# Presentation: 499934

## Ecological Accomplishments of the Large Scale Biosphere-Atmosphere Experiment in Amazonia 

Michael Keller
USDA Forest Service,
International Institute of Tropical Forestry

Representing the LBA-ECO Science Team

- Michael Keller
- USDA Forest Service,
- International Institute of Tropical Forestry
- Representing the LBA-ECO Science Team

- Long Bloody Arguments(LBA)

## Large Scale Biosphere-Atmosphere Experiment in Amazônia (LBA)

**Amaz****ô****nia**

**The Amazon region of South America as viewed by MODIS on NASA’s Terra satellite. **

**LBA is an international, multi-disciplinary cooperative research program led by Brazil.  NASA leads the U.S. participation in LBA, working in close partnership with the Brazilian leaders and scientists.**

**LBA is the largest cooperative international scientific project ever to study the interaction between tropical forests and the atmosphere.**

**climatological, ecological, biogeochemical, and hydrological functions of Amaz****ô****nia**** **
**impact of land use change on these functions****	**** **
**interactions between Amaz****ô****nia and the Earth system**** **

**LBA research is focused on producing new knowledge about the:**

## LBA Carbon Studies

- Setting the Scene (1997)
- Regional Carbon Fluxes and Land Use
- Secondary Forests
- Wetlands
- Old Growth Forests
- Beyond Phase III (Post 2008)

## The Longest Bloodiest Argument

- Is the Amazon region currently a source or a sink for atmospheric carbon dioxide?

## Land Use Change in Amazonia

- Land use change in the tropics accounted for ~ 20% of the anthropogenic C emissions in the 1990’s (1.6 out of 8 Pg C y-1)

- Tropical forest clearing, degradation, and re-growth are major sources of uncertainty in the global carbon balance.

**Land Use Change in Amazonia**

## Brazil routinely measures rates of deforestation

**1986**

**1997**

**Central Rondonia, Brazil:  Forest clearing 1986-1997**
**(Landsat imagery, forest=red) **Courtesy TRFIC–MSU

## Brazilian and US research teams have developed an early warning system for deforestation events greater than 25 ha based on NASA MODIS data and processing techniques developed through LBA research

- Courtesy:  R. DeFries

**Notes:**
ADD LBA CITATIONS – SEE DEFRIES PRESENTATION

## Quantification of the carbon losses from deforestation still admits large errors

- Source:  Houghton et al. *Nature *2000

## Saatchi et al. Global Change Biology (in press)

- Saatchi et al. *Global Change Biology (*in press*)*

- New maps of biomass combining ground based and remotely sensed data have the potential to greatly improve our estimates of the deforestation source of CO2

## Uncertainties related to “cryptic deforestation” raised by Nepstad et al. (1999)

- Selective logging...

- ... wildfire

- Photo:  M. Cochrane

- photo Dan Nepstad

## 12,000-20,000 km2 y-1 logging

- 12,000-20,000 km2 y-1 logging
- 16,000-23,000 km2 y-1 deforestation

- Asner et al. *Science *2005

## Condition and Fate of Logged Forests?

- Logging intensity (defined by remotely sensed forest canopy gap fraction) is high throughout most of the study region. Area-integrated gap fractions exceed 10% (high intensity) more than 75% of the time.
- The carbon lost through logging reaches 0.03 Pg y-1 excluding the effect of regeneration.

- Asner et al. *PNAS* 2006

## 32% of logged forest is cleared after 4 years

- Asner et al. *PNAS* 2006

## Distinguishing Fate of Deforestation with Phenology

**Distinguishing Fate of Deforestation with Phenology**

- Courtesy: R. DeFries

## Fate of deforestation from 2001-04 from MODIS phenology

- ~20% of deforestation in Mato Grosso is direct conversion of forest to cropland

## NEE vs PAR for Different Land Covers

- Fitzjarrald et al. (unpublished)

**forest**

**bare soil**

**pasture (dry)**

**pasture (wet)**

**rice**

**soybeans**

**Notes:**
Light curves (NEE vs PAR) for the pasture wet (circles), pasture wet (triangles), bare (pluses), rice (crosses), and soybean (diamonds) periods.  The thick curve represents the light curve for the nearby primary and cut forest sites (personal communication, Drs. Scott Miller and Scott Saleska).  During the bare soil period, we hypothesize that the NEE should approach the soil respiration rate (since there is no vegetation) even during the daytime.  Nearly constant efflux of CO2 from the soil is indeed observed during daytime for the bare soil period, indicating that the soil respiration rate is approximately constant.  Even though the nearby forest presents a bigger uptake during the daytime, it is offset by the high respiration rate thus the annual carbon uptake will be less than this site (Miller et al, 2004, Sakai et al, 2004).

