Carbon storage and change in Tennessee

Peter LiAssociate ProfessorTennessee Tech University

General ApproachEstimate the volume

of growing stock from forest inventories

Convert the growing stock to carbon

Derive estimates forother ecosystem

Carbon in Forest Ecosystems

Soil Carbon

Understory Forest Floor

Trees

Total CarbonStorage

Percentage of Forest Land in Tennessee, 1999

Carbon storage in the U.S. 57.8 billion tons (52.5 metric tons) of

carbon in the U.S. forest ecosystems 4 % of the carbon stored in the

world’s forest (Ajtay and others 1979) 5% of the world’s forest area On an average, the U.S. forest

contains 158,000 lbs organic carbon per acre (17.7 kg/m2)

Soil Carbon Soil carbon is closely related to

temperature and precipitation, with higher amount of soil carbon found in regions with cooler temperatures and higher precipitation.

The cooler temperatures slow the oxidation of soil carbon, while higher rainfall tends to produce more vegetation and thus fins roots and litter that are the main sources of organic soil carbon

Forest land change4 million acres less forest land from

1977 to 1987 (Waddell and others 1989)

Each year 4 million timberland acres are harvested and regenerated

4 million acres are damaged by wildfire and 2.5 million acres are damaged by insects and diseases (U.S. Forest)

Change in carbon storage

The rate of accumulation of carbon in live trees is related to the rate of the growth

The accumulation of carbon totals 508 million tons and the total removal of tree carbon (timber harvest, landclearing, and fuelwood use amounts to 391 million tons

A net of 117 million tons per year added to the storage of the carbon in the U.S.

Estimate Carbon Storage and Accumulation

Two stages-1) growing-stock volume was converted to total forest tree volume

Ratio of total volume to merchantable volume

Softwood - 1.786 and hardwood - 1.869

Forest Land in Tennessee

1989 1999 Change %

Forest Land 13,602.3 14,404.2 + 801.9 5.9

(in thousand acres)

Source of data: USDA, Forest Service, Southern Research Station

Carbon in Forest floor by type

Elm-ash cottonwood2.70 43 242 White-red-jack pine 3.74 64 134 Spruce-fir 5.91 0 19 Loblolly pine 5.18 1,334

1,401 Oak-hickory 3.29 9,477

10,148 Oak-gum-cypress 2.97 639 610 Maple-beech-birch 2.70 111 69 Non-stocked 3.29 6 97

tons/acre 1989 1999Forest area (acres)

total Floor Carbon in million tons 40.7 51.4

Carbon in Forest floor by type

Northern hardwood 16,663 8.33 0.00206 White pine 16,663 8.33 0.00206 Hemlock-sitka 14,222 7.11 0.00176 Spruce-fir 10,388 5.91 0.00146 Yellow pines 10,361 5.18 0.00128 Oak-pines 8,472 4.24 0.00105 Oak-hickory 6,582 3.29 0.00081 Bottomland h-wood 5,939 2.97 0.00073

lbs/acre tons/acre tons/m2

Understory carbon flux

2,924 lbs/acre x 14,404,000 acre =21 million tons - 1999

2,924 lbs/acre x 13,602,000 acre = 19.9 million tons - 1989

factor (2,924 lbs/acre) based on Vogt and others 1986

Total carbon in Forest Floor

4,785 lbs/acre x 14,404,000 2000 =

34.5 million tons of C - 1999

4,785 lbs/acre x 13,602,000 2000 = 32.5 million tons of C - 1989

data based on factor derived from Birdsey, 1992

Correction for the factor in Tennessee

40.7 million tons carbon was obtained from the 1989 forest land area in Tennessee - 1.3602 million acres

40.7 mil tons/1.3602 mil acres x2000 lbs/tons = 5984.4 lbs/acre -forest floor in Tennessee

Volume of growing stock and specie ratio

1989Growing stock in million cubic feetType S-wood H-wood Total Rs RhPine 1419.9 316.7 1736.6 0.82 0.18Oak-pine 834.2 873.3 1707.5 0.49 0.51Oak-hickory 555.6 11431.7 11987.3 0.05 0.95Oak-gum-cypress 78.6 967.7 1046.3 0.08 0.92Elm-ash-cottonwood 3.4 50.6 54 0.06 0.94Maple-beech-birch 3.5 147.3 150.8 0.02 0.98

1999Type S-wood H-wood Total Rs RhPine 2419.9 443.8 2863.7 0.85 0.15Oak-pine 1982 1094.4 3076.4 0.64 0.36Oak-hickory 16523 15928 32451 0.51 0.49Oak-gum-cypress 1149 1024 2173 0.53 0.47Elm-ash-cottonwood 350 350 700 0.50 0.50Maple-beech-birch 30.6 28.9 59.5 0.51 0.49

Data: USDA, Forest Service

Factor to calculate Total Biomass (tons C) from volume of Merchantible Timble (ft3)

Forest Type

TVMVtotal volume toMerchant volume

F: Factor to convert tree volume to Carbon (lbs)

