Part I; Trees tend to be long-lived, some reaching several thousand years old. Trees have been in existence for 370 million years. It is estimated that there are some three trillion mature trees in the world.
Part II; Trees are an important part of the terrestrial ecosystem providing essential habitats including many kinds of forest for communities of organisms. On the ground underneath trees there is shade, and often there is undergrowth, leaf litter, and decaying wood that provide other habitat. Trees stabilize the soil, prevent rapid run-off of rain water, help prevent desertification, have a role in climate control and help in the maintenance of biodiversity and ecosystem balance.
Part III; Canada has about 4 million square kilometres (1.5 million square miles) of forest land. More than 90% of forest land is publicly owned and about 50% of the total forest area is allocated for harvesting. These allocated areas are managed using the principles of sustainable forest management, which include extensive consultation with local stakeholders. About eight percent of Canada's forest is legally protected from resource development.