Satellite-based estimates reveal widespread forest degradation in the Amazon
Eric L Bullock1, Curtis E Woodcock1, Carlos Souza2
1Department of Earth & Environment, Boston University, Boston, MA, USA.
Global Change Biology
|February 6, 2020
Summary
Amazon forest disturbance, including deforestation and degradation, impacts 17% of the region. This previously underestimated forest damage and associated carbon emissions highlight critical ecological concerns.
Area of Science:
- Environmental Science
- Remote Sensing
- Ecology
Background:
- Forest disturbance in the Amazon, encompassing deforestation, degradation, and natural events, causes ecological damage and carbon emissions.
- The Amazon rainforest's role in the hydrologic cycle raises concerns about a potential ecosystem collapse tipping point.
Purpose of the Study:
- To map deforestation, degradation, and natural disturbance in the Amazon Ecoregion from 1995 to 2017 using time series analysis of Landsat data.
- To estimate the area and uncertainty of forest disturbance at biennial intervals.
Main Methods:
- Time series analysis of Landsat data to map forest disturbance.
- Stratification of the study area for sample unit selection based on land cover and disturbance history.
- Application of an unbiased statistical estimator to reference observations for area and uncertainty estimation.
Main Results:
- Degradation and natural disturbance affected as much forest area as deforestation between 1995 and 2017.
- An estimated 17% (1,036,800 ± 24,800 km²) of the original Amazon forest area was disturbed by 2017.
- The total disturbed forest area is 44%-60% greater than previously estimated.
Conclusions:
- Forest degradation and natural disturbance are significant contributors to Amazon forest loss, comparable to deforestation.
- The findings indicate an unaccounted source of carbon emissions and widespread damage to Amazonian forest ecosystems.
- Previous estimates of Amazon forest disturbance have significantly underestimated the total affected area.
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