1. Learning Target: Seed Dispersal
I Can… Describe different ways that seeds can be dispersed and discuss advantages and disadvantages of each method
I Will…
Define seed dispersal
List methods of seed dispersal including examples of plants for each method
Discuss advantages and disadvantages of each method

2. Seed Dispersal
Dispersal (the process or result of the spreading of organisms from one place to another) is important because:
It spreads the progeny (offspring) in order to colonize new environments
Reduces competition for resources with parents
Reduces chances of predators destroying all of the plant’s yearly seed production

3. Self Dispersal Plants disperse their seeds by forceful ejection
Explosive fruits
Witch Hazel
Squirting Cucumber

4. Self Dispersal
The peanut plant sows (buries) it own seeds

5. Wind Dispersal
Fruit and seeds may have special devices for wind dispersal
Plumes catch wind currents
Dandelion
Trees take advantage of their great heights for wind dispersal
Fruits with wings are used to slow descent to land
Maple
Ash

6. Fruits and/or seeds use flotation devices to travel by water ( in rivers, oceans, etc…)
Fruit may have air spaces and corky floats
Palm Coconuts
Water Dispersal

7. Animal Dispersal
Many plants depend on animals for seed dispersal
Offers nutritional reward
Animals learn to recognize ripened fruit colors
Fleshy fruit eaten and seeds dispersed in feces

8. Animal Dispersal
Some dry fruit attach and cling to animal’s fur (e.g. Beggar’s ticks)
Some have Velcro-like hooks that cling to fur (Burdock, Cockleburs)
Others have sticky substances that adhere to host (e.g. Mistletoe)

9. Methods of Seed Dispersal

10. Methods of Seed Dispersal

11. Seed Dispersal: Things that make you THINK
What carries the dandelion seed for miles?
What feature of trees gives them a particular advantage when dispersing seeds by air?
How does the squirting cucumber disperse its seeds?
What is the advantage of this?
Although plants use wind and water, what do most plants use as carriers for their seeds?
Blackberries on a tree do not ripen simultaneously, WHY?