1. Impacts of Arctic Tundra Wildfires on Carbon Cycling Mack MC, Bret-Harte MS, Hollingsworth TN, Jandt RR, Schuur EAG, Shaver GR, Verbyla DL (2011) Carbon loss from an unprecedented Arctic tundra wildfire. Nature 475:489-492. by Catherine Deschenes

2. Overview 1.Case 2.Methods 3.Results 4.Global Connection 5.Ecosystem Connection 6.Human Connection 7.Take Home

3. ACIA (2004)

4. Anaktuvuk River Fire, Alaska Bureau of Land Management, Alaska Fire Service (2007)

5. 1039 km 2 Area burned during the fire, doubling the total burned area in the region since 1950

6. Suppl. Figure 1 (large) Suppl. Figure 3 (small)

7. ➢ 2008 field campaign to evaluate C and N released from plant and soil of moist acidic tundra ecosystems during the fire. FOCUS:

8. Methods

9. Tundra soil profile Typical soil profile in wet tundra. (2010) State of Alaska Division of Spill Prevention and Response.

10. Suppl. Fig. 4 C, D, B, A (clockwise from top left) Eriophorum vaginatum

11. Field Sampling Methods 20 burned sites 11 unburned reference sites Suppl. Fig. 5

12. Carbon Dating Figure 1

13. Results

15. 31% (+/-3%) loss of combustible C 5X the annual NPP of moist Arctic tundra

16. → Similar in magnitude to annual net C sink for entire Arctic tundra biome (avg of last 25 years) → Extrapolation from MAT ecosystem (54% of burn area) 2.1 Tg C released in atmosphere *

18. ~21% loss of combustible N 400 years of N accumulation

19. NASA Langley Research Center

20. M. Ewert

22. 30% (+/-3%) decrease in soil organic layer Burning restricted to soil surface

23. So what? : Global Connection

24. Carbon

25. 496 Pg carbon 100 Pg carbon Arctic Wikipedia Commons Native Americans: Arctic culture area. Britannica Online for Kids.

26. Removal of organic layer: → 1.Loss of permafrost insulation 2.Thawing 3.Deep C release 4.Altered ecosystem C balance + Decreased albedo by 50- 71% + Increased ground heat flux Suppl. Fig. 4C, D

27. Lower Albedo= Permafrost thawing= methane+carbon dioxide

28. So what? : Ecosystem Connection

29. Arctic fire VS other climate-driven C loss pathways Stimulation of soil decomposition Stimulation of microbial activity Ground subsidence Jenny E. Ross/Corbis (2009) Neil Shubin USGS Alaska Science Center 30-50X more rapid (+amplification of pathways?)

30. Net C transfer into the atmosphere= warming ➔ Young soil lost+high grass survivorship = renewal of topsoil lost ➔ Shift to early-successional ecosystems with low C storage Recovery Scenario 1 Shorter fire regime (80-150 yrs)

31. Positive feedback to climate warming ➔ Shrubs have lower albedo ➔ Shrubs have higher productivity and biomass, and lower soil C stocks (inefficient C sinks) Recovery Scenario 2 Grasses die, shrubs prevail *

32. Arctic fire VS Arctic greening (-’ve feedback to global warming) rapid offset of greening through release of deep permafrost C pools Scott Goetz, Pieter Beck, and Kevin Guay, Woods Hole Research Center graminoid (grass) tundra → shrub tundra or boreal forest

33. Who cares? : Human Connection

34. ➔ Air quality ➔ Physical danger ➔ Local economy ➔ Ecosystem imbalance ➔ Local climate warming ➔ Subsidence amplification(?) ➔ Transportation and lifestyle ➔ Subsistence (fishing, hunting) The global community (all of us!) ➔ Global climate warming amplification (impacts on economy, populations, food supply, ecosystem imbalances, etc.) Northern communities (some Canadians)

35. Take Home ➢ The Anaktuvuk River Fire is a manifestation of an increasing fire regime in the Arctic tundra. ➢ Arctic tundra wildfires release significant amounts of young topsoil carbon and nitrogen, decrease tundra albedo while increasing ground heat flux and facilitating permafrost thawing (which releases CH4 and CO2). ➢ Impact: Rapid C loss in the Arctic ground goes into the atmosphere, causing positive feedback for local and global climate warming.

