Alarming Patterns of Mature Forest Loss in the Brazilian Atlantic Forest
Academic Background
The Brazilian Atlantic Forest is one of the world’s biodiversity hotspots, harboring a high number of endemic species and providing critical ecosystem services. However, a long history of deforestation has reduced its original forest cover to just 24%. Despite existing legal protections, the rate of forest loss remains alarming. To better understand the effectiveness of current laws in curbing deforestation, researchers conducted a comprehensive quantitative and qualitative time-series analysis of mature forest loss in the Brazilian Atlantic Forest. The study aims to reveal the spatial and temporal patterns of forest loss, assess its illegality, and provide scientific evidence for future conservation policies.
Source of the Paper
The study was conducted by Silvana Amaral, Jean Paul Metzger, Marcos Rosa, Bruno Vargas Adorno, Gabriel Crivellaro Gonçalves, and Luis Fernando Guedes Pinto. The authors are affiliated with Brazil’s National Institute for Space Research (INPE), the University of São Paulo, and the SOS Mata Atlântica Foundation. The paper was published in March 2025 in the journal Nature Sustainability, with the DOI 10.1038/s41893-025-01508-w.
Research Process
1. Data Collection and Processing
The study was based on satellite imagery data from 2010 to 2020, using Landsat and PlanetScope images to monitor forest cover changes. The research team first defined and identified mature forests as primary forests or secondary forests in middle to advanced stages of regeneration without significant disturbance. Through a combination of visual interpretation and automated classification, the team mapped 14,401 deforestation polygons, covering a total area of 186,289 hectares.
2. Spatial and Temporal Analysis
The researchers analyzed the spatial and temporal distribution of these deforestation polygons. Using kernel density analysis, the team identified two main deforestation hotspots: the northern hotspot (Bahia and Minas Gerais) and the southern hotspot (Paraná and Santa Catarina). Additionally, the study analyzed land tenure types associated with forest loss, including private lands, protected areas, indigenous lands, and settlement projects.
3. Land Use and Cover Change
To understand post-deforestation land use changes, the research team classified land use and cover (LULC) in 2021 using PlanetScope satellite imagery. They found that most deforested areas were converted to pasture, temporary crops, and secondary vegetation. These changes varied significantly across different land tenure types.
4. Greenhouse Gas Emission Estimation
The study also estimated greenhouse gas emissions resulting from forest loss between 2010 and 2020. Using methods from Brazil’s Greenhouse Gas Emissions and Removals Estimation System (SEEG), the team calculated that these losses emitted 89.14 million tons of CO2 equivalent (MtCO2e), accounting for 3% of Brazil’s total emissions in 2023.
Key Findings
1. Spatial Distribution of Forest Loss
The study revealed that forest loss was concentrated in Bahia and Minas Gerais (50%) and Paraná and Santa Catarina (16%). The northern hotspot’s forest loss was primarily associated with the clearing of seasonal deciduous forests and semi-deciduous forests, while the southern hotspot mainly involved the loss of mixed ombrophilous forests.
2. Land Tenure and Forest Loss
The study found that 73% of forest loss occurred on private lands, while protected areas and indigenous lands had lower deforestation rates. However, the deforestation rate in indigenous lands (0.8%) was close to the average on private lands (1.3%), indicating significant pressure on these areas.
3. Land Use Change
Post-deforestation land use changes showed that pasture and temporary crops were the primary conversion types. On private lands, pasture accounted for 38-43%, and temporary crops for 11-15%. In protected areas and indigenous lands, secondary vegetation was the dominant cover type, suggesting greater potential for forest recovery in these regions.
4. Greenhouse Gas Emissions
The estimated greenhouse gas emissions of 89.14 MtCO2e were primarily due to the loss of carbon stocks in mature forests. This result highlights that forest loss not only threatens biodiversity but also significantly impacts climate change.
Conclusions and Significance
The study reveals the severity of mature forest loss in the Brazilian Atlantic Forest and points out the limitations of current legal protections. The findings indicate that, despite legal safeguards, forest loss remains widespread and is largely illegal. The research underscores the importance of strengthening conservation measures, particularly in deforestation hotspots. Furthermore, the study provides scientific evidence for future forest restoration and conservation policies, especially in land use planning and carbon reduction strategies.
Research Highlights
- Hotspot Identification: For the first time, the study used kernel density analysis to identify two major deforestation hotspots in the Brazilian Atlantic Forest, revealing the driving factors behind forest loss in different regions.
- Land Tenure Analysis: The study detailed deforestation rates across different land tenure types, providing a basis for targeted conservation policies.
- Land Use Change: High-resolution satellite imagery revealed post-deforestation land use changes, offering critical data for understanding the long-term impacts of forest loss.
- Greenhouse Gas Emission Estimation: The study estimated greenhouse gas emissions from forest loss, providing scientific support for Brazil’s carbon reduction goals.
Additional Valuable Information
The study also noted that although secondary vegetation occupies a significant proportion of deforested areas, these secondary forests have low biodiversity and carbon stocks and are prone to further loss. Therefore, the research calls for future conservation policies to focus not only on curbing forest loss but also on the restoration and management of secondary forests.
The data and analysis results of the study have been made publicly available through the Zenodo platform for use by other researchers and policymakers.