Advances in Land Cover/Use Changes Advances in Land Cover/Use Changes for Biogeochemical and Hydrological for Biogeochemical and Hydrological ModelingModeling

Diógenes S. AlvesDiógenes S. Alves

Instituto Nacional de Pesquisas EspaciaisInstituto Nacional de Pesquisas Espaciais

http://www.dpi.inpe.br/dalves/Diogenes.htmlhttp://www.dpi.inpe.br/dalves/Diogenes.html

3rd LBA Conference3rd LBA Conference

Brasilia, 29 July 2004Brasilia, 29 July 2004

D. Alves, 3rd LBA ConferenceD. Alves, 3rd LBA Conference

RugendasRugendas

A tentative summary of land cover/use changes for biogeochemistry and hydrology:

1. Spatial concentration Pasture-dominated landscapes

2. Annuals in very large farms: soy beans, rice, mayse

3. Secondary vegetation decline; pasture growth4. Crop decline (small farms); pasture growth5. Cattle growing faster than pastures

Alves 2002 I.J.R.S.Alves 2002 I.J.R.S.

Spatial concentration of forest clearing:Spatial concentration of forest clearing:Landscapes increasingly pasture-dominatedLandscapes increasingly pasture-dominated

D. Alves, 3rd LBA ConferenceD. Alves, 3rd LBA Conference

Alves et al 2003 I.J.R.S.Alves et al 2003 I.J.R.S.

Deforestation, abandonment and Deforestation, abandonment and pasture-use intensification: pasture-use intensification: effects of effects of managementmanagement

D. Alves, 3rd LBA ConferenceD. Alves, 3rd LBA Conference

Distributions of cattle densities inDistributions of cattle densities inBrazilian Amazon: 1985-1995/96Brazilian Amazon: 1985-1995/96

Higher cattle densities occurred more frequently in 1995/96Higher cattle densities occurred more frequently in 1995/96

than in 1985. than in 1985. PASTURE INTENSIFICATION TRENDPASTURE INTENSIFICATION TREND

00.10.20.30.40.50.60.70.80.9

1

>=1.5 1.3-1.5

1.1-1.3

0.9-1.1

0.7-0.9

0.5-0.7

<0.5

Stocking rates (head ha-1)

Fre

quen

cy (

cum

)

1985

1995/96

D. Alves, 3rd LBA ConferenceD. Alves, 3rd LBA Conference

Alves in prep.Alves in prep.

Distributions of temporary crops inDistributions of temporary crops inBrazilian Amazon: 1985-1995/96Brazilian Amazon: 1985-1995/96

Crops represented larger fractions of land use in 1985 than in Crops represented larger fractions of land use in 1985 than in

1995/96 – 1995/96 – (almost) BASIN-WIDE RANCHING TREND(almost) BASIN-WIDE RANCHING TREND

D. Alves, 3rd LBA ConferenceD. Alves, 3rd LBA Conference

00.10.20.30.40.50.60.70.80.9

1

<3 3-6 6-9 9-12 12-15 15-18 >=18

Temp crops (% use)

Fre

quen

cy (

cum

)

1985

1995

Alves in prep.Alves in prep.

Alves in prep.Alves in prep.

Alves em prep.Alves em prep.

Crops inside and outside the “soy bean” pocketsCrops inside and outside the “soy bean” pockets

0102030405060708090

100

> 30% 25-30%

20-25%

15-20%

10-15%

5-10% < 5%

Crop area as a fraction of total area in agricultural use

Fra

ctio

n o

f to

tal c

rop

ar

ea (

%cu

m)

85 soy 95 soy

0102030405060708090

100

> 30% 25-30%

20-25%

15-20%

10-15%

5-10% < 5%

Crop area as a fraction of total area in agricultural use

Fra

ctio

n o

f to

tal c

rop

are

a (%

cum

)

85 n soy 95 n soy

0102030405060708090

100

< 100ha 100-200ha 200-500ha 500-1k ha > 1k ha

Size category

Fra

ctio

n o

f 19

95 c

rop

are

a in

siz

e ca

teg

ory

(%

cum

)

95 soy 95 no soy

Soy beans represent largeSoy beans represent largefractions of total land usefractions of total land useSoy bean implies land rotation Soy bean implies land rotation (young fallow or grass ?)(young fallow or grass ?)

D. Alves, 3rd LBA ConferenceD. Alves, 3rd LBA Conference

SummarySummary

D. Alves, 3rd LBA ConferenceD. Alves, 3rd LBA Conference

What follows from pasture use What follows from pasture use intensification ?intensification ?

– What mid/large-scale biogeochemical and What mid/large-scale biogeochemical and hydrological changes follow past use hydrological changes follow past use intensification ?intensification ?

– What will be the life cycle of pastures ?What will be the life cycle of pastures ?

– How pasture use intensification is being How pasture use intensification is being achieved ? (effects on biogeochemistry, run achieved ? (effects on biogeochemistry, run off ...)off ...)

– What are the pathways outside OLD/NEW What are the pathways outside OLD/NEW areas ?areas ?

– What are landscape configurations (forest, What are landscape configurations (forest, crops, sec vegetation, grasses) in soy-bean crops, sec vegetation, grasses) in soy-bean producing areas ?producing areas ?

– Biogeochemical and hydrological changes Biogeochemical and hydrological changes following agriculture intensification ?following agriculture intensification ?

Thank you ...Thank you ...