trees effected.

The leaves contain a material known as chlorophyll, which, in the
presence of light and heat, changes mineral substances into plant
food. Chlorophyll gives the leaves their green color. The cells
of the plant that are rich in chlorophyll have the power to
convert carbonic-acid gas into carbon and oxygen. These cells
combine the carbon and the soil water into chemical mixtures
which are partially digested when they reach the crown of the
tree. The water, containing salts, which is gathered by the
roots is brought up to the leaves. Here it combines with the
carbonic-acid gas taken from the air. Under the action of
chlorophyll and sunlight these substances are split up, the
carbon, oxygen and hydrogen being combined into plant food. It is
either used immediately or stored away for future emergency.

Trees breathe somewhat like human beings. They take in oxygen and
give off carbonic-acid gas. The air enters the tree through the
leaves and small openings in the bark, which are easily seen in
such trees as the cherry and birch. Trees breathe constantly, but
they digest and assimilate food only during the day and in the
presence of light. In the process of digestion and assimilation
they give off oxygen in abundance, but they retain most of the
carbonic acid gas, which is a plant food, and whatever part of it
is not used immediately is stored up by the tree and used for its
growth and development. Trees also give off their excess
moisture through the leaves and bark. Otherwise they would become
waterlogged during periods when the water is rising rapidly from
the roots.