During this period, a white oak tie would last only 7 years, and each mile of rail would require 6 acres of woodland for the timbers and ties. We value trees for many reasons, including their beauty during the seasons, their influences on our environment and the many species of birds and animals they shelter and feed. Trees have an effect on our air quality. For every pound of wood produced by a tree, it also provides a pound of oxygen and uses almost 1.5 pounds of carbon dioxide. Or an acre of trees uses 5,880 pounds of carbon dioxide and gives us 4,280 pounds of oxygen each year.
Trees are nature's air conditioners.
A single tree can transpire 100 gallons of water from its leaves in a single day. The cooling provided by this single tree is equivalent to five average room air conditioners running 20 hours per day. An acre of urban forest or park will transpire more than 1,600 gallons of water per day. A large tree may have 200,000 to 400,000 leaves, which act like a continuous air filter. An acre of trees may remove as much as 13 tons of dust each year.