Pyrogenic CarbonPyrogenic Carbon as a Component of as a Component of the C cycle in Boreal Forests?the C cycle in Boreal Forests?

Caroline Preston, Werner Kurz, Caroline Preston, Werner Kurz, Greg Rampley,Greg Rampley,PFC VictoriaPFC VictoriaMartin Simard, U of Wisconsin Madison Martin Simard, U of Wisconsin Madison Charlotte Norris, U of Alberta, EdmontonCharlotte Norris, U of Alberta, Edmonton

FireFire is the main disturbance in Boreal regions – is the main disturbance in Boreal regions – major loss of ecosystem productivitymajor loss of ecosystem productivity

JGR 2007

Role of Pyrogenic Carbon in Boreal RegionsRole of Pyrogenic Carbon in Boreal Regions

-ecological role? -ecological role? -direct role of charcoal??-direct role of charcoal??-importance of disturbance -importance of disturbance

remove thick organic layerremove thick organic layerchange vegetation successionchange vegetation succession

-long-term sink of highly stable soil C?-long-term sink of highly stable soil C?

-soot emissions into atmosphere-soot emissions into atmosphere

Boreal Pyrogenic C – as produced in the wildBoreal Pyrogenic C – as produced in the wild

Managed Biochar Soil AmendmentManaged Biochar Soil Amendment Boreal Wild CharBoreal Wild Char

Production efficiency High Low (5% ?)

Transformation High Lower (more H, O, N, S, smaller clusters)

Recalcitrance Higher Lower

Mineral Soil Protection Optimized Limited – mostly on or above surface

Environment Warmer, Cold (Frozen), aerobic anaerobic (peatlands)

What is BC What is BC (Pyrogenic C)?(Pyrogenic C)?

Approaches to BC AnalysisApproaches to BC Analysis

-visual char/charcoal (black, floats)-visual char/charcoal (black, floats)-resistance to thermal or photooxidation -resistance to thermal or photooxidation (with many variants)(with many variants)-NMR (also with photooxidation)-NMR (also with photooxidation)-BCPA (production of benzenepolycarboxylic acids)-BCPA (production of benzenepolycarboxylic acids)

For this effort, we just have to live with the results of For this effort, we just have to live with the results of this rich variety! For field samples, effects often balance this rich variety! For field samples, effects often balance out.out.

How much PyC is produced in boreal fires?How much PyC is produced in boreal fires?

How much PyC is in boreal soils?How much PyC is in boreal soils?

Production of charcoal and BC from forest biomass burning, on a mass or carbon basisProduction of charcoal and BC from forest biomass burning, on a mass or carbon basisBased on 500 g C kg-1 for biomass and 700 g C kg-1 for char, conversion of 1% of biomass to char on a mass basis is equivalent to 1.4% conversion on a C basis.Conversely, 1% conversion on a C basis corresponds to 0.71% on a mass basis.

Region/site/cause of fireRegion/site/cause of fire MethodMethod Char/BC productionChar/BC production SourceSource

(a) Boreal Forest

Boreal experimental crown fires (Siberia, Norway, Sweden, Canada)

Visual char collected in surface traps

235-932 kg/ha(ca. 2% fuel conversion)

3 studies

Siberia, Yenisey R., Scots pine, mainly surface fire

BPCA in forest floor 61 kg BPCA-BC/ha (0.7% forest floor C conversion)

Czimczik et al. (2003)

(b) Other Forest Regions

Virginia, USA, cutting and slash-burning loblolly pine

Visual char in forest floor

7400 kg/ha Schiffman and Johnson (1989)

Germany, Neolithic slash-and-burn emulation, deciduous forest

Visual char >1mm 7020 kg/ha (fuel conversion, 4.8% as mass, 8.1% as C)

Eckmeier et al. (2007)

Amazon; Forest clearing; cut, dried 2-3 months, burned, as per local practice.

