Short answers, pulled from the story.
An area must span at least 500 square kilometers to qualify as an intact forest landscape. This minimum size requirement ensures the ecosystem can support viable populations of diverse species.
Canada, Russia, and Brazil together hold 64 percent of the world's total IFL area. These three nations contain almost all remaining intact forest landscapes globally.
Environmental non-governmental organizations developed the term intact forest landscape in the early 1990s. Groups including Greenpeace and the World Resources Institute created the initial definition during that period.
Satellite imagery provides the primary data source for identifying intact forest landscapes globally through high spatial resolution images from the Global Land Cover Facility. Algorithms process information at approximately one millionth scale resolution to detect small disturbances invisible to coarser maps.
Large roaming animals require intact forest landscapes to maintain viable populations because fragmentation and habitat loss threaten plant and animal species with extinction. Species such as forest elephants, great apes, bears, wolves, tigers, jaguars, eagles, and deer depend on unfragmented habitats.