Forest Carbon Budgets, withexamples, mainly with a US temperate forest perspective

Linda S. Heath

USDA Forest Service

Northeastern Research Station

Durham, NH, USA

Many others: Jim Smith, Ken Skog,Rich Birdsey, FIA, etc.

Some global forest categories – a recent view

Biome Area (million km2)

Per area C change

(t C/ha/yr)

Total C pool

Tropical 17.5 0.37 553

Boreal 13.7 0.34 395

Temperate 10.4 0.34 292

Savannas/grassld

27.6 0.14 326

Source: Grace, 2004. Journal of Ecology 92:189-202.

Standards

• Standard, but relevant, definitions/protocols are important

-- carbon pools

-- vegetation types

-- land use

-- land cover

-- uncertainty

-- and others

Basic estimation of stocks and stock changes of forest C if you

have “field” inventory data • Carbon stock = Carbon/Area x Area (t ha) • C change = C stock at time 2 minus C

stock at time 1. Divide by length of period = carbon/year (t/ha/yr)

• Measured carbon stocks do not include harvests/disturbance in the sense the trees are no longer there. This amount must be added back in to the C estimate.

Another basic approach if you have field data

• Carbon change = Carbon change/Area x Area (t/ha/yr)

where carbon change may equal, for instance, biomass growth or soil respiration.

Outline/Some main points

• Carbon estimates needed for a number of reasons by decisionmakers at various scales

• Public involvement• Preferable if estimates are consistent,

transparent, verifiable, validated• Methods depend heavily on traditional forest

inventory/modeling system for projections• May need long-term projections (50 yr), decadal

trends rather than precise annual estimates

Current Approach for US Forest Carbon Budget – Part 1

• We use USDA Forest Inventory & Analysis (FIA) inventory data coupled with a modeling approach.

• Data from many field plots, collected by FIA beginning in 1950s. Area data from remote sensing.

• Several other relevant databases available.

Current Approach for US Forest Carbon Budget – Part 2

• Where FIA data are limited, develop/adopt models such as equations to estimate non-tree carbon, to a complex modeling system to track projections of C

• Model tracks carbon through harvested wood products (Skog and Nicholson 1998). Relies on data from US Dept of Commerce, other factors.

Large-scale field inventories include remote sensing for area estimation

For example, sample “points” located systematically over the “effective area” and land cover determined at the “point”

FIA Program Inventory Evolution

• In recent past, FIA periodically (5-14 years) measured all plots in a state in a 1-2 year timeframe.

• FIA recently adopted annualized inventory, with a subset of plots measured throughout the state each year. (5-7 years).

• Soil and litter layer carbon measured on subset of plots in new system.

National GHG reporting to UNFCCC

•Annual Greenhouse Gas (GHG) Emissions and Sinks Inventories (1990-present)

(US Environmental Protection Agency)- All sectors, we do forest estimates•Every 5 years, summary national communication- State Dept.

Public involvement

US forest C nonsoil stock change, 2003

0

50

100

150

200

250

1990 1992 1994 1996 1998 2000 2002

Mt

C/y

r Products

Biomass

Dead/FF

DRAFT: Smith and Heath for 2005 EPA GHG Inventory

12% of total U.S. CO2 emissions

Net C sequestration, Land Use Change and Forestry

0

50

100

150

200

250

2001

Car

bo

n (

Mt/

yr)

Lfill Yard Trim.Ag SoilsUrban TreesForest ProductsForest Ecosy.

14% of U.S. CO2 emissions

Source: EPA (2003), includes all effects. All are net sinks. No non-CO2

Other Nat’l GHG inventory reports

• Energy Information Administration (annual)

• USDA (first report 2003)

INCLUDES DETAIL AT STATE-LEVEL

Global Forest Assessment

• FAO• Estimates for1990, 2000, 2005•Consistent withvolumes, otherforest attributes

• IPCC Guidelines for National Greenhouse Gas Emissions and Sinks (1994-1996) Reference, Workbook, Reporting

• IPCC Good Practice Guidance for Land Use, Land Use Change and Forestry (2001-2003)

• IPCC Revision Guidelines (2004-2006) ? volumes. AFOLU: Agriculture, Forestry, and Other Land Use

Nations need to be consistent with the methodology in the guidelines

Conform to Everimproving International Reporting Guidelines

Montreal Process Criteria and Indicators of Sustainability

Criterion 5: Forest contribution to global carbon cycles

• Forest ecosystem C stocks & biomass pools (area x C/area)

