Seed dispersal

Seed dispersal presentation.

Seed dispersal is when seeds are transported from the plant to another area in order to grow.

Why do plants want to send their seeds away?

Well, they want to avoid competition.

If a mother plant and a baby plant are in the same place they will compete for water, sunlight and carbon dioxide. The baby plant is much weaker and therefore will, in most cases, not receive enough and die.

________________________________________________________________________

Methods of seed dispersal

ANIMAL DISPERSAL

1.- Some plants use hooks (ganchos). These attach themselves to the fur of mammals, feathers of birds or socks and trousers of humans and get carried from one place to another.

2.- Some plants cover their seeds with juicy fruit. The fruit is so yummy that is eaten by animals, but only the juicy parts are digested. The stones and pips leave the animal's body via the droppings (the poop) which may be some distance away from the parent plant.

3.- Animal burial. Hard nuts (like acorn) are usually destroyed if chewed or eaten. However, animals such as squirrels may store them to eat later and forget to go back to get them, giving them a chance to germinate.
On rare occasions, birds such as blue jays can transport acorns long distances.

WIND DISPERSAL

1.- Some plants attach "parachutes" made of thin hair to their seeds, like the dandelion, so they are carried away by the wind.

2.- Other plants, like the sycamore, design their seeds like if they were helicopters, so they spin as they fall from the tree, providing a longer time for dispersal by wind.

WATER DISPERSAL

Some plants grow near rivers, lakes, streams or oceans.

Their fruits can float, such as the water lily. When they fall from the plant and are carried away by the water.

Coconuts can travel for thousands of kilometres across seas and oceans.

EXPLODING PLANTS

Some plants, such us gorse and peas, disperse their own seeds. The pods dry and split open suddenly with some considerable force which throws their seeds for some distance.