biomass of amazonian forest and greenhouse gas emissions: new data and controversies philip m....
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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
.323
.8
05
101520253035
78 80 82 84 86 88 90 92 94 96 98 00 02
Ano
Tax
a d
e d
esm
atm
ento
(103
km
2/a
no
)
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)