• Forest C stock change

• Carbon in harvested wood

products

See National Report on Sustainable Forests—2003. FS-766

Conterminous US Forest C pools (Mt)

0

5,000

10,000

15,000

20,000

25,000

30,000

1953 1963 1977 1987 1997

Year

Car

bo

n p

oo

l (M

t)

Abovegrd live tree

Abovegrd standingdead tree

Understory

Down dead wood (inclstumps)

Forest floor

Belowground live tree(roots)

Belowground deadwood carbon

Indicator 26

Voluntary Reporting of Greenhouse Gases, US

(project level) • Established by Section 1605(b) of the Energy

Policy Act of 1992• ANY US-related activity that reduces emissions

of GHGs or increases C fixation can be reported

• Long and short reporting form, downloadable from web site

• Guidelines currently being updated• Administered by DOE’s Energy Information

Administration

Source: http://www.eia.doe.gov/oiaf/1605/frntvrgg.html

Carbon OnLine Estimation web tool, (beta)

Forest sector modeling system for projections of C in managed U.S. forests, ca. 2000

• TAMM – Timber Markets (Haynes/Adams)• ATLAS – Timber Inventory (Mills)• AREA (Alig)• NAPAP – Paper Markets (Ince)• TEM – Productivity/climate link

(Joyce/McGuire)• FORCARB2 – Carbon (Heath/Smith)• WOODCARB – C in HWP

(Skog/Nicholson)

Projection modeling system – Forest

Projections – Economic side

Alternative-to-base scenario comparisonsfor US forest carbon, ca. 1995

-100

0

100

200

300

400

500

600

700

1990 2000 2010 2020 2030 2040

Year

C d

iffer

ence

(Mt)

TP $110m

TP $220m

Inc recycle

Rpd recycle

Managed forest lands, US, 2008-2012 Projected avg. annual C stock change

C taken up by trees in managed forests

381.9

C released by harvesting trees -276.0

Net C taken up in Soil 52.4

Net C taken up in Floor 12.8

Net C taken up in Understory 0.7

Net C accrued in live biomass & soil

171.8

C increase in logging residue 26.1

C in products in use 39.1

C in products in landfills 51.3

C stored in products & landfills 90.4

Net C removals related to managed forests

288 +/- 15% Mt/yr

LULUCF, Submission by State Department, 2000

A summary of things to consider

• Consistent definitions (land uses, vegetation)• Scale issues (need overall inventory, but track

projects) • Boundaries create holes or double counting

(urban forests, land use change)• Boundaries are needed for activity

implementation (such as political level like State)• Identify anthropogenic effects (such as intended

or unintended enhanced or reduced growth vs growth)

• Transparency, verification, accuracy, precision, cost

Forest Carbon Components - Definitions

Down dead wood

Aboveground biomass = Live

trees + understory

Standing dead trees

Soil organic matter (1m)

Litter (Forest floor)

Belowground biomass

PRODUCTS

IN USE

Lumber

Plywood

Other panels

Solid wood

Paper

Recycled Paper

LANDFILLS

Landfill wood

Landfill paper

EMISSIONS

Waste wood, decayed or burned with no energy captured

Decay of products & landfills

BURNED FOR ENERGY

Products sent to landfills, recycling, emissions

Categories of fates of harvested wood

Forest carbon stock trends, 1953-2050

0

5000

10000

15000

20000

25000

30000

1953 1977 1997 2010 2030 2050

Fo

rest

car

bo

n (

Mt)

Forest floor

Understory

Belowground deadwood carbon

Down dead wood(incl stumps)

Abovegrd standingdead tree

Belowground livetree (roots)

Abovegrd live tree

Business as usual scenario projection, Haynes and others.

Contribution of forest products, Indicator 28

*Includes net imports*Includes net importsSource: Skog and Nicholson, 1998

0

50

100

150

200

Year

Ne

t c

arb

on

po

ol c

ha

ng

e p

er

yr

(Mt/

yr)

Emitted

Energy

Landfills

In use

1910 1920 1930 1940 1950 1960 1970 1980 1990 1997

Beginning year of annualized FIA data

Yearno data

19971998

199920002001200220032004

Compiled from FIA region web sites

Forest floor carbon accumulation, decay, and total, Southern pines: modeling approach for

older FIA data with missing pools

0

10

20

30

0 25 50 75

Years

Ca

rbo

n m

ass

de

nsi

ty (

Mg

/ha

)

Mixed or unknownage

SOURCE: Smith and Heath, 2002

accumulation

TOTAL

decomposition

Carbon OnLine Estimation web tool, (beta)

Projection modeling system – Forest

Projections – Economic side