Specie TypeRatio (R)

total

PinesOak-hickoryOak-pineMaple-beech-birchElm-ash-cottonwoodBottomlandhardwood

1.7861.7861.7861.786

1.786

1.786

1.8691.8691.8691.869

1.869

1.869

16.9017.7617.3315.25

12.48

12.03

19.8219.8219.8217.99

18.65

14.45

0.6940.3080.6940.308

0.012

0.004

0.3060.6920.3060.692

0.988

0.996

0.01460.05580.01490.0144

0.0107

0.0122

S H S H S H

Carbon in Forest Trees

TVMV= total volume to merchant volume (1.786 for softwood, 1.869 for hardwood

F = factor to convert tree volume to carbon (lbs)

V= tree volume in million cubic feet

2

1

6

1i jijijij VFTVMV

i = 1, Softwood, 2= hardwoodj=pines, oak-hickory, oak-pine, maple-beech-birch, elm-ash-cottonwood, and bottomland hardwood

Carbon in Trees,1989 and 19991989Growing stock in million cubic feet ConversionType S-wood H-wood Total Rs Rh TVMVs TVMVh Fs Fh to tons CarbonPine 1419.9 316.7 1736.6 0.82 0.18 1.786 1.869 16.9 19.82 0.000405 25.98Oak-pine 834.2 873.3 1707.5 0.49 0.51 1.786 1.869 17.76 19.82 0.000405 35.04Oak-hickory 555.6 11432 11987 0.05 0.95 1.786 1.869 17.33 19.82 0.000405 321.77Oak-gum-cypress 78.6 967.7 1046.3 0.08 0.92 1.786 1.869 15.25 17.99 0.000405 24.72Elm-ash-cottonwood 3.4 50.6 54 0.06 0.94 1.786 1.869 12.48 18.65 0.000405 1.20Maple-beech-birch 3.5 147.3 150.8 0.02 0.98 1.786 1.869 12.03 14.45 0.000405 2.92

Total 411.631999 ConversionType S-wood H-wood Total Rs Rh Carbon TVMVh Fs Fh to tons CarbonPine 1976 444 2420 0.82 0.18 1.786 1.869 16.9 19.82 0.000405 36.24Oak-pine 888 1094 1982 0.45 0.55 1.786 1.869 17.76 19.82 0.000405 41.87Oak-hickory 596 15928 16524 0.04 0.96 1.786 1.869 17.33 19.82 0.000405 446.10Oak-gum-cypress 125 1024 1149 0.11 0.89 1.786 1.869 15.25 17.99 0.000405 26.62Elm-ash-cottonwood 0.3 350 350.3 0.00 1.00 1.786 1.869 12.48 18.65 0.000405 8.10Maple-beech-birch 1.7 28.9 30.6 0.06 0.94 1.786 1.869 12.03 14.45 0.000405 0.58

Total 559.52Data: USDA, Forest Service

Average Carbon per acre (tree)

for 1989, 411.63 million tons/13.6 million acres * 2000 lbs/ton = 60,524 lbs/acre

for 1999, 559.2 million tons/14.404 million acres x 2000 lbs/tons = 77,645 lbs C/acre

compared to 57,694 lbs/acre from Birdsey, 1992

Soil Carbon

69,089 lbs C/acre x 13.602 million acres/2000 lbs/ton = 469.87 million tons - 1989

69089 lbs C/acre x 14.404 million acres/2000 lbs/ton = 497.58 million tons - 1999

Carbon Storage and Change

Total Carbon Storage in Forest Ecosystem (million tons)1989 1999 Change % Change %Change per Year

Forest Soil 470 498 28 6% 0.6%Understory 20 21 1 5% 0.5%Forest Floor 41 51 10 24% 2.4%Trees 412 560 148 36% 3.6%Total 943 1130 187 20% 2.0%

Carbon Storage Change

0

100

200

300

400

500

600

Forest Soil Understory Forest Floor Trees

0%

5%

10%

15%

20%

25%

30%

35%

40%

1989

1999

% Change

Average Carbon Storage

Carbon in Trees (lbs/acre)Birdsey/Koch 1989 1999 % Change/yr57,694 60,524 77,645 2.83%

Total Carbon per acreBirdsey/Koch 1989 1999 % Change per year134,491 138,656 156,900 1.32%

Reference/Data Grant, R.F. Izaurralde, R.C. Nyborg, >,, S.S., Soberg, E.D.,

and Jans Hammermeister, D. 1997. In: Soil Processes and the Carbon Cycle. R. Cal, J.M. Kimble, R.F. Follett, B.A. Stewart (Eds), Pp. 527-547. CRC Press, Boca Raton.

Birdsey, R.A. Carbon Storage and Accumulation in United States Forest Ecosystems, USDA Forest Service, General Technical Report W0-59, 1992

Vissage J.S. and Duncan K.L. Forest Statistics for Tennessee Counties-1989, USDA Forest Service Southern Forest Experiment Station, RB-SO-148

Schweitzer, C.J. Forest Statistics for Tennessee, 1999, USDA Forest Service, Southern Research Station, SRS-52

Detailed Landcover-Tennessee, Tennessee Wildlife Resources Agency, 2000, contact: Jeanette Jones

Land Cover and Land Use - 1983, US Fish and Wildlife Service, Cookeville, Tennessee, 2000

Summary Carbon sequestration process in

Tennessee is updated and computed The total Carbon storage in Forest

Ecosystem in Tennessee is increasing over the last decade.

Urbanization process reduced the potential of carbon sequestration

Updated factors used in computing the carbon accumulation in Forest

Acknowledgement

Financial assistance from Tennessee Tech University for presenting the findings in AGU meeting in San Francisco is greatly appreciated.