Visual char on soil or partially burned biomass

1600-6400 kg C/ha(1.3-2.9% fuel C conversion)

4 studies

Yellowstone National Park, after intense crowning wildfire

Visual char on CWD 6400 kg/ha(8% CWD conversion)

Tinker and Knight (2000)

Charcoal or BC Stocks – boreal typically <3000 hg/ha or <5% SOCCharcoal or BC Stocks – boreal typically <3000 hg/ha or <5% SOC

Region/site Method BC or Char Quantities Reference

(i) Forest floor/humus only

Sweden, lake islands, 1-350 y after fire Visual char 984-2074 kg/ha Zackrisson et al. (1996)

Canada, southern Quebec, 75 y after fire,

Visual char >2mm 343-1295 kg/ha Bélanger et al. (2004)+pers comm

Canada, northwestern Quebec, 51 sites, 24-2533 y after fire

Visual char > 2mm 0.1-3516 kg/ha Lecomte et al. (2006)+pers comm

Alaska, ca. 100 y black spruce A horizon

BC by CTOx 400-2590 kg BC/ha Kane et al. (2007)

(ii) Mineral soil or whole soil profile

Siberia, Yenisey R., Pinus sylvestris fire chronosequence study

BC by BPCA ≤ 3.5% of SOC in organic layer (up to 720 kg BC/ha)0.01-0.02% of SOC (1.6-2.5 kg BC/ha) for 0-100 cm mineral

Czimczik et al. (2005)

Siberia, Yenisey R., forest tundra BPCA (no conversion factor used)

0.6-3.0 % of SOC (highest in raised bogs on permafrost)220-34,400 kg BC/ha

Guggenberger et al. (2008)

France, Alpine conifer forests Visual char >0.4 mm 10-30,000 kg/ha Carcaillet and Talon (2001)

Non-forest sites

Switzerland, 23 monitoring sites, some forests, 0-10 cm

Thermal OX 1-6% of SOC, median 2% Bucheli et al. (2004)

Ontario, CT/NT, 0-20 cm per 5 cm Visual char in light fraction

6-13% of SOC Murage et al. (2007)

From Charlotte’s Just-completed MSc thesisFrom Charlotte’s Just-completed MSc thesis

Charlotte Norris

Location and major ecological zonations of jack pine sites on the Boreal Forest Transect Case Study (BFTCS)(BFTCS)

Fire 11 C Content 3.93 kgmFire 11 C Content 3.93 kgm-2-2Fire 4 C Content 2.60 kgmFire 4 C Content 2.60 kgm-2-2

Fire 29 C Content 3.33 kgmFire 29 C Content 3.33 kgm-2-2 Fire 91 C Content 3.09 kgmFire 91 C Content 3.09 kgm-2-2

CPMAS 13C NMR spectra from jack pine fire chronosequence

Soil organic Soil organic carbon chemistry carbon chemistry in the jack pine in the jack pine boreal forest.boreal forest.C. Norris, MSc. Thesis. U of Alberta (Sylvie A. Quideau, Jagtar S. Bhatti)

Forest Floor A Light Fr (<1 g/cc)

STOJP

CPMAS 13C NMR spectra from mature jack pine sites

FF, light Fr.

Soil organic Soil organic carbon chemistry carbon chemistry in the jack pine in the jack pine boreal forest.boreal forest.C. Norris, MSc. Thesis. U of Alberta (Sylvie A. Quideau, Jagtar S. Bhatti)

-150-100-50050100150200250300350400(ppm)

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79 y 91y STOJP

Black Spruce Forests, Flat Topography,Black Spruce Forests, Flat Topography,Without Fire - Paludification Without Fire - Paludification

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Pinus banksiana

Picea mariana - low severity

Picea mariana - high severity

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Pinus banksiana

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Picea mariana - high severity

Peat profile, 95 y since firePeat profile, 95 y since fire40 cm40 cm

Jack Pine: 19 High, 1 Low, Median 25 g/mJack Pine: 19 High, 1 Low, Median 25 g/m22

Plot 49 Jack Pine 155y High - 22.96 g/m2

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Jack Pine: 19 High, 1 Low, Median 25 g/mJack Pine: 19 High, 1 Low, Median 25 g/m22

Plot 67 Jack Pine 229 y High - 28.2 g/m2

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Black Spruce: 15 High, Median 36 g/mBlack Spruce: 15 High, Median 36 g/m22

Plot 4 Black Spruce 53y High - 38.1 g/m2

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Black Spruce: 15 High, Median 36 g/mBlack Spruce: 15 High, Median 36 g/m22

Plot 62 Black Spruce 52y High - 36.1 g/m2

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Black Spruce: 12 Low, Median 51 g/mBlack Spruce: 12 Low, Median 51 g/m22

Plot 13 Black Spruce 24y Low 48.87 g/m2

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Plot 68 Black Spruce 149 y Low - 61.7 g/m2

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Black Spruce: 12 Low, Median 51 g/mBlack Spruce: 12 Low, Median 51 g/m22

Jack Pine - By Monolith High Intensity Except 24y

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What happens to PyC?What happens to PyC?

