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.