About 47 percent of the forest's land is forested, and an additional 3 percent can support trees, but does not currently have any.

These streams supported trees that the Comanche used to build shelters.

It is believed that no more than 15% of Australia supported trees of any kind.

The local climate is warm enough throughout the year to support olive trees.

A carr is a fen which has developed to the point where it supports trees.

The floor of the canyon appeared extremely fertile, supporting numerous large trees and growing crops.

Some desert regions may support trees at base of mountains however, and thus distinct grasslands zones will not form in these areas.

The abundance of open prairie areas was often thought to be the result of poor soils that would not support trees or even crops.

Below 5,000 feet (1500 m), there is not enough precipitation to support trees.

Each zone is defined by whether it can support trees, and the presence of one or more indicator species.