Carbon storage and change in Tennessee Peter Li Associate Professor Tennessee Tech University

General Approach Estimate the volume of growing stock from forest inventories Convert the growing stock to carbon Derive estimates for other ecosystem

Carbon in Forest Ecosystems Soil Carbon Understory Forest Floor Trees Total Carbon Storage

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/m 2 )

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 change  4 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 and hardwood

Forest Land in Tennessee Change %  Forest Land13, , (in thousand acres) Source of data: USDA, Forest Service, Southern Research Station

Carbon in Forest floor by type  Elm-ash cottonwood  White-red-jack pine  Spruce-fir  Loblolly pine5.181,334 1,401  Oak-hickory3.299,47710,148  Oak-gum-cypress  Maple-beech-birch  Non-stocked tons/acre Forest area (acres) total Floor Carbon in million tons

Carbon in Forest floor by type  Northern hardwood16,  White pine16,  Hemlock-sitka14,  Spruce-fir10,  Yellow pines10,  Oak-pines 8,  Oak-hickory 6,  Bottomland h-wood 5, lbs/acre tons/acre tons/m 2

Understory carbon flux  2,924 lbs/acre x 14,404,000 acre =  21 million tons  2,924 lbs/acre x 13,602,000 acre =  19.9 million tons 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  4,785 lbs/acre x 13,602,000  2000 = 32.5 million tons of C 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 million acres  40.7 mil tons/ mil acres x2000 lbs/tons = lbs/acre -forest floor in Tennessee

Volume of growing stock and specie ratio

Factor to calculate Total Biomass (tons C) from volume of Merchantible Timble (ft3) Forest Type TVMV total volume to Merchant volume F: Factor to convert tree volume to Carbon (lbs) Specie Type Ratio (R) total Pines Oak-hickory Oak-pine Maple-beech -birch Elm-ash- cottonwood Bottomland hardwood S H

Carbon in Forest Trees  TVMV= total volume to merchant volume (1.786 for softwood, for hardwood  F = factor to convert tree volume to carbon (lbs)  V= tree volume in million cubic feet i = 1, Softwood, 2= hardwood j=pines, oak-hickory, oak-pine, maple-beech-birch, elm-ash-cottonwood, and bottomland hardwood

Carbon in Trees,1989 and 1999

Average Carbon per acre (tree)  for 1989, million tons/13.6 million acres * 2000 lbs/ton = 60,524 lbs/acre  for 1999, million tons/ 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 million acres/2000 lbs/ton = million tons  lbs C/acre x million acres/2000 lbs/ton = million tons

Carbon Storage and Change

Carbon Storage Change

Average Carbon Storage

Reference/Data  Grant, R.F. Izaurralde, R.C. Nyborg, >,, S.S., Soberg, E.D., and Jans Hammermeister, D In: Soil Processes and the Carbon Cycle. R. Cal, J.M. Kimble, R.F. Follett, B.A. Stewart (Eds), Pp 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 , 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.