Mature forest Forest fire After a forest fire

Mature forest

Forest fire

After a forest fire • • Does it remain empty and dead forever? What will this area look like in 200 years? Why? What aim does this suggest for today?

Aim • How will a forest recover from a fire that destroys it?

After a forest fire, what is left? • Soil, dead plant materials • What will happen to the remains? • The remains will be broken down by decomposers • What effect will it have on the remaining soil? • It will make the soil rich with carbon and nitrogen, nutrients

First organisms • Bacteria and fungi (decomposers) and lichen are the first organisms to return to a dead ecosystem • They are called pioneer organisms.

Describe what you think will happen next • We have this rich soil with nothing growing. • Will something start to grow? What? Why do you think this will grow? • Moss and grasses, plants that can grow close to the ground. • How do the seeds and other plants get to the burned forest?

What happens next? • After the grasses, larger plants can grow, such as shrubs • Then the trees will start to return • In 100 -200 years, the forest will look similar to what it looked like before the fire! • Succession is the return of living organisms to an environment that does not have life

How does the physical environment affect the living organisms? • Physical environment determines which organisms can grow and survive

How do the living organisms affect the physical environment? • Living things can modify the environment.

Ecological Succession

Climax community • The mature, stable community that returns after ecological succession is climax community • In this case, the mature forest is the climax community • What determines what plants make up a climax community?

What determines climax community? • The physical environment will determine which plants make up a climax community • For example, a hot, rainy environment will give you a tropic rainforest climax community • How do you know what animals will live in a climax community? • The types of plants present

Two types of succession • Primary succession-when living things start to grow on an area where there was no life before, such as on newly formed lava • Secondary succession-when living things start to grown on an area that replaces a former living community • Which type of succession is our forest fire succession? Why?

Another example of succession • http: //library. thinkquest. org/04 oct/00228/suc cession. htm

Succession in a pond

Succession after glacial melting

Have you seen ecological succession happen in New York City?

Do you see any succession happening in your bottle ecosystem?

Homework • Due tomorrow, Friday • Introduction section of bottle ecosystem lab report • Reminder: Unit 2, ecology exam on Monday. • If time, take your last observations for your bottle ecosystems.