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LC-05 Abstract

Anthropogenic Landscape Changes and the Dynamics of Amazonian Forest Biomass

William F. Laurance — James Cook University (US-PI)
Rita Guimaraes Mesquita — Instituto Nacional de Pesquisas da Amazonia -INPA (SA-PI)


Our study addresses the LBA Ecology theme of carbon storage and exchange. We propose a

combination of field studies and computer modeling to estimate above-ground biomass in

continuous forest, forest fragments, and secondary forests of different types through time

and to relate these measures to remote sensing data from LANDSAT TM images for a modified

landscape in central Amazonia. Our objective is to develop a predictive model of carbon

stocks and their dynamics based on readily identifiable landscape features derived from

remote sensing imagery.


existing data from a long-term phyto-demographic project in the Amazon, coupled with

additional fieldwork, to estimate standing biomass in continuous forest plots and forest

fragments. This unique data set includes over 57,000 marked trees in 66 permanent, one-

hectare plots. These plots were surveyed initially more than 15 years ago, and have been

re-censured 2-5 times to estimate tree growth, mortality, damage, and recruitment, thereby

allowing us to monitor the dynamics of Amazonian tree communities and their intrinsic

carbon stocks at a landscape level (ca. 1000 km2). In this project, we will

re-survey tree communities in all 66 permanent plots. Lianas will also be included in

these surveys because recent results suggest that they could exhibit markedly increased

growth rates in response to increasing atmospheric CO2.

BIOMASS DYNAMICS OF REGENERATING FORESTS: We will develop biomass estimates for

different ages and types of secondary forest, in order to assess the rate of carbon

accumulation in fallow and regenerating lands following different successional

trajectories. Both species-specific allometric equations and true destructive sampling in

the field will allow the calculation of biomass estimates.

LANDSCAPE ANALYSIS: We will use detailed time-series remote sensing imagery of our

extensive (20 X 50 km) research landscape in the central Amazon to produce a model of

carbon dynamics as a function of identifiable landscape features (e.g., fragment size and

shape, and the area and age of secondary forests). The procedure for the satellite

analyses will be the following:

1. Register all the thematic mapper images to a high resolution UTM map with precision

GPS data from the field

2. Image to image registration will then be performed using the base map as the

reference base

3. An unsupervised cluster classification will be run in conjunction with a

knowledge-based classifier to classify the 20 x 50 km proposed study area into the 11

categories above

4. The resulting classification will field checked and corrected where necessary for

each of the satellite images used in this study, based upon reference data collected in

the field using GPS, photographs, field notes, and aerial overflights

5. The resulting classification will be "vectorized" into an ArcInfo coverage

and further edited where necessary

6. Additional GIS layers of topography, river courses, roads, and biological

information, including biomass estimates for each time frame, will be co-registered with

the satellite data and included into the GIS

7. The resulting combination of the satellite classification(s) from

1982-1984-1986-1988-1990-1992-1994-1996 will be used to extrapolate the biological data

spatially over the landscape.

Products of Proposed Research

The proposed research will provide the following products within the three years of


1. Estimates of above-ground biomass stocks and their dynamics in primary tropical

rainforest, in rainforest patches of varying sizes, and in different types and ages of

secondary forests.

2. A spatially explicit model that links temporal changes in the BDFFP landscape to

predicted aboveground biomass stocks and their dynamics of above-ground biomass.

3. A working model of biomass dynamics and landscape features, available for testing in

other Amazonian landscapes.

4. Training Brazilian graduate students and research professionals (in-country

capacity- building).

Research Team Responsibilities

  • William F. Laurance: Biological Dynamics of Forest Fragments Project, Biomass estimates

    in forest fragments and continuous forest reserves

  • Jim Tucker: Remote Sensing imagery processing

  • Rita Mesquita: Biomass Dynamics of Regenerating Forests

  • G. Bruce Williamson: Biomass Dynamics of Regenerating Forests


Work will be carried out at the INPA reserve site "Biological Dynamics of Forest

Fragments Project".


  • 1980-1996 biomass estimates in forest fragments and forest reserves: June 1998 - June


  • Field re-census of plots: June 1998 - June 2000

  • Secondary forest estimates of biomass: June 1998 - June 1999


Last Updated: Jan 6, 1999

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