In the latest issue of Ecology and Society, Peter Potapov et al’s article Mapping the world’s intact forest landscapes by remote sensing. (Ecology and Society 13(2): 51). Shows a new map of global forests – showing the “intact forest” areas that are not directly transformed by human action.

The world’s intact forest landscapes (IFLs): IFL (green), Forest zone outside IFL (yellow).

The authors define an intact forest area as:

as an unbroken expanse of natural ecosystems within the zone of current forest extent, showing no signs of significant human activity, and large enough that all native biodiversity, including viable populations of wide-ranging species, could be maintained. Although all IFLs are within the forest zone, some may contain extensive naturally treeless areas, including grasslands, wetlands, lakes, alpine areas, and ice.

The data can be downloaded from the projects website as tiff, google earth, or shapefiles.

Compared to other global forest areas assessments the authors found:

• significantly less intact area in boreal forests than the World’s Wilderness Areas analysis (McCloskey and Spalding 1989) and the Frontier Forests analysis (Bryant et al. 1997) because of our more recent data allowing us to capture the effect of the expansion of oil and gas extraction infrastructure in Canada and Siberia, as well as the role of extensive human-caused fires accompanying industrial development of northern forests.
• more intact areas in dense tropical forests (the Amazon and Congo basins) and in boreal mountains (southern and eastern Siberia, Kamchatka, Alaska, and the Canadian Rocky Mountains) than was found in previous studies based on coarse-scale map and expert data analysis.
• the Human Footprint data set (Sanderson et al. 2002), which finds a significantly larger area to be intact within boreal regions and the southern part of the Amazon Basin in Brazil. Both areas were developed (by industrial logging and oil and gas extraction in Canada and Russia, and by agricultural clearing in Brazil) in recent decades, and these changes were not captured in the Human Footprint assessment.
• in some regions (i.e., Central Africa, boreal forests in Siberia and Canada) we found a smaller area to be intact than the Human Footprint map because we classified burned areas in the vicinity of infrastructure as not intact.
• The Landscape Domestication Analysis by The Nature Conservancy, which relied on existing transportation network maps, also overestimated the intact area (Kareiva et al. 2007).