《全球森林资源评估遥感调查》（英文）-92页_13mb

FRA 2020 Remote Sensing Survey Summary

Core Content

The FRA 2020 Remote Sensing Survey is a comprehensive global assessment conducted by the Food and Agriculture Organization (FAO) to evaluate changes in forest-related land use and land cover between 2000 and 2018. It provides critical insights into deforestation trends, forest area expansion, and the drivers of forest loss, offering a detailed and reliable dataset for global, regional, and ecoregion levels.

This survey builds on previous FRA remote sensing efforts and is part of the broader Global Forest Resources Assessment (FRA), which has been a key activity of the FAO since 1948. The results of the survey support international environmental goals, including the 2030 Sustainable Development Agenda, the UN Decade on Ecosystem Restoration, and the Rio Conventions (CBD, UNCCD, UNFCCC), by offering updated and spatially detailed data on forest dynamics.

Main Points

• Survey Overview:

  • Conducted by FAO in collaboration with the Joint Research Centre (JRC) of the European Commission.
  • Utilized Collect Earth Online, an open-source platform for land monitoring.
  • Involved over 800 national experts from 126 countries.
  • Aimed to fill gaps in national forest monitoring data, especially in Africa, Asia, and Oceania.

• Data Collection:

  • Based on a stratified systematic sampling design.
  • Used satellite imagery from over 400,000 sample sites.
  • Included participatory data collection and capacity-building workshops.
  • Implemented a hexagonal tessellation method for global sampling.

• Key Findings:

  • Global deforestation slowed significantly between 2010–2018 compared to 2000–2010.
    • Annual deforestation decreased from 11 Mha/year to 7.8 Mha/year.
    • Net forest area loss halved from 6.8 Mha/year to 3.1 Mha/year.
  • Agricultural expansion remains the main driver of deforestation, responsible for almost 90% of global forest loss.
    • Cropland expansion accounts for ~50% of deforestation.
    • Livestock grazing contributes to ~38.5%.
  • Oil palm cultivation alone caused 7% of global deforestation between 2000 and 2018.
  • Forest area in 2018 totaled 3.97 billion hectares, representing 30.8% of global land area.

• Forest Types:

  • Naturally regenerating forests dominate global forest areas.
  • Planted forests are growing, particularly in regions where afforestation efforts are active.
  • Mangroves are significant in coastal ecosystems, especially in tropical areas.

• Regional Variations:

  • South America had the highest deforestation rates.
  • Africa and Asia followed, with notable challenges in data consistency.
  • Forest area expansion was observed in various regions, particularly in Global Ecological Zones with favorable conditions.

• Comparisons:

  • The survey results were compared with FRA country reporting and other global datasets.
  • Differences were noted in forest area estimates and trends, highlighting the importance of remote sensing in providing more accurate and consistent data.

• Methodological Strengths:

  • A standardized methodology was used to ensure consistency and reliability.
  • Participatory approach helped improve data quality and regional representation.
  • Open-source tools and collaboration with international partners enhanced transparency and accessibility.

• Limitations and Future Work:

  • The survey faced challenges due to COVID-19, which impacted field data collection.
  • Future improvements may include better integration of satellite data and ground-truthing.
  • The survey supports the development of policies, practices, and investments for forest conservation and restoration.

Key Information

• Time Periods Analyzed:

  • 2000–2010
  • 2010–2018

• Geographic Scope:

  • Global (including FAO regions, Global Ecological Zones, and ecoregions).
  • Regional and subregional analyses were performed to provide localized insights.

• Drivers of Deforestation:

  • Cropland expansion is the primary driver.
  • Livestock grazing is the second major driver.
  • Other drivers include urbanization, logging, and agricultural conversion.

• Data Accuracy and Validation:

  • Quality assurance and quality control were implemented.
  • Accuracy assessments were conducted using confidence intervals.
  • The survey results were compared with other global datasets to validate findings.

• Publications and Licensing:

  • The report is published under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 IGO licence.
  • Users must cite the source and are not permitted to use the FAO logo or suggest FAO endorsement.

• Support and Collaboration:

  • The survey was funded by the European Union and the Government of Norway.
  • It was supported by international partners including SilvaCarbon, USGS, Google, and NASA.

Conclusion

The FRA 2020 Remote Sensing Survey provides a detailed and reliable assessment of global forest dynamics, offering insights into deforestation trends, forest area changes, and drivers of forest loss. It supports international environmental goals and contributes to policy development, conservation efforts, and sustainable forest management. The survey underscores the importance of remote sensing in improving the accuracy and consistency of global forest data, especially in regions with limited national monitoring capabilities.