Forest Landscape Integrity Index

• 1. Defining Forest Integrity

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  The Forest Landscape Integrity Index measures how much human activity has altered forest ecosystems. It treats integrity as the opposite of cumulative modification across a landscape. This approach combines mapped pressures, modeled indirect effects, and changes in connectivity to generate a continuous score from 0 to 10 for each 300-meter pixel. A score of 10 represents the least modified state, while 0 indicates the most heavily modified condition. The index was developed by an international research team led by the Wildlife Conservation Society. They integrated spatial data on observed and inferred human pressures with loss of forest connectivity. In ecology, ecological integrity refers to the extent to which an ecosystem's structure, species composition, and processes fall within their natural range of variation. Forest integrity is often discussed alongside deforestation but remains distinct from it. Deforestation involves area loss, whereas degradation describes declines in function without complete land-cover conversion. The FLII operationalizes this concept at the landscape scale rather than focusing solely on tree cover.

• 2. Mapping Global Pressures

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  Granham et al calculated the index using four main spatial inputs processed through Google Earth Engine. The first input defines forest extent as woody vegetation taller than 5 meters with at least 20 percent canopy cover. Researchers used global tree-cover estimates for the year 2000 and subtracted mapped tree-cover loss from 2001 to 2018. This method excludes temporary canopy loss to establish a stable baseline. Observed pressures represent human activities that can be mapped directly at a global scale. These include built infrastructure, agriculture, and recent deforestation events. Inferred pressures capture additional impacts occurring around observed pressure sources. Access-related extraction such as selective logging, fuelwood collection, and hunting are modeled as a decay function based on proximity to known access networks. Connectivity loss estimates reductions caused by forest fragmentation. This component captures how surrounding forest cover influences a given pixel's integrity score. The continuous FLII ranges from 0 to 10, providing granular data for each 300-meter square of forest.

• 3. The 2019 Global Results

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  In the study's global map for early 2019, 40.5 percent of forest area was classified as high integrity. This covered about 17.4 million square kilometers across the planet. Another 33.9 percent fell into medium integrity, representing 14.6 million square kilometers. Low integrity forests made up 25.6 percent of the total, covering 11 million square kilometers. High-integrity forests were concentrated in boreal regions of Russia and Canada. Large tropical forest blocks like the Amazon, Central Africa, and New Guinea also held significant areas. Only about 27 percent of high-integrity forest area fell within nationally designated protected areas. Meanwhile, 56 percent of forests located inside protected areas were classed as high integrity. The authors estimated that 91.2 percent of the world's remaining forests experienced some degree of human pressure. Thirty-one point two percent experienced observed pressures directly. No biome or biogeographic realm contained more than half of its forest area in the high-integrity class. Russia and Canada together contained about half of the global high-integrity forest area. The global mean FLII score stood at 7.76.

• 4. Country Rankings And Data

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  One hundred seventy-two countries have been ranked using this index. Each country displays a mean FLII score alongside data on low, medium, and high integrity areas. Some nations show perfect scores with zero low integrity land. Others display extensive degraded zones. For instance, one country recorded a mean score of 10 with only 68 square kilometers of high integrity forest. Another nation showed a mean score of 0.01 with just 7 square kilometers of intact forest. The dataset includes total forest area for each territory to provide context for the scores. Countries like Brazil and Indonesia appear lower on the list due to significant deforestation and infrastructure development. Nations such as Canada and Russia dominate the upper rankings with vast boreal reserves. The table provides specific figures for low integrity, medium integrity, and high integrity areas in square kilometers. This granular data allows researchers to compare conditions across different governance regimes and geographic regions. The interactive map and downloadable products make these statistics accessible for further analysis.

• 5. Policy And Conservation Use

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  The Forest Landscape Integrity Index has become a key tool for international conservation frameworks. It is referenced under Target 2 of the Kunming-Montreal Global Biodiversity Framework for monitoring ecological integrity. The World Resources Institute uses FLII as a measure of forest degradation in its Global Forest Review. The 2023 Forest Declaration Assessment includes FLII units lost per year as an indicator for tracking progress toward global goals. The European Commission's Joint Research Centre incorporated a Forest Landscape Integrity layer into its Global Forest Types 2020 map product. High Integrity Forest (HIFOR) methodology incorporates FLII thresholds in eligibility criteria for funding. This framework helps identify which forests qualify as high integrity for financial mechanisms. BirdLife International used FLII-based analyses to communicate trends within Key Biodiversity Areas identified for forest species. These applications demonstrate how scientific metrics translate into policy decisions and conservation strategies on the ground.

• 6. Research Applications And Validation

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  Researchers have applied FLII to compare forest condition across diverse governance and conservation regimes. Sze et al published a pan-tropical analysis in 2022 examining forest integrity overlaps with protected areas and Indigenous peoples' lands. Crowe et al released a study in 2023 assessing forest integrity within thousands of Key Biodiversity Areas. Their work highlighted the index's potential role in monitoring biodiversity-important sites globally. An ecosystem integrity index integrated multiple global datasets including field-based evaluation of boreal forests. This validation study checked how well FLII corresponds to actual ecological indicators found in the field. The index serves as an input or comparison layer in composite integrity metrics. It allows scientists to test hypotheses about forest health against real-world data. The method provides a consistent baseline for comparing conditions across different biomes and political boundaries.

• 7. Methodological Limitations

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  The original study described FLII as a conservative estimate due to several inherent constraints. Some pressures are difficult to map consistently at a global scale. Finer-scale infrastructure and small-scale extraction activities often escape detection. Forest modification prior to the year 2000 may not be reflected in the underlying global datasets used for calculation. The authors noted that the index does not explicitly account for all drivers of integrity loss. Climate change impacts and invasive species remain outside the current model scope. The forest extent definition can include tree crops and plantations which typically score as low integrity under the system. Despite these limitations, the index remains a valuable tool for understanding global forest condition. Researchers continue to update the approach as new global datasets become available. The project website offers an interactive map and downloadable data products for public use.