## Secondary Succession Is a Small Carbon Sink

**g**

**Secondary Succession Is a Small Carbon Sink**

- Potential biomass accumulation in regrowth

- 1-25
- 26-50
- 51-75
- 76-100
- 101-125
- 126-150
- 151-175
- 176-200
- 201-225

- AGA (Mg ha-1)

## Biomass Distribution in Altamira, Para Based on the Landsat Data

- D. Lu *IJRS* (2005)

- Biomass Distribution in Altamira, Para Based on the Landsat Data

## Nitrogen and Phosphorus Co-limit Growth of 2a Forest

- Davidson et al. *Ecol. Appl.* 2004

**Nitrogen and Phosphorus Co-limit Growth of 2****a**** Forest**

## Amazon Basin below 500m:  wetlands 17%, uplands 83%

**Amazon Basin below 500m:  wetlands 17%, uplands 83%**

**Lowland Amazon Basin **
**(<500 m asl) (5.19 million km****2****)**

**Methane Emission    22 Tg C y****-1**

## CO2 Flux from Waters of the Central Amazon  

- Richey et al. *Nature* 2002

-  **1.2  ± . 3 Mg C ha****-1**** y****-1**** (basin ~ .5 Gt y****-1****)**
**Net forest uptake: ~ 1 to ?? Mg C ha****-1**** y****-1****)**

**CO****2**** Flux from Waters of the Central Amazon**

## Potential CO2  Sources

**Isotopic Constraints**

- Source: Mayorga et al. *Nature* 2005

## Measured Carbon Fluxes in Amazonia

- Ometto et al. 2005

## Annual Carbon Balance

- With nighttime correction

- Range of annual sums using
- different hardware/software
- techniques

- Range of mean annual carbon
- exchange based on tree surveys
- over 16 years

- Without nighttime correction

- CO2 SOURCE

- CO2 SINK

- Miller et al., *Ecological Applications* (2004)

- Importance of proper correction of eddy covariance estimates

- LBA: Goulden/Rocha/Miller

## If a tree falls in the forest....

- Keller et al. *Science *1996

- “Who would risk siting a 45 m tower and $100,000 of delicate instrumentation near a senescent emergent?”

## Tree Mortality Probability Distribution Function 

- The temporal and spatial distribution of mortality events at the landscape scale can have important control over regional carbon balance.
- How frequently does a catastrophic mortality event initiating secondary succession strike a given patch of forest?

- Courtesy: J. Chambers

## Blowdown Vegetation Spectral Unmixing from Hyperion

- Brightest blue- white pixels represent areas with spectral reflectance most similar to blowdown pixels – these include land-use areas and other apparent natural gap disturbances.
- Intensity of blue represents fractional abundance of blowdown-like spectra in each unmixed pixel – threshold set at 40%.

- Courtesy: J. Chambers

## Eddy flux measurements shows net loss of carbon in Tapajos National forest in Amazonia 

- 6
- 5
- 4
- 3
- 2
- 1
- 0
- -1
- -2

- uptake

- loss to
- atmosphere

-  Accumulated Mg(C) ha-1

- Saleska et al. *Science* (2003)

- 2001	2002	2003

- Average Annual _C- Balance_

## MODIS EVI profile (2000-2004 average) depicting spatial-seasonal variability across the precipitation transect, from seasonally-moist forests of eastern Amazon to the more humid forests west of Manaus

- Huete et al, GRL 2006

## Forest Physiology

- Goulden et al., *Ecological Applications* (2004)

- Whole canopy photosynthesis using micrometeorological tower
- showed less photosynthesis during afternoon than morning for same light level

- afternoon

- morning

- CO2 uptake

- respiration

## Atmosphere

**Ocean**

**Land**

**ET**
**NPP**
**Rh**
**RivDis**

**Temp**
**Prec**
**Solar**

**SST**
**SLP**

**CO****2            ****H****2****O**

**H****2****O**

**NEP**
**NBP**

**NPP**

- Global Teleconnections of Climate, Water, and Carbon

- Courtesy:  C. Potter

## Ocean-Climate Correlations with Terrestrial Productivity

**        ****eastern Brazil   6.75****o**** S, 41.25****o**** W**

- Potter et al., 2003,  *J. Geophysical Research - Atmospheres*

## Is the Amazon forest vulnerable to change owing to the combined effects of climate variability and fire?

- Droughts per 100 y

- Area Under the Influence of
- Fire (MODIS & AVHRR Hot Spots)

- Courtesy:  W. Schroeder

- Hutyra et al. *GRL* 2005

- Probability of Drought

## Alternate States for Amazonia?

- M. Oyama and C. Nobre

- Forest Dominates Amazonia

- Savanna Dominates Amazonia

## LBA: A Model for Scientific Cooperation

- Brazil as host and leader.
- International partners (e.g. NASA) provide key resources in remote sensing, modeling, organization and implementation of large scale field campaigns.
- LBA is seen as a model for IGBP regional studies such as the monsoon Asia initiative.

## Education and Training:

**Education and Training****:**
-  Brazilian requirement provided enormous leverage
- Brazil’s Federal Government contributed over R$2M
- Over 240 new Ph.D.’s!

## Public Outreach:

**Public Outreach****:**
- Maintaining good relations with local communities is hard work and a requirement for a successful research effort.

- Teaching local people about satellite imagery in Assis, Brazil

## Thanks to our award-winning Project Office!