Apoyo en la toma de decisiones en agricultura a través de las Mesas Técnicas ...
Does growing soy destroy Amazon rainforest?
1. The role of pasture and soybean in deforestation of the
Brazilian Amazon
Elizabeth Barona – CIAT
Glenn Hyman - CIAT
Navin Ramankutty – McGill University.
Oliver Coomes – McGill University
AAG - Annual meeting 2010
Washington D.C..
2. Million hectares
Brazil’s territory ~ 850
Potential farmland 320
Cultivated land – all 60
crops
Source: Ministry of Agriculture - Brazil
“the increasing role of large-
scale agriculture and the
vast remaining potential
expansion of farming in
Amazon is causing concern
about deforestation and the
loss of ecosystem goods
and services “(Foley 2007;
Fearnside 2005; Morton
2006).
3. Deforestation in the Amazon
Agriculture
Agriculture
Roads
Roads
Cattle ranching
Cattle ranching
Logging
Logging
Fire
4. International debate
Deforestation is related to growth of the cattle industry
Cattle, not soy, drives Amazon deforestation: News Report
http://www.reuters.com/article/idUSTRE53D65C20090414.
Deforestation is related to the expanding soybean
sector
Expansion of cropland (mainly soy) into areas previously
covered by forest has become one of the main causes of
deforestation in southern Brazilian Amazon. (Morton et. al
2006)
Soybean is expanding into land previously under
pasture, and not causing new deforestation (Mueller,
2003; Brandao et.al 2005)
5. Is soybean or pasture expansion the key driver of
deforestation in the Brazilian Amazon?
• Agricultural expansion
•Soybean versus Pasture
• Data at municipality level for the entire Amazon for 2000-2006
• Census/Survey from IBGE
• Estimated annual pasture (based on livestock data)
• Deforestation from INPE
•Relationship between agricultural expansion and deforestation
•Spatial patterns, statistical relationship, and potential
spatial shift in land use cover were analyzed over the
period 2000-2006
13. Data Processing
Compiling census data on
land use for 2000-2006:
- Total harvested Area
(IBGE/SIDRA database)
- Estimated pastures (IBGE
Livestock data)
Deforestation
INPE (The National Institute for
space research in Brazil) /
PRODES (Amazon
Deforestation Project): Annual
deforested areas based on
LANDSAT Images
15. Estimated pasture area (from IBGE Livestock data):
1- Total Livestock unit
L ,t ∑i ,k A i )
T i )= N,t ) fU(,k
U( (
k
2- Livestock stocking density and linear interpolation
S( = i / i, = 2
L i) T( ) ( )t 1 ,0
Dt L , P
, Ut , t 9 0
9 6
6
S i2 −Di1
L (,0 ) L (,9 )
D 0 6 S 9
6
S it =Di1 +
L (, ) L (,9 )
D S 9
6 ( 1 ) t=0 ,0 . 2
t−6 ,
9
9 2 2 . 0
0 0 . 0
0 1, , 6
(0 −6 )
20 1
6 99
3- Estimated area under pasture for 2000-2006
T i)
L ,t
U(
P(,t
es
t i )= , t=0 ,0 ,. 2
2 2 ., 0
0 0 . 0
0 1 6
L (,t
S i)
D
25. Main findings
Consistent with other studies, soybean
expansion is replacing pasture areas
However, soybeans may have displaced pasture
further north into the forest areas, causing
indirect deforestation there.
Even if the proximate cause of deforestation
were mainly ranching, it is likely that soy
cultivation is a major underlying cause
26. CONCLUSION
Need for more large-scale studies and more field-based research to
test the land-use displacement hypothesis.
Policy makers face important tradeoffs to satisfy the demands of the
cattle and soybean industries vs conservation interests: policies that
benefit one group, will likely work to the detriment of the others.
The dynamics of land-use changes are complex, and simple-
minded policies to curb deforestation, without a full understanding of
the underlying dynamics, will not work