Introduction:The way trees spread their seeds
Trees reproduce in a very different way
than animals and humans. Trees and other plants produce new plants by
making seeds. These seeds must get to a place so that they can start to
make a new tree. Trees have four ways to spread their seeds. This process
is known as seed dispersal
The first form of seed dispersal is wind.
Some trees produce seeds that can use the wind to carry it away from the
parent tree to a suitable place for it to grow. What do you think these
types of seeds would look like? Would they be heavy or light?
The second form of seed dispersal is
animals. Animals can help spread seeds in several ways. In some trees the
seed is in the middle of a fruit. When an animal eats the fruit it cannot
digest the seed and the seed is expelled when it goes to the bathroom.
Some animals bury the seeds to store them, like when you store food in the
refrigerator. Some of these seeds do not get eaten and sprout into new
trees. Animals with fur can also help trees disperse their seeds. Some
seeds can attach themselves to the fur of an animal, and at a later time
it will fall off and it will grow. These seeds are commonly known as burs.
What shape do you think these seeds would be? Have you ever had burs stick
to your clothes when you walk around trees?
The third form of seed dispersal is by
water. Trees that are located near the water take advantage of this
resource and use it to spread their seeds. The seed drops into the water
and floats until the water pushes it onto the shore. Then the seed sprouts
into a tree. Where do you think these types of trees are located? What
problems could these seeds have?
There is a fourth type of seed dispersal.
It is called discharge dispersal. These type of trees spit their seeds to
the ground surrounding the parent tree. These types of trees, however, are
not common in North America. Therefore we shall focus only on the first
three types of seed dispersal. |