36. Thank you! Questions?

37. Photo Sources ACIA. (2004) Carbon cycle in the Arctic. Retrieved from http://www.xplora.org/downloads/Knoppix/ESPERE/ESPEREdez05/ESPEREde/www.atmosphere.mpg.de/enid/0,55a304092d09/Zukunft_der_Arktis/Leben_in_der_Arktis_3 w0.html. http://www.xplora.org/downloads/Knoppix/ESPERE/ESPEREdez05/ESPEREde/www.atmosphere.mpg.de/enid/0,55a304092d09/Zukunft_der_Arktis/Leben_in_der_Arktis_3 w0.html Britannica Online for Kids. Native Americans: Arctic culture area. [Map/Still]. Retrieved from http://kids.britannica.com/elementary/art-192332. http://kids.britannica.com/elementary/art-192332 Bureau of Land Management, Alaska Fire Service. (2007) Anaktuvuk River Fire. Retrieved from http://hermes.mbl.edu/news/features/anaktuvuk.html. http://hermes.mbl.edu/news/features/anaktuvuk.html Compass: http://www.clipartbest.com/cliparts/ncX/8oo/ncX8ooecB.png Ecocem Ireland Ltd. Albedo diagram [graphic]. Retrieved from http://www.ecocem.ie/index.php?p=environmental&q=albedo. http://www.ecocem.ie/index.php?p=environmental&q=albedo Jenny E. Ross/Corbis. (2009) Thawing permafrost on the tundra of Wrangel Island. Retrieved from https://www.newscientist.com/article/dn27420-microbes-play-villainous- role-in-arctic-climate-change/. https://www.newscientist.com/article/dn27420-microbes-play-villainous- role-in-arctic-climate-change/ M. Ewert. Tundra. Retrieved from https://www.flickr.com/photos/mewerts/4680757869/sizes/l/in/photostream/. https://www.flickr.com/photos/mewerts/4680757869/sizes/l/in/photostream/ NASA Langley Research Center. Boreal Forest Fire. Retrieved from http://www.colorado.edu/geography/blanken/GEOG%206181%20Fall%202003/rech/pages/fire2.gif. http://www.colorado.edu/geography/blanken/GEOG%206181%20Fall%202003/rech/pages/fire2.gif Native Americans: Arctic culture area. [Map/Still]. In Britannica Online for Kids. Retrieved from http://kids.britannica.com/elementary/art-192332 http://kids.britannica.com/elementary/art-192332 Neil Shubin (photographer). Arctic Bone Nurseries. Retrieved from http://static1.squarespace.com/static/544591e6e4b0135285aeb5b6/t/566aee0240667acc25b71f0c/1449848323270/. http://static1.squarespace.com/static/544591e6e4b0135285aeb5b6/t/566aee0240667acc25b71f0c/1449848323270/ Scott Goetz, Pieter Beck, and Kevin Guay, Woods Hole Research Center[data graphic]. Greening of the Arctic. Retrieved from http://www.amnh.org/explore/science- bulletins/bio/visualizations/greening-of-the-arctic/dataset-information. http://www.amnh.org/explore/science- bulletins/bio/visualizations/greening-of-the-arctic/dataset-information State of Alaska Division of Spill Prevention and Response. (2010) Typical soil profile in wet tundra. Retrieved from https://dec.alaska.gov/spar/ppr/r_d/ttman/images/P-2-web- images/soil_profile_wet_sedge_opt_500.jpeg. https://dec.alaska.gov/spar/ppr/r_d/ttman/images/P-2-web- images/soil_profile_wet_sedge_opt_500.jpeg USGS Alaska Science Center. Arctic ground subsidence. Retrieved from http://eros.usgs.gov/lir/changing-arctic-ecosystems-mapping-long-term-changes-vegetation- important-migratory-birds-and. http://eros.usgs.gov/lir/changing-arctic-ecosystems-mapping-long-term-changes-vegetation- important-migratory-birds-and "800px-Map-Tundra" by [[user:]] - self-made from Image:BlankMap-World.png. Licensed under FAL via Commons - https://commons.wikimedia.org/wiki/File:800px-Map- Tundra.png#/media/File:800px-Map-Tundra.png. https://commons.wikimedia.org/wiki/File:800px-Map- Tundra.png#/media/File:800px-Map-Tundra.png