 Kyoto Protocol AWGLCA –seeks global agreement for further co- operative action, now and post-2012 –engagement with ‘heavy hitters’ (US, China, India) –includes REDD
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Department of Forest and Ecosystem Science Forests leading to Copenhagen Article 3.3 sinks – no real change Article 3.4 –Differing positions –Australia remains conservative –Baseline a continuing challenge REDD+restoration
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Department of Forest and Ecosystem Science Nabuurs et al 2007 Forestry. in IPCC 4th Assessment report Forest-based mitigation options
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Department of Forest and Ecosystem Science Garnaut potential estimates ActivityPotential CO 2 -e uptake/yr Post-1990 plantations 50 Mt by 2020 Pre-1990 eucalypt forests (cease harvesting) 136 Mt CO 2 -e for 100 years Carbon farming (plantations) 143 Mt CO 2 -e for 20 years Garnaut review 2007. Includes allowance for 100 GWPs)
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Department of Forest and Ecosystem Science Defining forest degradation Forest productivity Genes, tree vigour and quality Forest species composition compared with a ‘natural’ state Impacted soils, water, nutrients or broader landscape features Carbon stock
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Department of Forest and Ecosystem Science Forest degradation a proposed definition ‘A human-induced process that results in long-term reduction in forest carbon stocks’ forest canopy cover is sufficient for the land to be defined as forest Challenges defining ‘long-term’, extent of reduction in carbon stocks Forest area considered subject to ‘degradation’
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Department of Forest and Ecosystem Science Forest management carbon accounting principles 1.Determine the forest area subject to management 2.Identify human-induced activities 3.Assess change in carbon stock associated with these activities 4.Comprehensive accounting: –include lands subject to past or present management 5.Balanced accounting –include all changes in carbon stocks
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Department of Forest and Ecosystem Science Balanced accounting Emissions Harvest Removal of wood products Site preparation Decay of residues Fire Disease Uptake Regrowth Accounting pools Above and below ground live biomass Dead organic matter Soil carbon
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Department of Forest and Ecosystem Science Case studies Australia Native forest harvesting Wildfire Papua New Guinea Forest harvesting Shifting cultivation
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Department of Forest and Ecosystem Science CO 2 uptake in Australian Managed Native Forest Forest typeNet area (Mha) Weighted Net growth (tC/ha/yr) Total CO 2 uptake (Mt) Rainforests1.330.58 2.8 Tall Dense Eucalypt Forests 3.242.40 28.5 Medium Dense Eucalypt Forests 6.710.95 23.3 Medium Sparse Eucalypt Forests 2.030.18 1.3 Callitris Forests0.300.25 0.3 Other Forests1.290.24 1.1 TOTAL14.891.03 57.3 2007 National Greenhouse Gas Inventory Appendix 7.B
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Department of Forest and Ecosystem Science Harvest emissions = Wood removals (m 3 ) * C in roundwood (0.35) * Slash Ratio (0.9)
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Department of Forest and Ecosystem Science CO 2 losses due to harvest Net uptake of 32 to 37 Mt CO 2 per year
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Department of Forest and Ecosystem Science NF management options Further reduce removals? – Consider leakage, cost, social impacts Reduce ‘slash factor’ –greater or less utilisation? –potential impacts on CWD or regeneration success Increase growth? –Ensure fully stocked stands Further benefits generally marginal
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Department of Forest and Ecosystem Science Wildfire 2007 Australian National Greenhouse Gas Inventory
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Department of Forest and Ecosystem Science
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Australian emissions 06 and 07 2007 National Greenhouse Gas Inventory
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Department of Forest and Ecosystem Science Biomass lost in wildfire assumed to recover in 5 years
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Department of Forest and Ecosystem Science Wildfire and carbon Wildfire human induced? Frequency may increase with climate change This may change species composition and C stock Impacts can be mitigated through education, effective suppression, prescribed burning Better quantify impacts on C stocks Factoring in long-term disturbance cycles
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Department of Forest and Ecosystem Science Fire-harvest interactions Hurteau et al 2008 Carbon protection and fire risk reduction: toward a full accounting of forest carbon offsets. Frontiers in Ecology
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Department of Forest and Ecosystem Science PNG forests
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Department of Forest and Ecosystem Science PNG drivers of forest change Conversion to plantation agriculture – limited Fire –Extensive in some regions but forest recovers Mining –Localised impacts except along Fly River
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Department of Forest and Ecosystem Science Shifting cultivation 11 million hectares used by local farmers Fallow –50% > 15 yrs –43% 5-15 yrs –7% Little conversion of primary forest Allen et al. 2001. Food security for Papua New Guinea: Proceedings of the Papua New Guinea food and nutrition 2000 conference. Australian Centre for International Agricultural Research (Proceedings 99), Canberra, pp. 529-553
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Department of Forest and Ecosystem Science Timber harvesting Last 20 years average of 1.75 M m 3 logs exported 120,000 ha/year harvest area 3.2 M ha impacted C stock reduction of 44.4 t/ha 17 tCO 2 per m 3 wood removed
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Department of Forest and Ecosystem Science PNG harvest emissions
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Department of Forest and Ecosystem Science PNG regrowth uptake
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Department of Forest and Ecosystem Science PNG net emissions
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Department of Forest and Ecosystem Science Baseline option – base year Base year eg. 2000 7.6 Mt/yr
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Department of Forest and Ecosystem Science Baseline option – Base period Base period eg. 1990’s 21Mt/yr
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Department of Forest and Ecosystem Science Baseline option - BAU ?
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Department of Forest and Ecosystem Science Best options for PNG Reduce harvest rate –Long term sustainable supply –Management capacity –Accessibility, operability and market factors Reduce harvest impacts Support post-harvest regeneration and rehabilitation Encourage industry diversification
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Department of Forest and Ecosystem Science Degradation? ACTIVITY Native forest harvesting in Australia Wildfire ? Shifting cultivation in PNG Forest harvesting in PNG
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Department of Forest and Ecosystem Science Key points Definition of forest degradation still uncertain Need to adopt balanced and comprehensive accounting Need improved monitoring frameworks based on field measurement Baseline, leakage and economic and social impacts are important policy considerations
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