A Framework for Understanding Carbon in Pacific Northwest Forests

1. A Framework for Understanding Carbon in Pacific Northwest Forests Nikola Smith, Karen Bennett, and Tom DeMeo In cooperation with Beverly Law and students, College of Forestry, Oregon State University

2. Purpose and Objectives • Agencies are charged with responding to climate change • Consistently hearing from the field folks want practical guidance on addressing adaptation • We felt the first step was to look at the magnitude of carbon stored by major ecoregions, as a way to understand priorities

3. Carbon-Related Public Comments are Occurring with Increasing Frequency • What are the consequences of removing XX mmbf of timber on forest carbon storage? • How do alternatives compare from a carbon perspective? • How do prescribed burning and thinning alter fire severity, insect attacks and long-term carbon storage? • What are the impacts of grazing on carbon pools?

4. Regional Carbon Assessment Project Objectives • Provide regional guidance for responding to public comments on the impact of individual unit projects on carbon sequestration • Identification of: • The relevant magnitude of carbon by ecosystem • How this carbon is distributed in the ecosystem • The effects of different management techniques on carbon? • Where the greatest benefits will occur if the objective is to sequester carbon • What this mean for management strategies across the region?

5. Forests and Carbon - Globally • Globally forest ecosystems store more than 80% of all terrestrial aboveground C and more than 70% of all soil organic C. (Jandl et al 2007) • Globally, soils sequester 2-3 times the carbon of aboveground vegetation • Forest carbon sequestration has been recognized as an immediate strategy for reducing atmospheric CO2 concentrations. • The IPCC estimates that 12-15% of global fossil fuel emissions could be offset by improved management of terrestrial ecosystems. (IPCC 2001)

6. Forests and Carbon in the US • In the US >90% of the net carbon sink occurs on forest lands (EPA 2005) • Forests in the U.S. sequester approximately 10% of U.S. net GHG emissions annually. (Birdsey et al 2006) • In US 31-33% of C is in trees and 50-59% is in soil • Potential to increase carbon storage 40% in the next 40 years with altered forest management regimes in the US • Public forests hold 30% of the total US forest volume

7. The PNW and Northern California - a Unique Niche in the US Carbon Story Hypothetical undisturbed forest biomass carbon (USGS open file report 2009))

8. Factors Affecting Carbon Sequestration • Soil properties • Climate (temperature & precipitation) • Tree Species • Disturbance • stand age • Fire • Harvest • Management Actions

9. Relevant Carbon Pools Above Ground Below Ground • Live • Trees/shrub/forb/grass • Dead • Trees/shrub/forb/grass • Detritus • LWD • Litterfall • Animals • Duff • Animal decomposition • Microbes • Fine and coarse roots • Soil organic matter • Soil water • Charcoal • Rock (e.g. limestone)

10. Summary of carbon by ecoregion and vegetation type 5 - 7 times as much potential carbon per unit area fixed on the westside versus the eastside forests The C density in PNW OG forests is equivalent to tropical rainforest levels Large potential to sequester more carbon than is currently there Data from Beverly Law and students, College of Forestry, Oregon State University

11. Soil Carbon at 1 m depth • OR coastal soils stored 10X more C than eastern Oregon • Soils with higher total SOC stored more C deeper in the profile than soils with lower total SOC

12. Above Ground Carbon - Washington

13. Carbon Pools • Almost all pools were consistent between provinces in % TEC Mean SOC values varied widely between provinces highlighting the large biogeoclimatic variability Total below ground 29.4-50.4 % of TEC (lower than global averagea)

14. Differences in Douglas-fir between ecoregions

15. Disturbances and management actions affecting carbon • Wildfires = ~ 2.5% of the amount of fossil fuel emissions in Oregon per year (Miegs et al. 2009) • Thinning - depends on the type and location of treatment. • Some thinning on the east side reduces C more than fires associated with not thinning (Boerner 2008) • Mechanical treatment leads to more carbon fixation over time than prescribed fire or fire plus mechanical treatments (Stephens et al 2009). Beneficial effects are ecosystem-specific. • Thinning on westside – C is quickly replaced by rapid growth (Harmon 20007).

16. Good reasons to thin • Protect wildland-urban interface and firefighter safety • Improve landscape resiliency (improve fire regime condition class) • Improve wildlife habitat (e.g., spotted owl habitat in dry forests) • Improve soil moisture availability on the driest sites

17. Young stands • Perception • Young stands west of the Cascade Crest sequester more C than old growth forests because they are growing so rapidly. • This considers only tree and forest products accounting. With full carbon accounting there is a large cost to C with initial conversion of a landscape dominated by old forests – decomposition and storage matters.

18. Findings of Regional Carbon Assessment • The relative magnitude of carbon sequestration varies significantly across ecosystems • Westside a huge carbon sink of national significance and there is potential to add to it • Total above ground C in Coast Range, West Cascades, and Klamath Mountains is 5-7 times as much as in East Cascades or Blue Mountains – similar in WA • Oregon forests contain more C than Washington forests

19. Region Carbon Findings (cont.) • More than other US forested systems PNW able to store more C through management and conservation due to the larger component of C above ground • Existing carbon storage per hectare could double between 2000-2050 (Alig et al) on the west side. • Soil carbon storage is 10X higher in the Oregon Coast Range than in eastern Oregon • Carbon is more evenly distributed through the entire soil profile in western OR than in eastside soils • Dead wood in Klamath Province about 50-60% less than in Coast Range or West Cascades • Due to warmer temps and more fire

20. Conclusions • Long-term landscape scale is the correct scale to examine forest carbon. NOT project level. • If disturbance regimes become less severe or less frequent, landscapes will store more C. • If disturbances become more severe or the mean interval decreases, the landscape will store less C. • Assessments of “leakage” requires one to move beyond the landscape scale to assess unintended negative consequences of sequestration efforts

21. Where do we go from here? • Develop into a Regional white paper/GTR for guidance • Continue research synthesis of effects of various management activities on various carbon pools • Continually seek feedback and questions from the field