How long does it last in soil?How long does it last in soil?

Is it a long-term C sink?Is it a long-term C sink?

How long does PyC last in Boreal Soils?How long does PyC last in Boreal Soils?

Our prevous best guesstimate: half-life around 5-10 ky, Our prevous best guesstimate: half-life around 5-10 ky, depending on environment – but a portion could go on depending on environment – but a portion could go on decade or century timescalesdecade or century timescalesThe high values are biased by the survivors – maybe k The high values are biased by the survivors – maybe k = 0.001 y= 0.001 y-1-1 is realistic (compare 0.0033/y for slow soil C is realistic (compare 0.0033/y for slow soil C in CFS model)in CFS model)

How is PyC lost from boreal How is PyC lost from boreal soils?soils?

CO2

Microbial decomposition

Chemical oxidation

Photo-oxidation

Consumption by another fire

SOM, humics, DOC

Incorporating Charcoal/BC into theIncorporating Charcoal/BC into theC Budget Model of the Canadian Forest SectorC Budget Model of the Canadian Forest Sector

-a very preliminary attempt!-a very preliminary attempt!

Poor Site, Regular Intensity

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Black Carbon/Charcoal - Regular Intensity Fire

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Research needs to model soil PyCResearch needs to model soil PyC

-data on soil/peat stocks by any method (look for -data on soil/peat stocks by any method (look for paleochar unpublished data)paleochar unpublished data)-production and stocks in non-soil pools, esp. CWD-production and stocks in non-soil pools, esp. CWD-BC analysis of Mackenzie DOC and Beaufort sediments -BC analysis of Mackenzie DOC and Beaufort sediments -incubations and field decomp studies-incubations and field decomp studies-more attention to abiotic processes-more attention to abiotic processes-comparison of BC methods relevant to wildfire -comparison of BC methods relevant to wildfire charcoalcharcoal-interdisciplinary approaches needed -interdisciplinary approaches needed

-ecological effects -separate direct charcoal effects -ecological effects -separate direct charcoal effects from vegetation succession and forest floor removalfrom vegetation succession and forest floor removal

Some Research Needs for CBISome Research Needs for CBI

-Agronomic (including forestry, pasture) – rates, -Agronomic (including forestry, pasture) – rates, changes in soil properties, effects on yields, etc.changes in soil properties, effects on yields, etc.

-chemical characterization of char (elemental analysis, -chemical characterization of char (elemental analysis, including H, nutrients, NMR, PAHs, metals)including H, nutrients, NMR, PAHs, metals)

-how do we track BC/PyC/biochar added to soil? -how do we track BC/PyC/biochar added to soil?

-we need some standard materials and interlab -we need some standard materials and interlab comparisionscomparisions

Guggenberger et al., GCB 2008, Forest tundra, SiberiaGuggenberger et al., GCB 2008, Forest tundra, Siberia

BPCA BC = 0.6 to 3.0% of SOC220-34 400 kg BPCA BC/ha (especially preserved in permafrost)

Export of BPCA-BC in streamwater (mostly DOC) during ice-free period, June 1-Oct. 31/03

Total DOC export: 2.6 g/m2 (1143 kg from catchment)

BPCA-BC export: 3.9% of DOC (44 kg) 0.1 g BPCA-BC/m2, mostly during snowmelt!mostly during snowmelt!

