BIOMASS OF AMAZONIAN FOREST AND GREENHOUSE GAS EMISSIONS: NEW DATA AND CONTROVERSIES

Philip M. FearnsideEuler M. NogueiraBruce W. Nelson

Instituto Nacional de Pesquisas da Amazônia - INPA

1 2 3Density type

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Woo

d de

nsity

(g.

c m-³

)

1=Heartwood 2=disk 3=re-hydrated heartwood

1.36 m 33% 66% topSample Position (stem height)

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Bas

ic D

ensi

ty

Mean density values obtained from dry weight determined at 80 and 103oC, fresh volume and volume obtained through re-hydration.

Density (sampling position) N

Temperature for determination of the dry weight, mean (standard deviation), comparison of means*

80oC 103oC

Breast height (~1.36 m above the ground) 310 0.712 (0.119)aA 0.704 (0.117)aB

Top of the bole (at location of the first thick branch) 307 0.654 (0.093)bA 0.647 (0.093)bB

Arithmetic mean of the bole (density at breast height and at the top of the bole)

307 0.683 (0.102)cA 0.675 (0.101)cB

Average arithmetic of the bole (breast height, top of the bole and 2 intermediate samples)

73 0.682 (0.099)cA 0.675 (0.098)bcB

Average adjusted for the volume of the segments of the bole (breast height, top of the bole and 2 intermediate samples)

71 0.678 (0.100)abcA 0.670 (0.099)abcB

Heartwood (green volume) 149 0.775 (0.162)dA 0.766 (0.158)dBα

Heartwood (re-hydrated volume) 149 - 0.785 (0.167)dß

CORREÇÕES ÀS ESTIMATIVAS DE BIOMASSA DE EMISSÕES

Correção ao biomassa de floresta primária: -5,3%Correção às emissões líquidas comprometidas: -5,7%Magnitude da correção: -14 X 106 t C equiv. CO2

Estimativa revisada:

Emissões líquidas comprometidas em 1990: 249 X 106 t C equiv. CO2

We emphasize that the revised density values will not reduce the discrepancies between the various published estimates for forest biomass and emissions in Amazonia and for the tropics as a whole; instead, all estimates will shift in parallel to a lower level.

Achard et al. (2002). estimate of net emissions by end of 10-yr time horizon:

Biomass emission (190 Mg C ha-1 stock × 0.72 emitted) 138.6 Mg C ha-1

Uptake (5.5 Mg C ha-1 regenerated yr-1 × 0.3 [proportion regenerated.] × 10 yrs -16.5 Mg C ha-1

Net emission = 122.1 Mg C ha -1

Adjustments needed to Achard et al. calculation:

Live biomass (8% × 190 Mg C ha-1) 15.2 Mg C ha-1 (=+12.4%)

Necromass (6% × 205 Mg C ha-1) 12.3 Mg C ha-1 (=+10.1%)

Soil carbon (9.6% × 205 Mg C ha-1 long-term gross emission) 19.7 Mg C ha-1 (=+16.1%)

Regrowth over 10 years (16.5 – 7.3 Mg C ha-1) 9.2 Mg C ha-1 (=+7.5%)

Inherited uptake -5.5 Mg C ha-1 (=-4.5%)

Inherited emissions(205 Mg C ha-1 × 0.28) 57.5 Mg C ha-1 (=+47.1%)

Trace gases (15.3% × 130.5 Mg C ha-1 net emission) 35.3 Mg C equivalent ha -1 (+28.9%)

Logging unknown

Surface fires unknown

Edge effects on net increase in edge length unknown

TOTAL 143.6 Mg C ha -1 (=117.6%)

EMISSÃO LÍQUIDO COMPROMETIDO EM 1990

Fonte Emissão (milhões de t C CO2-eq.)

Porcento da emissão bruta (%)

Queimada inicial 81,2 30,4

Requeimadas 17,7 6,6

Decomposição 156,2 58,5

Gado 0,1 0,02

Solo (1 m) 11,9 4,5

Emissão bruta 267,1 100

Absorção -17,7 -6,6

Emissão líquida 249,4 93,4

B. Taxa anual de desmatamento

18,220

,4

20,4

20,4

18,2

17,319

,013

,811

,1 13,8

14,9

14,9

29,1

18,2

13,2

17,420,4

20,4

20,4

20,4

20,4

20,4

20,4

20,4 23

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101520253035

78 80 82 84 86 88 90 92 94 96 98 00 02

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DEMATAMENTO & EMISSÕES

        1988-1994 2003           

Taxa de desmatamento na Amazônia Legal (103 km2/ano)

15.2 23.8

Emissões líquidas comprometidas do desmatamento na Amazônia Legal  

(106 t CO2-equiv. C/ano)    

 Ponto médio de cenários baixo e alto de gases-traço 275 429

 Componentes do inventário Sem correções de densidade     252

 Inventário brasileiro preliminar (out 02) (Floresta amazônica) 117

  Descrepância 115%

     

 

   

COMPONENTS INCLUDED IN EMISSIONS ESTIMATES

Fearnside Houghton Achard MCT et al et al

2000 2001 2002 2002Above-ground live dicot trees X X X XPalms X 0 0 0Vines X 0 0 XOther non-tree components X 0 0 0Below-ground biomass X X X 0Necromass X partial partial 0

Soil carbon X 0 0 (X)Regrowth X X X XInherited emissions & uptake X 0 0 XTrace-gas impact X 0 0 (X)