1. Learning Target: Seed Dispersal I Can… Describe different ways that seeds can be dispersed and explain advantages of the different methods • I Will… • Define seed dispersal • List methods of seed dispersal including examples of plants for each method • Discuss advantages 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 http://youtu.be/5WQ6qhhJS2M

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 http://youtu.be/6loGKPKDqCw

10. 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?