Trees
are the largest plants on earth. They are complex organisms
that harness energy from the sun to reduce the impact of global
warming and help maintain balanced ecosystems.
How Trees Help the Planet
One large, healthy tree can:
• lift up to 4000 litres of water from the ground and
release it into the air
• absorb as many as 7000 dust particles per litre of
air
• absorb 75 per cent of the CO2 produced by the average
car
• provide a day’s oxygen for up to four people
More
facts about trees and how they reduce Carbon.
Parts of a tree are:
- leaves and needles
- buds
- cones and flowers
- branches and twigs
- trunk or stem
- roots
Leaves and Needles
Leaves and needles are the food factories in the tree's crown.
Food-making, or photosynthesis, begins when the sun's warmth
and light is trapped by green chlorophyll in the leaves.
This energy is used to combine carbon dioxide from the
atmosphere with water drawn from the roots to create sugar
and starch. The inner bark then carries this food to all
living parts of the tree. In turn, oxygen and water are
released into the atmosphere as by-products of photosynthesis.
Buds
Every spring the tree grows taller as a new set of branches
develops at its top, and wider as buds develop along the older
branches, twigs and tips. Soft tissue inside the buds is protected
from damage by a tough covering of moisture-saving bud scales.
Cones and Flowers
Trees produce flowers or cones that hold fertilized seeds.
In late summer or fall, the seeds come loose and are scattered
by wind, water and wildlife. Within each seed is the soft
tissue that is the basis a new tree. Seeds have a tough coating
that protects them during dispersal to their new home.
Branches and Twigs
Branches and twigs support the leaves, holding them up to
receive the sun's light and warmth. They also produce buds
that form new twigs, leaves and flowers.
Trunk
The trunk is the main stem of the tree. It supports the crown
of branches, leaves/needles and transports food and water
throughout the tree. The tough, outer bark protects the tree
from heat, cold, moisture loss and injury. The soft inner
bark carries food from the leaves and needles to all living
parts of the tree. Beneath the inner bark is a thin layer
called the cambium that each year develops new cells of inner
bark on its outer wall and new sapwood cells on its inner
wall. The sapwood carries water from the roots up to the leaves/needles.
As the tree grows, old inner layers of sapwood die and become
heartwood, a rigid fiber that gives the tree its strength.
Roots
The roots act as an anchor, holding the tree firmly in place.
They grow and spread out underground from the root tips, forming
a huge network that draws nutrients to the tree and protects
the soil from erosion. Small root hairs grow out from the
roots to absorb water and minerals from the soil.
Photos by Clayton Rollins |