Logging in the Brazilian Amazon

Michael Keller

USDA Forest Service

Int’l Institute of Tropical Forestry

Logging in the Brazilian Amazon

• Extent of Logging

• Logging Techniques

• Logging Effects – Carbon

• Long Term Sustainability?

Selective Logging

Nepstad et al, 1999

Logging Centers in the Brazilian Amazon Region

1999 2000

AutoMCU Results

Asner et al., in press

Logging Approaches

• Conventional Logging

• Reduced Impact Logging

• Sustained Yield Management

• Sustainable Forest Management

Pereira et al. (2002) Forest Ecology and Management)

0%

10%

20%

30%

40%

50%

60%

70%

0 10 20 30 40 50 60 70 80

Volume Harvested (m^3)

Can

op

y L

ost

(%)

CL

RIL

CL Best Fit

RIL Best Fit

Pereira et al. (2002) Forest Ecology and Management

Logging and Carbon

• Carbon losses and recovery following logging

• Comparison of logging practices

Carbon Loss (Tg C) from Logging30 Year Integration, 15000 km2 y-1

Slow decay Fast decay

Conventional

Logging28.7 29.1

Reduced

Impact18.5 18.3

(Keller et al. in press)

Logging and Sustainability

• Biological– Water and Energy Exchange– Carbon Storage– Nutrient Cycling– Habitat and Diversity

• Production system

• Economic and social

Potential Nutrient Limitation: Selective Logging (30 m3 removed each 30 y)

[Nutrients in kg ha-1 y-1]

ElementNutrient in Soil (1 m)

Nutrient in Harvest

Stock/Removal (Years)

N 9010 56 4805P 1676 1 44701K 111 14 246Mg (*) 43 9 143Ca 63 18 105

(*) Estimated maximum Mg owing to detection limit

Data from Silver et al. 2000 and Fernandes et al. 1997

Logging and Sustainability

• Production Systems– Given realistic inputs, costs, and

benefits, at what rate can logs be selectively removed from the forest over a long period of harvest cycles?

– A critical factor in determining production system sustainability is the range of species acceptable to the market.

Keller et al. in press

CAFOGROM Model (Alder & Silva)

Logging and Sustainability

• Long term sustainability of logging depends upon protection of the forest against risks such as fire.

Susceptibility

 

 

Forest Fire

Logging

Forest Fire

Risk: Positive Flammability Feedback

Source: Nepstad et al. 2001

Conclusions

• Selective logging may release substantial carbon to the atmosphere but this is highly dependent upon area logged and the logging techniques.

• Nutrients, with the possible exception of K, Mg, and Ca, are unlikely to severely limit productivity on most soils

• With good management, current models suggest that log production may be maintained at presently profitable levels if the number of merchantable species increases in the future

Acknowledgements

• Natalino Silva, Greg Asner,

• MCT and the LBA Central Office at CPTEC

• LBA-ECO Project

• Johan Zweede and FFT

• NASA, US Forest Service, USAID, DFID, EMBRAPA

Estimation of Potential Nutrient Limitation: Selective Logging (30 m3

removed each 30 y) [Nutrients in kg ha-

1 y-1]

(*) Estimated maximum Mg owing to detection limit

Data from Silver et al. 2000, Fernandes et al. 1997, & Williams et al. 1997

ElementNutrient in Soil (1 m)

Removed per year

Rainfall Input per year

N 9010 1.88 4.16P 1676 0.04 0.34K 111 0.45 0.90Mg (*) 43 0.30 0.30Ca 63 0.60 1.32