Fire Prevention as a GHG Mitigation Strategy Presented by Robert Beach, RTI International Brent Sohngen, The Ohio State University Presented at Forestry and Agriculture Greenhouse Gas Modeling Forum March 6-8, 2007 Shepherdstown, West Virginia RTI International is a trade name of Research Triangle Institute 3040 Cornwallis Road ■ P.O. Box ■ Research Triangle Park, NC Phone Fax

2 Introduction Heightened concern in recent years that intensive human intervention may have made forests more susceptible to negative effects of wildfires Evidence that fire management interventions such as prescribed burning and thinning can reduce potential hazards related to wildland fires by removing smaller materials that can act as ladders for fires Healthy Forests Restoration Act called for widespread thinning in US forests in order to help make them less susceptible to the negative effects of fires Potential for reduction in the impacts of fires suggests that additional short-term carbon emissions could lead to smaller emissions in the future if large fires are reduced Implications for carbon sequestration in fire-prone stands This is an exploratory study to examine the net carbon effects (accounting for time) of thinning using the Forest Vegetation Simulator-Fire and Fuels Extension (FVS-FFE) model

3 Study Region and Plots Representative ponderosa pine stands in the Eastern Cascades region of Oregon Region has been identified as having high build-up of fuels in forests, that could potentially lead to large-scale consequences if fires break out Ponderosa pine is the dominant species in the Eastern Cascades Plot data obtained from the US Department of Agriculture, Forest Service, Forest Inventory and Analysis

4 Models Used FVS-FFE model to assess biomass stocks, thinning options, and simulated fire effects FVS models stand dynamics, including growth of forests, mortality, and other attributes The Fire and Fuels Extension can be used to model changes in biomass in different pools over time and to simulate the effects of a fire on these pools as well as modeling residual stand growth. FFE can be used to simulate the effects of fires under different weather conditions Examined carbon storage and emission profile over a 100-year period with and without thinning and with and without a fire

5 Models (2) Fuel Reduction Cost Simulator (Fight et al., 2006) was used to estimate costs of extracting materials from thinning operations Used cut list from FVS to identify the trees that were thinned Benefits of extracting marketable materials were estimated using price data from the OR Dept of Forestry Estimated non-CO2 emissions (methane, nitrous oxide) from wildfire using EPA emission factors

6 Assumptions Thinning from below until 50 sq ft basal area Material in the range of 5"-7" is used for pulp and material >7" dbh is used for sawtimber All remaining material is assumed to be chipped and burned onsite, leading to an immediate emission Calculate carbon stock in standing biomass using factors from Smith et al (2003)

7 Representative Stand Stand Identifier => Stand "90513" Latitude; Longitude ; Sampling Weight15,968 Month/Year Measured07/2004 Elevation (ft)/Slope2105/40% Age70 ft3 per acre /site class1792/20 – 50 ft3/acre/year Trees per acre319 Crowning Index (MPH) 47.5

8 Change in Carbon Stock with Thinning

9 Unthinned Stand with Fire in 2010

10 Change in C Storage from Thinning Relative to Baseline

11 Thinning without Fire Immediate release of carbon from thinning Thinned stand slowly begins to approach carbon storage of unthinned stand over time PV of carbon change over 100 years from case study stand is tC/ha without fire PV of carbon change with fire is actually even more negative in this case at tC/ha Harvesting operation cost: $678/acre Value of wood harvested: $498/acre Net value: -$180/acre

12 Other Stands Across the 487 ponderosa pine stands in the Eastern Cascades of OR available from FIA data Over half had lower carbon emissions from fires when they had been thinned However, only in a minority of cases (<20%) were the lower emissions from fire sufficient to offset the higher emissions from thinning

13 Timing of Thinning and Fires We also examined a number of scenarios that varied the timing between thinning and the fire Initially we thought that the findings may be related to the fire occurring shortly after thinning However, it made relatively little qualitative difference in changes in carbon storage

14 Conclusions Based on our simulations and assumptions, thinning tended to result in lower discounted net carbon storage In the absence of wildfires, carbon storage is reduced relative to baseline due to the removal of carbon during thinning With wildfires, the majority of plots examined did have lower emissions if they had been thinned, but not sufficiently lower to offset the emissions from thinning

15 Future Research/Extensions Alternative fire models FOFEM, CONSUME, others Accounting for interactions with other stands Prescribed burning Quantify factors impacting effectiveness of thinning in reducing emissions Include harvesting Stochastic wildfires Examination of climate effects