What Makes a Forest an Ancient Forest?

The term refers to forest ecosystems as a whole, rather than to the individual trees within it. Natural disturbance such as storm damage, insect infestation and natural mortality will be present, as will regeneration from such disturbance. Human impact is characterized by low level hunting, fishing and harvesting of forest products, and in some cases, to low density shifting agriculture with prolonged fallow periods.

Ancient Forests are made up of frontier forests, primary forest fragments and old-growth forests. These forests are home to the majority of plant and animal species found on land. Frontier forests are the world's few remaining large areas of natural forest that have not been significantly altered by human activity. Roughly 20 percent of the world's original forest cover remains as frontier. Primary forest fragments are forest areas that have only been subjected to minimal human disturbance, are smaller than frontier forests and therefore cannot always support healthy populations of large predators. Old-growth forests are stands of old trees, some of which may be regrowth from intensive logging or clearance in the distant past.

Biological diversity or biodiversity refers to the rich abundance and diversity of life on Earth. Half of all species of life on Earth are living in the Ancient Forests, and many more are dependant indirectly on forest habitats, such as estuaries and wetlands that are fed by rivers that flow out of forests, and which are important in maintaining healthy ocean and fresh water fish populations. Deforestation is currently the leading cause of extinction.