Many conservation goals rely on forests that are relatively intact and undisturbed. Credit: SPOT
While much of the world’s forests have been lost to deforestation, equally concerning is the modification of these habitats by humans. We rely on forests to hold on to carbon, help in the fight against climate change, serve as habitat for species, and reverse land degradation. Yet, once disturbed, forests are unable to perform these functions as well as they once could.
There are many forms of forest disturbance, and monitoring all of these at a global scale across different forest types can be challenging. For example, fragmentation can happen at multiple scales, and some disturbances, like road building, aren’t easily identified without fine-scale data.
A recent paper attempts to bring together different measures of forest degradation across the globe into one index. The resulting Forest Landscape Integrity Index serves as a world-wide measure of remaining forest resources and their current state. Ecosystem integrity refers to the extent to which a forest’s structure and function are undisturbed, and can now be measured to greater accuracy using satellite imagery and improved metrics for habitat health.
Based on this index, there has been a huge loss of forest integrity across the globe: just 40% of forests were found to have high integrity. Of these areas with high integrity, one-third still showed some form of human modification, and just one-quarter fell within protected areas. Disturbance patterns were variable across the globe, and large-scale trends could be seen, such as decreased human disturbance in northern latitudes. The biogeographical regions with the highest integrity index values included northern Russia, Canada and the Rocky Mountains, the Amazon, Central Africa, and New Guinea.
By bringing together multiple sources of data on forest disturbance, and providing a transparent framework, this tool can be used to inform future management and policy decisions.
Forest Landscape Integrity Index map. From Grantham et al. 2020. Nature communications 11:1-10.
References:
Grantham, H.S., Duncan, A., Evans, T.D., Jones, K.R., Beyer, H.L., Schuster, R., Walston, J., Ray, J.C., Robinson, J.G., Callow, M. and Clements, T. et al. 2020. Anthropogenic modification of forests means only 40% of remaining forests have high ecosystem integrity. Nature communications 11: 1-10.