In 100 y, loss = 10 g BPCA-BC/m2, similar to estimated productionsimilar to estimated productionBC contributes to TOC in Arctic sedimentsBC contributes to TOC in Arctic sediments

For comparison - Moore, GBC 2003For comparison - Moore, GBC 2003Sites near Thompson MN, DOC export in streams, approx 3 g/m2

Elmquist et al.Elmquist et al. 2008. Pan-Arctic patterns in BC sources….Global Biogeochem. Cycles 22, GB 2018

Elmquist et al. 2008Elmquist et al. 2008Annual Fluxes of Soot BC from Arctic Rivers (Tg)Annual Fluxes of Soot BC from Arctic Rivers (Tg)

TotalTotal FossilFossil ModernModern ProductionProductionPan-BorealPan-Boreal 0.2020.202 0.1590.159 0.0420.042 0.380.38EurasiaEurasia 0.1010.101 0.0760.076 0.0270.027 0.310.31North AmNorth Am 0.1010.101 0.0850.085 0.0150.015 0.070.07

(Gustaffson CTO method)(Gustaffson CTO method)

Global Wildfire Emissions 1960-2000Global Wildfire Emissions 1960-2000(Schultz et al. 2008)(Schultz et al. 2008)2078 Tg/y (1410-3140, higher in more recent years)2078 Tg/y (1410-3140, higher in more recent years)

Pan-Boreal Emissions - TgPan-Boreal Emissions - Tg(Balshi et al. 2007,1996-2002, simulations without CO(Balshi et al. 2007,1996-2002, simulations without CO22 effect effect

(Charcoal/BC = 5%, Atmos. Soot 0.15%)(Charcoal/BC = 5%, Atmos. Soot 0.15%)

(Tg)(Tg) TotalTotal Char/BCChar/BC SootSootPan-BorealPan-Boreal 255255 12.712.7 0.380.38

EurasiaEurasia 209209 10.410.4 0.310.31

North AmNorth Am 45.745.7 2.32.3 0.0690.069 CanadaCanada 32.332.3 1.61.6 0.0480.048 AlaskaAlaska 13.713.7 0.690.69 0.0210.021

Boreal Soil CBoreal Soil C Global: C in boreal peat and soil – 600 PgGlobal: C in boreal peat and soil – 600 PgCanada: C in peat – 113 Pg, in forest soil 65 Pg, Total 178 (Bhatti)Canada: C in peat – 113 Pg, in forest soil 65 Pg, Total 178 (Bhatti)BC (est. as 5% SOC): 5650 Tg in peat, 3250 Tg in forest (8900 Tg)BC (est. as 5% SOC): 5650 Tg in peat, 3250 Tg in forest (8900 Tg)

Canada: Boreal BC/Char Production: 1.6-2 Tg BC/y?Canada: Boreal BC/Char Production: 1.6-2 Tg BC/y?In 10,000 y = 16,000-20,000 Tg C – how much has been lost?In 10,000 y = 16,000-20,000 Tg C – how much has been lost?

Compare Canada - All Forest and Wetland Soils – 164.5 Pg C, Compare Canada - All Forest and Wetland Soils – 164.5 Pg C, litter inputs 900 Tg C/y (Ju and Chen 2008)litter inputs 900 Tg C/y (Ju and Chen 2008)

How does BC/charcoal production compare with annual transfer How does BC/charcoal production compare with annual transfer of litter to stabilized pool?of litter to stabilized pool?

How do BC/charcoal pools compare with SLOW pool of DOC How do BC/charcoal pools compare with SLOW pool of DOC (Dead Organic C) in C budget models? (k = 0.0033/y, Q10=0)(Dead Organic C) in C budget models? (k = 0.0033/y, Q10=0)

By Monolith - Black Spruce High Intensity

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By Monolith - Black Spruce Low Intensity

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Van Krevelen plot for Molar H/C and O/C - Van Krevelen plot for Molar H/C and O/C - Biomass to GraphiteBiomass to Graphite

50y50yThin FF 10-15 cmThin FF 10-15 cm

Fresh WoodCP

Charred CP

CharredBD

Scots Pine wood fromScots Pine wood fromSiberian wildfireSiberian wildfireJuly 2000July 2000

Southern Old Jack Southern Old Jack Pine SitePine Site

Jack Pine Upland Site – Mineral Soil Fractions

Eluviated Dystric Brunisol

Ae <63 μm, 49% of soil C112-165 ppm – 15% of NMR

Bm <63 m, 53% of soil C

BC?BC?

Wardle et al., Science 320, p. 629, 2008. 10-year field Wardle et al., Science 320, p. 629, 2008. 10-year field incubation of humus, lab-produced charcoal and mixincubation of humus, lab-produced charcoal and mix

C loss – around 0.5 mg/g/yC loss – around 0.5 mg/g/y(charcoal also enhanced humus decomposition)(charcoal also enhanced humus decomposition)